Econstudentlog

Wikipedia articles of interest

i. Llama. From the article:

“Llamas have an unusual reproductive cycle for a large animal. Female llamas are induced ovulators. Through the act of mating, the female releases an egg and is often fertilized on the first attempt. Female llamas do not go into “heat” or have an estrus cycle.[5]

Like humans, llama males and females mature sexually at different rates. Females reach puberty at approximately 12 months. However, males do not become sexually mature until approximately 3 years.[6]

Mating

Llamas mate with the female in a kush (lying down) position, which is fairly unusual in a large animal. They mate for an extended period of time (20–45 minutes), also unusual in a large animal.” [...]

“Llamas which are well-socialized and trained to halter and lead after weaning are very friendly and pleasant to be around. They are extremely curious and most will approach people easily. However, llamas that are bottle-fed or over-socialised and over-handled as youngsters will become extremely difficult to handle when mature, when they will begin to treat humans as they treat each other, which is characterized by bouts of spitting, kicking and neck wrestling. Anyone having to bottle-feed a cria should keep contact to a minimum and stop as soon as possible.” [...]

“Using llamas as livestock guards in North America began in the early 1980s and some sheep producers have used llamas successfully since then.[16][17] They are used most commonly in the in western regions of the US where larger predators such as the coyote are prevalent. Typically a single gelding (castrated male) is used.

Research suggests the use of multiple guard llamas is not as effective as one llama. Multiple male llamas tend to bond with one another, rather than with the livestock, and may ignore the flock. A gelded male of two years of age bonds closely with its new charges and is instinctively very effective in preventing predation. Some llamas appear to bond more quickly to sheep or goats if they are introduced just prior to lambing. Many sheep and goat producers indicate a special bond quickly develops between lambs and their guard llama and that the llama is particularly protective of the lambs.”

I had no clue people use animals like llamas to guard livestock.

ii. Dreyfus affair.

iii. Fibonacci number.

“In mathematics, the Fibonacci numbers are the numbers in the following integer sequence:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, … (sequence A000045 in OEIS).

By definition, the first two Fibonacci numbers are 0 and 1, and each subsequent number is the sum of the previous two.”

The article is a bit technical but it has a lot more on the subject.

iv. Norman conquest of southern Italy. Also, this. A map from the article (text: “The Kingdom of Sicily (in green) in 1154, representing the extent of Norman conquest in Italy over several decades of activity by independent adventurers”):

v. English longbow.

“The range of the medieval weapon is unknown, with estimates from 165 to 228 m (180 to 249 yds). [...] The longbow had a long range and high accuracy, but not both at the same time. Most of the longer range shooting mentioned in stories was not marksmanship, but rather thousands of archers launching volleys of arrows at an entire army. Longbowmen armies would aim at an area and shoot a rain of arrows hitting indiscriminately at anyone in the area, a decidedly un-chivalrous but highly effective means of combat.” [...]

“A typical military longbow archer would be provided with between 60 and 72 arrows at the time of battle. Most archers would not loose arrows at maximum rate, as it would exhaust even the most experienced man. “With the heaviest bows (a modern warbow archer) does not like to try for more than six a minute.”[31] Not only are the arms and shoulder muscles tired from the exertion, but the fingers holding the bowstring become strained; therefore, actual rates of shooting in combat would vary considerably. Ranged volleys at the beginning of the battle would differ markedly from the closer, aimed shots as the battle progressed and the enemy neared. Arrows were not unlimited, so archers and their commanders took every effort to ration their use to the situation at hand.

Nonetheless, resupply during battle was available. Young boys were often employed to run additional arrows to longbow archers while in their positions on the battlefield.[32] “The longbow was the machine gun of the Middle Ages: accurate, deadly, possessed of a long range and rapid rate of fire, the flight of its missiles was likened to a storm.”[2] This rate was much higher than that of its Western European projectile rival on the battlefield, the crossbow. It was also much higher than the standard early firearms (although the lower training requirements and greater penetration of firearms eventually led to the longbow falling into disuse).”

Here’s some related stuff.

About these ads

September 6, 2011 - Posted by | knowledge sharing, wikipedia

3 Comments »

  1. Re Fibonacci numbers: I’d like to add, more as a curiosity or FYI item, that there is a non-trivial minority of people in the technical analysis community who take Fibonacci numbers very seriously – see Fibonacci retracement for an example. It would be comic, if it weren’t tragic. It should be self-evident to anyone with IQ above room temperature that this is weapons-grade Pareidolia, unless you believe that many/most of the market participants trade on similar beliefs, in which case it’s worse than an illusion – it’s delusion. We have not evolved nearly as far as we think from our ancestors who saw omens everywhere around them.

    Comment by Plamus | September 7, 2011 | Reply

    • Thanks for the comment. And no, we haven’t.

      But most of those technical analysis guys have IQs way above room temperature, right? Incidentally, pretty much everyone does in Europe – we use the Celcius scale…

      High IQ individuals are in my model of the world somewhat less irrational (better time management skills on average, better ability to link cause and effect and evaluate risks -ll-, ect.), but they have a lot of blind spots and part of what makes them look more rational is the fact that they’re better at hiding the irrationality behind various complex structures. A guy with an IQ of 80 and a guy with an IQ of 120 might both believe in God, but most often it’s not the same God they believe in – and an atheist with an IQ of 80 will have a much harder time debating the smart guy, even if both of the gods are just figments of the religious people’s imagination.

      I personally somehow like to think that irrational beliefs are to some degree, and will continue to be, an important part of the formation and maintenance of various social bonds – if you don’t have any really good reason to think/believe X doing it anyway signals trust and tribal affiliation, which is just super important and has been for members of our species as long as it has been engaged in (semi-)complex social behaviour. Having good reasons for believing X implicitly dilutes the signal, whereas on the other hand accepting and defending publicly what the ‘rational selves’ in the back of our minds know to be bad reasons for believing X strengthens the signal.

      Thank you for introducing me to the Pareidolia concept.

      Comment by US | September 7, 2011 | Reply

  2. You are most welcome. It’s technically apophenia, of which pareidolia is a subset, but pareidolia just rolls off the tongue. I remember finding that concept very illuminating when I learned about it.

    Comment by Plamus | September 15, 2011 | Reply


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 146 other followers

%d bloggers like this: