The Ice Age (II)

I really liked the book, recommended if you’re at all interested in this kind of stuff. Below some observations from the book’s second half, and some related links:

“Charles MacLaren, writing in 1842, […] argued that the formation of large ice sheets would result in a fall in sea level as water was taken from the oceans and stored frozen on the land. This insight triggered a new branch of ice age research – sea level change. This topic can get rather complicated because as ice sheets grow, global sea level falls. This is known as eustatic sea level change. As ice sheets increase in size, their weight depresses the crust and relative sea level will rise. This is known as isostatic sea level change. […] It is often quite tricky to differentiate between regional-scale isostatic factors and the global-scale eustatic sea level control.”

“By the late 1870s […] glacial geology had become a serious scholarly pursuit with a rapidly growing literature. […] [In the late 1880s] Carvill Lewis […] put forward the radical suggestion that the [sea] shells at Moel Tryfan and other elevated localities (which provided the most important evidence for the great marine submergence of Britain) were not in situ. Building on the earlier suggestions of Thomas Belt (1832–78) and James Croll, he argued that these materials had been dredged from the sea bed by glacial ice and pushed upslope so that ‘they afford no testimony to the former subsidence of the land’. Together, his recognition of terminal moraines and the reworking of marine shells undermined the key pillars of Lyell’s great marine submergence. This was a crucial step in establishing the primacy of glacial ice over icebergs in the deposition of the drift in Britain. […] By the end of the 1880s, it was the glacial dissenters who formed the eccentric minority. […] In the period leading up to World War One, there was [instead] much debate about whether the ice age involved a single phase of ice sheet growth and freezing climate (the monoglacial theory) or several phases of ice sheet build up and decay separated by warm interglacials (the polyglacial theory).”

“As the Earth rotates about its axis travelling through space in its orbit around the Sun, there are three components that change over time in elegant cycles that are entirely predictable. These are known as eccentricity, precession, and obliquity or ‘stretch, wobble, and roll’ […]. These orbital perturbations are caused by the gravitational pull of the other planets in our Solar System, especially Jupiter. Milankovitch calculated how each of these orbital cycles influenced the amount of solar radiation received at different latitudes over time. These are known as Milankovitch Cycles or Croll–Milankovitch Cycles to reflect the important contribution made by both men. […] The shape of the Earth’s orbit around the Sun is not constant. It changes from an almost circular orbit to one that is mildly elliptical (a slightly stretched circle) […]. This orbital eccentricity operates over a 400,000- and 100,000-year cycle. […] Changes in eccentricity have a relatively minor influence on the total amount of solar radiation reaching the Earth, but they are important for the climate system because they modulate the influence of the precession cycle […]. When eccentricity is high, for example, axial precession has a greater impact on seasonality. […] The Earth is currently tilted at an angle of 23.4° to the plane of its orbit around the Sun. Astronomers refer to this axial tilt as obliquity. This angle is not fixed. It rolls back and forth over a 41,000-year cycle from a tilt of 22.1° to 24.5° and back again […]. Even small changes in tilt can modify the strength of the seasons. With a greater angle of tilt, for example, we can have hotter summers and colder winters. […] Cooler, reduced insolation summers are thought to be a key factor in the initiation of ice sheet growth in the middle and high latitudes because they allow more snow to survive the summer melt season. Slightly warmer winters may also favour ice sheet build-up as greater evaporation from a warmer ocean will increase snowfall over the centres of ice sheet growth. […] The Earth’s axis of rotation is not fixed. It wobbles like a spinning top slowing down. This wobble traces a circle on the celestial sphere […]. At present the Earth’s rotational axis points toward Polaris (the current northern pole star) but in 11,000 years it will point towards another star, Vega. This slow circling motion is known as axial precession and it has important impacts on the Earth’s climate by causing the solstices and equinoxes to move around the Earth’s orbit. In other words, the seasons shift over time. Precession operates over a 19,000- and 23,000-year cycle. This cycle is often referred to as the Precession of the Equinoxes.”

The albedo of a surface is a measure of its ability to reflect solar energy. Darker surfaces tend to absorb most of the incoming solar energy and have low albedos. The albedo of the ocean surface in high latitudes is commonly about 10 per cent — in other words, it absorbs 90 per cent of the incoming solar radiation. In contrast, snow, glacial ice, and sea ice have much higher albedos and can reflect between 50 and 90 per cent of incoming solar energy back into the atmosphere. The elevated albedos of bright frozen surfaces are a key feature of the polar radiation budget. Albedo feedback loops are important over a range of spatial and temporal scales. A cooling climate will increase snow cover on land and the extent of sea ice in the oceans. These high albedo surfaces will then reflect more solar radiation to intensify and sustain the cooling trend, resulting in even more snow and sea ice. This positive feedback can play a major role in the expansion of snow and ice cover and in the initiation of a glacial phase. Such positive feedbacks can also work in reverse when a warming phase melts ice and snow to reveal dark and low albedo surfaces such as peaty soil or bedrock.”

“At the end of the Cretaceous, around 65 million years ago (Ma), lush forests thrived in the Polar Regions and ocean temperatures were much warmer than today. This warm phase continued for the next 10 million years, peaking during the Eocene thermal maximum […]. From that time onwards, however, Earth’s climate began a steady cooling that saw the initiation of widespread glacial conditions, first in Antarctica between 40 and 30 Ma, in Greenland between 20 and 15 Ma, and then in the middle latitudes of the northern hemisphere around 2.5 Ma. […] Over the past 55 million years, a succession of processes driven by tectonics combined to cool our planet. It is difficult to isolate their individual contributions or to be sure about the details of cause and effect over this long period, especially when there are uncertainties in dating and when one considers the complexity of the climate system with its web of internal feedbacks.” [Potential causes which have been highlighted include: The uplift of the Himalayas (leading to increased weathering, leading over geological time to an increased amount of CO2 being sequestered in calcium carbonate deposited on the ocean floor, lowering atmospheric CO2 levels), the isolation of Antarctica which created the Antarctic Circumpolar Current (leading to a cooling of Antarctica), the dry-out of the Mediterranean Sea ~5mya (which significantly lowered salt concentrations in the World Ocean, meaning that sea water froze at a higher temperature), and the formation of the Isthmus of Panama. – US].

“[F]or most of the last 1 million years, large ice sheets were present in the middle latitudes of the northern hemisphere and sea levels were lower than today. Indeed, ‘average conditions’ for the Quaternary Period involve much more ice than present. The interglacial peaks — such as the present Holocene interglacial, with its ice volume minima and high sea level — are the exception rather than the norm. The sea level maximum of the Last Interglacial (MIS 5) is higher than today. It also shows that cold glacial stages (c.80,000 years duration) are much longer than interglacials (c.15,000 years). […] Arctic willow […], the northernmost woody plant on Earth, is found in central European pollen records from the last glacial stage. […] For most of the Quaternary deciduous forests have been absent from most of Europe. […] the interglacial forests of temperate Europe that are so familiar to us today are, in fact, rather atypical when we consider the long view of Quaternary time. Furthermore, if the last glacial period is representative of earlier ones, for much of the Quaternary terrestrial ecosystems were continuously adjusting to a shifting climate.”

“Greenland ice cores typically have very clear banding […] that corresponds to individual years of snow accumulation. This is because the snow that falls in summer under the permanent Arctic sun differs in texture to the snow that falls in winter. The distinctive paired layers can be counted like tree rings to produce a finely resolved chronology with annual and even seasonal resolution. […] Ice accumulation is generally much slower in Antarctica, so the ice core record takes us much further back in time. […] As layers of snow become compacted into ice, air bubbles recording the composition of the atmosphere are sealed in discrete layers. This fossil air can be recovered to establish the changing concentration of greenhouse gases such as carbon dioxide (CO2) and methane (CH4). The ice core record therefore allows climate scientists to explore the processes involved in climate variability over very long timescales. […] By sampling each layer of ice and measuring its oxygen isotope composition, Dansgaard produced an annual record of air temperature for the last 100,000 years. […] Perhaps the most startling outcome of this work was the demonstration that global climate could change extremely rapidly. Dansgaard showed that dramatic shifts in mean air temperature (>10°C) had taken place in less than a decade. These findings were greeted with scepticism and there was much debate about the integrity of the Greenland record, but subsequent work from other drilling sites vindicated all of Dansgaard’s findings. […] The ice core records from Greenland reveal a remarkable sequence of abrupt warming and cooling cycles within the last glacial stage. These are known as Dansgaard–Oeschger (D–O) cycles. […] [A] series of D–O cycles between 65,000 and 10,000 years ago [caused] mean annual air temperatures on the Greenland ice sheet [to be] shifted by as much as 10°C. Twenty-five of these rapid warming events have been identified during the last glacial period. This discovery dispelled the long held notion that glacials were lengthy periods of stable and unremitting cold climate. The ice core record shows very clearly that even the glacial climate flipped back and forth. […] D–O cycles commence with a very rapid warming (between 5 and 10°C) over Greenland followed by a steady cooling […] Deglaciations are rapid because positive feedbacks speed up both the warming trend and ice sheet decay. […] The ice core records heralded a new era in climate science: the study of abrupt climate change. Most sedimentary records of ice age climate change yield relatively low resolution information — a thousand years may be packed into a few centimetres of marine or lake sediment. In contrast, ice cores cover every year. They also retain a greater variety of information about the ice age past than any other archive. We can even detect layers of volcanic ash in the ice and pinpoint the date of ancient eruptions.”

“There are strong thermal gradients in both hemispheres because the low latitudes receive the most solar energy and the poles the least. To redress these imbalances the atmosphere and oceans move heat polewards — this is the basis of the climate system. In the North Atlantic a powerful surface current takes warmth from the tropics to higher latitudes: this is the famous Gulf Stream and its northeastern extension the North Atlantic Drift. Two main forces drive this current: the strong southwesterly winds and the return flow of colder, saltier water known as North Atlantic Deep Water (NADW). The surface current loses much of its heat to air masses that give maritime Europe a moist, temperate climate. Evaporative cooling also increases its salinity so that it begins to sink. As the dense and cold water sinks to the deep ocean to form NADW, it exerts a strong pull on the surface currents to maintain the cycle. It returns south at depths >2,000 m. […] The thermohaline circulation in the North Atlantic was periodically interrupted during Heinrich Events when vast discharges of melting icebergs cooled the ocean surface and reduced its salinity. This shut down the formation of NADW and suppressed the Gulf Stream.”


Archibald Geikie.
Andrew Ramsay (geologist).
Albrecht Penck. Eduard BrücknerGunz glaciation. Mindel glaciation. Riss glaciation. Würm.
Perihelion and aphelion.
Deep Sea Drilling Project.
δ18O. Isotope fractionation.
Marine isotope stage.
Cesare Emiliani.
Nicholas Shackleton.
Brunhes–Matuyama reversal. Geomagnetic reversal. Magnetostratigraphy.
Climate: Long range Investigation, Mapping, and Prediction (CLIMAP).
Uranium–thorium dating. Luminescence dating. Optically stimulated luminescence. Cosmogenic isotope dating.
The role of orbital forcing in the Early-Middle Pleistocene Transition (paper).
European Project for Ice Coring in Antarctica (EPICA).
Younger Dryas.
Lake Agassiz.
Greenland ice core project (GRIP).
J Harlen Bretz. Missoula Floods.
Pleistocene megafauna.


February 25, 2018 Posted by | Astronomy, Engineering, Geology, History, Paleontology, Physics | Leave a comment

The Ice Age (I)

I’m currently reading this book. Some observations and links related to the first half of the book below:

“It is important to appreciate from the outset that the Quaternary ice age was not one long episode of unremitting cold climate. […] By exploring the landforms, sediments, and fossils of the Quaternary Period we can identify glacials: periods of severe cold climate when great ice sheets formed in the high middle latitudes of the northern hemisphere and glaciers and ice caps advanced in mountain regions around the world. We can also recognize periods of warm climate known as interglacials when mean air temperatures in the middle latitudes were comparable to, and sometimes higher than, those of the present. As the climate shifted from glacial to interglacial mode, the large ice sheets of Eurasia and North America retreated allowing forest biomes to re-colonize the ice free landscapes. It is also important to recognize that the ice age isn’t just about advancing and retreating ice sheets. Major environmental changes also took place in the Mediterranean region and in the tropics. The Sahara, for example, became drier, cooler, and dustier during glacial periods yet early in the present interglacial it was a mosaic of lakes and oases with tracts of lush vegetation. A defining feature of the Quaternary Period is the repeated fluctuation in climate as conditions shifted from glacial to interglacial, and back again, during the course of the last 2.5 million years or so. A key question in ice age research is why does the Earth’s climate system shift so dramatically and so frequently?”

“Today we have large ice masses in the Polar Regions, but a defining feature of the Quaternary is the build-up and decay of continental-scale ice sheets in the high middle latitudes of the northern hemisphere. […] the Laurentide and Cordilleran ice sheets […] covered most of Canada and large tracts of the northern USA during glacial stages. Around 22,000 years ago, when the Laurentide ice sheet reached its maximum extent during the most recent glacial stage, it was considerably larger in both surface area and volume (34.8 million km3) than the present-day East and West Antarctic ice sheets combined (27 million km3). With a major ice dome centred on Hudson Bay greater than 4 km thick, it formed the largest body of ice on Earth. This great mass of ice depressed the crust beneath its bed by many hundreds of metres. Now shed of this burden, the crust is still slowly recovering today at rates of up to 1 cm per year. Glacial ice extended out beyond the 38th parallel across the lowland regions of North America. Chicago, Boston, and New York all lie on thick glacial deposits left by the Laurentide ice sheet. […] With huge volumes of water locked up in the ice sheets, global sea level was about 120 m lower than present at the Last Glacial Maximum (LGM), exposing large expanses of continental shelf and creating land bridges that allowed humans, animals, and plants to move between continents. Migration from eastern Russia to Alaska, for example, was possible via the Bering land bridge.”

“Large ice sheets also developed in Europe. […] The British Isles lie in an especially sensitive location on the Atlantic fringe of Europe between latitudes 50 and 60° north. Because of this geography, the Quaternary deposits of Britain record especially dramatic shifts in environmental conditions. The most extensive glaciation saw ice sheets extend as far south as the Thames Valley with wide braided rivers charged with meltwater and sediment from the ice margin. Beyond the glacial ice much of southern Britain would have been a treeless, tundra steppe environment with tracts of permanently frozen ground […]. At the LGM […] [t]he Baltic and North Seas were dry land and Britain was connected to mainland Europe. Beyond the British and Scandinavian ice sheets, much of central and northern Europe was a treeless tundra steppe habitat. […] During warm interglacial stages […] [b]road-leaved deciduous woodland with grassland was the dominant vegetation […]. In the warmest parts of interglacials thermophilous […] insects from the Mediterranean were common in Britain whilst the large mammal fauna of the Last Interglacial (c.130,000 to 115,000 years ago) included even more exotic species such as the short tusked elephant, rhinoceros, and hippopotamus. In some interglacials, the rivers of southern Britain contained molluscs that now live in the Nile Valley. For much of the Quaternary, however, climate would have been in an intermediate state (either warming or cooling) between these glacial and interglacial extremes.”

“Glaciologists make a distinction between three main types of glacier (valley glaciers, ice caps, and ice sheets) on the basis of scale and topographic setting. A glacier is normally constrained by the surrounding topography such as a valley and has a clearly defined source area. An ice cap builds up as a dome-like form on a high plateau or mountain peak and may feed several outlet glaciers to valleys below. Ice sheets notionally exceed 50,000 km2 and are not constrained by topography.”

“We live in unusual times. For more than 90 per cent of its 4.6-billion-year history, Earth has been too warm — even at the poles — for ice sheets to form. Ice ages are not the norm for our planet. Periods of sustained (over several million years) large-scale glaciation can be called glacial epochs. Tillites in the geological record tells us that the Quaternary ice age is just one of at least six great glacial epochs that have taken place over the last three billion years or so […]. The Quaternary itself is the culmination of a much longer glacial epoch that began around 35 million years ago (Ma) when glaciers and ice sheets first formed in Antarctica. This is known as the Cenozoic glacial epoch. There is still much to learn about these ancient glacial epochs, especially the so-called Snowball Earth states of the Precambrian (before 542 Ma) when the boundary conditions for the global climate system were so different to those of today. […] This book is concerned with the Quaternary ice age – it has the richest and most varied records of environmental change. Because its sediments are so recent they have not been subjected to millions of years of erosion or deep burial and metamorphism. […] in aquatic settings, such as lakes and peat bogs, organic materials such as insects, leaves, and seeds, as well as microfossils such as pollen and fungal spores can be exceptionally well preserved in the fossil record. This allows us to create very detailed pictures of past ecosystems under glacial and interglacial conditions. This field of research is known as Quaternary paeloecology.”

“An erratic […] is a piece of rock that has been transported from its place of origin. […] Many erratics stand out because they lie on bedrock that is very different to their source. […] Erratics are normally associated with transport by glaciers or ice sheets, but in the early 19th century mechanisms such as the great deluge or rafting on icebergs were commonly invoked. […] Enormous erratic boulders […] were well known to 18th- and 19th-centery geologists. […] Their origin was a source of lively and protracted debate […] Early observers of Alpine glaciers had noted the presence of large boulders on the surface of active glaciers or forming part of the debris pile at the glacier snout. These were readily explainable, but erratic boulders had long been noted in locations that defied rational explanations. The erratics found at elevations far above their known sources, and in places such as Britain where glaciers were absent, were especially problematic for early students of landscape history. […] A huge deluge […] was commonly invoked to explain the disposition of such boulders and many saw them as more hard evidence in support of the Biblical flood. […] At this time, the Church of England held a strong influence over much of higher education and especially so in Cambridge and Oxford.”

Venetz [in the early 19th century] produced remarkably detailed topographic maps of lateral and terminal moraines that lay far down valley of the modern glaciers. He was able to show that many glaciers had advanced and retreated in the historical period. His was the first systematic analysis of climate-glacier-landscape interactions. […] In 1821, Venetz presented his findings to the Société Helvétiques des Sciences Naturelles, setting out Perraudin’s ideas alongside his own. The paper had little impact, however, and would not see publication until 1833. […] Jean de Charpentier [in his work] paid particular attention to the disposition of large erratic blocks and the occurrence of polished and striated bedrock surfaces in the deep valleys of western Switzerland. A major step forward was Charpentier’s recognition of a clear relationship between the elevation of the erratic blocks in the Rhône Valley and the vertical extent of glacially smoothed rock walls. He noted that the bedrock valley sides above the erratic blocks were not worn smooth because they must have been above the level of the ancient glacier surface. The rock walls below the erratics always bore the hallmarks of contact with glacial ice. We call this boundary the trimline. It is often clearly marked in hard bedrock because the texture of the valley sides above the glacier surface is fractured due to attack by frost weathering. The detachment of rock particles above the trimline adds debris to lateral moraines and the glacier surface. These insights allowed Charpentier to reconstruct the vertical extent of former glaciers for the first time. Venetz and Perraudin had already shown how to demarcate the length and width of glaciers using the terminal and lateral moraines in these valleys. Charpentier described some of the most striking erratic boulders in the Alps […]. As Charpentier mapped the giant erratics, polished bedrock surfaces, and moraines in the Rhône Valley, it became clear to him that the valley must once have been occupied by a truly enormous glacier or ‘glacier-monstre’ as he called it. […] In 1836, Charpentier published a key paper setting out the main findings of their [his and Venetz’] glacial work”.

“Even before Charpentier was thinking about large ice masses in Switzerland, Jens Esmark (1763-1839) […] had suggested that northern European glaciers had been much more extensive in the past and were responsible for the transport of large erratic boulders and the formation of moraines. Esmark also recognized the key role of deep bedrock erosion by glacial ice in the formation of the spectacular Norwegian fjords. He worked out that glaciers in Norway had once extended down to sea level. Esmark’s ideas were […] translated into English and published […] in 1826, a decade in advance of Charpentier’s paper. Esmark discussed a large body of evidence pointing to an extensive glaciation of northern Europe. […] his thinking was far in advance of his contemporaries […] Unfortunately, even Esmark’s carefully argued paper held little sway in Britain and elsewhere […] it would be many decades before there was general acceptance within the geological community that glaciers could spread out across low gradient landscapes. […] in the lecture theatres and academic societies of Paris, Berlin, and London, the geological establishment was slow to take up these ideas, even though they were published in both English and French and were widely available. Much of the debate in the 1820s and early 1830s centred on the controversy over the evolution of valleys between the fluvialists (Hutton, Playfair, and others), who advocated slow river erosion, and the diluvialists (Buckland, De la Beche, and others) who argued that big valleys and large boulders needed huge deluges. The role of glaciers in valley and fjord formation was not considered. […] The key elements of a glacial theory were in place but nobody was listening. […] It would be decades before a majority accepted that vast tracts of Eurasia and North America had once been covered by mighty ice sheets.”

“Most geologists in 1840 saw Agassiz’s great ice sheet as a retrograde step. It was just too catastrophist — a blatant violation of hard-won uniformitarian principles. It was the antithesis of the new rational geology and was not underpinned by carefully assembled field data. So, for many, as an explanation for the superficial deposits of the Quaternary, it was no more convincing than the deluge. […] Ancient climates were [also] supposed to be warmer not colder. The suggestion of a freezing glacial epoch in the recent geological past, followed by the temperate climate of the present, still jarred with the conventional wisdom that Earth history, from its juvenile molten state to the present, was an uninterrupted record of long-term cooling without abrupt change. Lyell’s drift ice theory [according to which erratics (and till) had been transported by icebergs drifting in water, instead of glaciers transporting the material over land – US] also provided an attractive alternative to Agassiz’s ice age because it did not demand a period of cold glacial climate in areas that now enjoy temperate conditions. […] If anything, the 1840 sessions at the Geological Society had galvanized support for floating ice as a mechanism for drift deposition in the lowlands. Lyell’s model proved to be remarkably resilient—its popularity proved to be the major obstacle to the wider adoption of the land ice theory. […] many refused to believe that glacier ice could advance across gently sloping lowland terrain. This was a reasonable objection at this time since the ice sheets of Greenland and Antarctica had not yet been investigated from a glaciological point of view. It is not difficult to understand why many British geologists rejected the glacial theory when the proximity and potency of the sea was so obvious and nobody knew how large ice sheets behaved.”

Hitchcock […] was one of the first Americans to publicly embrace Agassiz’s ideas […] but he later stepped back from a full endorsement, leaving a role for floating ice. This hesitant beginning set the tone for the next few decades in North America as its geologists began to debate whether they could see the work of ice sheets or icebergs. There was a particularly strong tradition of scriptural geology in 19th-century North America. Its practitioners attempted to reconcile their field observations with the Bible and there were often close links with like-minded souls in Britain. […] If the standing of Lyell extended the useful lifespan of the iceberg theory, it was gradually worn down by a growing body of field evidence from Europe and North America that pointed to the action of glacier ice. […] The continental glacial theory prevailed in North America because it provided a much better explanation for the vast majority of the features recorded in the landscape. The striking regularity and fixed alignment of many features could not be the work of icebergs whose wanderings were governed by winds and ocean currents. The southern limit of the glacial deposits is often marked by pronounced ridges in an otherwise low-relief landscape. These end moraines mark the edge of the former ice sheet and they cannot be formed by floating ice. It took a long time to put all the pieces of evidence together in North America because of the vast scale of the territory to be mapped. Once the patterns of erratic dispersal, large-scale scratching of bedrock, terminal moraines, drumlin fields, and other features were mapped, their systematic arrangement argued strongly against the agency of drifting ice. Unlike their counterparts in Britain, who were never very far from the sea, geologists working deep in the continental interior of North America found it much easier to dismiss the idea of a great marine submergence. Furthermore, icebergs just did not transport enough sediment to account for the enormous extent and great thickness of the Quaternary deposits. It was also realized that icebergs were just not capable of planing off hard bedrock to create plateau surfaces. Neither were they able to polish, scratch, or cut deep grooves into ancient bedrock. All these features pointed to the action of land-based glacial ice. Slowly, but surely, the reality of vast expanses of glacier ice covering much of Canada and the northern states of the USA became apparent.”


