Econstudentlog

God’s utility function

“The total amount of suffering per year in the natural world is beyond all decent contemplation. During the minute that it takes me to compose this sentence, thousands of animals are being eaten alive, many others are running for their lives, whimpering with fear, others are slowly being devoured from within by rasping parasites, thousands of all kinds are dying of starvation, thirst and disease. It must be so. If there is ever a time of plenty, this very fact will automatically lead to an increase in population until the natural state of starvation and misery is restored. In a universe of electrons and selfish genes, blind physical forces and genetic replication, some people are going to get hurt, other people are going to get lucky, and you won’t find any rhyme or reason in it, nor any justice. The universe that we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil and no good, nothing but pitiless indifference. As that unhappy poet A. E. Housman put it:

For nature, heartless, witless nature
Will neither care nor know

DNA neither cares nor knows. DNA just is. And we dance to its music.”

Richard Dawkins, here’s the link. I recently read that Leslie Nielsen has died. The day he did, so did more than 150.000 other humans alone.

November 29, 2010 Posted by | quotes/aphorisms | Leave a comment

The language of science

Some common phrases in scientific papers and what they really mean (here’s the link, via Ed Yong):

“It can be shown”

Somebody said they did this, but I can’t duplicate their results. I can’t even find the reference, or else I would have cited that instead. [In economics, this phrase has a lot of different meanings, depending on who the writer or lecturer is. Usually I translate that sentence simply by adding an apostrophe and a t – US]

“Of great theoretical and practical importance”

Means it is interesting to me or else I want it to be interesting to somebody with money so they will fund my research.

“The most reliable results are those obtained by Smith.”

Smith is or was my graduate research assistant.

“It is believed that…”

I think this (and either no one agrees with me or else I didn’t consult anyone).

“It is generally believed that”

I think this and at least one other person agrees with me.

“Additional work will be required to elucidate the mechanism”

I don’t have a clue what is going on and I’m not going to be the one to figure it out.

November 25, 2010 Posted by | science | Leave a comment

Wikipedia articles of interest

1. Evolutionary history of plants.

“Evidence suggests that an algal scum formed on the land 1,200 million years ago, but it was not until the Ordovician period, around 450 million years ago, that land plants appeared.”

The period before 450 million years ago of course covers more than 9/10ths of the history of the Earth.

“The early Devonian landscape was devoid of vegetation taller than waist height. Without the evolution of a robust vascular system, taller heights could not be attained. There was, however, a constant evolutionary pressure to attain greater height. The most obvious advantage is the harvesting of more sunlight for photosynthesis – by overshadowing competitors – but a further advantage is present in spore distribution, as spores (and, later, seeds) can be blown greater distances if they start higher.”

However plants didn’t stay short for long: “the late Devonian Archaeopteris, a precursor to gymnosperms which evolved from the trimerophytes,[38] reached 30 m in height.”

Here’s what the Earth looked like back then (Wikipedia, link):

This is all part of why it’s so difficult to imagine what earth was like when you go millions of years back in time. We take so many things in our environment for granted. Grasses as we know them didn’t come about until somewhere around the K-T boundary.

2. Acid-base reaction

“An acid-base reaction is a chemical reaction, that occurs between an acid and a base. Several concepts that provide alternative definitions for the reaction mechanisms involved and their application in solving related problems exist. Despite several differences in definitions, their importance becomes apparent as different methods of analysis when applied to acid-base reactions for gaseous or liquid species, or when acid or base character may be somewhat less apparent.”

