28 February 2010

Why do sheep have wool?

Sheep didn't always have wool.

Wool will not protect them from predators. No predators would mind getting some wool in their mouth for a good meal, besides the lion (or other predators) can always spit it out (ever heard of owl pellets?).

Most predators pick up their prey by it's scent, having a longer haircut simply isn't going to help.

Shield them from cold? If other animals living in that region didn't need as much wool to make it through winter, why the sheep? Sure it keeps them warmer but during summer farmers have to give the sheep a hair cut so they don't end up with heatstroke (that is a good indication their long wool didn't evolved naturally).

So why do they sheep have wool? ... Human.

Sheep didn't always have wool, they had hair. More than 10,000 years ago, sheep hair was more like deer hair is today, short and thick. The earliest human hunted them for their meat. As we gradually change our lifestyle from hunter gatherers to farmers, sheep was one of the earliest animals to be domesticated.

Sometime not too much later people also began to make clothes, instead of just wearing furs. Since they had sheepskins around, one of the fibers they used was sheep hair. They noticed that although none of the sheep hair was really any good for spinning, because it was too thick and brittle, some of the hair from the stomach, the underside of the sheep, was better than the rest. And people began breeding the sheep that had the most good hair together, trying to get some hair you could spin.

It took thousands of years, many many generations of sheep, and from records we know that by about 5,000 BC people could begin to spin wool. So the sheep as we know it today has been having their wool for only a little over 5,000 years.

this is taken from my YA!
http://answers.yahoo.com/question/index;_ylt=AhQrEHWRxBxKpdgXpNSv3ZsjzKIX;_ylv=3?qid=20100207053209AALVDLH

Hypothetical vs Theoretical?

The difference between a hypothetical situation and a theoretical situation.

In everyday conversation (unlike scientist) we usually don't make that distinction, which means you can use both words interchangeably.

To answer your question, your friend asked a "hypothetical" question.

When you suggestion a hypothetical situation, you are making up or imagining a situation that could have or could not exist in real life. E.g. Hypothetically if someone shot you in the leg, would you cry? or What will you do if you discovered that you have 100,000 children?

A theoretical question have to be proven. E.g. Wormholes exist theoretically but we haven't found any yet (the laws of physics allow for wormhole to exist, meaning you can calculate it or it's theoretically possible). The 2nd example I used above will not be valid in a theoretical question because it is impossible to happen.

*this is taken from my YA.
http://answers.yahoo.com/question/index;_ylt=AhQrEHWRxBxKpdgXpNSv3ZsjzKIX;_ylv=3?qid=20100207155657AAYT73p

01 February 2010

What did Alexander Graham Bell really said the first time he used the phone?

March 10, 1876

Bell wrote in his diary:
... I then shouted into M [the mouthpiece] the following sentence
"Mr. Watson -- come here -- I want to see you."
To my delight he came and declared that he had heard and understood what I said.

reference:
http://www.wired.com/science/discoveries/news/2008/03/dayintech_0310

* this is taken from my YA.
http://answers.yahoo.com/question/index;_ylt=AtGtAuoWsjhZIU33bcTtN5wjzKIX;_ylv=3?qid=20100207032903AAfIE0B