The Parallel Roads of Glen Roy.
William Boyd Dawkins.
Adams mammoth.
Georges Cuvier.
Cirque (geology). Arête. Tarn. Moraine. Drumlin. Till/Tillite. Glacier morphology.
James Hutton.
William Buckland.
Charles Lyell.
Giétro Glacier.
Cwm Idwal.
Timothy Abbott Conrad. Charles Whittlesey. James Dwight Dana.

February 23, 2018 Posted by | Books, Ecology, Geography, Geology, History, Paleontology | Leave a comment

Rivers (II)

Some more observations from the book and related links below.

“By almost every measure, the Amazon is the greatest of all the large rivers. Encompassing more than 7 million square kilometres, its drainage basin is the largest in the world and makes up 5% of the global land surface. The river accounts for nearly one-fifth of all the river water discharged into the oceans. The flow is so great that water from the Amazon can still be identified 125 miles out in the Atlantic […] The Amazon has some 1,100 tributaries, and 7 of these are more than 1,600 kilometres long. […] In the lowlands, most Amazonian rivers have extensive floodplains studded with thousands of shallow lakes. Up to one-quarter of the entire Amazon Basin is periodically flooded, and these lakes become progressively connected with each other as the water level rise.”

“To hydrologists, the term ‘flood’ refers to a river’s annual peak discharge period, whether the water inundates the surrounding landscape or not. In more common parlance, however, a flood is synonymous with the river overflowing it’s banks […] Rivers flood in the natural course of events. This often occurs on the floodplain, as the name implies, but flooding can affect almost all of the length of the river. Extreme weather, particularly heavy or protracted rainfall, is the most frequent cause of flooding. The melting of snow and ice is another common cause. […] River floods are one of the most common natural hazards affecting human society, frequently causing social disruption, material damage, and loss of life. […] Most floods have a seasonal element in their occurence […] It is a general rule that the magnitude of a flood is inversely related to its frequency […] Many of the less predictable causes of flooding occur after a valley has been blocked by a natural dam as a result of a landslide, glacier, or lava flow. Natural dams may cause upstream flooding as the blocked river forms a lake and downstream flooding as a result of failure of the dam.”

“The Tigris-Euphrates, Nile, and Indus are all large, exotic river systems, but in other respects they are quite different. The Nile has a relatively gentle gradient in Egypt and a channel that has experienced only small changes over the last few thousand years, by meander cut-off and a minor shift eastwards. The river usually flooded in a regular and predictable way. The stability and long continuity of the Egyptian civilization may be a reflection of its river’s relative stability. The steeper channel of the Indus, by contrast, has experienced major avulsions over great distances on the lower Indus Plain and some very large floods caused by the failure of glacier ice dams in the Himalayan mountains. Likely explanations for the abandonment of many Harappan cities […] take account of damage caused by major floods and/or the disruption caused by channel avulsion leading to a loss of water supply. Channel avulsion was also a problem for the Sumerian civilization on the alluvial plain called Mesopotamia […] known for the rise and fall of its numerous city states. Most of these cities were situated along the Euphrates River, probably because it was more easily controlled for irrigation purposes than the Tigris, which flowed faster and carried much more water. However, the Euphrates was an anastomosing river with multiple channels that diverge and rejoin. Over time, individual branch channels ceased to flow as others formed, and settlements located on these channels inevitably declined and were abandoned as their water supply ran dry, while others expanded as their channels carried greater amounts of water.”

“During the colonization of the Americas in the mid-18th century and the imperial expansion into Africa and Asia in the late 19th century, rivers were commonly used as boundaries because they were the first, and frequently the only, features mapped by European explorers. The diplomats in Europe who negotiated the allocation of colonial territories claimed by rival powers knew little of the places they were carving up. Often, their limited knowledge was based solely on maps that showed few details, rivers being the only distinct physical features marked. Today, many international river boundaries remain as legacies of those historical decisions based on poor geographical knowledge because states have been reluctant to alter their territorial boundaries from original delimitation agreements. […] no less than three-quarters of the world’s international boundaries follow rivers for at least part of their course. […] approximately 60% of the world’s fresh water is drawn from rivers shared by more than one country.”

“The sediments carried in rivers, laid down over many years, represent a record of the changes that have occurred in the drainage basin through the ages. Analysis of these sediments is one way in which physical geographers can interpret the historical development of landscapes. They can study the physical and chemical characteristics of the sediments itself and/or the biological remains they contain, such as pollen or spores. […] The simple rate at which material is deposited by a river can be a good reflection of how conditions have changed in the drainage basin. […] Pollen from surrounding plants is often found in abundance in fluvial sediments, and the analysis of pollen can yield a great deal of information about past conditions in an area. […] Very long sediment cores taken from lakes and swamps enable us to reconstruct changes in vegetation over very long time periods, in some cases over a million years […] Because climate is a strong determinant of vegetation, pollen analysis has also proved to be an important method for tracing changes in past climates.”

“The energy in flowing and falling water has been harnessed to perform work by turning water-wheels for more than 2,000 years. The moving water turns a large wheel and a shaft connected to the wheel axle transmits the power from the water through a system of gears and cogs to work machinery, such as a millstone to grind corn. […] The early medieval watermill was able to do the work of between 30 and 60 people, and by the end of the 10th century in Europe, waterwheels were commonly used in a wide range of industries, including powering forge hammers, oil and silk mills, sugar-cane crushers, ore-crushing mills, breaking up bark in tanning mills, pounding leather, and grinding stones. Nonetheless, most were still used for grinding grains for preparation into various types of food and drink. The Domesday Book, a survey prepared in England in AD 1086, lists 6,082 watermills, although this is probably a conservative estimate because many mills were not recorded in the far north of the country. By 1300, this number had risen to exceed 10,000. [..] Medieval watermills typically powered their wheels by using a dam or weir to concentrate the falling water and pond a reserve supply. These modifications to rivers became increasingly common all over Europe, and by the end of the Middle Ages, in the mid-15th century, watermills were in use on a huge number of rivers and streams. The importance of water power continued into the Industrial Revolution […]. The early textile factories were built to produce cloth using machines driven by waterwheels, so they were often called mills. […] [Today,] about one-third of all countries rely on hydropower for more than half their electricity. Globally, hydropower provides about 20% of the world’s total electricity supply.”

“Deliberate manipulation of river channels through engineering works, including dam construction, diversion, channelization, and culverting, […] has a long history. […] In Europe today, almost 80% of the total discharge of the continent’s major rivers is affected by measures designed to regulate flow, whether for drinking water supply, hydroelectric power generation, flood control, or any other reason. The proportion in individual countries is higher still. About 90% of rivers in the UK are regulated as a result of these activities, while in the Netherlands this percentage is close to 100. By contrast, some of the largest rivers on other continents, including the Amazon and the Congo, are hardly manipulated at all. […] Direct and intentional modifications to rivers are complemented by the impacts of land use and land use changes which frequently result in the alteration of rivers as an unintended side effect. Deforestation, afforestation, land drainage, agriculture, and the use of fire have all had significant impacts, with perhaps the most extreme effects produced by construction activity and urbanization. […] The major methods employed in river regulation are the construction of large dams […], the building of run-of-river impoundments such as weirs and locks, and by channelization, a term that covers a range of river engineering works including widening, deepening, straightening, and the stabilization of banks. […] Many aspects of a dynamic river channel and its associated ecosystems are mutually adjusting, so a human activity in a landscape that affects the supply of water or sediment is likely to set off a complex cascade of other alterations.”

“The methods of storage (in reservoirs) and distribution (by canal) have not changed fundamentally since the earliest river irrigation schemes, with the exception of some contemporary projects’ use of pumps to distribute water over greater distances. Nevertheless, many irrigation canals still harness the force of gravity. Half the world’s large dams (defined as being 15 metres or higher) were built exclusively or primarily for irrigation, and about one-third of the world’s irrigated cropland relies on reservoir water. In several countries, including such populous nations as India and China, more than 50% of arable land is irrigated by river water supplied from dams. […] Sadly, many irrigation schemes are not well managed and a number of environmental problems are frequently experienced as a result, both on-site and off-site. In many large networks of irrigation canals, less than half of the water diverted from a river or reservoir actually benefits crops. A lot of water seeps away through unlined canals or evaporates before reaching the fields. Some also runs off the fields or infiltrates through the soil, unused by plants, because farmers apply too much water or at the wrong time. Much of this water seeps back into nearby streams or joins underground aquifers, so can be used again, but the quality of water may deteriorate if it picks up salts, fertilizers, or pesticides. Excessive applications of irrigation water often result in rising water tables beneath fields, causing salinization and waterlogging. These processes reduce crop yields on irrigation schemes all over the world.”

“[Deforestation can contribute] to the degradation of aquatic habitats in numerous ways. The loss of trees along river banks can result in changes in the species found in the river because fewer trees means a decline in plant matter and insects falling from them, items eaten by some fish. Fewer trees on river banks also results in less shade. More sunlight reaching the river results in warmer water and the enhanced growth of algae. A change in species can occur as fish that feed on falling food are edged out by those able to feed on algae. Deforestation also typically results in more runoff and more soil erosion. This sediment may cover spawning grounds, leading to lower reproduction rates. […] Grazing and trampling by livestock reduces vegetation cover and causes the compaction of soil, which reduces its infiltration capacity. As rainwater passes over or through the soil in areas of intensive agriculture, it picks up residues from pesticides and fertilizers and transport them to rivers. In this way, agriculture has become a leading source of river pollution in certain parts of the world. Concentration of nitrates and phosphates, derived from fertilizers, have risen notably in many rivers in Europe and North America since the 1950s and have led to a range of […] problems encompassed under the term ‘eutrophication’ – the raising of biological productivity caused by nutrient enrichment. […] In slow-moving rivers […] the growth of algae reduces light penetration and depletes the oxygen in the water, sometimes causing fish kills.”

“One of the most profound ways in which people alter rivers is by damming them. Obstructing a river and controlling its flow in this way brings about a raft of changes. A dam traps sediments and nutrients, alters the river’s temperature and chemistry, and affects the processes of erosion and deposition by which the river sculpts the landscape. Dams create more uniform flow in rivers, usually by reducing peak flows and increasing minimum flows. Since the natural variation in flow is important for river ecosystems and their biodiversity, when dams even out flows the result is commonly fewer fish of fewer species. […] the past 50 years or so has seen a marked escalation in the rate and scale of construction of dams all over the world […]. At the beginning of the 21st century, there were about 800,000 dams worldwide […] In some large river systems, the capacity of dams is sufficient to hold more than the entire annual discharge of the river. […] Globally, the world’s major reservoirs are thought to control about 15% of the runoff from the land. The volume of water trapped worldwide in reservoirs of all sizes is no less than five times the total global annual river flow […] Downstream of a reservoir, the hydrological regime of a river is modified. Discharge, velocity, water quality, and thermal characteristics are all affected, leading to changes in the channel and its landscape, plants, and animals, both on the river itself and in deltas, estuaries, and offshore. By slowing the flow of river water, a dam acts as a trap for sediment and hence reduces loads in the river downstream. As a result, the flow downstream of the dam is highly erosive. A relative lack of silt arriving at a river’s delta can result in more coastal erosion and the intrusion of seawater that brings salt into delta ecosystems. […] The dam-barrier effect on migratory fish and their access to spawning grounds has been recognized in Europe since medieval times.”

“One of the most important effects cities have on rivers is the way in which urbanization affects flood runoff. Large areas of cities are typically impermeable, being covered by concrete, stone, tarmac, and bitumen. This tends to increase the amount of runoff produced in urban areas, an effect exacerbated by networks of storm drains and sewers. This water carries relatively little sediment (again, because soil surfaces have been covered by impermeable materials), so when it reaches a river channel it typically causes erosion and widening. Larger and more frequent floods are another outcome of the increase in runoff generated by urban areas. […] It […] seems very likely that efforts to manage the flood hazard on the Mississippi have contributed to an increased risk of damage from tropical storms on the Gulf of Mexico coast. The levées built along the river have contributed to the loss of coastal wetlands, starving them of sediment and fresh water, thereby reducing their dampening effect on storm surge levels. This probably enhanced the damage from Hurricane Katrina which struck the city of New Orleans in 2005.”


Onyx River.
Yangtze. Yangtze floods.
Missoula floods.
Murray River.
Southeastern Anatolia Project.
Water conflict.
Fulling mill.
Maritime transport.
Lock (water navigation).
Yellow River.
Aswan High Dam. Warragamba Dam. Three Gorges Dam.
River restoration.

January 16, 2018 Posted by | Biology, Books, Ecology, Engineering, Geography, Geology, History | Leave a comment

Random stuff

I have almost stopped posting posts like these, which has resulted in the accumulation of a very large number of links and studies which I figured I might like to blog at some point. This post is mainly an attempt to deal with the backlog – I won’t cover the material in too much detail.

i. Do Bullies Have More Sex? The answer seems to be a qualified yes. A few quotes:

“Sexual behavior during adolescence is fairly widespread in Western cultures (Zimmer-Gembeck and Helfland 2008) with nearly two thirds of youth having had sexual intercourse by the age of 19 (Finer and Philbin 2013). […] Bullying behavior may aid in intrasexual competition and intersexual selection as a strategy when competing for mates. In line with this contention, bullying has been linked to having a higher number of dating and sexual partners (Dane et al. 2017; Volk et al. 2015). This may be one reason why adolescence coincides with a peak in antisocial or aggressive behaviors, such as bullying (Volk et al. 2006). However, not all adolescents benefit from bullying. Instead, bullying may only benefit adolescents with certain personality traits who are willing and able to leverage bullying as a strategy for engaging in sexual behavior with opposite-sex peers. Therefore, we used two independent cross-sectional samples of older and younger adolescents to determine which personality traits, if any, are associated with leveraging bullying into opportunities for sexual behavior.”

“…bullying by males signal the ability to provide good genes, material resources, and protect offspring (Buss and Shackelford 1997; Volk et al. 2012) because bullying others is a way of displaying attractive qualities such as strength and dominance (Gallup et al. 2007; Reijntjes et al. 2013). As a result, this makes bullies attractive sexual partners to opposite-sex peers while simultaneously suppressing the sexual success of same-sex rivals (Gallup et al. 2011; Koh and Wong 2015; Zimmer-Gembeck et al. 2001). Females may denigrate other females, targeting their appearance and sexual promiscuity (Leenaars et al. 2008; Vaillancourt 2013), which are two qualities relating to male mate preferences. Consequently, derogating these qualities lowers a rivals’ appeal as a mate and also intimidates or coerces rivals into withdrawing from intrasexual competition (Campbell 2013; Dane et al. 2017; Fisher and Cox 2009; Vaillancourt 2013). Thus, males may use direct forms of bullying (e.g., physical, verbal) to facilitate intersexual selection (i.e., appear attractive to females), while females may use relational bullying to facilitate intrasexual competition, by making rivals appear less attractive to males.”

The study relies on the use of self-report data, which I find very problematic – so I won’t go into the results here. I’m not quite clear on how those studies mentioned in the discussion ‘have found self-report data [to be] valid under conditions of confidentiality’ – and I remain skeptical. You’ll usually want data from independent observers (e.g. teacher or peer observations) when analyzing these kinds of things. Note in the context of the self-report data problem that if there’s a strong stigma associated with being bullied (there often is, or bullying wouldn’t work as well), asking people if they have been bullied is not much better than asking people if they’re bullying others.

ii. Some topical advice that some people might soon regret not having followed, from the wonderful Things I Learn From My Patients thread:

“If you are a teenage boy experimenting with fireworks, do not empty the gunpowder from a dozen fireworks and try to mix it in your mother’s blender. But if you do decide to do that, don’t hold the lid down with your other hand and stand right over it. This will result in the traumatic amputation of several fingers, burned and skinned forearms, glass shrapnel in your face, and a couple of badly scratched corneas as a start. You will spend months in rehab and never be able to use your left hand again.”

iii. I haven’t talked about the AlphaZero-Stockfish match, but I was of course aware of it and did read a bit about that stuff. Here’s a reddit thread where one of the Stockfish programmers answers questions about the match. A few quotes:

“Which of the two is stronger under ideal conditions is, to me, neither particularly interesting (they are so different that it’s kind of like comparing the maximum speeds of a fish and a bird) nor particularly important (since there is only one of them that you and I can download and run anyway). What is super interesting is that we have two such radically different ways to create a computer chess playing entity with superhuman abilities. […] I don’t think there is anything to learn from AlphaZero that is applicable to Stockfish. They are just too different, you can’t transfer ideas from one to the other.”

“Based on the 100 games played, AlphaZero seems to be about 100 Elo points stronger under the conditions they used. The current development version of Stockfish is something like 40 Elo points stronger than the version used in Google’s experiment. There is a version of Stockfish translated to hand-written x86-64 assembly language that’s about 15 Elo points stronger still. This adds up to roughly half the Elo difference between AlphaZero and Stockfish shown in Google’s experiment.”

“It seems that Stockfish was playing with only 1 GB for transposition tables (the area of memory used to store data about the positions previously encountered in the search), which is way too little when running with 64 threads.” [I seem to recall a comp sci guy observing elsewhere that this was less than what was available to his smartphone version of Stockfish, but I didn’t bookmark that comment].

“The time control was a very artificial fixed 1 minute/move. That’s not how chess is traditionally played. Quite a lot of effort has gone into Stockfish’s time management. It’s pretty good at deciding when to move quickly, and when to spend a lot of time on a critical decision. In a fixed time per move game, it will often happen that the engine discovers that there is a problem with the move it wants to play just before the time is out. In a regular time control, it would then spend extra time analysing all alternative moves and trying to find a better one. When you force it to move after exactly one minute, it will play the move it already know is bad. There is no doubt that this will cause it to lose many games it would otherwise have drawn.”

iv. Thrombolytics for Acute Ischemic Stroke – no benefit found.

“Thrombolysis has been rigorously studied in >60,000 patients for acute thrombotic myocardial infarction, and is proven to reduce mortality. It is theorized that thrombolysis may similarly benefit ischemic stroke patients, though a much smaller number (8120) has been studied in relevant, large scale, high quality trials thus far. […] There are 12 such trials 1-12. Despite the temptation to pool these data the studies are clinically heterogeneous. […] Data from multiple trials must be clinically and statistically homogenous to be validly pooled.14 Large thrombolytic studies demonstrate wide variations in anatomic stroke regions, small- versus large-vessel occlusion, clinical severity, age, vital sign parameters, stroke scale scores, and times of administration. […] Examining each study individually is therefore, in our opinion, both more valid and more instructive. […] Two of twelve studies suggest a benefit […] In comparison, twice as many studies showed harm and these were stopped early. This early stoppage means that the number of subjects in studies demonstrating harm would have included over 2400 subjects based on originally intended enrollments. Pooled analyses are therefore missing these phantom data, which would have further eroded any aggregate benefits. In their absence, any pooled analysis is biased toward benefit. Despite this, there remain five times as many trials showing harm or no benefit (n=10) as those concluding benefit (n=2), and 6675 subjects in trials demonstrating no benefit compared to 1445 subjects in trials concluding benefit.”

“Thrombolytics for ischemic stroke may be harmful or beneficial. The answer remains elusive. We struggled therefore, debating between a ‘yellow’ or ‘red’ light for our recommendation. However, over 60,000 subjects in trials of thrombolytics for coronary thrombosis suggest a consistent beneficial effect across groups and subgroups, with no studies suggesting harm. This consistency was found despite a very small mortality benefit (2.5%), and a very narrow therapeutic window (1% major bleeding). In comparison, the variation in trial results of thrombolytics for stroke and the daunting but consistent adverse effect rate caused by ICH suggested to us that thrombolytics are dangerous unless further study exonerates their use.”

“There is a Cochrane review that pooled estimates of effect. 17 We do not endorse this choice because of clinical heterogeneity. However, we present the NNT’s from the pooled analysis for the reader’s benefit. The Cochrane review suggested a 6% reduction in disability […] with thrombolytics. This would mean that 17 were treated for every 1 avoiding an unfavorable outcome. The review also noted a 1% increase in mortality (1 in 100 patients die because of thrombolytics) and a 5% increase in nonfatal intracranial hemorrhage (1 in 20), for a total of 6% harmed (1 in 17 suffers death or brain hemorrhage).”

v. Suicide attempts in Asperger Syndrome. An interesting finding: “Over 35% of individuals with AS reported that they had attempted suicide in the past.”

Related: Suicidal ideation and suicide plans or attempts in adults with Asperger’s syndrome attending a specialist diagnostic clinic: a clinical cohort study.

“374 adults (256 men and 118 women) were diagnosed with Asperger’s syndrome in the study period. 243 (66%) of 367 respondents self-reported suicidal ideation, 127 (35%) of 365 respondents self-reported plans or attempts at suicide, and 116 (31%) of 368 respondents self-reported depression. Adults with Asperger’s syndrome were significantly more likely to report lifetime experience of suicidal ideation than were individuals from a general UK population sample (odds ratio 9·6 [95% CI 7·6–11·9], p<0·0001), people with one, two, or more medical illnesses (p<0·0001), or people with psychotic illness (p=0·019). […] Lifetime experience of depression (p=0·787), suicidal ideation (p=0·164), and suicide plans or attempts (p=0·06) did not differ significantly between men and women […] Individuals who reported suicide plans or attempts had significantly higher Autism Spectrum Quotient scores than those who did not […] Empathy Quotient scores and ages did not differ between individuals who did or did not report suicide plans or attempts (table 4). Patients with self-reported depression or suicidal ideation did not have significantly higher Autism Spectrum Quotient scores, Empathy Quotient scores, or age than did those without depression or suicidal ideation”.

The fact that people with Asperger’s are more likely to be depressed and contemplate suicide is consistent with previous observations that they’re also more likely to die from suicide – for example a paper I blogged a while back found that in that particular (large Swedish population-based cohort-) study, people with ASD were more than 7 times as likely to die from suicide than were the comparable controls.

Also related: Suicidal tendencies hard to spot in some people with autism.

This link has some great graphs and tables of suicide data from the US.

Also autism-related: Increased perception of loudness in autism. This is one of the ‘important ones’ for me personally – I am much more sound-sensitive than are most people.

vi. Early versus Delayed Invasive Intervention in Acute Coronary Syndromes.