There are quite a few different theories described in the article, I didn’t know that I didn’t know this. The article contains a brilliant example of a case where ‘everybody knew that this theory was true until it was proven wrong’:

“The first scientific concept of acids and bases was provided by Antoine Lavoisier circa 1776. Since Lavoisier’s knowledge of strong acids was mainly restricted to oxoacids, such as HNO3 (nitric acid) and H2SO4 (sulfuric acid), which tend to contain central atoms in high oxidation states surrounded by oxygen, and since he was not aware of the true composition of the hydrohalic acids (HF, HCl, HBr (hydrogen fluroide), and HI) (hydrogen iodide), he defined acids in terms of their containing oxygen, which in fact he named from Greek words meaning “acid-former” (from the Greek οξυς (oxys) meaning “acid” or “sharp” and γεινομαι (geinomai) meaning “engender”). The Lavoisier definition was held as absolute truth for over 30 years, until the 1810 article and subsequent lectures by Sir Humphry Davy in which he proved the lack of oxygen in H2S, H2Te, and the hydrohalic acids.”

3. Anglo-Zulu War. This article is part of the featured British Empire Portal, which contains quite a few articles I’ll probably have to read at some point. As written in the introduction to the portal: “By 1921, the British Empire held sway over a population of about 458 million people, approximately one-quarter of the world’s population. It covered about 36.6 million km² (14.2 million square miles), about a quarter of Earth’s total land area.” If you want to understand the world of 100 years ago, or the world some time before that, you really can’t ignore the history of the British Empire.

4. Medieval technology. Mostly links, but there are lots of them, and I’d guess there are quite a few good articles hidden here. Did you know that functional buttons – buttons with buttonholes for fastening or closing clothes – wasn’t invented until the 13th century?

November 24, 2010 Posted by | biology, Chemistry, Geology, history, Paleontology, wikipedia | 2 Comments

Quotes

1. “Some would ask, how could a perfect God create a universe filled with so much that is evil. They have missed a greater conundrum: why would a perfect God create a universe at all?”

Sister Miriam Godwinson – “But for the Grace of God”, Sid Meiers Alpha Centauri. Because he was bored? would be a snarky but ineffective reply; why/how the ¤%#$ would an all-powerful being be bored – isn’t that like a contradiction in terms? ‘Well, someone had to do it…’ doesn’t really work either.

2. “Ancient people came up with some amazing ideas, like how to make fire, tools, and languages. Those ideas have stuck around, and become integrated in our daily lives to the point where they barely seem like knowledge anymore. The great thing is that we don’t have to read ancient cave writings to be reminded that fire can keep us warm; we simply haven’t forgotten. That’s why more people agree that fire can heat your home than on how the universe began.”

Academian.

3. “The only people we call ‘normal’ are people we don’t really know.”

Kelly Oxford. Kind of like a social version of the Heisenberg uncertainty principle.

I was somewhat preoccupied with what constituted normality in my childhood because I didn’t consider myself part of it, because of my diabetes; for instance normal children were allowed to eat a birthday cake with chocolate.* ‘Normal’ was something other people were, but probably not all other people, so I often asked my parents what was ‘normal’ in other areas and my parents didn’t really seem to know the answer, or they just didn’t answer – I figured it was because the concept wasn’t well-defined. I’m pretty sure it isn’t.

4. “The mind is not a vessel to be filled, but a fire to be kindled.” Plutarch.

5. “In these several schools let there be dwellings for teachers, who shall be brought from foreign parts by pay, and let them teach those who attend the schools the art of war and the art of music, and the children shall come not only if their parents please, but if they do not please; there shall be compulsive education, as the saying is, of all and sundry, as far this is possible; and the pupils shall be regarded as belonging to the state rather than to their parents.”

Plato, The Laws.

6. “The problem with people who have no vices is that generally you can be pretty sure they’re going to have some pretty annoying virtues.”

Elizabeth Taylor.

7. “He has fought a good fight and has had to face every difficulty except popularity.”

Oscar Wilde.