“Earlier trials have shown that a routine invasive strategy improves outcomes in patients with acute coronary syndromes without ST-segment elevation. However, the optimal timing of such intervention remains uncertain. […] We randomly assigned 3031 patients with acute coronary syndromes to undergo either routine early intervention (coronary angiography ≤24 hours after randomization) or delayed intervention (coronary angiography ≥36 hours after randomization). The primary outcome was a composite of death, myocardial infarction, or stroke at 6 months. A prespecified secondary outcome was death, myocardial infarction, or refractory ischemia at 6 months. […] Early intervention did not differ greatly from delayed intervention in preventing the primary outcome, but it did reduce the rate of the composite secondary outcome of death, myocardial infarction, or refractory ischemia and was superior to delayed intervention in high-risk patients.”

vii. Some wikipedia links:

Behrens–Fisher problem.
Sailing ship tactics (I figured I had to read up on this if I were to get anything out of the Aubrey-Maturin books).
Anatomical terms of muscle.
Phatic expression (“a phatic expression […] is communication which serves a social function such as small talk and social pleasantries that don’t seek or offer any information of value.”)
Three-domain system.
Beringian wolf (featured).
Subdural hygroma.
Cayley graph.
Schur polynomial.
Solar neutrino problem.
Hadamard product (matrices).
True polar wander.
Newton’s cradle.

viii. Determinant versus permanent (mathematics – technical).

ix. Some years ago I wrote a few English-language posts about some of the various statistical/demographic properties of immigrants living in Denmark, based on numbers included in a publication by Statistics Denmark. I did it by translating the observations included in that publication, which was only published in Danish. I was briefly considering doing the same thing again when the 2017 data arrived, but I decided not to do it as I recalled that it took a lot of time to write those posts back then, and it didn’t seem to me to be worth the effort – but Danish readers might be interested to have a look at the data, if they haven’t already – here’s a link to the publication Indvandrere i Danmark 2017.

x. A banter blitz session with grandmaster Peter Svidler, who recently became the first Russian ever to win the Russian Chess Championship 8 times. He’s currently shared-second in the World Rapid Championship after 10 rounds and is now in the top 10 on the live rating list in both classical and rapid – seems like he’s had a very decent year.

xi. I recently discovered Dr. Whitecoat’s blog. The patient encounters are often interesting.

December 28, 2017 Posted by | Astronomy, autism, Biology, Cardiology, Chess, Computer science, History, Mathematics, Medicine, Neurology, Physics, Psychiatry, Psychology, Random stuff, Statistics, Studies, Wikipedia, Zoology | Leave a comment

The history of astronomy

It’s been a while since I read this book, and I was for a while strongly considering not blogging it at all. In the end I figured I ought to cover it after all in at least a little bit of detail, though when I made the decision to cover the book here I also decided not to cover it in nearly as much detail as I usually cover the books in this series.

Below some random observations from the book which I found sufficiently interesting to add here.

“The Almagest is a magisterial work that provided geometrical models and related tables by which the movements of the Sun, Moon, and the five lesser planets could be calculated for the indefinite future. […] Its catalogue contains over 1,000 fixed stars arranged in 48 constellations, giving the longitude, latitude, and apparent brightness of each. […] the Almagest would dominate astronomy like a colossus for 14 centuries […] In the universities of the later Middle Ages, students would be taught Aristotle in philosophy and a simplified Ptolemy in astronomy. From Aristotle they would learn the basic truth that the heavens rotate uniformly about the central Earth. From the simplified Ptolemy they would learn of epicycles and eccentrics that violated this basic truth by generating orbits whose centre was not the Earth; and those expert enough to penetrate deeper into the Ptolemaic models would encounter equant theories that violated the (yet more basic) truth that heavenly motion is uniform. […] with the models of the Almagest – whose parameters would be refined over the centuries to come – the astronomer, and the astrologer, could compute the future positions of the planets with economy and reasonable accuracy. There were anomalies – the Moon, for example, would vary its apparent size dramatically in the Ptolemaic model but does not do so in reality, and Venus and Mercury were kept close to the Sun in the sky by a crude ad hoc device – but as a geometrical compendium of how to grind out planetary tables, the Almagest worked, and that was what mattered.”

“The revival of astronomy – and astrology – among the Latins was stimulated around the end of the first millennium when the astrolabe entered the West from Islamic Spain. Astrology in those days had a [‘]rational[‘] basis rooted in the Aristotelian analogy between the microcosm – the individual living body – and the macrocosm, the cosmos as a whole. Medical students were taught how to track the planets, so that they would know when the time was favourable for treating the corresponding organs in their patients.” [Aaargh! – US]

“The invention of printing in the 15th century had many consequences, none more significant than the stimulus it gave to the mathematical sciences. All scribes, being human, made occasional errors in preparing a copy of a manuscript. These errors would often be transmitted to copies of the copy. But if the works were literary and the later copyists attended to the meaning of the text, they might recognize and correct many of the errors introduced by their predecessors. Such control could rarely be exercised by copyists required to reproduce texts with significant numbers of mathematical symbols. As a result, a formidable challenge faced the medieval student of a mathematical or astronomical treatise, for it was available to him only in a manuscript copy that had inevitably become corrupt in transmission. After the introduction of printing, all this changed.”

“Copernicus, like his predecessors, had been content to work with observations handed down from the past, making new ones only when unavoidable and using instruments that left much to be desired. Tycho [Brahe], whose work marks the watershed between observational astronomy ancient and modern, saw accuracy of observation as the foundation of all good theorizing. He dreamed of having an observatory where he could pursue the research and development of precision instrumentation, and where a skilled team of assistants would test the instruments even as they were compiling a treasury of observations. Exploiting his contacts at the highest level, Tycho persuaded King Frederick II of Denmark to grant him the fiefdom of the island of Hven, and there, between 1576 and 1580, he constructed Uraniborg (‘Heavenly Castle’), the first scientific research institution of the modern era. […] Tycho was the first of the modern observers, and in his catalogue of 777 stars the positions of the brightest are accurate to a minute or so of arc; but he himself was probably most proud of his cosmology, which Galileo was not alone in seeing as a retrograde compromise. Tycho appreciated the advantages of heliocentic planetary models, but he was also conscious of the objections […]. In particular, his inability to detect annual parallax even with his superb instrumentation implied that the Copernican excuse, that the stars were too far away for annual parallax to be detected, was now implausible in the extreme. The stars, he calculated, would have to be at least 700 times further away than Saturn for him to have failed for this reason, and such a vast, purposeless empty space between the planets and the stars made no sense. He therefore looked for a cosmology that would have the geometrical advantages of the heliocentric models but would retain the Earth as the body physically at rest at the centre of the cosmos. The solution seems obvious in hindsight: make the Sun (and Moon) orbit the central Earth, and make the five planets into satellites of the Sun.”

“Until the invention of the telescope, each generation of astronomers had looked at much the same sky as their predecessors. If they knew more, it was chiefly because they had more books to read, more records to mine. […] Galileo could say of his predecessors, ‘If they had seen what we see, they would have judged as we judge’; and ever since his time, the astronomers of each generation have had an automatic advantage over their predecessors, because they possess apparatus that allows them access to objects unseen, unknown, and therefore unstudied in the past. […] astronomers [for a long time] found themselves in a situation where, as telescopes improved, the two coordinates of a star’s position on the heavenly sphere were being measured with ever increasing accuracy, whereas little was known of the star’s third coordinate, distance, except that its scale was enormous. Even the assumption that the nearest stars were the brightest was […rightly, US] being called into question, as the number of known proper motions increased and it emerged that not all the fastest-moving stars were bright.”

“We know little of how Newton’s thinking developed between 1679 and the visit from Halley in 1684, except for a confused exchange of letters between Newton and the Astronomer Royal, John Flamsteed […] the visit from the suitably deferential and tactful Halley encouraged Newton to promise him written proof that elliptical orbits would result from an inverse-square force of attraction residing in the Sun. The drafts grew and grew, and eventually resulted in The Mathematical Principles of Natural Philosophy (1687), better known in its abbreviated Latin title of the Principia. […] All three of Kepler’s laws (the second in ‘area’ form), which had been derived by their author from observations, with the help of a highly dubious dynamics, were now shown to be consequences of rectilinear motion under an inverse-square force. […] As the drafts of Principia multiplied, so too did the number of phenomena that at last found their explanation. The tides resulted from the difference between the effects on the land and on the seas of the attraction of Sun and Moon. The spinning Earth bulged at the equator and was flattened at the poles, and so was not strictly spherical; as a result, the attraction of Sun and Moon caused the Earth’s axis to wobble and so generated the precession of the equinoxes first noticed by Hipparchus. […] Newton was able to use the observed motions of the moons of Earth, Jupiter, and Saturn to calculate the masses of the parent planets, and he found that Jupiter and Saturn were huge compared to Earth – and, in all probability, to Mercury, Venus, and Mars.”

December 5, 2017 Posted by | Astronomy, Books, History, Mathematics, Physics | Leave a comment


A few quotes from the book and some related links below. Here’s my very short goodreads review of the book.


“The main naturally occurring radionuclides of primordial origin are uranium-235, uranium-238, thorium-232, their decay products, and potassium-40. The average abundance of uranium, thorium, and potassium in the terrestrial crust is 2.6 parts per million, 10 parts per million, and 1% respectively. Uranium and thorium produce other radionuclides via neutron- and alpha-induced reactions, particularly deeply underground, where uranium and thorium have a high concentration. […] A weak source of natural radioactivity derives from nuclear reactions of primary and secondary cosmic rays with the atmosphere and the lithosphere, respectively. […] Accretion of extraterrestrial material, intensively exposed to cosmic rays in space, represents a minute contribution to the total inventory of radionuclides in the terrestrial environment. […] Natural radioactivity is [thus] mainly produced by uranium, thorium, and potassium. The total heat content of the Earth, which derives from this radioactivity, is 12.6 × 1024 MJ (one megajoule = 1 million joules), with the crust’s heat content standing at 5.4 × 1021 MJ. For comparison, this is significantly more than the 6.4 × 1013 MJ globally consumed for electricity generation during 2011. This energy is dissipated, either gradually or abruptly, towards the external layers of the planet, but only a small fraction can be utilized. The amount of energy available depends on the Earth’s geological dynamics, which regulates the transfer of heat to the surface of our planet. The total power dissipated by the Earth is 42 TW (one TW = 1 trillion watts): 8 TW from the crust, 32.3 TW from the mantle, 1.7 TW from the core. This amount of power is small compared to the 174,000 TW arriving to the Earth from the Sun.”

“Charged particles such as protons, beta and alpha particles, or heavier ions that bombard human tissue dissipate their energy locally, interacting with the atoms via the electromagnetic force. This interaction ejects electrons from the atoms, creating a track of electron–ion pairs, or ionization track. The energy that ions lose per unit path, as they move through matter, increases with the square of their charge and decreases linearly with their energy […] The energy deposited in the tissues and organs of your body by ionizing radiation is defined absorbed dose and is measured in gray. The dose of one gray corresponds to the energy of one joule deposited in one kilogram of tissue. The biological damage wrought by a given amount of energy deposited depends on the kind of ionizing radiation involved. The equivalent dose, measured in sievert, is the product of the dose and a factor w related to the effective damage induced into the living matter by the deposit of energy by specific rays or particles. For X-rays, gamma rays, and beta particles, a gray corresponds to a sievert; for neutrons, a dose of one gray corresponds to an equivalent dose of 5 to 20 sievert, and the factor w is equal to 5–20 (depending on the neutron energy). For protons and alpha particles, w is equal to 5 and 20, respectively. There is also another weighting factor taking into account the radiosensitivity of different organs and tissues of the body, to evaluate the so-called effective dose. Sometimes the dose is still quoted in rem, the old unit, with 100 rem corresponding to one sievert.”

“Neutrons emitted during fission reactions have a relatively high velocity. When still in Rome, Fermi had discovered that fast neutrons needed to be slowed down to increase the probability of their reaction with uranium. The fission reaction occurs with uranium-235. Uranium-238, the most common isotope of the element, merely absorbs the slow neutrons. Neutrons slow down when they are scattered by nuclei with a similar mass. The process is analogous to the interaction between two billiard balls in a head-on collision, in which the incoming ball stops and transfers all its kinetic energy to the second one. ‘Moderators’, such as graphite and water, can be used to slow neutrons down. […] When Fermi calculated whether a chain reaction could be sustained in a homogeneous mixture of uranium and graphite, he got a negative answer. That was because most neutrons produced by the fission of uranium-235 were absorbed by uranium-238 before inducing further fissions. The right approach, as suggested by Szilárd, was to use separated blocks of uranium and graphite. Fast neutrons produced by the splitting of uranium-235 in the uranium block would slow down, in the graphite block, and then produce fission again in the next uranium block. […] A minimum mass – the critical mass – is required to sustain the chain reaction; furthermore, the material must have a certain geometry. The fissile nuclides, capable of sustaining a chain reaction of nuclear fission with low-energy neutrons, are uranium-235 […], uranium-233, and plutonium-239. The last two don’t occur in nature but can be produced artificially by irradiating with neutrons thorium-232 and uranium-238, respectively – via a reaction called neutron capture. Uranium-238 (99.27%) is fissionable, but not fissile. In a nuclear weapon, the chain reaction occurs very rapidly, releasing the energy in a burst.”

“The basic components of nuclear power reactors, fuel, moderator, and control rods, are the same as in the first system built by Fermi, but the design of today’s reactors includes additional components such as a pressure vessel, containing the reactor core and the moderator, a containment vessel, and redundant and diverse safety systems. Recent technological advances in material developments, electronics, and information technology have further improved their reliability and performance. […] The moderator to slow down fast neutrons is sometimes still the graphite used by Fermi, but water, including ‘heavy water’ – in which the water molecule has a deuterium atom instead of a hydrogen atom – is more widely used. Control rods contain a neutron-absorbing material, such as boron or a combination of indium, silver, and cadmium. To remove the heat generated in the reactor core, a coolant – either a liquid or a gas – is circulating through the reactor core, transferring the heat to a heat exchanger or directly to a turbine. Water can be used as both coolant and moderator. In the case of boiling water reactors (BWRs), the steam is produced in the pressure vessel. In the case of pressurized water reactors (PWRs), the steam generator, which is the secondary side of the heat exchanger, uses the heat produced by the nuclear reactor to make steam for the turbines. The containment vessel is a one-metre-thick concrete and steel structure that shields the reactor.”

“Nuclear energy contributed 2,518 TWh of the world’s electricity in 2011, about 14% of the global supply. As of February 2012, there are 435 nuclear power plants operating in 31 countries worldwide, corresponding to a total installed capacity of 368,267 MW (electrical). There are 63 power plants under construction in 13 countries, with a capacity of 61,032 MW (electrical).”

“Since the first nuclear fusion, more than 60 years ago, many have argued that we need at least 30 years to develop a working fusion reactor, and this figure has stayed the same throughout those years.”

“[I]onizing radiation is […] used to improve many properties of food and other agricultural products. For example, gamma rays and electron beams are used to sterilize seeds, flour, and spices. They can also inhibit sprouting and destroy pathogenic bacteria in meat and fish, increasing the shelf life of food. […] More than 60 countries allow the irradiation of more than 50 kinds of foodstuffs, with 500,000 tons of food irradiated every year. About 200 cobalt-60 sources and more than 10 electron accelerators are dedicated to food irradiation worldwide. […] With the help of radiation, breeders can increase genetic diversity to make the selection process faster. The spontaneous mutation rate (number of mutations per gene, for each generation) is in the range 10-8–10-5. Radiation can increase this mutation rate to 10-5–10-2. […] Long-lived cosmogenic radionuclides provide unique methods to evaluate the ‘age’ of groundwaters, defined as the mean subsurface residence time after the isolation of the water from the atmosphere. […] Scientists can date groundwater more than a million years old, through chlorine-36, produced in the atmosphere by cosmic-ray reactions with argon.”

“Radionuclide imaging was developed in the 1950s using special systems to detect the emitted gamma rays. The gamma-ray detectors, called gamma cameras, use flat crystal planes, coupled to photomultiplier tubes, which send the digitized signals to a computer for image reconstruction. Images show the distribution of the radioactive tracer in the organs and tissues of interest. This method is based on the introduction of low-level radioactive chemicals into the body. […] More than 100 diagnostic tests based on radiopharmaceuticals are used to examine bones and organs such as lungs, intestines, thyroids, kidneys, the liver, and gallbladder. They exploit the fact that our organs preferentially absorb different chemical compounds. […] Many radiopharmaceuticals are based on technetium-99m (an excited state of technetium-99 – the ‘m’ stands for ‘metastable’ […]). This radionuclide is used for the imaging and functional examination of the heart, brain, thyroid, liver, and other organs. Technetium-99m is extracted from molybdenum-99, which has a much longer half-life and is therefore more transportable. It is used in 80% of the procedures, amounting to about 40,000 per day, carried out in nuclear medicine. Other radiopharmaceuticals include short-lived gamma-emitters such as cobalt-57, cobalt-58, gallium-67, indium-111, iodine-123, and thallium-201. […] Methods routinely used in medicine, such as X-ray radiography and CAT, are increasingly used in industrial applications, particularly in non-destructive testing of containers, pipes, and walls, to locate defects in welds and other critical parts of the structure.”

“Today, cancer treatment with radiation is generally based on the use of external radiation beams that can target the tumour in the body. Cancer cells are particularly sensitive to damage by ionizing radiation and their growth can be controlled or, in some cases, stopped. High-energy X-rays produced by a linear accelerator […] are used in most cancer therapy centres, replacing the gamma rays produced from cobalt-60. The LINAC produces photons of variable energy bombarding a target with a beam of electrons accelerated by microwaves. The beam of photons can be modified to conform to the shape of the tumour, which is irradiated from different angles. The main problem with X-rays and gamma rays is that the dose they deposit in the human tissue decreases exponentially with depth. A considerable fraction of the dose is delivered to the surrounding tissues before the radiation hits the tumour, increasing the risk of secondary tumours. Hence, deep-seated tumours must be bombarded from many directions to receive the right dose, while minimizing the unwanted dose to the healthy tissues. […] The problem of delivering the needed dose to a deep tumour with high precision can be solved using collimated beams of high-energy ions, such as protons and carbon. […] Contrary to X-rays and gamma rays, all ions of a given energy have a certain range, delivering most of the dose after they have slowed down, just before stopping. The ion energy can be tuned to deliver most of the dose to the tumour, minimizing the impact on healthy tissues. The ion beam, which does not broaden during the penetration, can follow the shape of the tumour with millimetre precision. Ions with higher atomic number, such as carbon, have a stronger biological effect on the tumour cells, so the dose can be reduced. Ion therapy facilities are [however] still very expensive – in the range of hundreds of millions of pounds – and difficult to operate.”

“About 50 million years ago, a global cooling trend took our planet from the tropical conditions at the beginning of the Tertiary to the ice ages of the Quaternary, when the Arctic ice cap developed. The temperature decrease was accompanied by a decrease in atmospheric CO2 from 2,000 to 300 parts per million. The cooling was probably caused by a reduced greenhouse effect and also by changes in ocean circulation due to plate tectonics. The drop in temperature was not constant as there were some brief periods of sudden warming. Ocean deep-water temperatures dropped from 12°C, 50 million years ago, to 6°C, 30 million years ago, according to archives in deep-sea sediments (today, deep-sea waters are about 2°C). […] During the last 2 million years, the mean duration of the glacial periods was about 26,000 years, while that of the warm periods – interglacials – was about 27,000 years. Between 2.6 and 1.1 million years ago, a full cycle of glacial advance and retreat lasted about 41,000 years. During the past 1.2 million years, this cycle has lasted 100,000 years. Stable and radioactive isotopes play a crucial role in the reconstruction of the climatic history of our planet”.


CUORE (Cryogenic Underground Observatory for Rare Events).
Lawrence Livermore National Laboratory.
Marie Curie. Pierre Curie. Henri Becquerel. Wilhelm Röntgen. Joseph Thomson. Ernest Rutherford. Hans Geiger. Ernest Marsden. Niels Bohr.
Ruhmkorff coil.
Pitchblende (uraninite).
Polonium. Becquerel.
Alpha decay. Beta decay. Gamma radiation.
Plum pudding model.
Robert Boyle. John Dalton. Dmitri Mendeleev. Frederick Soddy. James Chadwick. Enrico Fermi. Lise Meitner. Otto Frisch.
Periodic Table.
Exponential decay. Decay chain.
Particle accelerator. Cockcroft-Walton generator. Van de Graaff generator.
Barn (unit).
Nuclear fission.
Manhattan Project.
Chernobyl disaster. Fukushima Daiichi nuclear disaster.
Electron volt.
Thermoluminescent dosimeter.
Silicon diode detector.
Enhanced geothermal system.
Chicago Pile Number 1. Experimental Breeder Reactor 1. Obninsk Nuclear Power Plant.
Natural nuclear fission reactor.
Gas-cooled reactor.
Generation I reactors. Generation II reactor. Generation III reactor. Generation IV reactor.
Nuclear fuel cycle.
Accelerator-driven subcritical reactor.
Thorium-based nuclear power.
Small, sealed, transportable, autonomous reactor.
Fusion power. P-p (proton-proton) chain reaction. CNO cycle. Tokamak. ITER (International Thermonuclear Experimental Reactor).
Sterile insect technique.
Phase-contrast X-ray imaging. Computed tomography (CT). SPECT (Single-photon emission computed tomography). PET (positron emission tomography).
Boron neutron capture therapy.
Radiocarbon dating. Bomb pulse.
Radioactive tracer.
Radithor. The Radiendocrinator.
Radioisotope heater unit. Radioisotope thermoelectric generator. Seebeck effect.
Accelerator mass spectrometry.
Atomic bombings of Hiroshima and Nagasaki. Treaty on the Non-Proliferation of Nuclear Weapons. IAEA.
Nuclear terrorism.
Swiss light source. Synchrotron.
Chronology of the universe. Stellar evolution. S-process. R-process. Red giant. Supernova. White dwarf.
Victor Hess. Domenico Pacini. Cosmic ray.
Allende meteorite.
Age of the Earth. History of Earth. Geomagnetic reversal. Uranium-lead dating. Clair Cameron Patterson.
Glacials and interglacials.
Taung child. Lucy. Ardi. Ardipithecus kadabba. Acheulean tools. Java Man. Ötzi.
Argon-argon dating. Fission track dating.

November 28, 2017 Posted by | Archaeology, Astronomy, Biology, Books, Cancer/oncology, Chemistry, Engineering, Geology, History, Medicine, Physics | Leave a comment

The fall of Rome

“According to the conventional view of things, the military and political disintegration of Roman power in the West precipitated the end of a civilization. Ancient sophistication died, leaving the western world in the grip of a ‘Dark Age’ of material and intellectual poverty, out of which it was only slowly to emerge. […] a much more comfortable vision of the end of empire [has been] spreading in recent years through the English-speaking world. […] There has been a sea change in the language used to describe post-Roman times. Words like ‘decline’ and ‘crisis’ […] have largely disappeared from historians’ vocabularies, to be replaced by neutral terms, like ‘transition’, ‘change’, and ‘transformation’. […] some historians in recent decades have also questioned the entire premiss that the dissolution of the Roman empire in the West was caused by hostile and violent invasion. […] some recent works […] present the theory of peaceful accommodation as a universally applicable model to explain the end of the Roman empire.”

Ward Perkins’ book is a work which sets out to show why he thinks those people are wrong, presenting along the way much evidence for widespread violence and disruption throughout the Western Empire towards the end. Despite the depressing topics covered therein I really enjoyed the book; Perkins spends a lot of time on material culture aspects and archaeological remains – it’s perhaps a telling fact that the book’s appendix deals with the properties of pottery and potsherds, and how important these kinds of material remains might be in terms of helping to make sense of things which happened in the far past. A general problem in a collapse setting is that when conditions deteriorate a lot, the sort of high-quality evidence that historians and archaeologists love to look at tend to disappear; censuses stop being taken (so you have to guess at how many people were around, instead of knowing it reasonably well – which can be particularly annoying if the disrupting factor was also killing people), innumeracy and illiteracy increase (translating to fewer written sources available), and so on. I should perhaps interpose that these sorts of issues do not just pertain to historical sources from the past; similar problems also arise in various analytical contexts today. Countries in a state of crisis (war, epidemics) tend to produce poor and questionable data, if any data can be gathered at all, a point I recall being covered in Newman & DeRouen’s book; related topics were also discussed in M’ikanatha & Iskander’s book as people working in public health sometimes face these problems as well (that work was of course focused on disease surveillance aspects, and in that context I might mention that the authors mentioned that poor data availability does not really necessarily mean that no data is ‘available’; for example in such settings (cheap) proxy data of various kinds may sometimes be usefully employed to inform resource allocation decisions, even if the use of such data would not be cost-effective or meaningful in a different setting). Another point of relevance is of course that some types of evidence survive the passage of time much better than others; pottery is much harder to destroy than low-quality parchment.

The point of looking at things like pottery and coins (a related topic I recall Webster covering in some detail in his book about The Roman Invasion of Britain) is not mainly that it’s super interesting to look at different types of pottery or coins – the point is that these types of material remains tend to be extremely informative about many things besides the artifacts themselves. Pottery was used for storing goods, and those goods aren’t around any longer but the pottery still is. And ‘pottery’ is not just ‘pottery’; different types of pottery required different levels of skill, and an important variable here is the level of standardization – Roman pottery was in general of high quality and was highly standardized; by examining e.g. clay content you can actually often tell where the pottery was made; specific producers produced pottery that was easily date-able. Coins were used for purchasing things and widespread use of them implies the existence of trading networks not relying on barter trade. Different coins had different values and there are important insights to be gathered from the properties of these artifacts; Joseph Tainter e.g. talks in his book about how the silver content of Roman coins gradually decreased over time, indicating at some periods that the empire was apparently undergoing quite severe inflation (the Roman military was compensated in coin, not goods, so by tweaking the amount of copper or silver in those coins the emperors could save a bit of money – which many of them did). If the amount of low-denomination coins drops a lot this might be an indication that people were reverting to barter trade. And so on. If you find some Roman coins in a field in Britain, it might mean that there used to be a Roman garrison there. If people used to use roof tiles and build buildings out of stone, rather than wood, and you observe that they stopped doing that, that’s also a clue that something changed.

A lot of the kind of evidence Perkins looks at in his book is to some extent indirect evidence, but the point is that there’s a lot of it, and if different sources tell roughly similar stories it sort of starts getting hard to argue against. To give a sense of the scale of the material remains available, one single source in Rome, Monte Testaccio, is made up entirely of broken oil amphorae imported to Rome from south-western Spain during the 2nd and 3rd century and is estimated to contain the remains of 53 million amphorae. An image of how the remains of one particular pottery manufacturer operating in Oxford in the 3rd and 4th century are distributed throughout Britain yield something like 100 different English sites where that pottery has been found. Again, the interesting thing here is not only the pottery itself, but also all the things people transported using those vessels, and all those other things (lost from the archaeological record) that might have been transported from A to B if they were willing to transport brittle pottery vessels that far around. And it’s very interesting to see distributions like that and then start comparing them with the sort of distributions you’ll get if you look for stuff produced, say, 200 years later. Coins, pottery, roof tiles, amphorae, animal bones (there’s evidence that Roman cows were larger than their Early Medieval counterparts), new construction (e.g. temples) – look at what people left behind, compare the evidence you get from the time of the Empire with what came after; this is a very big part of what Perkins does in his book.

While looking at the evidence it becomes obvious that some regions were more severely affected than others, and Perkins goes into those details as well. In general it seems that Britain was the most severely affected region, with other regions doing somewhat better; the timing also varied greatly. Greece (and much of the Eastern Empire) actually experienced a period of expansion (increased density of settlements, new churches and monasteries, stone rural houses) during the fifth century but around 600 AD the Aegean was severely hit and experienced severe disruption where former great cities became little but abandoned ghost towns. Perkins also takes care to deal with the ‘barbarians’ in at least some detail (Peter Heather covers that stuff in a lot more detail in his book Empires and Barbarians, if people are curious to know more about these topics), not lumping them all together into One Great Alliance to Take Down the Empire (quite often these guys were at war with each other). The evidence is presented in some detail, which also means that if you walk away from the book still thinking Perkins hasn’t made a good case for his beliefs, well, you’ll at least know where the author is coming from and why he holds the views he does.

I’ve added some more quotes from the book below. If you’re interested in these topics this book is a must read.

“The Germanic invaders of the western empire seized or extorted through the threat of force the vast majority of the territories in which they settled, without any formal agreement on how to share resources with their new Roman subjects. The impression given by some recent historians that most Roman territory was formally ceded to them as part of a treaty is quite simply wrong. Whenever the evidence is moderately full, as it is from the Mediterranean provinces, conquest or surrender to the threat of force was definitely the norm, not peaceful settlement. […] The experience of conquest was, of course, very varied across the empire. Some regions were overrun brutally but swiftly. […] Other regions, particularly those near the frontiers of the empire, suffered much more prolonged violence. […] Even those few regions that eventually passed relatively peacefully into Germanic control had all previously experienced invasion and devastation.”

“Throughout the time that the Roman empire existed, the soldiery of many towns were maintained at public expense for the defence of the frontier. When this practice fell into abeyance, both these troops and the frontier disappeared. […] It has rightly been observed that the deposition in 476 of the last emperor resident in Italy, Romulus Augustulus, caused remarkably little stir: the great historian of Antiquity, Momigliano, called it the ‘noiseless fall of an empire’.39 But the principal reason why this event passed almost unnoticed was because contemporaries knew that the western empire, and with it autonomous Roman power, had already disappeared in all but name. […] The story of the loss of the West is not a story of great set-piece battles, like Hadrianopolis, heroically lost by the Romans in the field. […] The West was lost mainly through failure to engage the invading forces successfully and to drive them back. This caution in the face of the enemy, and the ultimate failure to drive him out, are best explained by the severe problems that there were in putting together armies large enough to feel confident of victory. Avoiding battle led to a slow attrition of the Roman position, but engaging the enemy on a large scale would have risked immediate disaster […] Roman military dominance over the Germanic peoples was considerable, but never absolute and unshakable. […] even at the best of times, the edge that the Romans enjoyed over their enemies, through their superior equipment and organization, was never remotely comparable, say, to that of Europeans in the nineteenth century […] although normally the Romans defeated barbarians when they met them in battle, they could and did occasionally suffer disasters.”

“Italy suffered from the presence of large hostile armies in 401-2 (Alaric and the Goths), in 405-6 (Radagaisus), and again from 408 to 412 (Alaric, for the second time); Gaul was devastated in the years 407-9 by the Vandals, Alans, and Sueves; and the Iberian peninsula by the same peoples, from 409. The only regions of the western empire that had not been profoundly affected by violence by 410 were Africa and the islands of the Mediterranean […] Radagaisus’ incursion was successfully crushed, but it was immediately followed by a disastrous sequence of events: the crossing of the Rhine by Vandals, Sueves, and Alans at the very end of 406; the usurpation of Constantine III in 407, taking with him the resources of Britain and much of Gaul; and the Goths’ return to Italy in 408. […] Some of the lost territories were temporarily recovered in the second decade of the century; but much (the whole of Britain and a large part of Gaul and Spain) was never regained, and even reconquered provinces took many years to get back to full health […] the imperial recovery was only short-lived; in 429 it was brought definitely to an end by the successful crossing of the Vandals into Africa, and the devastation of the western empire’s last remaining secure tax base. […] There was, of course, a close connection between failure ‘abroad’ and the usurpations and rebellions ‘at home’. […] As in other periods of history, failure against foreign enemies and civil war were very closely linked, indeed feeding off each other.”

“Some accounts of the invasions [and maps of them] […] seem to be describing successive campaigns in a single war, with the systematic and progressive seizure of territory by the various armies of a united German coalition. If this had really been the case, the West would almost certainly have fallen definitely in the very early fifth century, and far less of the structures of imperial times would have survived into the post-Roman period. The reality was very much more messy and confused […] The different groups of incomers were never united, and fought each other, sometimes bitterly, as often as they fought the ‘Romans’ – just as the Roman side often gave civil strife priority over warfare against the invaders.35 When looked at in detail, the ‘Germanic invasions’ of the fifth century break down into a complex mosaic of different groups, some imperial, some local, and some Germanic, each jockeying for position against or in alliance with the others, with the Germanic groups eventually coming out on top. [As already mentioned, Heather is the book to read if you’re interested in these topics – US] […] Because the military position of the imperial government in the fifth century was weak, and because the Germanic invaders could be appeased, the Romans on occasion made treaties with particular groups, formally granting them territory on which to settle in return for their alliance. […] The interests of the centre when settling Germanic peoples, and those of the locals who had to live with the arrangements, certainly did not always coincide. […] The imperial government was entirely capable of selling its provincial subjects downriver, in the interests of short-term political and military gain. […] Sidonius Apollinaris, bishop of Clermont and a leader of the resistance to the Visigoths, recorded his bitterness: ‘We have been enslaved, as the price of other people’s security.41‘”

“[A]rchaeological evidence now available […] shows a startling decline in western standards of living during the fifth to seventh centuries.1 […] Ceramic vessels, of different shapes and sizes, play an essential part in the storage, preparation, cooking, and consumption of foodstuffs. They certainly did so in Roman times […] amphorae, not barrels, were the normal containers for transport and domestic storage of liquids. […] Pots are low-value, high-bulk items, with the additional disadvantage of being brittle […] and they are difficult and expensive to pack and transport, being heavy, bulky, and easy to break. If, despite these disadvantages, vessels (both fine tableware and more functional items) were being made to a high standard and in large quantities, and if they were travelling widely and percolating through even the lower levels of society – as they were in the Roman period – then it is much more likely than not that other goods, whose distribution we cannot document with the same confidence, were doing the same. […] There is, for instance, no reason to suppose that the huge markets in clothing, footware, and tools were less sophisticated than that in pottery. […] In the post-Roman West, almost all this material sophistication disappeared. Specialized production and all of the most local distribution became rare, unless for luxury goods; and the impressive range and quantity of high-quality functional goods, which had characterized the Roman period, vanished, or, at the very least, were drastically reduced. The middle and lower markets, which under the Romans had absorbed huge quantities of basic, but good-quality, items, seem to have almost entirely disappeared. […] There is no area of the post-Roman West that I know of where the range of pottery available in the sixth and seventh centuries matches that of the Roman period, and in most areas the decline in quality is startling. Furthermore, it was not only quality and diversity that declined; the overall quantities of pottery in circulation also fell dramatically. […] what had once been widely diffused products had become luxury items.”

“What we observe at the end of the Roman world is not a ‘recession’ […] with an essentially similar economy continuing to work at a reduced pace. Instead, what we see is a remarkable qualitative change, with the disappearance of entire industries and commercial networks. The economy of the post-Roman West is not that of the fourth century reduced in scale, but a very different and far less sophisticated entity.43 This is at its starkest and most obvious in Britain. A number of basic skills disappeared entirely during the fifth century, to be reintroduced only centuries later. […] All over Britain the art of making pottery on a wheel disappeared in the early fifth century, and was not reintroduced for almost 300 years. The potter’s wheel is not an instrument of cultural identity. Rather, it is a functional innovation that facilitates the rapid production of thin-walled ceramics; and yet it disappeared from Britain. […] post-Roman Britain in fact sank to a level of economic complexity well below that of the pre-Roman Iron Age. Southern Britain, in the years before the Roman conquest of AD 43, was importing quantities of Gaulish wine and Gaulish pottery; it had its own native pottery industries with regional distribution of their wares; it even had native silver coinages […] The settlement pattern of later iron-age Britain also reflects emerging economic complexity, with substantial coastal settlements […] which were at least partly dependent on trade. None of these features can be found reliably in fifth- and sixth-century post-Roman Britain. It is really only in about AD 700, three centuries after the disintegration of the Romano-British economy, that southern Britain crawled back to the level of economic complexity foudn in the pre-Roman Iron Age, with evidence of pots imported from the Continents, the first substantial and wheel-turned Anglo-Saxon pottery industry […], the striking of silver coins, and the emergence of coastal trading towns […] In the western Mediterranean, the economic regression was by no means as total as it was in Britain. […] But it must be remembered that in the Mediterranean world the level of economic complexity and sophistication reached in the Roman period was very considerably higher than anything ever attained in Britain. The fall in economic complexity may in fact have been as remarkable as that in Britain; but, since in the Mediterranean it started from a much higher point, it also bottomed out at a higher level. […] in some areas at least a very similar picture can be found to that sketched out above – of a regression, taking the economy way below levels of complexity reached in the pre-Roman period.”

“The enormity of the economic disintegration that occurred at the end of the empire was almost certainly a direct result of […] specialization. The post-Roman world reverted to levels of economic simplicity […] with little movement of goods, poor housing, and only the most basic manufactured items. The sophistication of the Roman period, by spreading high-quality goods widely in society, had destroyed the local skills and local networks that, in pre-Roman times, had provided lower-level economic complexity. It took centuries for people in the former empire to reacquire the skills and the regional networks that would take them back to these pre-Roman levels of sophistication. […] The Roman period is sometimes seen as enriching only the elite, rather than enhancing the standard of living of the population at large. […] I think this, and similar views, are mistaken. For, me, what is most striking about the Roman economy is precisely the fact that it was not solely an elite phenomenon, but one that made basic good-quality items available right down the social scale. […] good-quality pottery was widely available, and in regions like Italy even the comfort of tiled roofs. I would also seriously question the romantic assumption that economic simplicity meant a freer or more equal society.”

“There was no single moment, nor even a single century of collapse. The ancient economy disappeared at different times and at varying speeds across the empire. […] It was […] the fifth-century invasions that […] brought down the ancient economy in the West. However, this does not mean that the death of the sophisticated ancient world was intended by the Germanic peoples. The invaders entered the empire with a wish to share in its high standard of living, not to destroy it […] But, although the Germanic peoples did not intend it, their invasions, the disruptions these caused, and the consequent dismembering of the Roman state were undoubtedly the principal cause of death of the Roman economy.”

“Reading and writing (and a grounding in classical literature) were in Roman times an essential mark of status. […] illiterates amongst the Roman upper classes were very rare indeed. […] In a much simpler world, the urgent need to read and write declined, and with it went the social pressure on the secular elite to be literate. Widespread literacy in the post-Roman West definitely became confined to the clergy. […] It is a striking fact, and a major contrast with Roman times, that even great rulers could be illiterate in the early Middle Ages.”

“The changing perspectives of scholarship are always shaped in part by wider developments in modern society. There is inevitably a close connection between the way we view our own world and the way we interpret the past. […] [T]here is a real danger for the present day in a vision of the past that explicitly sets out to eliminate all crisis and all decline. The end of the Roman West […] destroyed a complex civilization, throwing the inhabitants of the West back to a standard of living typical of prehistoric times. Romans before the fall were as certain as we are today that their world would continue for ever substantially unchanged. They were wrong.”


September 18, 2017 Posted by | Archaeology, Books, History | Leave a comment

The Antarctic

“A very poor book with poor coverage, mostly about politics and history (and a long collection of names of treaties and organizations). I would definitely not have finished it if it were much longer than it is.”

That was what I wrote about the book in my goodreads review. I was strongly debating whether or not to blog it at all, but I decided in the end to just settle for some very lazy coverage of the book, only consisting of links to content covered in the book. I only cover the book here to at least have some chance of remembering which kinds of things were covered in the book later on.

If you’re interested enough in the Antarctic to read a book about it, read Scott’s Last Expedition instead of this one (here’s my goodreads review of Scott).


Antarctica (featured).
Antarctic Convergence.
Antarctic Circle.
Southern Ocean.
Antarctic Circumpolar Current.
West Antarctic Ice Sheet.
East Antarctic Ice Sheet.
McMurdo Dry Valleys.
Patagonian toothfish.
Antarctic krill.
Fabian Gottlieb von Bellingshausen.
Edward Bransfield.
James Clark Ross.
United States Exploring Expedition.
Heroic Age of Antarctic Exploration (featured).
Nimrod Expedition (featured).
Roald Amundsen.
Wilhelm Filchner.
Japanese Antarctic Expedition.
Terra Nova Expedition (featured).
Lincoln Ellsworth.
British Graham Land expedition.
German Antarctic Expedition (1938–1939).
Operation Highjump.
Operation Windmill.
Operation Deep Freeze.
Commonwealth Trans-Antarctic Expedition.
Caroline Mikkelsen.
International Association of Antarctica Tour Operators.
Territorial claims in Antarctica.
International Geophysical Year.
Antarctic Treaty System.
Operation Tabarin.
Scientific Committee on Antarctic Research.
United Nations Convention on the Law of the Sea.
Convention on the Continental Shelf.
Council of Managers of National Antarctic Programs.
British Antarctic Survey.
International Polar Year.
Antarctic ozone hole.
Gamburtsev Mountain Range.
Pine Island Glacier (‘good article’).
Census of Antarctic Marine Life.
Lake Ellsworth Consortium.
Antarctic fur seal.
Southern elephant seal.
Grytviken (whaling-related).
International Convention for the Regulation of Whaling.
International Whaling Commission.
Ocean Drilling Program.
Convention on the Regulation of Antarctic Mineral Resource Activities.
Agreement on the Conservation of Albatrosses and Petrels.

July 3, 2017 Posted by | Biology, Books, Geography, Geology, History, Wikipedia | Leave a comment

Random stuff

It’s been a long time since I last posted one of these posts, so a great number of links of interest has accumulated in my bookmarks. I intended to include a large number of these in this post and this of course means that I surely won’t cover each specific link included in this post in anywhere near the amount of detail it deserves, but that can’t be helped.

i. Autism Spectrum Disorder Grown Up: A Chart Review of Adult Functioning.

“For those diagnosed with ASD in childhood, most will become adults with a significant degree of disability […] Seltzer et al […] concluded that, despite considerable heterogeneity in social outcomes, “few adults with autism live independently, marry, go to college, work in competitive jobs or develop a large network of friends”. However, the trend within individuals is for some functional improvement over time, as well as a decrease in autistic symptoms […]. Some authors suggest that a sub-group of 15–30% of adults with autism will show more positive outcomes […]. Howlin et al. (2004), and Cederlund et al. (2008) assigned global ratings of social functioning based on achieving independence, friendships/a steady relationship, and education and/or a job. These two papers described respectively 22% and 27% of groups of higher functioning (IQ above 70) ASD adults as attaining “Very Good” or “Good” outcomes.”

“[W]e evaluated the adult outcomes for 45 individuals diagnosed with ASD prior to age 18, and compared this with the functioning of 35 patients whose ASD was identified after 18 years. Concurrent mental illnesses were noted for both groups. […] Comparison of adult outcome within the group of subjects diagnosed with ASD prior to 18 years of age showed significantly poorer functioning for those with co-morbid Intellectual Disability, except in the domain of establishing intimate relationships [my emphasis. To make this point completely clear, one way to look at these results is that apparently in the domain of partner-search autistics diagnosed during childhood are doing so badly in general that being intellectually disabled on top of being autistic is apparently conferring no additional disadvantage]. Even in the normal IQ group, the mean total score, i.e. the sum of the 5 domains, was relatively low at 12.1 out of a possible 25. […] Those diagnosed as adults had achieved significantly more in the domains of education and independence […] Some authors have described a subgroup of 15–27% of adult ASD patients who attained more positive outcomes […]. Defining an arbitrary adaptive score of 20/25 as “Good” for our normal IQ patients, 8 of thirty four (25%) of those diagnosed as adults achieved this level. Only 5 of the thirty three (15%) diagnosed in childhood made the cutoff. (The cut off was consistent with a well, but not superlatively, functioning member of society […]). None of the Intellectually Disabled ASD subjects scored above 10. […] All three groups had a high rate of co-morbid psychiatric illnesses. Depression was particularly frequent in those diagnosed as adults, consistent with other reports […]. Anxiety disorders were also prevalent in the higher functioning participants, 25–27%. […] Most of the higher functioning ASD individuals, whether diagnosed before or after 18 years of age, were functioning well below the potential implied by their normal range intellect.”

Related papers: Social Outcomes in Mid- to Later Adulthood Among Individuals Diagnosed With Autism and Average Nonverbal IQ as Children, Adults With Autism Spectrum Disorders.

ii. Premature mortality in autism spectrum disorder. This is a Swedish matched case cohort study. Some observations from the paper:

“The aim of the current study was to analyse all-cause and cause-specific mortality in ASD using nationwide Swedish population-based registers. A further aim was to address the role of intellectual disability and gender as possible moderators of mortality and causes of death in ASD. […] Odds ratios (ORs) were calculated for a population-based cohort of ASD probands (n = 27 122, diagnosed between 1987 and 2009) compared with gender-, age- and county of residence-matched controls (n = 2 672 185). […] During the observed period, 24 358 (0.91%) individuals in the general population died, whereas the corresponding figure for individuals with ASD was 706 (2.60%; OR = 2.56; 95% CI 2.38–2.76). Cause-specific analyses showed elevated mortality in ASD for almost all analysed diagnostic categories. Mortality and patterns for cause-specific mortality were partly moderated by gender and general intellectual ability. […] Premature mortality was markedly increased in ASD owing to a multitude of medical conditions. […] Mortality was significantly elevated in both genders relative to the general population (males: OR = 2.87; females OR = 2.24)”.

“Individuals in the control group died at a mean age of 70.20 years (s.d. = 24.16, median = 80), whereas the corresponding figure for the entire ASD group was 53.87 years (s.d. = 24.78, median = 55), for low-functioning ASD 39.50 years (s.d. = 21.55, median = 40) and high-functioning ASD 58.39 years (s.d. = 24.01, median = 63) respectively. […] Significantly elevated mortality was noted among individuals with ASD in all analysed categories of specific causes of death except for infections […] ORs were highest in cases of mortality because of diseases of the nervous system (OR = 7.49) and because of suicide (OR = 7.55), in comparison with matched general population controls.”

iii. Adhesive capsulitis of shoulder. This one is related to a health scare I had a few months ago. A few quotes:

Adhesive capsulitis (also known as frozen shoulder) is a painful and disabling disorder of unclear cause in which the shoulder capsule, the connective tissue surrounding the glenohumeral joint of the shoulder, becomes inflamed and stiff, greatly restricting motion and causing chronic pain. Pain is usually constant, worse at night, and with cold weather. Certain movements or bumps can provoke episodes of tremendous pain and cramping. […] People who suffer from adhesive capsulitis usually experience severe pain and sleep deprivation for prolonged periods due to pain that gets worse when lying still and restricted movement/positions. The condition can lead to depression, problems in the neck and back, and severe weight loss due to long-term lack of deep sleep. People who suffer from adhesive capsulitis may have extreme difficulty concentrating, working, or performing daily life activities for extended periods of time.”

Some other related links below:

The prevalence of a diabetic condition and adhesive capsulitis of the shoulder.
“Adhesive capsulitis is characterized by a progressive and painful loss of shoulder motion of unknown etiology. Previous studies have found the prevalence of adhesive capsulitis to be slightly greater than 2% in the general population. However, the relationship between adhesive capsulitis and diabetes mellitus (DM) is well documented, with the incidence of adhesive capsulitis being two to four times higher in diabetics than in the general population. It affects about 20% of people with diabetes and has been described as the most disabling of the common musculoskeletal manifestations of diabetes.”