*{It turned out to be a rather long note, which is why I put it here. Anyway…} That was before intensive insulinotherapy. Until I started that treatment regime in secondary school, I basically took insulin and then decided how much to eat based on that – after I started on II I’ve now been able to, at least to a much greater degree, decide how hungry I am and then take insulin to match the food intake, instead of the other way around. Type 1 diabetics who are not on intensive insulinotherapy or something equivalent (pump, ect.) have a much more limited decision-making range when it comes to what and when to eat – they can’t do like normal people who just eat when they’re hungry. Physical exercise poses similar problems, I could never have run the marathon if I’d been on conventional insulinotherapy. People on CI take relatively slow-working insulin, often of a type that’s programmed to peak at specific points during the day, corresponding to standard meal times. Miss a meal and you’ll end up hypoglycemic, whether you were hungry or not (though that problem of lack of appetite is less of a problem than the problem that would arise if no food is available at the time where the insulin level peaks – a diabetic about to go into shock feels like he’s about to die of hunger, because that’s what (/s)he is). On CI, if you adjust a dose in the morning because you need to go for a run in an hour, it’ll have consequenses for your bloodsugar at dinner 12 hours later. I got on II pretty much because it was no longer possible for me to live anything resembling a normal life on the CI treatment regimen; I was quite physically active at that time, and there was simply no way to tweak the doses so that I didn’t end up in the hospital regularly. II is a much more common treatment regime in developed countries like Denmark than it is in poor countries.

November 22, 2010 Posted by | diabetes, quotes/aphorisms | Leave a comment

Book recommendations(?)

I’m about to send out my Christmas wish list. A few of the books on the list so far:

1. ‘Reflections; or Sentences and Moral Maxims’ – François de La Rochefoucauld. I know I could just print it out, as it’s available online, but I’d rather have a book. I hate to read books online, so I haven’t even completed it yet, though I really love that book.

2. ‘The Devil’s dictionary’ – Ambrose Bierce. (-ll-, apart from the ‘haven’t completed it yet’, I have, but it was a lot of work. Strange how much more difficult it is for me to read a book online than it is to read other online stuff like, say, wikipedia articles. I don’t quite get how it works, but I’ll never like reading books online, it’s an unpleasant experience.)

3. ‘The Aeneid’ – Virgil.

4. [a lot of Discworld books]

5. In search of lost time – Proust (not necessarily all volumes, but..)

6. A Short History of Nearly Everything – Bryson. I’ve already read this book as I borrowed it from my big brother at one point, but at the time I considered it one of the best books I’d ever read and I want it on my book shelf.

What else should be on that list? I should probably add that I have added books recommended by readers to my wish lists before, on more than one occasion. Actually I believe both Proust and Virgil are on the list as a result of reader recommendations, though it gets difficult over time to remember stuff like that. I read less books now than I did a year ago but I usually read a lot during the vacations, so don’t be afraid to recommend something that takes a couple of days to get through. [When using the words ‘a couple of days’ I don’t mean the time it would take if I read an hour a day or something like that; ‘a couple of days’ could be 30-40 hours of reading. I read the last 2/3rds-3/4ths of The Complete Sherlock Holmes in ~4 days during the Summer, and I read more than 12 hours/day a couple of those days – if it’s a good book, the time component doesn’t matter all that much.]

November 21, 2010 Posted by | books, random stuff | 8 Comments

Wikipedia articles of interest

1. Trajan.

Roman Emperor from 98 AD to 117 AD. This is what the Roman Empire looked like at the end of his reign:

You can file this one under: ‘Yet more stuff I should have learned something about when I was younger.’ Before I started at the university, I learned a lot of the stuff the various schools I was enrolled in had to offer – but I didn’t learn much outside school. I really dislike now that I wasted so much time back then. I still do, btw., ie. waste a lot of time – old habits die hard but it’s better than it used to be. No, it’s not that I consider all the time that is spent not collecting knowledge like this wasted, no way; I just don’t have all that many better things to be doing with my time when I’m not doing the stuff I have to do, like studying the stuff that’s actually related to my exams, so my tradeoffs don’t look quite like those of a more ordinary person – who might have, say, a lot of what might be termed ‘social obligations’. I think of reading stuff like this as somehow more virtuous than reading tv-tropes or kibitzing a game of chess between two GMs and most certainly more virtuous than watching an episode of House, which I also happen to be doing every now and then.
Robin Lane Fox did include Trajan’s ruling period in his book but it’s been a while since I read that anyway and there wasn’t a lot of stuff about that guy in there. Here’s one sentence, perhaps not exactly displaying Trajan in the best possible light: “Between May 107 and November 109 Trajan celebrated his conquest of Dacia (modern Romania) with more than twenty weeks of blood sports, showing more than 5,500 pairs of gladiators and killing over 11,000 animals.” Though it should probably also be noted that such ‘blood sports’ were quite popular among the populace as well back then. (how much did I actually quote from that book here on the blog back when I’d read it? I now think perhaps my coverage of the book back then was somewhat lacking, perhaps I should have included more stuff? Well, it’s not too late, if I get ’round to it, maybe..).

2. Ants. File under: ‘These guys are pretty amazing’. There are more than four times as many estimated ant species (22.000) as there are species of mammals combined (5.400) – more than 12.500 ant species have already been classified. They’ve been around for more than 100 million years:

“Ants evolved from a lineage within the vespoid wasps. Phylogenetic analysis suggests that ants arose in the mid-Cretaceous period about 110 to 130 million years ago. After the rise of flowering plants about 100 million years ago they diversified and assumed ecological dominance around 60 million years ago.”

According to one of the source articles to the article:

“Ants are arguably the greatest success story in the history of terrestrial metazoa. On average, ants monopolize 15–20% of the terrestrial animal biomass, and in tropical regions where ants are especially abundant, they monopolize 25% or more.”

3. Cell.

4. Autoregressive model. ‘The type of stuff people like me work with on a near-daily basis’. [‘economics? That’s a bit like philosophy, right?’ – I got that comment once not long ago out in the Real World. In some ways it kinda is, sort of, or there are at least some elements the two systems have in common within relevant subsystems; but if you actually ask a question like that the answer will always be ‘No’.]

5. International Space Station. A featured article. Some stats:

Mass: 369,914 kg
Length: 51 m
Width: 109 m

“The cost of the station has been estimated by ESA as €100 billion over 30 years,[25] and, although estimates range from 35 to 160 billion US dollars, the ISS is believed to be the most expensive object ever constructed.”

The link [25] in the article states that: “The European share, at around 8 billion Euros spread over the whole programme, amounts to just one Euro spent by every European every year…”

November 18, 2010 Posted by | biology, econometrics, history, statistics, wikipedia | Leave a comment

A game

I’ve put it up here, doesn’t require Java. I was black. The computer much preferred 29…fxg4 to …f4, but it’s an eval difference between -3,5 and -2, so basically both moves are winning – actually the position was won long before this move was played. No other moves were much disliked by the machine and I played much better here than I did last time I played a game in the club. Moves below, just in case the game is removed from the server later on you can always plug it into a pgn-viewer if you’re curious:

1.d4 Nf6
2.Nf3 g6
3.b3 d5
4.Bb2 Bg7
5.Nbd2 0-0
6.e3 c5
7.Be2 b6
8.0-0 Bb7
9.Rb1 Nbd7
10.a3 Rc8
11.Ne5 Nxe5
12.dxe5 Ne4
13.Nxe4 dxe4
14.Qc1 Qd5
15.c4 Qe6
16.Qc3 Rcd8
17.Rfd1 Bc6
18.a4 a5
19.Ba1 Rd6
20.Rxd6 exd6
21.Qe1 Bxe5
22.Bxe5 Qxe5
23.g3 d5
24.Qc1 d4
25.Bf1 d3 (if the position wasn’t already won for black by move 22, it certainly is now. My opponent plays on roughly another 10 moves though)
26.Qd2 h5
27.Bg2 h4
28.g4 f5
29.h3 f4
30.Rb2 fxe3
31.fxe3 Qg3
32.Ra2 Rf3
33.Kh1 Rxe3
34.Qc3 Re1+

Resigned, 0-1

Yes, in case you were in doubt I have trouble sleeping.