Adhesive Capsulitis (review article).
“Patients with type I diabetes have a 40% chance of developing a frozen shoulder in their lifetimes […] Dominant arm involvement has been shown to have a good prognosis; associated intrinsic pathology or insulin-dependent diabetes of more than 10 years are poor prognostic indicators.15 Three stages of adhesive capsulitis have been described, with each phase lasting for about 6 months. The first stage is the freezing stage in which there is an insidious onset of pain. At the end of this period, shoulder ROM [range of motion] becomes limited. The second stage is the frozen stage, in which there might be a reduction in pain; however, there is still restricted ROM. The third stage is the thawing stage, in which ROM improves, but can take between 12 and 42 months to do so. Most patients regain a full ROM; however, 10% to 15% of patients suffer from continued pain and limited ROM.”

Musculoskeletal Complications in Type 1 Diabetes.
“The development of periarticular thickening of skin on the hands and limited joint mobility (cheiroarthropathy) is associated with diabetes and can lead to significant disability. The objective of this study was to describe the prevalence of cheiroarthropathy in the well-characterized Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort and examine associated risk factors […] This cross-sectional analysis was performed in 1,217 participants (95% of the active cohort) in EDIC years 18/19 after an average of 24 years of follow-up. Cheiroarthropathy — defined as the presence of any one of the following: adhesive capsulitis, carpal tunnel syndrome, flexor tenosynovitis, Dupuytren’s contracture, or a positive prayer sign [related link] — was assessed using a targeted medical history and standardized physical examination. […] Cheiroarthropathy was present in 66% of subjects […] Cheiroarthropathy is common in people with type 1 diabetes of long duration (∼30 years) and is related to longer duration and higher levels of glycemia. Clinicians should include cheiroarthropathy in their routine history and physical examination of patients with type 1 diabetes because it causes clinically significant functional disability.”

Musculoskeletal disorders in diabetes mellitus: an update.
“Diabetes mellitus (DM) is associated with several musculoskeletal disorders. […] The exact pathophysiology of most of these musculoskeletal disorders remains obscure. Connective tissue disorders, neuropathy, vasculopathy or combinations of these problems, may underlie the increased incidence of musculoskeletal disorders in DM. The development of musculoskeletal disorders is dependent on age and on the duration of DM; however, it has been difficult to show a direct correlation with the metabolic control of DM.”

Rheumatic Manifestations of Diabetes Mellitus.

Prevalence of symptoms and signs of shoulder problems in people with diabetes mellitus.

Musculoskeletal Disorders of the Hand and Shoulder in Patients with Diabetes.
“In addition to micro- and macroangiopathic complications, diabetes mellitus is also associated with several musculoskeletal disorders of the hand and shoulder that can be debilitating (1,2). Limited joint mobility, also termed diabetic hand syndrome or cheiropathy (3), is characterized by skin thickening over the dorsum of the hands and restricted mobility of multiple joints. While this syndrome is painless and usually not disabling (2,4), other musculoskeletal problems occur with increased frequency in diabetic patients, including Dupuytren’s disease [“Dupuytren’s disease […] may be observed in up to 42% of adults with diabetes mellitus, typically in patients with long-standing T1D” – link], carpal tunnel syndrome [“The prevalence of [carpal tunnel syndrome, CTS] in patients with diabetes has been estimated at 11–30 % […], and is dependent on the duration of diabetes. […] Type I DM patients have a high prevalence of CTS with increasing duration of disease, up to 85 % after 54 years of DM” – link], palmar flexor tenosynovitis or trigger finger [“The incidence of trigger finger [/stenosing tenosynovitis] is 7–20 % of patients with diabetes comparing to only about 1–2 % in nondiabetic patients” – link], and adhesive capsulitis of the shoulder (5–10). The association of adhesive capsulitis with pain, swelling, dystrophic skin, and vasomotor instability of the hand constitutes the “shoulder-hand syndrome,” a rare but potentially disabling manifestation of diabetes (1,2).”

“The prevalence of musculoskeletal disorders was greater in diabetic patients than in control patients (36% vs. 9%, P < 0.01). Adhesive capsulitis was present in 12% of the diabetic patients and none of the control patients (P < 0.01), Dupuytren’s disease in 16% of diabetic and 3% of control patients (P < 0.01), and flexor tenosynovitis in 12% of diabetic and 2% of control patients (P < 0.04), while carpal tunnel syndrome occurred in 12% of diabetic patients and 8% of control patients (P = 0.29). Musculoskeletal disorders were more common in patients with type 1 diabetes than in those with type 2 diabetes […]. Forty-three patients [out of 100] with type 1 diabetes had either hand or shoulder disorders (37 with hand disorders, 6 with adhesive capsulitis of the shoulder, and 10 with both syndromes), compared with 28 patients [again out of 100] with type 2 diabetes (24 with hand disorders, 4 with adhesive capsulitis of the shoulder, and 3 with both syndromes, P = 0.03).”

Association of Diabetes Mellitus With the Risk of Developing Adhesive Capsulitis of the Shoulder: A Longitudinal Population-Based Followup Study.
“A total of 78,827 subjects with at least 2 ambulatory care visits with a principal diagnosis of DM in 2001 were recruited for the DM group. The non-DM group comprised 236,481 age- and sex-matched randomly sampled subjects without DM. […] During a 3-year followup period, 946 subjects (1.20%) in the DM group and 2,254 subjects (0.95%) in the non-DM group developed ACS. The crude HR of developing ACS for the DM group compared to the non-DM group was 1.333 […] the association between DM and ACS may be explained at least in part by a DM-related chronic inflammatory process with increased growth factor expression, which in turn leads to joint synovitis and subsequent capsular fibrosis.”

It is important to note when interpreting the results of the above paper that these results are based on Taiwanese population-level data, and type 1 diabetes – which is obviously the high-risk diabetes subgroup in this particular context – is rare in East Asian populations (as observed in Sperling et al., “A child in Helsinki, Finland is almost 400 times more likely to develop diabetes than a child in Sichuan, China”. Taiwanese incidence of type 1 DM in children is estimated at ~5 in 100.000).

iv. Parents who let diabetic son starve to death found guilty of first-degree murder. It’s been a while since I last saw one of these ‘boost-your-faith-in-humanity’-cases, but they in my impression do pop up every now and then. I should probably keep at hand one of these articles in case my parents ever express worry to me that they weren’t good parents; they could have done a lot worse…

v. Freedom of medicine. One quote from the conclusion of Cochran’s post:

“[I]t is surely possible to materially improve the efficacy of drug development, of medical research as a whole. We’re doing better than we did 500 years ago – although probably worse than we did 50 years ago. But I would approach it by learning as much as possible about medical history, demographics, epidemiology, evolutionary medicine, theory of senescence, genetics, etc. Read Koch, not Hayek. There is no royal road to medical progress.”

I agree, and I was considering including some related comments and observations about health economics in this post – however I ultimately decided against doing that in part because the post was growing unwieldy; I might include those observations in another post later on. Here’s another somewhat older Westhunt post I at some point decided to bookmark – I in particular like the following neat quote from the comments, which expresses a view I have of course expressed myself in the past here on this blog:

“When you think about it, falsehoods, stupid crap, make the best group identifiers, because anyone might agree with you when you’re obviously right. Signing up to clear nonsense is a better test of group loyalty. A true friend is with you when you’re wrong. Ideally, not just wrong, but barking mad, rolling around in your own vomit wrong.”

vi. Economic Costs of Diabetes in the U.S. in 2012.

“Approximately 59% of all health care expenditures attributed to diabetes are for health resources used by the population aged 65 years and older, much of which is borne by the Medicare program […]. The population 45–64 years of age incurs 33% of diabetes-attributed costs, with the remaining 8% incurred by the population under 45 years of age. The annual attributed health care cost per person with diabetes […] increases with age, primarily as a result of increased use of hospital inpatient and nursing facility resources, physician office visits, and prescription medications. Dividing the total attributed health care expenditures by the number of people with diabetes, we estimate the average annual excess expenditures for the population aged under 45 years, 45–64 years, and 65 years and above, respectively, at $4,394, $5,611, and $11,825.”

“Our logistic regression analysis with NHIS data suggests that diabetes is associated with a 2.4 percentage point increase in the likelihood of leaving the workforce for disability. This equates to approximately 541,000 working-age adults leaving the workforce prematurely and 130 million lost workdays in 2012. For the population that leaves the workforce early because of diabetes-associated disability, we estimate that their average daily earnings would have been $166 per person (with the amount varying by demographic). Presenteeism accounted for 30% of the indirect cost of diabetes. The estimate of a 6.6% annual decline in productivity attributed to diabetes (in excess of the estimated decline in the absence of diabetes) equates to 113 million lost workdays per year.”

vii. Total red meat intake of ≥0.5 servings/d does not negatively influence cardiovascular disease risk factors: a systemically searched meta-analysis of randomized controlled trials.

viii. Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials. Did I blog this paper at some point in the past? I could not find any coverage of it on the blog when I searched for it so I decided to include it here, even if I have a nagging suspicion I may have talked about these findings before. What did they find? The short version is this:

“A modest reduction in salt intake for four or more weeks causes significant and, from a population viewpoint, important falls in blood pressure in both hypertensive and normotensive individuals, irrespective of sex and ethnic group. Salt reduction is associated with a small physiological increase in plasma renin activity, aldosterone, and noradrenaline and no significant change in lipid concentrations. These results support a reduction in population salt intake, which will lower population blood pressure and thereby reduce cardiovascular disease.”

ix. Some wikipedia links:

Heroic Age of Antarctic Exploration (featured).

Wien’s displacement law.

Kuiper belt (featured).

Treason (one quote worth including here: “Currently, the consensus among major Islamic schools is that apostasy (leaving Islam) is considered treason and that the penalty is death; this is supported not in the Quran but in the Hadith.[42][43][44][45][46][47]“).

Lymphatic filariasis.

File:World map of countries by number of cigarettes smoked per adult per year.

Australian gold rushes.

Savant syndrome (“It is estimated that 10% of those with autism have some form of savant abilities”). A small sidenote of interest to Danish readers: The Danish Broadcasting Corporation recently featured a series about autistics with ‘special abilities’ – the show was called ‘The hidden talents’ (De skjulte talenter), and after multiple people had nagged me to watch it I ended up deciding to do so. Most of the people in that show presumably had some degree of ‘savantism’ combined with autism at the milder end of the spectrum, i.e. Asperger’s. I was somewhat conflicted about what to think about the show and did consider blogging it in detail (in Danish?), but I decided against it. However I do want to add here to Danish readers reading along who’ve seen the show that they would do well to repeatedly keep in mind that a) the great majority of autistics do not have abilities like these, b) many autistics with abilities like these presumably do quite poorly, and c) that many autistics have even greater social impairments than do people like e.g. (the very likeable, I have to add…) Louise Wille from the show).

Quark–gluon plasma.

Simo Häyhä.

Chernobyl liquidators.

Black Death (“Over 60% of Norway’s population died in 1348–1350”).

Renault FT (“among the most revolutionary and influential tank designs in history”).

Weierstrass function (“an example of a pathological real-valued function on the real line. The function has the property of being continuous everywhere but differentiable nowhere”).

W Ursae Majoris variable.

Void coefficient. (“a number that can be used to estimate how much the reactivity of a nuclear reactor changes as voids (typically steam bubbles) form in the reactor moderator or coolant. […] Reactivity is directly related to the tendency of the reactor core to change power level: if reactivity is positive, the core power tends to increase; if it is negative, the core power tends to decrease; if it is zero, the core power tends to remain stable. […] A positive void coefficient means that the reactivity increases as the void content inside the reactor increases due to increased boiling or loss of coolant; for example, if the coolant acts as a neutron absorber. If the void coefficient is large enough and control systems do not respond quickly enough, this can form a positive feedback loop which can quickly boil all the coolant in the reactor. This happened in the RBMK reactor that was destroyed in the Chernobyl disaster.”).

Gregor MacGregor (featured) (“a Scottish soldier, adventurer, and confidence trickster […] MacGregor’s Poyais scheme has been called one of the most brazen confidence tricks in history.”).


Irish Civil War.

March 10, 2017 Posted by | Astronomy, autism, Cardiology, Diabetes, Economics, Epidemiology, Health Economics, History, Infectious disease, Mathematics, Medicine, Papers, Physics, Psychology, Random stuff, Wikipedia | Leave a comment

The Second World War (IV)

This will be my last post about the book(s). You can read my previous posts about it(/them) here, here, and here. In this post I’ve included some quotes and observations from the last few hundred pages.

“In wartime […] truth is so precious that she should always be attended by a bodyguard of lies.”

“On June 10 [1944] General Montgomery reported that he was sufficiently established ashore to receive a visit. […] Montgomery, smiling and confident, met me at the beach as we scrambled out of our landing craft. His army had already penetrated seven or eight miles inland. There was very little firing or activity. […] The General was in the highest spirits. I asked him how far away was the actual front. He said about three miles. I asked him if he had a continuous line. He said, “No.” “What is there then to prevent an incursion of German armour breaking up our luncheon?” He said he did not think they would come. […] In the first six days 326,000 men, 54,000 vehicles, and 104,000 tons of stores were landed. […] [German] divisions arrived piecemeal, short of equipment, and fatigued by long night marches, and were thrown into the line as they came. […] On June 17, at Margival, near Soissons, Hitler held a conference with Rundstedt and Rommel. His two generals pressed on him strongly the folly of bleeding the German Army to death in Normandy. They urged that before it was destroyed the Seventh Army should make an orderly withdrawal towards the Seine […] Hitler would not agree. Here, as in Russia and Italy, he demanded that no ground should be given up and all should fight where they stood. The generals were of course right. […] by the middle of July thirty Allied divisions were ashore. Half were American and half British and Canadian. Against these the Germans had gathered twenty-seven divisions. But they had already suffered 160,000 casualties, and General Eisenhower estimated their fighting value as no higher than sixteen divisions. […] By August 30 our troops were crossing the Seine at many points. Enemy losses had been tremendous: 400,000 men, half of them prisoners, 1,300 tanks, 20,000 vehicles, 1,500 field guns. […] the Seine was reached six days ahead of the planned time.”

[During a visit to the Italian front:] [General] Alexander had planned an early start and a long day on the front. He had also promised to take me wherever I wanted to go. […] We first climbed by motor up a high outstanding rock pinnacle, upon the top of which a church and village were perched. The inhabitants, men and women, came out to greet us from the cellars in which they had been sheltering. It was at once plain that the place had just been bombarded. Masonry and wreckage littered the single street. “When did this stop?” Alexander asked the small crowd who gathered round us, grinning rather wryly. “About a quarter of an hour ago,” they said. […] Presently Alexander said that we had better not stay any longer, as the enemy would naturally be firing at observation posts like this and might begin again. […] We got into our cars accordingly, and in half an hour were across the river, where the road ran into undulating groves of olives, brightly patched with sunshine. Having got an officer guide from one of the battalions engaged, we pushed on through these glades till the sounds of rifle and machine-gun fire showed we were getting near to the front line. Presently warning hands brought us to a standstill. It appeared there was a minefield, and it was only safe to go where other vehicles had already gone without mishap. […] [We] found a very good place in the stone building, which was in fact an old château overlooking a rather sharp declivity. Here one certainly could see all that was possible. The Germans were firing with rifles and machine-guns from thick scrub on the farther side of the valley, about five hundred yards away. Our front line was beneath us. The firing was desultory and intermittent. But this was the nearest I got to the enemy and the time I heard the most bullets in the Second World War. After about half an hour we went back to our motor-cars and made our way to the river”.

The book has some interesting coverage of the Warsaw Uprising. The short story to people who don’t know it is that the Polish resistance movement started a major uprising in the city of Warsaw when the Soviet forces were very close to the city, a move encouraged by the Soviets [“Soviet broadcasting stations had for a considerable time been urging the Polish population to drop all caution and start a general revolt against the Germans”]. What the Soviets did as a response to the uprising was then to halt their advance rather than keep it going, in order to let the German army help Stalin get rid of the non-communist Polish resistance. Stalin also explicitly refused to allow British and American aircraft providing supplies to the Poles to land on Soviet […Polish…] territory. The tactics changed slightly over time: “On September 10, after six weeks of Polish torment, the Kremlin appeared to change their tactics. […] They wished to have the non-Communist Poles destroyed to the full, but also to keep alive the idea that they were going to their rescue.” So they pretended to try to help, but really did very little. “The struggle in Warsaw had lasted more than sixty days. Of the 40,000 men and women of the Polish Underground Army about 15,000 fell. Out of a population of a million nearly 200,000 had been stricken. […] When the Russians entered the city three months later [they were at points less than 10 miles away from the city when the uprising began] they found little but shattered streets and the unburied dead. Such was their liberation of Poland, where they now rule.” It should perhaps be obvious, but of course Stalin’s deceit did not stop there – this later sequence of events is also illustrative:

“At the beginning of March 1945 the Polish Underground were invited by the Russian Political Police to send a delegation to Moscow to discuss the formation of a united Polish Government along the lines of the Yalta agreement. This was followed by a written guarantee of personal safety and it was understood that the party would later be allowed if the negotiations were successful to travel to London for talks with the Polish Government in exile. On March 27 General Leopold Okulicki, the successor of General Bor-Komorowski in command of the Underground Army, two other leaders, and an interpreter had a meeting in the suburbs of Warsaw with a Soviet representative. They were joined the following day by eleven leaders representing the major political parties in Poland. One other Polish leader was already in Russian hands. No one returned from the rendezvous. On April 6 the Polish Government in exile issued a statement in London giving the outline of this sinister episode. The most valuable representatives of the Polish Underground had disappeared without a trace in spite of the formal Russian offer of safe-conduct. Questions were asked in Parliament and stories have since spread of the shooting of local Polish leaders in the areas at this time occupied by the Soviet armies […] On May 18 Stalin publicly denied that the arrested Polish leaders had ever been invited to Moscow […] The prisoners were accused of subversion, terrorism, and espionage, and all except one admitted wholly or in part the charges against them. […] This was in fact the judicial liquidation of the leadership of the Polish Underground which had fought so heroically against Hitler. The rank and file had already died in the ruins of Warsaw.”

“In the autumn of 1942 only three American aircraft-carriers were afloat; a year later there were fifty; by the end of the war there were more than a hundred. This achievement had been matched by an increase in aircraft production which was no less remarkable.”

“The number of divisions that could be sustained [in Europe, 1944], and the speed and range of their advance, depended […] entirely on harbours, transport, and supplies. Relatively little ammunition was being used, but food, and above all petrol, governed every movement.”

“You are responsible for maintaining order in Athens and for neutralising or destroying all E.A.ME.L.A.S. bands approaching the city. […] Naturally E.L.A.S will try to put women and children in the van where shooting may occur. You must be clever about this and avoid mistakes. But do not hesitate to fire at any armed male in Athens who assails the British authority or Greek authority with which we are working. Do not […] hesitate to act as if you were in a conquered city where a local rebellion is in progress.” (Telegram to General Scobie. Here’s a related wiki link. Churchill observes in the book that: “I felt grave concern about the whole business, but I was sure that there should be no room for doubts or hedging. I had in my mind Arthur Balfour’s celebrated telegram in the eighties to the British authorities in Ireland: “Don’t hesitate to shoot.” […] There was a furious storm about it in the House of Commons of those days, but it certainly prevented loss of life.”)

“I saw quite plainly that Communism would be the peril civilization would have to face after the defeat of Nazism and Fascism. It did not fall to us to end the task in Greece. […] I told the President [Roosevelt] that we ought to occupy as much of Austria as possible, as it was “undesirable that more of Western Europe than necessary should be occupied by the Russians.”” [Churchill’s subsequent italics] […] “I deem it highly important that we should shake hands with the Russians as far to the east as possible.” [telegram from Churchill to Eisenhower sent in the late stage of the war.]

“Poland was discussed at no fewer than seven out of the eight plenary meetings of the Yalta Conference, and the British record contains an interchange on this topic of nearly eighteen thousand words between Stalin, Roosevelt, and myself. […] A large body of opinion in Great Britain was shocked at the idea of moving millions of people by force. Great success had been achieved in disentangling the Greek and Turkish populations after the last war […] but in that case under a couple of millions of people had been moved. […] I was not afraid of the problem of transferring populations, so long as it was proportionate to what the Poles could manage and to what could be put into Germany. But it was a matter which required study, not as a question of principle, but of the numbers which would have to be handled.”

“As war waged by a coalition draws to its end political aspects have a mounting importance. […] At this time the points at issue did not seem to the United States Chiefs of Staff to be of capital importance. They were of course unnoticed by and unknown to the public, and were all soon swamped, and for the time being effaced, by the flowing tide of victory. Nevertheless, as will not now be disputed, they played a dominating part in the destiny of Europe […] The indispensable political direction was lacking [due to Roosevelt’s illness and death] at the moment when it was most needed. The United States stood on the scene of victory, master of world fortunes, but without a true and coherent design. Britain, though still very powerful, could not act decisively alone. I could at this stage only warn and plead. Thus the climax of apparently measureless success was to me a most unhappy time. I moved amid cheering crowds, or sat at a table adorned with congratulations and blessings from every part of the Grand Alliance, with an aching heart and a mind oppressed by forebodings.
The destruction of German military power had brought with it a fundamental change in the relations between Communist Russia and the Western democracies. They had lost their common enemy, which was almost their sole bond of union. […] Apprehension for the future and many perplexities filled my mind as I moved among the cheering crowds of Londoners in their hour of well-won rejoicing after all they had gone through. […] Japan was still unconquered. The atomic bomb was still unborn. The world was in confusion. […] The Soviet menace, to my eyes, had already replaced the Nazi foe. But no comradeship against it existed. […] I had seen it all before. I remembered that other joy-day nearly thirty years before, when I had driven with my wife from the Ministry of Munitions through similar multitudes convulsed with enthusiasm to Downing Street to congratulate the Prime Minister. Then, as at this time, I understood the world situation as a whole. But then at least there was no mighty army that we need fear […] How stands the scene after eight years have passed? The Russian occupation line in Europe runs from Lübeck to Linz. Czechoslovakia has been engulfed. The Baltic states, Poland, Roumania, and Bulgaria have been reduced to satellite States under totalitarian Communist rule. Yugoslavia has broken loose. Greece alone is saved. Our armies are gone, and it will be a long time before even sixty divisions can be again assembled opposite Russian forces, which in armour and manpower are in overwhelming strength. This also takes no account of all that has happened in the Far East. The danger of a third World War, under conditions at the outset of grave disadvantage, casts its lurid shadow over the free nations of the world.” [The last quote in the above paragraph was written in 1953.]

“Over a million prisoners were taken in the first three weeks of April”.

“there never was a moment’s discussion as to whether the atomic bomb should be used or not. […] the decision whether or not to use the atomic bomb to compel the surrender of Japan was never even an issue. There was unanimous, automatic, unquestioned agreement around our table; nor did I ever hear the slightest suggestion that we should do otherwise.”

“In sixty-eight months of fighting 781 German U-boats were lost. For more than half this time the enemy held the initiative. […] In the final count British and British-controlled forced destroyed 500 out of the 632 submarines known to have been sunk at sea by the Allies. In the First World War eleven million tons of shipping were sunk, and in the second fourteen and a half million tons, by U-boats alone. If we add the loss from other causes the totals become twelve and three-quarter million and twenty-one and a half million. Of this the British bore over 60 per cent. in the first war and over half in the second. […] It would be a mistake to suppose that the fate of Japan was settled by the atomic bomb. Her defeat was certain before the first bomb fell, and was brought about by overwhelming maritime power. […] Her shipping had been destroyed. She had entered the war with over five and a half million tons, later much augmented by captures and new construction, but her convoy system and escorts were inadequate and ill-organised. Over eight and a half million tons of Japanese shipping were sunk, of which five million fell to submarines. We, an island power, equally dependent on the sea, can read the lesson and understand our own fate had we failed to master the U-boats.”