November 18, 2010 Posted by | Chess | Leave a comment

The problem

1. Optimize total societal utility conditional on the relevant budget constraints.

2. -ll- utility conditional on the relevant budget constraints and conditional on optimizing behaviour of households and firms.

3. Maximize utility of public employees conditional on political demands, the government budget constraint and optimizing behaviour of households and firms.

4. Maximize utility of public employees conditional on political demands, the government budget constraint and estimates of the empirically relevant compositions of sets of optimizing and non-optimizing behaviour of households and firms (nominal rigidities, information asymmetries, market imperfections in general, hyperbolic discounting, ect.).

5. Maximize utility of public employees in your own Department conditional on likelihood of re-election of the minister in charge of the Department, his incentives (Maximize Department size), the time constraint, the minimal amount of useful/relevant data, department size…

6. Maximize career prospects conditional on current and future likely office coalitions, risk of job-loss, future wage, Department size…

7. Maximize personal utility conditional on the utility set and behaviour of the rest of the Departmental employees as well as decisionmakers in other Departments with influence over personal utility, likelihood of re-election of all politicians relevant to the decisionmaking process…

8. Maximize… – holy s$#@, I forgot that I had to pick up the kid from day care!

If I could draw, I’d have made a cartoon.

November 17, 2010 Posted by | random stuff | Leave a comment

Why people talk so much and listen so little?

Today’s dilbert cartoon. I’m reminded of Kelly Oxford’s recent tweet: “I’d be less introverted if the conversations in my head weren’t better than the conversations I have with other people.”

Maybe I’d rather state it somewhat like this: “As long as I only have the conversations in my own head, I can’t tell how stupid I sound when I say something – which makes me feel much better than if I actually talk.” I neither talk much with nor listen much to other people, so that tradeoff is much less relevant than the other, but anyway…

November 16, 2010 Posted by | random stuff | Leave a comment

Wikipedia articles of interest

1. Allopatric speciation.

“Allopatric speciation (from the ancient Greek allos, “other” + Greek patrā, “fatherland”) or geographic speciation is speciation that occurs when biological populations of the same species become isolated due to geographical changes such as mountain building or social changes such as emigration. The isolated populations then undergo genotypic and/or phenotypic divergence as: (a) they become subjected to different selective pressures, (b) they independently undergo genetic drift, and (c) different mutations arise in the populations’ gene pools.[1] The separate populations over time may evolve distinctly different characteristics. If the geographical barriers are later removed, members of the two populations may be unable to successfully mate with each other, at which point, the genetically isolated groups have emerged as different species.”

2. Oradour-sur-Glane. Lots of ugly stuff was going on behind the lines on the eastern front. But very bad things happened in Western Europe too. As well as thousands of kilometers to the east as well. This link has a lot of stuff you probably don’t want to know about Japanese war crimes. Here’s one bit:

“If you were a Nazi prisoner of war from Britain, America, Australia, New Zealand or Canada (but not Russia) you faced a 4% chance of not surviving the war; [by comparison] the death rate for Allied POWs held by the Japanese was nearly 30%.”

“According to the findings of the Tokyo Tribunal, the death rate among POWs from Asian countries, held by Japan was 27.1%.[25] The death rate of Chinese POWs was much higher because—under a directive ratified on August 5, 1937 by Emperor Hirohito—the constraints of international law on treatment of those prisoners was removed.[26] Only 56 Chinese POWs were released after the surrender of Japan.[27] After March 20, 1943, the Japanese Navy was under orders to execute all prisoners taken at sea.[28]”

3. Gossypiboma.

“Gossypiboma or textiloma is the technical term for a surgical complications resulting from foreign materials, such as a surgical sponge, accidentally left inside a patient’s body. The term “gossypiboma” is derived from the Latin gossypium (cotton) and the Swahili boma (place of concealment) and describes a mass within a patient’s body comprising a cotton matrix surrounded by a foreign body granuloma.[1][2] “Textiloma” is derived from textile (surgical sponges have historically been made of cloth) and the suffix “-oma”, meaning a tumor or growth, and is used in place of gossypiboma due to the increasing use of synthetic materials in place of cotton.[1]”

[…]

“The actual incidence of gossypiboma is difficult to determine, possibly due to a reluctance to report occurrences arising from fear of legal repercussions, but retained surgical sponges is reported to occur once in every 3000 to 5000 abdominal operations[2] and are most frequently discovered in the abdomen.[3] The incidence of retained foreign bodies following surgery has a reported rate of 0.01% to 0.001%, of which gossypibomas make up 80% of cases.”

This study stated that: “The incidence of surgical sponge being retained during operation is difficult to estimate, but it has been reported as 1 in 100-3000 for all surgical interventions and 1 in 1000-1500 for intra-abdominal operations[4]. Retained sponges are most frequently observed in patients with obesity, during emergency operations[6] and following laparoscopic interventions[7]. Retained sponges are most frequently observed in patients with obesity, during emergency operations [6] and following laparoscopic interventions.”

Notice the high bound estimate (1 in 100) in that quote, it’s much higher than the wikipedia stat. There seems to be huge uncertainty as to just how great this problem is. If you want to avoid it, don’t be fat, don’t have emergency surgery and avoid minimally invasive surgery/laparoscopic procedures.

4. Hadley cell.

For those who’ve only had geography in Danish, the ‘trade winds‘ mentioned in the article are what we call ‘passat-vindene’ in Denmark.

5. Pont du Gard.

While reading a bit about sanitation in Ancient Rome, I followed the link to the article, then the thought struck me: ‘I’ve been there’. Maybe I haven’t, but I certainly might have been; I was in Provence with the family many, many years ago and I (now) remember that we saw a huge aqueduct like this.

November 15, 2010 Posted by | biology, genetics, Geography, history, medicine, wikipedia | 2 Comments

Another video

Reminds me a lot of the ‘campaign to get rid of dihydrogen monoxide’ I saw a while ago. Some will laugh, some will cry, I thought it was pretty funny:

Nobody likes to look stupid, perhaps smart people in particular don’t because they’ve invested more in their ‘I’m smart’ (/self-)image, and not knowing what a word means makes you look stupid. Better to sign quickly and that way ‘hide the stupidity’, it always works whenever the petition isn’t a prank petition like this one. I don’t consider the ‘National School of Excellence’ part to be all that significant, I’d been surprised if he’d been unable to coax some of those girls into signing the petition (anyway if that’d been the case, there’d been no video).

In school one of the primary things people learn is that they’re supposed to be able to answer most of the teacher’s questions. If they can’t, it’s usually because they haven’t done their homework. If you ask people about stuff that they think they’re somehow ‘supposed to know about’, expect to get a lot more wrong guesses than if you ask them about stuff they don’t think they’re supposed to know about. Granted, if you ask school kids who are in a school that’s supposed to be for smart people, expect them to think that they ought to know everything. Not knowing the answer either means you haven’t done your homework or that you’re stupid and both those options make you look bad.

November 12, 2010 Posted by | stupidity | Leave a comment

A video

The previous video in the series, which he mentions a few times, is here. And of course there’s a lot more here, under the ‘Biology’ section.

November 11, 2010 Posted by | biology, Khan Academy, Lectures | Leave a comment

Quotes

1. “He was so learned that he could name a horse in nine languages; so ignorant that he bought a cow to ride on.” (Benjamin Franklin)

2. “Whoever shall maintain that wrong is done to heretics and blasphemers in punishing them makes himself an accomplice in their crime and guilty as they are. There is no question here of man’s authority; it is God who speaks, and clear it is what law he will have kept in the church, even to the end of the world. Wherefore does he demand of us a so extreme severity, if not to show us that due honor is not paid him, so long as we set not his service above every human consideration, so that we spare not kin, nor blood of any, and forget all humanity when the matter is to combat for His glory.” (John Calvin, the link has some context.)

3. “Bad books on writing and thoughtless English professors solemnly tell beginners to write what you know, which explains why so many mediocre novels are about English professors contemplating adultery.” (Joe Haldeman, warning: TV Tropes link!)