June 25, 2016 Posted by | Books, History | Leave a comment

The Second World War (III)

You can read my previous posts about the book here and here. I gave the book 5 stars on goodreads. Below I have added some more quotes from the stuff in the middle, on various topics. I expect to post at least one more post about the book later on; there’s a lot of interesting stuff in here, and in order for me to have at least some chance of remembering some of that stuff later on I think I need to blog it.

“The battle [of Crete] began on the morning of May 20 [1941] […] It was the first large-scale airborne attack in the annals of war. […] When the battle joined we did not know what were the total resources of Germany in parachute troops. The 11th Air Corps might have been only one of half a dozen such units. It was not till many months afterwards that we were sure it was the only one.” (This quote highlights, I think, one aspect of the war which is easy to miss for people who ‘wasn’t there’; how much uncertainty there was, about a lot of things that the enemy might be doing, or might not be doing, or might be planning to do. Espionage will get you only so far).

“Prime Minister to Stafford Cripps               3 Apr 41

Following from me to M. Stalin, provided it can be personally delivered by you:
I have sure information from a trusted agent that when the Germans thought they had got Yugoslavia in the net – that is to say, after March 20 – they began to move three out of the five Panzer divisions from Roumania to Southern Poland. The moment they heard of the Serbian revolution this movement was countermanded. Your Excellency will readily appreciate the significance of these facts.”

(If the significance of these facts is not clear to people unfamiliar with the scene at the time, here’s what Churchill thought: “This shuffling and reversal of about sixty trains could not be concealed from our agents on the spot. To me it illuminated the whole Eastern scene like a lightning-flash. The sudden movement to Cracow of so much armour needed in the Balkan sphere could only mean Hitler’s intention to invade Russia in May. […] The fact that the Belgrade revolution had required their return to Roumania involved perhaps a delay from May to June. I cast about for some means of warning Stalin […] I made the message short and cryptic, hoping that this very fact, and that it was the first message I had sent him since my formal telegram of June 25, 1940, commending Sir Stafford Cripps as Ambassador, would arrest his attention and make him ponder. […] This was the only message before the attack that I sent Stalin direct.” When Churchill and Stalin later briefly discussed the warning during their 1942 Moscow conference, Stalin remarked that he remembered the warning, and added: “I did not need any warnings. I knew war would come, but I thought I might gain another six months or so.”)

“Almost all responsible military opinion held that the Russian armies would soon be defeated and largely destroyed. […] President Roosevelt was considered very bold when he proclaimed in September that the Russian front would hold and that Moscow could not be taken. […] Even in August 1942, after my visit to Moscow and the conferences there, General Brooke, who had accompanied me, adhered to the opinion that the Caucasus Mountains would be traversed and the basin of the Caspian dominated by German forces, and we prepared accordingly on the largest possible scale for a defensive campaign in Syria and Persia.”

“In the whole of the war ninety-one merchant ships were lost on the Arctic route, amounting to 7.8 per cent. of the loaded vessels outward bound and 3.8 per cent. of those returning. Only fifty-five of these were in escorted convoys. Of about four million tons of cargo dispatched from America and the United Kingdom, an eighth was lost. In this arduous work the Merchant Navy lost 829 lives, while the Royal Navy paid a still heavier price. Two cruisers and seventeen other war-ships were sunk and 1,840 officers and men died. The forty convoys to Russia carried the huge total of £428,000,000 worth of material, including 5,000 tanks and over 7,000 aircraft from Britain alone. […] The […] extreme difficulties of the Arctic route, together with future strategic possibilities, made [the] creation of a major supply route to Russia through the Persian gulf [a] prime objective. […] Starting in September 1941, this enterprise, begun and developed by the British Army, and presently to be adopted and expanded by the United States, enabled us to send to Russia, over a period of four and a half years, five million tons of supplies.”

“As we had flown [back to Britain, after the Arcadia Conference] for more than ten hours through mist and had had only one sight of a star in that time, we might well be slightly off our course. Wireless communication was of course limited by the normal war-time rules. It was evident from the discussions which were going on that we did not know where we were. Presently Portal, who had been studying the position, had a word with the captain, and then said to me, “We are going to turn north at once.” […] As I left the aircraft [after the landing] the [air] captain remarked, “I never felt so much relieved in my life as when I landed you safely in the harbour.” I did not appreciate the significance of his remark at the moment. Later on I learnt that if we had held on our course for another five or six minutes before turning northwards we should have been over the German batteries in Brest. We had slanted too much to the southward during the night. Moveover, the decisive correction which had been made brought us in, not from the south-west, but from just east of south – that is to say, from the enemy’s direction rather than from that from which we were expected. This had the result, as I was told some weeks later, that we were reported as a hostile bomber coming in from Brest, and six Hurricanes from Fighter Command were ordered out to shoot us down. However, they failed in their mission.”

“By the end of March [1942] the first phase of the Japanese war plan had achieved a success so complete that it surprised even its authors. Japan was master of Hong Kong, Siam, Malaya, and nearly the whole of the immense island region forming the Dutch East Indies. Japanese troops were plunging deeply into Burma. In the Philippines the Americans still fought on at the Corregidor, but without hope of relief. […] Whether it was wiser to organize their new perimeter thoroughly or by surging forward to gain greater depth for its defence seemed for [the Japanese leaders] a balanced strategic problem. After deliberations in Tokyo the more ambitious course was adopted. […] The Japanese High Command had shown the utmost skill and daring in making and executing their plans. They started however upon a foundation which did not measure world forces in true proportion. They never comprehended the latent might of the United States. […] they were drawn into a gamble, which even if it had won would only have lengthened their predominance by perhaps a year, and, as they lost, cut it down by an equal period. In the actual result they exchanged a fairly strong and gripped advantage for a wide and loose domain, which it was beyond their power to hold; and, being beaten in this outer area, they found themselves without the forces to make a coherent defence of their inner and vital zone. Nevertheless at this moment in the world struggle no one could be sure that Germany would not break Russia, or drive her beyond the Urals, and then be able to come back and invade Britain; or as an alternative spread through the Caucasus and Persia to join hands with the Japanese vanguards in India.”

Churchill included these interesting thoughts on the status of affairs roughly in the middle of the war: “I had now been twenty-eight months at the head of affairs, during which we had sustained an almost unbroken series of military defeats. […] The fact that we were no longer alone, but instead had the two most mighty nations in the world in alliance fighting desperately at our side, gave indeed assurances of ultimate victory. But this, by removing the sense of mortal peril, only made criticism more free. Was it strange that the whole character and system of the war direction, for which I was responsible, should have been brought into question and challenge? It is indeed remarkable that I was not […] dismissed from power, or confronted with demands for changes in my methods, which it was known I should never accept. I should then have vanished from the scene with a load of calamity on my shoulders, and the harvest, at last to be reaped, would have been ascribed to my belated disappearance.”

“In September [1942] 30 per cent. of Axis shipping supplying North Africa was sunk, largely by air action. In October the figure rose to 40 per cent. The loss of petrol was 66 per cent. […] There had been serious derangements in the enemy’s command. Rommel had gone to hospital in Germany at the end of September and his place was taken by General Stumme. Within twenty-four hours of the start of the battle [of El Alamein] Stumme died of a heart attack. [Talk about bad timing…] […] The Battle of El Alamein differed from all previous fighting in the Desert. The front was limited, heavily fortified, and held in strength. There was no flank to turn. A break-through must be made by whoever was the stronger and wished to take the offensive. In this way we are led back to the battles of the First World War on the Western Front. […] It may almost be said, “Before Alamein we never had a victory. After Alamein we never had a defeat.”

An important thing I learned from the book was the answer to the question why the (Western) Allied forces were mainly fighting in Africa during the first part of the war, but didn’t seemingly really do much else aside from trying to keep the Germans from bombing their cities and sinking their ships. A very important point is that landing craft was the binding constraint, and these were in desperately short supply, and it took a lot of time to build up the supply. It would have made no sense for the Allied to have tried to unload substantial numbers of soldiers in Europe during the first years; they would have been slaughtered, and valuable landing crafts would have been lost. What might have happened, had such a strategy been pursued, might have been repeated experiences like those of the Dieppe raid, where almost 60 % of the soldiers who made it ashore were killed, wounded or captured, and the rest had to be evacuated within hours. So instead the Allied leaders tried to seek out the enemy where they were actually capable of taking him on, and that way bind resources of his which could not be used on the Eastern front – which ended up meaning mainly military engagements in Africa and the Mediterranean. Operation Torch could be initiated successfully significantly sooner than any sort of successful cross-Channel operation could.

“[In May 1943] there were 185 German divisions on the Russian front. […] Brooke [during a strategy meeting at that time] set out our whole Mediterranean strength [available for operations in the near future]. Deducting seven divisions to be sent home for the cross-Channel operation and two to cover British commitments to Turkey, there would be twenty-seven Allied divisions available in the Mediterranean area. […] In the initial assault [of the invasion of Sicily] nearly 3,000 ships and landing-craft took part, carrying between them 160,000 men, 14,000 vehicles, 600 tanks, and 1,800 guns.” And still this was small potatoes compared to the forces engaged in conflict on the Eastern front – which makes you think…

“In 1940 and 1941 we lost four million tons of merchant shipping a year. In 1942, after the United States was our Ally, this figure nearly doubled, and the U-boats sank ships faster than the Allies could build them. During 1943, thanks to the immense shipbuilding programme of the United States, the new tonnage at last surpassed losses at sea from all causes, and the second quarter saw, for the first time, U-boat losses exceed their rate of replacement. […] In May alone forty U-boats perished in the ocean. […] The convoys came through intact, the supply line was safe, the decisive battle had been fought and won. […] The extirpation of Axis power in North Africa opened to our convoys the direct route to Egypt, India, and Australia […] The long haul round the Cape, which had cost us so dear in time, effort, and tonnage, would soon be ended. The saving of an average of forty-five days for each convoy to the Middle East increased magnificently at one stroke the fertility of our shipping.”

May 20, 2016 Posted by | Books, History | Leave a comment

Random stuff

I find it difficult to find the motivation to finish the half-finished drafts I have lying around, so this will have to do. Some random stuff below.


(15.000 views… In some sense that seems really ‘unfair’ to me, but on the other hand I doubt neither Beethoven nor Gilels care; they’re both long dead, after all…)

ii. New/newish words I’ve encountered in books, on or elsewhere:

Agleyperipeteia, disseverhalidom, replevinsocage, organdie, pouffe, dyarchy, tauricide, temerarious, acharnement, cadger, gravamen, aspersion, marronage, adumbrate, succotash, deuteragonist, declivity, marquetry, machicolation, recusal.

iii. A lecture:

It’s been a long time since I watched it so I don’t have anything intelligent to say about it now, but I figured it might be of interest to one or two of the people who still subscribe to the blog despite the infrequent updates.

iv. A few wikipedia articles (I won’t comment much on the contents or quote extensively from the articles the way I’ve done in previous wikipedia posts – the links shall have to suffice for now):

Duverger’s law.

Far side of the moon.

Preference falsification.

Russian political jokes. Some of those made me laugh (e.g. this one: “A judge walks out of his chambers laughing his head off. A colleague approaches him and asks why he is laughing. “I just heard the funniest joke in the world!” “Well, go ahead, tell me!” says the other judge. “I can’t – I just gave someone ten years for it!”).

Political mutilation in Byzantine culture.

v. World War 2, if you think of it as a movie, has a highly unrealistic and implausible plot, according to this amusing post by Scott Alexander. Having recently read a rather long book about these topics, one aspect I’d have added had I written the piece myself would be that an additional factor making the setting seem even more implausible is how so many presumably quite smart people were so – what at least in retrospect seems – unbelievably stupid when it came to Hitler’s ideas and intentions before the war. Going back to Churchill’s own life I’d also add that if you were to make a movie about Churchill’s life during the war, which you could probably relatively easily do if you were to just base it upon his own copious and widely shared notes, then it could probably be made into a quite decent movie. His own comments, remarks, and observations certainly made for a great book.

May 15, 2016 Posted by | Astronomy, Computer science, History, Language, Lectures, Mathematics, Music, Random stuff, Russia, Wikipedia | Leave a comment

The Second World War (II)

Here’s my first post about Churchill’s book(s). In this post I’ll add some further observations and data; I’m roughly two-thirds through the book(s) at this point.

“a significant proportion of our whole war effort had to be devoted to combating the mine. A vast output of material and money was diverted from other tasks, and many thousands of men risked their lives night and day in the minesweepers alone. The peak figure was reached in June 1944, when nearly sixty thousand were thus employed.”

“On January 10, 1940, anxieties about the Western Front received confirmation. A German staff major of the 7th Air Division had been ordered to take some documents to headquarters in Cologne. He missed his train and decided to fly. His machine overshot the mark and made a forced landing in Belgium, where Belgian troops arrested him and impounded his papers, which he tried desperately to destroy. These contained the entire and actual scheme for the invasion of Belgium, Holland, and France on which Hitler had resolved. […] I was told about all this at the time […] It was argued in all three countries concerned that probably it was a plant. But this could not be true. There could be no sense in the Germans trying to make the Belgians believe that they were going to attack them in the near future. This might make them do the very last thing the Germans wanted, namely, make a plan with the French and British Armies […] I therefore believed in the impending attack. We appealed to Belgium, but the Belgian King and his Army staff merely waited, hoping that all would turn out well. […] no further action of any kind was taken by the Allies or the threatened States. […] Hitler, […] ordered, after venting his anger, new variants [of the invasion plans] to be prepared.”

“until July 1944 Britain and her Empire had a substantially larger number of divisions in contact with the enemy than the United States. This general figure includes not only the European and African spheres but also all the war in Asia against Japan. […] Out of 781 German and 85 Italian U-boats destroyed in the European theatre, the Atlantic and Indian Oceans, 594 were accounted for by British sea and air forces […] of shipping losses by enemy action suffered by all nations throughout the war […] 80 per cent. were suffered in the Atlantic Ocean, including British coastal waters and the North Sea. Only 5 per cent. were lost in the Pacific. […] Up till the end of 1943 the British discharge of bombs upon Germany had in the aggregate exceeded by eight tons to one those cast from American machines”

“My relations with the President [Roosevelt – US] gradually became so close that the chief business between our two countries was virtually conducted by […] personal interchanges between him and me. […] In all I sent him nine hundred and fifty messages, and received about eight hundred in reply.”

“Altogether there came to the rescue of the Army under the ceaseless air bombardment of the enemy about eight hundred and sixty vessels […] at 2.23 p.m. on June 4 the Admiralty, in agreement with the French, announced that Operation “Dynamo” was now completed. More than 338,000 British and Allied troops had been landed in England. […] On June 17 it was announced that the Pétain Government had asked for an armistice, ordering all French forces to cease fighting, without even communicating this information to our troops. General Brooke was consequently told to come away with all men he could embark and any equipment he could save. We repeated now on a considerable scale, though with larger vessels, the Dunkirk evacuation. Over twenty thousand Polish troops who refused to capitulate cut their way to the sea and were carried by our ships to Britain. […] In all there were evacuated from all French harbours 136,000 British troops and 310 guns; a total, with the Poles, of 156,000 men.”

“Hitler and Stalin had much in common as totalitarians, and their systems of government were akin. […] On June 14, the day Paris fell, Moscow sent an ultimatum to Lithuania accusing her and the other Baltic States of military conspiracy against the U.S.S.R. and demanding radical changes of government and military concessions. On June 15 Red Army troops invaded the country. Latvia and Estonia were exposed to the same treatment. […] A Russian ultimatum to Roumania was delivered to the Roumanian Minister in Moscow at 10 p.m. on June 26. The cession of Bessarabia and the norther part of the province of Bukovina was demanded […] On June 27 Roumanian troops were withdrawn from the two provinces concerned, and the territories passed into Russian hands. […] On August 3-6 the pretence of pro-Soviet friendly and democratic Governments [in the Baltic] was swept away, and the Kremlin annexed the Baltic States to the Soviet Union.”

“From September 7 to November 3 an average of two hundred German bombers attacked London every night. […] The night raids were accompanied by more or less continuous daylight attacks by small groups or even single enemy planes, and the sirens often sounded at brief intervals throughout the whole twenty-four hours. To this curious existence the seven million inhabitants of London accustomed themselves. […] We did not know how long it would last. We had no reason to suppose that it would not go on getting worse. […] In the twelve months from June 1940 to June 1941 our civilian casualties were 43,381 killed and 40,856 seriously injured, a total of 94,237.”

“The only thing that ever really frightened me during the war was the U-boat peril. […] we poised and pondered together on this problem. It did not take the form of flaring battles and glittering achievements. It manifested itself through statistics, diagrams, and curves unknown to the nation, incomprehensible to the public. […] At the outset the Admiralty naturally thought first of bringing the ships safely to port, and judged their success by a minimum of sinkings. But now this was no longer the test. We all realised that the life and war effort of the country depended equally upon the weight of imports safely landed. In the week ending June 8, during the height of the battle in France, we had brought into the country about a million and a quarter tons of cargo, exclusive of oil. From this peak figure imports had declined at the end of July to less than 750,000 tons a week. […] I became increasingly concerned about this ominous fall in imports. “I see,” I minuted to the First Lord in the middle of February, 1941, “that entrances of ships with cargo in January were less than half of what they were last January.” The very magnitude and refinement of our protective measures – convoy, diversion, degaussing [a method employed to counteract magnetic mines – US], mine-clearance, the avoidance of the Mediterranean – the lengthening of most voyages in time and distance and the delays at the ports through bombing and the black-out, all reduced the operative fertility of our shipping to an extent even more serious than the actual losses. […] To the U-boat scourge was soon added air attack far out on the ocean by long-range aircraft. […] Powerful German cruisers were active. […] formidable vessels compelled the employment on convoy duty of nearly every available British capital ship. At one period the Commander-in-Chief of the Home Fleet had only one battleship in hand.”

“In the three months ending with May [1941] U-boats alone sank 142 ships, of 818,000 tons, of which 99 were British. […] in the same three months of March, April, and May 179 ships, of 545,000 tons, were sunk by air attack, mainly in the coastal regions. […] In the Atlantic [1942] proved the toughest [year] of the whole war. […] By the end of January [1942] thirty-one ships, of nearly 200,000 tons, had been sunk off the coast off the United States and Canadian coast. […] In February they destroyed seventy-one ships, of 384,000 tons, in the Atlantic, of which all but two were sunk in the American zone. […] The American Army Air Force, which controlled almost all military shore-based aircraft, had no training in anti-submarine warfare, whereas the Navy, equipped with float-planes and amphibians, had no means to carry it out, and in these crucial months an effective American defence system was only achieved with painful, halting steps. […] It was not until the end of the year that a complete interlocking convoy system covering all [the] immense areas [involved] became fully effective. […] In seven months the Allied losses in the Atlantic from U-boats alone amounted to over three million tons, which included 181 British ships of 1,130,000 tons. Less than one-tenth occurred in convoys. All this cost the enemy up to July no more than fourteen U-boats sunk throughout the Atlantic and Arctic Oceans, and of these kills only six were in North American waters. […] during [August] U-boats sank 108 vessels […] Between January and October 1942 the number of U-boats had more than doubled. 196 were operational […] All our escorts had to be cut to the bone for the sake of our main operations in Africa, and in November our losses at sea were the heaviest of the whole war, including 117 ships, of over 700,000 tons, by U-boats alone, another 100,000 from other causes.”

April 19, 2016 Posted by | Books, History | Leave a comment

Einstein quotes

“Einstein emerges from this collection of quotes, drawn from many different sources, as a complete and fully rounded human being […] Knowledge of the darker side of Einstein’s life makes his achievement in science and in public affairs even more miraculous. This book shows him as he was – not a superhuman genius but a human genius, and all the greater for being human.”

I’ve recently read The Ultimate Quotable Einstein, from the foreword of which the above quote is taken, which contains roughly 1600 quotes by or about Albert Einstein; most of the quotes are by Einstein himself, but the book also includes more than 50 pages towards the end of the book containing quotes by others about him. I was probably not in the main target group, but I do like good quote collections and I figured there might be enough good quotes in the book for it to make sense for me to give it a try. On the other hand after having read the foreword by Freeman Dyson I knew there would probably be a lot of quotes in the book which I probably wouldn’t find too interesting; I’m not really sure why I should give a crap if/why a guy who died more than 60 years ago and whom I have never met and never will was having an affair during the early 1920s, or why I should care what Einstein thought about his mother or his ex-wife, but if that kind of stuff interests you the book has stuff about those kinds of things as well. My own interest in Einstein, such as it is, is mainly in ‘Einstein the scientist’ (and perhaps also in this particular context ‘Einstein the aphorist’), not ‘Einstein the father’ or ‘Einstein the husband’. I also don’t find the political views which he held to be very interesting, but again if you want to know what Einstein thought about things like Zionism, pacifism, and world government the book includes quotes about such topics as well.

Overall I should say that I was a little underwhelmed by the book and the quotes it includes, but I would also note that people who are interested in knowing more about Einstein will likely find a lot of valuable source material here, and that I did give the book 3 stars on goodreads. I did learn a lot of new things about Einstein by reading the book, but this is not surprising given how little I knew about him before I started reading the book; for example I had no idea that he was offered the presidency of Israel a few years before his death. I noticed only two quotes which were included more than once (a quote on pages 187-188 was repeated on page 453, and a quote on page 295 was repeated on page 455), and although I cannot guarantee that there aren’t any other repeats almost all quotes included in the book are unique, in the sense that they’re only included once in the coverage. However it should also be mentioned in this context that there are a few quotes on specific themes which are very similar to other quotes included elsewhere in the coverage. I do consider this unavoidable considering the number of quotes included, though.

I have included some sample quotes from the book below – I have tried to include quotes on a wide variety of topics. All quotes without a source below are sourced quotes by Einstein (the book also contains a small collection of quotes ‘attributed to Einstein’, many of which are either not sourced or sourced in such a manner that Calaprice did not feel convinced that the quote was actually by Einstein – none of the quotes from that part of the book’s coverage are included below).

“When a blind beetle crawls over the surface of a curved branch, it doesn’t notice that the track it has covered is indeed curved. I was lucky enough to notice what the beetle didn’t notice.” (“in answer to his son Eduard’s question about why he is so famous, 1922.”)

“The most valuable thing a teacher can impart to children is not knowledge and understanding per se but a longing for knowledge and understanding” (see on a related note also Susan Engel’s book – US)

“Teaching should be such that what is offered is perceived as a valuable gift and not as a hard duty.”

“I am not prepared to accept all his conclusions, but I consider his work an immensely valuable contribution to the science of human behavior.” (Einstein said this about Sigmund Freud during an interview. Yeah…)

“I consider him the best of the living writers.” (on Bertrand Russell. Russell incidentally also admired Einstein immensely – the last part of the book, including quotes by others about Einstein, includes this one by him: “Of all the public figures that I have known, Einstein was the one who commanded my most wholehearted admiration.”)

“I cannot understand the passive response of the whole civilized world to this modern barbarism. Doesn’t the world see that Hitler is aiming for war?” (1933. Related link.)

“Children don’t heed the life experience of their parents, and nations ignore history. Bad lessons always have to be learned anew.”

“Few people are capable of expressing with equanimity opinions that differ from the prejudices of their social environment. Most people are even incapable of forming such opinions.”

“Sometimes one pays most for things one gets for nothing.”

“Thanks to my fortunate idea of introducing the relativity principle into physics, you (and others) now enormously overrate my scientific abilities, to the point where this makes me quite uncomfortable.” (To Arnold Sommerfeld, 1908)

“No fairer destiny could be allotted to any physical theory than that it should of itself point out the way to the introduction of a more comprehensive theory, in which it lives on as a limiting case.”

“Mother nature, or more precisely an experiment, is a resolute and seldom friendly referee […]. She never says “yes” to a theory; but only “maybe” under the best of circumstances, and in most cases simply “no”.”

“The aim of science is, on the one hand, a comprehension, as complete as possible, of the connection between the sense experiences in their totality, and, on the other hand, the accomplishment of this aim by the use of a minimum of primary concepts and relations.” A related quote from the book: “Although it is true that it is the goal of science to discover rules which permit the association and foretelling of facts, this is not its only aim. It also seeks to reduce the connections discovered to the smallest possible number of mutually independent conceptual elements. It is in this striving after the rational unification of the manifold that it encounters its greatest successes.”

“According to general relativity, the concept of space detached from any physical content does not exist. The physical reality of space is represented by a field whose components are continuous functions of four independent variables – the coordinates of space and time.”

“One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike – and yet it is the most precious thing we have.”

“”Why should I? Everybody knows me there” (upon being told by his wife to dress properly when going to the office). “Why should I? No one knows me there” (upon being told to dress properly for his first big conference).”

“Marriage is but slavery made to appear civilized.”

“Nothing is more destructive of respect for the government and the law of the land than passing laws that cannot be enforced.”

“Einstein would be one of the greatest theoretical physicists of all time even if he had not written a single line on relativity.” (Max Born)

“Einstein’s [violin] playing is excellent, but he does not deserve his world fame; there are many others just as good.” (“A music critic on an early 1920s performance, unaware that Einstein’s fame derived from physics, not music. Quoted in Reiser, Albert Einstein, 202-203″)

April 12, 2016 Posted by | Books, History, Physics, Quotes/aphorisms, Science | Leave a comment

The Second World War (I?)

“I am perhaps the only man who has passed through both the two supreme cataclysms of recorded history in high executive office. Whereas […] in the First World War I filled responsible but subordinate posts, I was in this second struggle with Germany for more than five years the head of His Majesty’s Government. I write therefore from a different standpoint and with more authority than was possible in my earlier books. I do not describe it as history, for that belongs to another generation. But I claim with confidence that it is a contribution to history which will be of service to the future.”

“Let no one look down on those honourable, well-meaning men whose actions are chronicled in these pages without searching his own heart, reviewing his own discharge of public duty, and applying the lessons of the past to his future conduct.”

I am currently reading this book, which is really an abridgement of 6 different volumes written by Churchill. All of the stuff included is Churchill’s own stuff; the only thing that has been done is that some stuff has been left out, and some of the remaining stuff has been rearranged. Which means that you in this book get four books/subsections, rather than six. The titles of these are: Milestones to disaster (1919-May 10, 1940), Alone (May 10, 1940-June 22, 1941), The Grand Alliance (Sunday, December 7, 1941 and onwards), and Triumph and Tragedy (1943-1945). I have by now finished Book 1 (the Milestones to Disaster part), and I’ve read close to 100 pages of Book 2. It’s great stuff, and very detailed. In this post I have included quotes from roughly the first 150 pages of the book’s coverage, all of which belong to the ‘Milestones to disaster’ part.

“When Marshall Foch heard of the signing of the Peace Treaty of Versailles he observed with singular accuracy: “This is not peace. It is an Armistice for twenty years.””

[In the context of the reparations:] “whereas about £1,000 millions of German assets were appropriated by the victorious Powers, more than £1,500 millions were lent a few years later to Germany, principally by the United States and Great Britain […] until 1931 the victors, and particularly the United States, concentrated their efforts upon extorting by vexatious foreign controls their annual reparations from Germany. The fact that these payments were made only from far larger American loans reduced the whole process to the absurd. Nothing was reaped except ill-will. […] History will characterize all these transactions as insane. […] All this is a sad story of complicated idiocy”

“Deliberate extermination of whole populations was contemplated and pursued by both Germany and Russia in the Eastern war.”

“”We are apparently finished and done with economic cycles as we have known them,” said the President of the New York Stock Exchange in September.” [That would be September, 1929. Talk about bad timing… – US]

“The opinions of the Press and public were in no way founded upon reality […] delight in smooth-sounding platitudes, refusal to face unpleasant facts, desire for popularity and electoral success irrespective of the vital interests of the State, genuine love of peace and pathetic belief that love can be its sole foundation, obvious lack of intellectual vigour […] marked ignorance […] the utter devotion […] to sentiment apart from reality […]: all these constituted a picture of British fatuity and fecklessness which, though devoid of guile, was not devoid of guilt, and, though free from wickedness or evil design, played a definite part in the unleashing upon the world of horrors and miseries which, even so far as they have unfolded, are already beyond comparison in human experience. […] It is difficult to find a parallel to the unwisdom of the British and weakness of the French Governments, who none the less reflected the opinion of their Parliaments in this disastrous period” [the period in question being the early thirties – US].

“Several visitors of consequence came to me from Germany and poured their hearts out in their bitter distress. Most of these were executed by Hitler during the war.”

“It would be wrong in judging the policy of the British Government not to remember the passionate desire for peace which animated the uninformed, misinformed majority of the British people, and seemed to threaten with political extinction any party or politician who dared to take any other line. This, of course, is no excuse for political leaders who fall short of their duty. It is much better for parties or politicians to be turned out of office than to imperil the life of the nation. […] To be so entirely convinced and vindicated in a matter of life and death to one’s country, and not to be able to make Parliament and the nation heed the warning, or bow to the proof by taking action, was an experience most painful.”

“the number of Germans under regular military training in 1936 was 1,511,000 men. The effective strength of the French Army, apart from reserves, in the same year was 623,000 men, of whom only 407,000 were in France.”

Abyssinia [see also this] was a member of the League of Nations. By a curious inversion it was Italy who had in 1923 pressed for her inclusion, and Britain who had opposed it. The British view was that the character of the Ethiopian Government and the conditions prevailing in that wild land of tyranny, slavery, and tribal war were not consonant with membership of the League. But the Italians had had their way” [incidentally if you want an update on how things are going in that part of the world, apropos all those migrants coming to Europe from that region these days, here’s some updated information: “Eritrea is a one-party state in which national legislative elections have been repeatedly postponed.[111] According to Human Rights Watch, the government’s human rights record is considered among the worst in the world. […] In June 2015, a 500-page United Nations Human Rights Council report accused Eritrea’s government of extrajudicial executions, torture, indefinitely prolonged national service and forced labour, and indicated that sexual harassment, rape and sexual servitude by state officials are also widespread.” (wikipedia)]

“One day in 1937 I had a meeting with Herr von Ribbentrop, German ambassador to Britain. […] he had asked Hitler to let him come over to London in order to make the full case for an Anglo-German entente or even alliance. […] What was required was that Britain should give Germany a free hand in the East of Europe. She must have her Lebensraum […] All that was asked of the British Commonwealth and Empire was not to interfere. There was a large map on the wall, and the Ambassador several times led me to it to illustrate his projects. After hearing all this I said at once that I was sure the British Government would not agree to give Germany a free hand in Eastern Europe. […] Ribbentrop turned abruptly away. He then said, “In that case, war is inevitable. There is no way out. The Fuehrer is resolved. Nothing will stop him and nothing will stop us.” We then returned to our chairs.” [At this time Churchill was just an MP, so Ribbentrop was not asking Churchill himself to consent to the proposed scheme and ‘make a deal’; he was trying to figure out if there was any deal to be made. The year after, on July 26, 1938, Lord Halifax, the British Foreign Minister, incidentally stated in Parliament that: “I do not believe that those responsible for the Government of any country in Europe to-day want war.” – US]

“On the day of the march of the German armies into Austria we heard that Goering had given a solemn assurance to the Czech Minister in Berlin that Germany had “no evil intentions towards Czechoslovakia” […] On the evening of the 26th [of September, 1938 – US] Hitler spoke in Berlin. […] He said categorically that the Czechs must clear out of the Sudetenland, but once this was settled he had no more interest in what happened to Czechoslovakia. “This is the last territorial claim I have to make in Europe.” […] Chamberlain returned to England [after signing the agreement – US]. […] from the windows of Downing Street he waved his piece of paper again and used these words, “This is the second time in our history that there has come back from Germany to Downing Street peace with honour. I believe it is peace for our time.”

“In 1938-39 British military expenditure of all kinds reached £304 millions,* and German was at least £1,500 millions. It is probable that in the last year before the outbreak Germany manufactured at least double, and possibly treble, the munitions of Britain and France put together […] in the single year 1938 Hitler had annexed to the Reich and brought under his absolute rule […] a total of over ten millions of subjects, toilers, and soldiers. […] The German armies were not capable of defeating the French in 1938 or 1939. The vast tank production with which they broke the French front did not come into existence till 1940”

“if you will not fight for the right when you can easily win without bloodshed, if you will not fight when your victory will be sure and not too costly, you may come to the moment when you will have to fight with all the odds against you and only a precarious chance of survival. There may even be a worse case. You may have to fight when there is no hope of victory, because it is better to perish than live as slaves.”

“At the Kremlin in August 1942 Stalin, in the early hours of the morning, gave me one aspect of the Soviet position. “We formed the impression,” said Stalin, “that the British and French governments were not resolved to go to war if Poland were attacked, but that they hoped the diplomatic line-up of Britain, France, and Russia would deter Hitler. We were sure it would not.””

“There were known to be twenty thousand organised German Nazis in England at this time [at the end of August, 1939US], and it would only have been in accord with their procedure in other friendly countries that the outbreak of war should be preceded by a sharp prelude of sabotage and murder. I had at that time no official protection, and I did not wish to ask for any; but I thought myself sufficiently prominent to take precautions. I had enough information to convince me that Hitler recognised me as a foe. My former Scotland Yard detective, Inspector Thompson, was in retirement. I told him to come along and bring his pistol with him. I got out my own weapons, which were good. While one slept the other watched.”


April 6, 2016 Posted by | Books, History | Leave a comment

Random Stuff

i. Some new words I’ve encountered (not all of them are from, but many of them are):

Uxoricide, persnickety, logy, philoprogenitive, impassive, hagiography, gunwale, flounce, vivify, pelage, irredentism, pertinacity,callipygous, valetudinarian, recrudesce, adjuration, epistolary, dandle, picaresque, humdinger, newel, lightsome, lunette, inflect, misoneism, cormorant, immanence, parvenu, sconce, acquisitiveness, lingual, Macaronic, divot, mettlesome, logomachy, raffish, marginalia, omnifarious, tatter, licit.

ii. A lecture:

I got annoyed a few times by the fact that you can’t tell where he’s pointing when he’s talking about the slides, which makes the lecture harder to follow than it ought to be, but it’s still an interesting lecture.

iii. Facts about Dihydrogen Monoxide. Includes coverage of important neglected topics such as ‘What is the link between Dihydrogen Monoxide and school violence?’ After reading the article, I am frankly outraged that this stuff’s still legal!

iv. Some wikipedia links of interest:


Steganography […] is the practice of concealing a file, message, image, or video within another file, message, image, or video. The word steganography combines the Greek words steganos (στεγανός), meaning “covered, concealed, or protected”, and graphein (γράφειν) meaning “writing”. […] Generally, the hidden messages appear to be (or be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some implementations of steganography that lack a shared secret are forms of security through obscurity, whereas key-dependent steganographic schemes adhere to Kerckhoffs’s principle.[1]

The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages—no matter how unbreakable—arouse interest, and may in themselves be incriminating in countries where encryption is illegal.[2] Thus, whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing the fact that a secret message is being sent, as well as concealing the contents of the message.”

H. H. Holmes. A really nice guy.

Herman Webster Mudgett (May 16, 1861 – May 7, 1896), better known under the name of Dr. Henry Howard Holmes or more commonly just H. H. Holmes, was one of the first documented serial killers in the modern sense of the term.[1][2] In Chicago, at the time of the 1893 World’s Columbian Exposition, Holmes opened a hotel which he had designed and built for himself specifically with murder in mind, and which was the location of many of his murders. While he confessed to 27 murders, of which nine were confirmed, his actual body count could be up to 200.[3] He brought an unknown number of his victims to his World’s Fair Hotel, located about 3 miles (4.8 km) west of the fair, which was held in Jackson Park. Besides being a serial killer, H. H. Holmes was also a successful con artist and a bigamist. […]

Holmes purchased an empty lot across from the drugstore where he built his three-story, block-long hotel building. Because of its enormous structure, local people dubbed it “The Castle”. The building was 162 feet long and 50 feet wide. […] The ground floor of the Castle contained Holmes’ own relocated drugstore and various shops, while the upper two floors contained his personal office and a labyrinth of rooms with doorways opening to brick walls, oddly-angled hallways, stairways leading to nowhere, doors that could only be opened from the outside and a host of other strange and deceptive constructions. Holmes was constantly firing and hiring different workers during the construction of the Castle, claiming that “they were doing incompetent work.” His actual reason was to ensure that he was the only one who fully understood the design of the building.[3]

Minnesota Starvation Experiment.

“The Minnesota Starvation Experiment […] was a clinical study performed at the University of Minnesota between November 19, 1944 and December 20, 1945. The investigation was designed to determine the physiological and psychological effects of severe and prolonged dietary restriction and the effectiveness of dietary rehabilitation strategies.

The motivation of the study was twofold: First, to produce a definitive treatise on the subject of human starvation based on a laboratory simulation of severe famine and, second, to use the scientific results produced to guide the Allied relief assistance to famine victims in Europe and Asia at the end of World War II. It was recognized early in 1944 that millions of people were in grave danger of mass famine as a result of the conflict, and information was needed regarding the effects of semi-starvation—and the impact of various rehabilitation strategies—if postwar relief efforts were to be effective.”

“most of the subjects experienced periods of severe emotional distress and depression.[1]:161 There were extreme reactions to the psychological effects during the experiment including self-mutilation (one subject amputated three fingers of his hand with an axe, though the subject was unsure if he had done so intentionally or accidentally).[5] Participants exhibited a preoccupation with food, both during the starvation period and the rehabilitation phase. Sexual interest was drastically reduced, and the volunteers showed signs of social withdrawal and isolation.[1]:123–124 […] One of the crucial observations of the Minnesota Starvation Experiment […] is that the physical effects of the induced semi-starvation during the study closely approximate the conditions experienced by people with a range of eating disorders such as anorexia nervosa and bulimia nervosa.”

Post-vasectomy pain syndrome. Vasectomy reversal is a risk people probably know about, but this one seems to also be worth being aware of if one is considering having a vasectomy.

Transport in the Soviet Union (‘good article’). A few observations from the article:

“By the mid-1970s, only eight percent of the Soviet population owned a car. […]  From 1924 to 1971 the USSR produced 1 million vehicles […] By 1975 only 8 percent of rural households owned a car. […] Growth of motor vehicles had increased by 224 percent in the 1980s, while hardcore surfaced roads only increased by 64 percent. […] By the 1980s Soviet railways had become the most intensively used in the world. Most Soviet citizens did not own private transport, and if they did, it was difficult to drive long distances due to the poor conditions of many roads. […] Road transport played a minor role in the Soviet economy, compared to domestic rail transport or First World road transport. According to historian Martin Crouch, road traffic of goods and passengers combined was only 14 percent of the volume of rail transport. It was only late in its existence that the Soviet authorities put emphasis on road construction and maintenance […] Road transport as a whole lagged far behind that of rail transport; the average distance moved by motor transport in 1982 was 16.4 kilometres (10.2 mi), while the average for railway transport was 930 km per ton and 435 km per ton for water freight. In 1982 there was a threefold increase in investment since 1960 in motor freight transport, and more than a thirtyfold increase since 1940.”

March 3, 2016 Posted by | Biology, Cryptography, History, Language, Lectures, Ophthalmology, Random stuff, Wikipedia, Zoology | Leave a comment

A few lectures

The sound quality of this lecture is not completely optimal – there’s a recurring echo popping up now and then which I found slightly annoying – but this should not keep you from watching the lecture. It’s a quite good lecture, and very accessible – I don’t really think you even need to know anything about genetics to follow most of what he’s talking about here; as far as I can tell it’s a lecture intended for people who don’t really know much about population genetics. He introduces key concepts as they are needed and he does not go much into the technical details which might cause people trouble (this of course also makes the lecture somewhat superficial, but you can’t get everything). If you’re the sort of person who wants details not included in the lecture you’re probably already reading e.g. Razib Khan (who incidentally recently blogged/criticized a not too dissimilar paper from the one discussed in the lecture, dealing with South Asia)…

I must admit that I actually didn’t like this lecture very much, but I figured I might as well include it in this post anyway.

I found some questions included and some aspects of the coverage a bit ‘too basic’ for my taste, but other people interested in chess reading along here may like Anna’s approach better; like Krause’s lecture I think it’s an accessible lecture, despite the fact that it actually covers many lines in quite a bit of detail. It’s a long lecture but I don’t think you necessarily need to watch all of it in one go (…or at all?) – the analysis of the second game, the Kortschnoj-Gheorghiu game, starts around 45 minutes in so that might for example be a good place to include a break, if a break is required.

February 1, 2016 Posted by | Anthropology, Archaeology, Chess, Computer science, Evolutionary biology, Genetics, History, Lectures | Leave a comment

A couple of lectures and a little bit of random stuff

i. Two lectures from the Institute for Advanced Studies:

The IAS has recently uploaded a large number of lectures on youtube, and the ones I blog here are a few of those where you can actually tell from the title what the lecture is about; I find it outright weird that these people don’t include the topic covered in the lecture in their lecture titles.

As for the video above, as usual for the IAS videos it’s annoying that you can’t hear the questions asked by the audience, but the sound quality of this video is at least quite a bit better than the sound quality of the video below (which has a couple of really annoying sequences, in particular around the 15-16 minutes mark (it gets better), where the image is also causing problems, and in the last couple of minutes of the Q&A things are also not exactly optimal as the lecturer leaves the area covered by the camera in order to write something on the blackboard – but you don’t know what he’s writing and you can’t see the lecturer, because the camera isn’t following him). I found most of the above lecture easier to follow than I did the lecture posted below, though in either case you’ll probably not understand all of it unless you’re an astrophysicist – you definitely won’t in case of the latter lecture. I found it helpful to look up a few topics along the way, e.g. the wiki articles about the virial theorem (/also dealing with virial mass/radius), active galactic nucleus (this is the ‘AGN’ she refers to repeatedly), and the Tully–Fisher relation.

Given how many questions are asked along the way it’s really annoying that you in most cases can’t hear what people are asking about – this is definitely an area where there’s room for improvement in the context of the IAS videos. The lecture was not easy to follow but I figured along the way that I understood enough of it to make it worth watching the lecture to the end (though I’d say you’ll not miss much if you stop after the lecture – around the 1.05 hours mark – and skip the subsequent Q&A). I’ve relatively recently read about related topics, e.g. pulsar formation and wave- and fluid dynamics, and if I had not I probably would not have watched this lecture to the end.

ii. A update. I’m slowly working my way up to the ‘Running Dictionary’ rank (I’m only a walking dictionary at this point); here’s some stuff from my progress page:

I recently learned from a note added to a list that I’ve actually learned a very large proportion of all words available on, which probably also means that I may have been too harsh on the word selection algorithm in past posts here on the blog; if there aren’t (/m)any new words left to learn it should not be surprising that the algorithm presents me with words I’ve already mastered, and it’s not the algorithm’s fault that there aren’t more words available for me to learn (well, it is to the extent that you’re of the opinion that questions should be automatically created by the algorithm as well, but I don’t think we’re quite there yet at this point). The aforementioned note was added in June, and here’s the important part: “there are words on your list that can’t teach yet. can teach over 12,000 words, but sadly, these aren’t among them”. ‘Over 12.000’ – and I’ve mastered 11.300. When the proportion of mastered words is this high, not only will the default random word algorithm mostly present you with questions related to words you’ve already mastered; but it actually also starts to get hard to find lists with many words you’ve not already mastered – I’ll often load lists with one hundred words and then realize that I’ve mastered every word on the list. This is annoying if you have a desire to continually be presented with both new words as well as old ones. Unless increases the rate with which they add new words I’ll run out of new words to learn, and if that happens I’m sure it’ll be much more difficult for me to find motivation to use the site.

With all that stuff out of the way, if you’re not a regular user of the site I should note – again – that it’s an excellent resource if you desire to increase your vocabulary. Below is a list of words I’ve encountered on the site in recent weeks(/months?):

Copaceticfrumpyelisiontermagantharridanquondam, funambulist, phantasmagoriaeyelet, cachinnate, wilt, quidnunc, flocculent, galoot, frangible, prevaricate, clarion, trivet, noisome, revenant, myrmidon (I have included this word once before in a post of this type, but it is in my opinion a very nice word with which more people should be familiar…), debenture, teeter, tart, satiny, romp, auricular, terpsichorean, poultice, ululation, fusty, tangy, honorarium, eyas, bumptious, muckraker, bayou, hobble, omphaloskepsis, extemporize, virago, rarefaction, flibbertigibbet, finagle, emollient.

iii. I don’t think I’d do things exactly the way she’s suggesting here, but the general idea/approach seems to me appealing enough for it to be worth at least keeping in mind if I ever decide to start dating/looking for a partner.

iv. Some wikipedia links:

Tarrare (featured). A man with odd eating habits and an interesting employment history (“Dr. Courville was keen to continue his investigations into Tarrare’s eating habits and digestive system, and approached General Alexandre de Beauharnais with a suggestion that Tarrare’s unusual abilities and behaviour could be put to military use.[9] A document was placed inside a wooden box which was in turn fed to Tarrare. Two days later, the box was retrieved from his excrement, with the document still in legible condition.[9][17] Courville proposed to de Beauharnais that Tarrare could thus serve as a military courier, carrying documents securely through enemy territory with no risk of their being found if he were searched.” Yeah…).

Cauda equina syndromeCastleman’s disease, Astereognosis, Familial dysautonomia, Homonymous hemianopsia, Amaurosis fugax. All of these are of course related to content covered in the Handbook.

1740 Batavia massacre (featured).

v. I am also fun.

October 30, 2015 Posted by | Astronomy, History, Immunology, Language, Lectures, Medicine, Neurology, Personal, Physics, Random stuff, Wikipedia | Leave a comment

Random stuff

It’s been a while since I posted anything here so I figured I should at least post something…

i. A few Khan Academy videos I watched a while back:

(No comments)

(Bookmark remark: (‘Not completely devoid of slight inaccuracies as usual – e.g. in meningitis, neck stiffness is not as much as symptom as it is a clinical sign (see Chamberlain’s symptoms and signs…))’

(Bookmark remark: ‘Very simplified, but not terrible’)

(No comments)

ii. I previously read the wiki on strategic bombing during WW2, but the article did not really satisfy my curiosity and it turns out that the wiki also has a great (featured) article about Air raids on Japan (a topic not covered in a great amount of detail in the aforementioned wiki article). A few random observations from the article:

“Overall, the attacks in May destroyed 94 square miles (240 km2) of buildings, which was equivalent to one seventh of Japan’s total urban area.”