4. “Man is not a rational animal, he is a rationalizing animal.” (Robert Heinlein. Maybe it’s a repeat, but I don’t think so – though I know I’ve said the same thing myself at multiple occasions.)

5. “Delusions are often functional. A mother’s opinions about her children’s beauty, intelligence, goodness, et cetera ad nauseam, keep her from drowning them at birth.” (-ll-)

6. “Men rarely (if ever) manage to dream up a god superior to themselves. Most gods have the manners and morals of a spoiled child.” (-ll-)

7. “Being poor is a full time job.” (Kelly Oxford. Here’s her twitter account.)

8. “Liquid: I’ve been up all night doing research.
Ocelot: Research? On what?
Liquid: Well, it was supposed to be on the current geopolitics of modern nuclear weaponry.
Ocelot: This is a Wikipedia page about Mick Jagger.
Liquid: I got slightly sidetracked.
—The Last Days Of FOXHOUND”

(TV Tropes. Well, I can certainly relate. Would never be caught dead reading about someone/-thing like Mick Jagger though. Much more likely I’d actually be reading an article on ‘the current geopolitics of modern nuclear weaponry’, if I ever were to have this conversation with anyone – but then again, if so that subject wouldn’t have been what I’d intended to be reading about in the first place. Most likely I’d have started somewhere like this, or this. Or – the flattering version – this.).

November 4, 2010 Posted by | quotes/aphorisms | Leave a comment

Wikipedia articles of interest

1. Bessemer process.

“The Bessemer process was the first inexpensive industrial process for the mass-production of steel from molten pig iron. The process is named after its inventor, Henry Bessemer, who took out a patent on the process in 1855. The process was independently discovered in 1851 by William Kelly.[1][2] The process had also been used outside of Europe for hundreds of years, but not on an industrial scale.[3] The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten.”

[…]

“The Bessemer process revolutionized steel manufacture by decreasing its cost, from £40 per long ton to £6-7 per long ton during its introduction, along with greatly increasing the scale and speed of production of this vital raw material. The process also decreased the labor requirements for steel-making. Prior to its introduction, steel was far too expensive to make bridges or the framework for buildings and thus wrought iron had been used throughout the Industrial Revolution. After the introduction of the Bessemer process, steel and wrought iron became similarly priced, and most manufacturers turned to steel. The availability of cheap steel allowed large bridges to be built and enabled the construction of railroads, skyscrapers, and large ships.”

2. Neighborhoods of Chicago.

This is so cool! This is just one of the links, here’s another. Imagine how long it would take to get a standard book/paper-encyclopedia published if it were to contain information on this scale. Google earth is not the only thing that revolutionizes our potential knowledge of stuff like this at the moment.

3. Harmonic mean.

“In mathematics, the harmonic mean (sometimes called the subcontrary mean) is one of several kinds of average. Typically, it is appropriate for situations when the average of rates is desired.”

I’ve omitted the formula because wordpress isn’t a very good tool to use when it comes to mathematical stuff such as this. Go have a look if you’re interested. If you have children that are in school and get math problems about, say, calculating the average speed of a car trip – I know I got that kind of problems back then – which they have trouble solving, this is a good tool to know. Do note that “the arithmetic mean is often mistakenly used in places calling for the harmonic mean.”

4. Battle of Borodino. Why you should know about something like this? Well, it might be useful if you ever get into an argument with coal miners from Llanddarog

5. Hooke’s law.

“In mechanics, and physics, Hooke’s law of elasticity is an approximation that states that the extension of a spring is in direct proportion with the load applied to it. Many materials obey this law as long as the load does not exceed the material’s elastic limit. Materials for which Hooke’s law is a useful approximation are known as linear-elastic or “Hookean” materials. Hooke’s law in simple terms says that strain is directly proportional to stress.”

November 2, 2010 Posted by | economic history, history, mathematics, Physics, wikipedia | Leave a comment