“In Tokyo, Osaka, Nagoya, Yokohama, Kobe, and Kawasaki, “over 126,762 people were killed … and a million and a half dwellings and over 105 square miles (270 km2) of urban space were destroyed.”[136] In Tokyo, Osaka and Nagoya, “the areas leveled (almost 100 square miles (260 km2)) exceeded the areas destroyed in all German cities by both the American and English air forces (approximately 79 square miles (200 km2)).”[136]

“In financial terms, the Allied air campaign and attacks on merchant ships destroyed between one third and a quarter of Japan’s wealth.[289]

“Approximately 40 percent of the urban area of the 66 cities subjected to area attacks were destroyed.[290] This included the loss of about 2.5 million housing units, which rendered 8.5 million people homeless.”

iii. A few longer lectures I’ve watched recently but did not think were particularly good: The Fortress (GM Akobian, Chess), Safety in the Nuclear Industry (Philip Thomas, Gresham College), War, Health and Medicine: The medical lessons of World War I (Mark Harrison, Gresham College – topic had potential, somehow did not like ‘the delivery’; others may find it worth watching).

iv. I play a lot of (too much) chess these days, so I guess it makes sense to post a little on this topic as well. Here’s a list of some of my recent opponents on the ICC: GM Zurab Azmaiparashvili, IM Jerzy Slaby, IM Petar Gojkovic, GM Goran Kosanovic, IM Jeroen Bosch, WGM Alla Grinfeld. I recall encountering a few titled players when I started out on the ICC and my rating was still adjusting and stabilizing, but now I’ve sort of fixed at a level around 1700-1800 in both the 1, 3 and 5 minute pools – sometimes a bit higher, sometimes a bit lower (and I’ve played relatively few 5 minute games so far)). This is a level where at least in bullet some of the semi-regular opponents I’ll meet in the rating pool are guys like these. I was quite dissatisfied with my play when I started out on the ICC because I hadn’t realized how tough it is to maintain a high rating there; having a closer look at which sort of opponents I was actually facing gradually made me realize I was probably doing quite well, all things considered. Lately I’ve been thinking that I have probably even been doing quite a bit better than I’d thought I had. See also this and this link. I’ve gradually concluded that I’m probably never ‘going back’ now that I’ve familiarized myself with the ICC server.

And yes, I do occasionally win against opposition like that, also on position – below an example from a recent game against a player not on the list above (there are quite a few anonymous title-holders as well on the server):

Click to view full size – the list to the lower left is a list of other players online on the server at that point in time, ordered by rating; as should be clear, lots of title-holders have relatively low ratings (I’m not completely sure which rating pool was displayed in the sidebar at that time, but the defaults on display for me are 5- or 3-minutes, so for example the international master ‘softrain’ thus had either a 3 or 5 minute rating of 1799 at that time. Do note that ICC requires proof for titles to display on the server; random non-titled players do not display as titleholders on the ICC (actually the formally approved titled accounts obviously do not account for all accounts held by title-holders as some titled players on the server use accounts which do not give away the fact that they have a title).

v. A few words I’ve recently encountered on Anaphora, usufruct, mimesis, amanuensis, peculate, elide, ataraxia, myrmidon, velleity.

vi. A few other wiki links: Fritz Haber, Great Stink (featured), Edward Low (a really nice guy, it seems – “A story describes Low burning a French cook alive, saying he was a “greasy fellow who would fry well”, and another tells he once killed 53 Spanish captives with his cutlass.[6]“), 1940 Soviet ultimatum to Lithuania (‘good article’).

vii. A really cute paper from the 2013 Christmas edition of the British Medical Journal: Were James Bond’s drinks shaken because of alcohol induced tremor? Here’s the abstract:

Objective To quantify James Bond’s consumption of alcohol as detailed in the series of novels by Ian Fleming.

Design Retrospective literature review.

Setting The study authors’ homes, in a comfy chair.

Participants Commander James Bond, 007; Mr Ian Lancaster Fleming.

Main outcome measures Weekly alcohol consumption by Commander Bond.

Methods All 14 James Bond books were read by two of the authors. Contemporaneous notes were taken detailing every alcoholic drink taken. Predefined alcohol unit levels were used to calculate consumption. Days when Bond was unable to consume alcohol (such as through incarceration) were noted.

Results After exclusion of days when Bond was unable to drink, his weekly alcohol consumption was 92 units a week, over four times the recommended amount. His maximum daily consumption was 49.8 units. He had only 12.5 alcohol free days out of 87.5 days on which he was able to drink.

Conclusions James Bond’s level of alcohol intake puts him at high risk of multiple alcohol related diseases and an early death. The level of functioning as displayed in the books is inconsistent with the physical, mental, and indeed sexual functioning expected from someone drinking this much alcohol. We advise an immediate referral for further assessment and treatment, a reduction in alcohol consumption to safe levels, and suspect that the famous catchphrase “shaken, not stirred” could be because of alcohol induced tremor affecting his hands.”

viii. A couple of other non-serious links which I found hilarious:
1) The Prof(essor) or Hobo quiz (via SSC).
2) Today’s SMBC. I’ll try to remember the words in the votey in the highly unlikely case I’ll ever have use for them – in my opinion it would be a real tragedy if one were to miss an opportunity to make a statement like that, given that it was at all suitable to the situation at hand..

July 6, 2015 Posted by | Chess, Diabetes, Epidemiology, History, Immunology, Infectious disease, Khan Academy, Lectures, Medicine, Personal | Leave a comment

Wikipedia articles of interest

i. Motte-and-bailey castle (‘good article’).

“A motte-and-bailey castle is a fortification with a wooden or stone keep situated on a raised earthwork called a motte, accompanied by an enclosed courtyard, or bailey, surrounded by a protective ditch and palisade. Relatively easy to build with unskilled, often forced labour, but still militarily formidable, these castles were built across northern Europe from the 10th century onwards, spreading from Normandy and Anjou in France, into the Holy Roman Empire in the 11th century. The Normans introduced the design into England and Wales following their invasion in 1066. Motte-and-bailey castles were adopted in Scotland, Ireland, the Low Countries and Denmark in the 12th and 13th centuries. By the end of the 13th century, the design was largely superseded by alternative forms of fortification, but the earthworks remain a prominent feature in many countries. […]

Various methods were used to build mottes. Where a natural hill could be used, scarping could produce a motte without the need to create an artificial mound, but more commonly much of the motte would have to be constructed by hand.[19] Four methods existed for building a mound and a tower: the mound could either be built first, and a tower placed on top of it; the tower could alternatively be built on the original ground surface and then buried within the mound; the tower could potentially be built on the original ground surface and then partially buried within the mound, the buried part forming a cellar beneath; or the tower could be built first, and the mound added later.[25]

Regardless of the sequencing, artificial mottes had to be built by piling up earth; this work was undertaken by hand, using wooden shovels and hand-barrows, possibly with picks as well in the later periods.[26] Larger mottes took disproportionately more effort to build than their smaller equivalents, because of the volumes of earth involved.[26] The largest mottes in England, such as Thetford, are estimated to have required up to 24,000 man-days of work; smaller ones required perhaps as little as 1,000.[27] […] Taking into account estimates of the likely available manpower during the period, historians estimate that the larger mottes might have taken between four and nine months to build.[29] This contrasted favourably with stone keeps of the period, which typically took up to ten years to build.[30] Very little skilled labour was required to build motte and bailey castles, which made them very attractive propositions if forced peasant labour was available, as was the case after the Norman invasion of England.[19] […]

The type of soil would make a difference to the design of the motte, as clay soils could support a steeper motte, whilst sandier soils meant that a motte would need a more gentle incline.[14] Where available, layers of different sorts of earth, such as clay, gravel and chalk, would be used alternatively to build in strength to the design.[32] Layers of turf could also be added to stabilise the motte as it was built up, or a core of stones placed as the heart of the structure to provide strength.[33] Similar issues applied to the defensive ditches, where designers found that the wider the ditch was dug, the deeper and steeper the sides of the scarp could be, making it more defensive. […]

Although motte-and-bailey castles are the best known castle design, they were not always the most numerous in any given area.[36] A popular alternative was the ringwork castle, involving a palisade being built on top of a raised earth rampart, protected by a ditch. The choice of motte and bailey or ringwork was partially driven by terrain, as mottes were typically built on low ground, and on deeper clay and alluvial soils.[37] Another factor may have been speed, as ringworks were faster to build than mottes.[38] Some ringwork castles were later converted into motte-and-bailey designs, by filling in the centre of the ringwork to produce a flat-topped motte. […]

In England, William invaded from Normandy in 1066, resulting in three phases of castle building in England, around 80% of which were in the motte-and-bailey pattern. […] around 741 motte-and-bailey castles [were built] in England and Wales alone. […] Many motte-and-bailey castles were occupied relatively briefly and in England many were being abandoned by the 12th century, and others neglected and allowed to lapse into disrepair.[96] In the Low Countries and Germany, a similar transition occurred in the 13th and 14th centuries. […] One factor was the introduction of stone into castle building. The earliest stone castles had emerged in the 10th century […] Although wood was a more powerful defensive material than was once thought, stone became increasingly popular for military and symbolic reasons.”

ii. Battle of Midway (featured). Lots of good stuff in there. One aspect I had not been aware of beforehand was that Allied codebreakers also here (I was quite familiar with the works of Turing and others in Bletchley Park) played a key role:

“Admiral Nimitz had one priceless advantage: cryptanalysts had partially broken the Japanese Navy’s JN-25b code.[45] Since the early spring of 1942, the US had been decoding messages stating that there would soon be an operation at objective “AF”. It was not known where “AF” was, but Commander Joseph J. Rochefort and his team at Station HYPO were able to confirm that it was Midway; Captain Wilfred Holmes devised a ruse of telling the base at Midway (by secure undersea cable) to broadcast an uncoded radio message stating that Midway’s water purification system had broken down.[46] Within 24 hours, the code breakers picked up a Japanese message that “AF was short on water.”[47] HYPO was also able to determine the date of the attack as either 4 or 5 June, and to provide Nimitz with a complete IJN order of battle.[48] Japan had a new codebook, but its introduction had been delayed, enabling HYPO to read messages for several crucial days; the new code, which had not yet been cracked, came into use shortly before the attack began, but the important breaks had already been made.[49][nb 8]

As a result, the Americans entered the battle with a very good picture of where, when, and in what strength the Japanese would appear. Nimitz knew that the Japanese had negated their numerical advantage by dividing their ships into four separate task groups, all too widely separated to be able to support each other.[50][nb 9] […] The Japanese, by contrast, remained almost totally unaware of their opponent’s true strength and dispositions even after the battle began.[27] […] Four Japanese aircraft carriers — Akagi, Kaga, Soryu and Hiryu, all part of the six-carrier force that had attacked Pearl Harbor six months earlier — and a heavy cruiser were sunk at a cost of the carrier Yorktown and a destroyer. After Midway and the exhausting attrition of the Solomon Islands campaign, Japan’s capacity to replace its losses in materiel (particularly aircraft carriers) and men (especially well-trained pilots) rapidly became insufficient to cope with mounting casualties, while the United States’ massive industrial capabilities made American losses far easier to bear. […] The Battle of Midway has often been called “the turning point of the Pacific”.[140] However, the Japanese continued to try to secure more strategic territory in the South Pacific, and the U.S. did not move from a state of naval parity to one of increasing supremacy until after several more months of hard combat.[141] Thus, although Midway was the Allies’ first major victory against the Japanese, it did not radically change the course of the war. Rather, it was the cumulative effects of the battles of Coral Sea and Midway that reduced Japan’s ability to undertake major offensives.[9]

One thing which really strikes you (well, struck me) when reading this stuff is how incredibly capital-intensive the war at sea really was; this was one of the most important sea battles of the Second World War, yet the total Japanese death toll at Midway was just 3,057. To put that number into perspective, it is significantly smaller than the average number of people killed each day in Stalingrad (according to one estimate, the Soviets alone suffered 478,741 killed or missing during those roughly 5 months (~150 days), which comes out at roughly 3000/day).

iii. History of time-keeping devices (featured). ‘Exactly what it says on the tin’, as they’d say on TV Tropes.

It took a long time to get from where we were to where we are today; the horologists of the past faced a lot of problems you’ve most likely never even thought about. What do you do for example do if your ingenious water clock has trouble keeping time because variation in water temperature causes issues? Well, you use mercury instead of water, of course! (“Since Yi Xing’s clock was a water clock, it was affected by temperature variations. That problem was solved in 976 by Zhang Sixun by replacing the water with mercury, which remains liquid down to −39 °C (−38 °F).”).

iv. Microbial metabolism.

Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics. The specific metabolic properties of a microbe are the major factors in determining that microbe’s ecological niche, and often allow for that microbe to be useful in industrial processes or responsible for biogeochemical cycles. […]

All microbial metabolisms can be arranged according to three principles:

1. How the organism obtains carbon for synthesising cell mass:

2. How the organism obtains reducing equivalents used either in energy conservation or in biosynthetic reactions:

3. How the organism obtains energy for living and growing:

In practice, these terms are almost freely combined. […] Most microbes are heterotrophic (more precisely chemoorganoheterotrophic), using organic compounds as both carbon and energy sources. […] Heterotrophic microbes are extremely abundant in nature and are responsible for the breakdown of large organic polymers such as cellulose, chitin or lignin which are generally indigestible to larger animals. Generally, the breakdown of large polymers to carbon dioxide (mineralization) requires several different organisms, with one breaking down the polymer into its constituent monomers, one able to use the monomers and excreting simpler waste compounds as by-products, and one able to use the excreted wastes. There are many variations on this theme, as different organisms are able to degrade different polymers and secrete different waste products. […]

Biochemically, prokaryotic heterotrophic metabolism is much more versatile than that of eukaryotic organisms, although many prokaryotes share the most basic metabolic models with eukaryotes, e. g. using glycolysis (also called EMP pathway) for sugar metabolism and the citric acid cycle to degrade acetate, producing energy in the form of ATP and reducing power in the form of NADH or quinols. These basic pathways are well conserved because they are also involved in biosynthesis of many conserved building blocks needed for cell growth (sometimes in reverse direction). However, many bacteria and archaea utilize alternative metabolic pathways other than glycolysis and the citric acid cycle. […] The metabolic diversity and ability of prokaryotes to use a large variety of organic compounds arises from the much deeper evolutionary history and diversity of prokaryotes, as compared to eukaryotes. […]

Many microbes (phototrophs) are capable of using light as a source of energy to produce ATP and organic compounds such as carbohydrates, lipids, and proteins. Of these, algae are particularly significant because they are oxygenic, using water as an electron donor for electron transfer during photosynthesis.[11] Phototrophic bacteria are found in the phyla Cyanobacteria, Chlorobi, Proteobacteria, Chloroflexi, and Firmicutes.[12] Along with plants these microbes are responsible for all biological generation of oxygen gas on Earth. […] As befits the large diversity of photosynthetic bacteria, there are many different mechanisms by which light is converted into energy for metabolism. All photosynthetic organisms locate their photosynthetic reaction centers within a membrane, which may be invaginations of the cytoplasmic membrane (Proteobacteria), thylakoid membranes (Cyanobacteria), specialized antenna structures called chlorosomes (Green sulfur and non-sulfur bacteria), or the cytoplasmic membrane itself (heliobacteria). Different photosynthetic bacteria also contain different photosynthetic pigments, such as chlorophylls and carotenoids, allowing them to take advantage of different portions of the electromagnetic spectrum and thereby inhabit different niches. Some groups of organisms contain more specialized light-harvesting structures (e.g. phycobilisomes in Cyanobacteria and chlorosomes in Green sulfur and non-sulfur bacteria), allowing for increased efficiency in light utilization. […]

Most photosynthetic microbes are autotrophic, fixing carbon dioxide via the Calvin cycle. Some photosynthetic bacteria (e.g. Chloroflexus) are photoheterotrophs, meaning that they use organic carbon compounds as a carbon source for growth. Some photosynthetic organisms also fix nitrogen […] Nitrogen is an element required for growth by all biological systems. While extremely common (80% by volume) in the atmosphere, dinitrogen gas (N2) is generally biologically inaccessible due to its high activation energy. Throughout all of nature, only specialized bacteria and Archaea are capable of nitrogen fixation, converting dinitrogen gas into ammonia (NH3), which is easily assimilated by all organisms.[14] These prokaryotes, therefore, are very important ecologically and are often essential for the survival of entire ecosystems. This is especially true in the ocean, where nitrogen-fixing cyanobacteria are often the only sources of fixed nitrogen, and in soils, where specialized symbioses exist between legumes and their nitrogen-fixing partners to provide the nitrogen needed by these plants for growth.

Nitrogen fixation can be found distributed throughout nearly all bacterial lineages and physiological classes but is not a universal property. Because the enzyme nitrogenase, responsible for nitrogen fixation, is very sensitive to oxygen which will inhibit it irreversibly, all nitrogen-fixing organisms must possess some mechanism to keep the concentration of oxygen low. […] The production and activity of nitrogenases is very highly regulated, both because nitrogen fixation is an extremely energetically expensive process (16–24 ATP are used per N2 fixed) and due to the extreme sensitivity of the nitrogenase to oxygen.” (A lot of the stuff above was of course for me either review or closely related to stuff I’ve already read in the coverage provided in Beer et al., a book I’ve talked about before here on the blog).

v. Uranium (featured). It’s hard to know what to include here as the article has a lot of stuff, but I found this part in particular, well, interesting:

“During the Cold War between the Soviet Union and the United States, huge stockpiles of uranium were amassed and tens of thousands of nuclear weapons were created using enriched uranium and plutonium made from uranium. Since the break-up of the Soviet Union in 1991, an estimated 600 short tons (540 metric tons) of highly enriched weapons grade uranium (enough to make 40,000 nuclear warheads) have been stored in often inadequately guarded facilities in the Russian Federation and several other former Soviet states.[12] Police in Asia, Europe, and South America on at least 16 occasions from 1993 to 2005 have intercepted shipments of smuggled bomb-grade uranium or plutonium, most of which was from ex-Soviet sources.[12] From 1993 to 2005 the Material Protection, Control, and Accounting Program, operated by the federal government of the United States, spent approximately US $550 million to help safeguard uranium and plutonium stockpiles in Russia.[12] This money was used for improvements and security enhancements at research and storage facilities. Scientific American reported in February 2006 that in some of the facilities security consisted of chain link fences which were in severe states of disrepair. According to an interview from the article, one facility had been storing samples of enriched (weapons grade) uranium in a broom closet before the improvement project; another had been keeping track of its stock of nuclear warheads using index cards kept in a shoe box.[45]

Some other observations from the article below:

“Uranium is a naturally occurring element that can be found in low levels within all rock, soil, and water. Uranium is the 51st element in order of abundance in the Earth’s crust. Uranium is also the highest-numbered element to be found naturally in significant quantities on Earth and is almost always found combined with other elements.[10] Along with all elements having atomic weights higher than that of iron, it is only naturally formed in supernovae.[46] The decay of uranium, thorium, and potassium-40 in the Earth’s mantle is thought to be the main source of heat[47][48] that keeps the outer core liquid and drives mantle convection, which in turn drives plate tectonics. […]

Natural uranium consists of three major isotopes: uranium-238 (99.28% natural abundance), uranium-235 (0.71%), and uranium-234 (0.0054%). […] Uranium-238 is the most stable isotope of uranium, with a half-life of about 4.468×109 years, roughly the age of the Earth. Uranium-235 has a half-life of about 7.13×108 years, and uranium-234 has a half-life of about 2.48×105 years.[82] For natural uranium, about 49% of its alpha rays are emitted by each of 238U atom, and also 49% by 234U (since the latter is formed from the former) and about 2.0% of them by the 235U. When the Earth was young, probably about one-fifth of its uranium was uranium-235, but the percentage of 234U was probably much lower than this. […]

Worldwide production of U3O8 (yellowcake) in 2013 amounted to 70,015 tonnes, of which 22,451 t (32%) was mined in Kazakhstan. Other important uranium mining countries are Canada (9,331 t), Australia (6,350 t), Niger (4,518 t), Namibia (4,323 t) and Russia (3,135 t).[55] […] Australia has 31% of the world’s known uranium ore reserves[61] and the world’s largest single uranium deposit, located at the Olympic Dam Mine in South Australia.[62] There is a significant reserve of uranium in Bakouma a sub-prefecture in the prefecture of Mbomou in Central African Republic. […] Uranium deposits seem to be log-normal distributed. There is a 300-fold increase in the amount of uranium recoverable for each tenfold decrease in ore grade.[75] In other words, there is little high grade ore and proportionately much more low grade ore available.”

vi. Radiocarbon dating (featured).

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method of determining the age of an object containing organic material by using the properties of radiocarbon (14C), a radioactive isotope of carbon. The method was invented by Willard Libby in the late 1940s and soon became a standard tool for archaeologists. Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire 14C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of 14C it contains begins to reduce as the 14C undergoes radioactive decay. Measuring the amount of 14C in a sample from a dead plant or animal such as piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less 14C there is to be detected, and because the half-life of 14C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.

The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. […]

The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than did previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the “radiocarbon revolution”.”

I’ve read about these topics before in a textbook setting (e.g. here), but/and I should note that the article provides quite detailed coverage and I think most people will encounter some new information by having a look at it even if they’re superficially familiar with this topic. The article has a lot of stuff about e.g. ‘what you need to correct for’, which some of you might find interesting.

vii. Raccoon (featured). One interesting observation from the article:

“One aspect of raccoon behavior is so well known that it gives the animal part of its scientific name, Procyon lotor; “lotor” is neo-Latin for “washer”. In the wild, raccoons often dabble for underwater food near the shore-line. They then often pick up the food item with their front paws to examine it and rub the item, sometimes to remove unwanted parts. This gives the appearance of the raccoon “washing” the food. The tactile sensitivity of raccoons’ paws is increased if this rubbing action is performed underwater, since the water softens the hard layer covering the paws.[126] However, the behavior observed in captive raccoons in which they carry their food to water to “wash” or douse it before eating has not been observed in the wild.[127] Naturalist Georges-Louis Leclerc, Comte de Buffon, believed that raccoons do not have adequate saliva production to moisten food thereby necessitating dousing, but this hypothesis is now considered to be incorrect.[128] Captive raccoons douse their food more frequently when a watering hole with a layout similar to a stream is not farther away than 3 m (10 ft).[129] The widely accepted theory is that dousing in captive raccoons is a fixed action pattern from the dabbling behavior performed when foraging at shores for aquatic foods.[130] This is supported by the observation that aquatic foods are doused more frequently. Cleaning dirty food does not seem to be a reason for “washing”.[129] Experts have cast doubt on the veracity of observations of wild raccoons dousing food.[131]

And here’s another interesting set of observations:

“In Germany—where the racoon is called the Waschbär (literally, “wash-bear” or “washing bear”) due to its habit of “dousing” food in water—two pairs of pet raccoons were released into the German countryside at the Edersee reservoir in the north of Hesse in April 1934 by a forester upon request of their owner, a poultry farmer.[186] He released them two weeks before receiving permission from the Prussian hunting office to “enrich the fauna.” [187] Several prior attempts to introduce raccoons in Germany were not successful.[188] A second population was established in eastern Germany in 1945 when 25 raccoons escaped from a fur farm at Wolfshagen, east of Berlin, after an air strike. The two populations are parasitologically distinguishable: 70% of the raccoons of the Hessian population are infected with the roundworm Baylisascaris procyonis, but none of the Brandenburgian population has the parasite.[189] The estimated number of raccoons was 285 animals in the Hessian region in 1956, over 20,000 animals in the Hessian region in 1970 and between 200,000 and 400,000 animals in the whole of Germany in 2008.[158][190] By 2012 it was estimated that Germany now had more than a million raccoons.[191]

June 14, 2015 Posted by | Archaeology, Biology, Botany, Geology, History, Microbiology, Physics, Wikipedia, Zoology | Leave a comment