The Interesting Facts Thread

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Interesting fact?

Why do cockroaches die in upside down-position.

"Cockroaches are not used to living on a polished marble or vinyl floor. They are more used to a ruguous living plane including leaves and sticks and other vegetable debris. Thus when a cockroach finds itself on its back (by some mistake in its orienteering) it may have trouble righting itself if there is not debris around to grab hold of with its legs. (Try it, put a cockroach on its back on a polished floor with and without some crinkled paper.)
Third, often we come across dead cockroaches in buildings that have died of insecticide. Most of these insecticides are organophosphate nerve poisons. The nerve poison often inhibits cholinesterase, an enzyme that breaks down acetyl choline (ACh), a neurotransmitter. With extra ACh in the nervous system, the cockroach has muscular spasms which often result in the cockroach flipping on its back. Without muscular coordination the cockroach cannot right itself and eventually dies in its upside down-position."

And this:

"Creatures with exoskeletons frequently have a primitive muscle/blood flow circulation system tied into each other and it is hydraulic by nature. The natural state of their legs is curled up and a force of exertion combined with the pushing of blood through their legs causes them to straighten. They have fine motor control of this which allows them to move, in fact it's probably unconscious such as the way we move our limbs, the process is lsot on us we just know we can do it.

Now, when the insect in question hasn't got enough food or water they grow weak, or with something like old age. So they find it harder to exert to force their legs "open" So imagine their standing on all their legs and can't summon the effort to keep the set on one side open. That side will collapse and they will tip. This causes them to roll over onto their backs. You can try this with a healthy insect and they will tilt and get back up but it's a strain and they use their legs a lot. When they are too weak to do this they are stuck, and frequently die shortly afterwards as they become too weak to right themselves."
 
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Cats are self-sufficient creatures.

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Quote from Wikipedia link previously provided:

"Contrary to a widespread perception, the real number 0.999...—where the decimal point is followed by an infinite sequence of nines—is exactly equal to 1.[173] They are two different ways of writing the same real number.[174] A 2009 study by Weller et al.[175] states that "Tall and Schwarzenberger (1978) asked first year university mathematics students whether 0.999... is equal to 1. The majority of the students thought that 0.999... is less than 1." Weller et al. go on to describe their own controlled experiment, performed "during the 2005 fall semester at a major research university in the southern United States. Pre-service elementary and middle school teachers from all five sections of a sophomore-level mathematics content course on number and operation participated in the study." The results are striking: "On the question of whether .999...=1, 72% of the control group and 83% of the experimental group expressed their view that .999... is not equal to 1."


Would any of you who are big on math care to comment?!

Peace,

Dave
 
Would any of you who are big on math care to comment?!

I suspect, that poor students were asked to select valid answers from multiple choices, but they forgot how to answer this particular question. Some of them forgot if they learned it before, or not. Some knew, but they were not certain because they did not have access to Internet. Some were overqualified and dismissed by professors, due to job security reasons.

It has nothing to do with math, it is result of typical modern American education. Students don't learn math. They learn to guess and remember right answers, because very often they are taught to select some answers as only valid ones, even if other answers are valid as well.
 
Read up here:
0.999... - Wikipedia, the free encyclopedia...

and before you know it, we'll have a 0/0=? debate

They learn to guess and remember right answers, because very often they are taught to select some answers as only valid ones, even if other answers are valid as well.
You could say that's the whole negative of education, You learn simply what the "right" answers are rather then what all the possibility's are which are also correct. There was a great presentation done by RSA a while back about education reform, and many problems with the current education were brought up... Ah, found it:
YouTube - RSA Animate - Changing Education Paradigms
 
How much money is £1 billion?

Well, if you imagine a trail of £20 notes laid end to end, to reach £1 billion you'd have to drive 4600 miles!

Quite a few individuals possess personal fortunes greater than £1 billion. What ridiculous, sad, shallow people they must be, to have kept on going beyond the first few miles.
 
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Joined 2002
0.999 recurring is equal to one because the difference is infinitely small.
Isn't that obvious?

Oh yes, that they are functionally equivalent for any practical purpose is evident.

But they are not the same thing. To wildly abuse Turing, how much data is required to encode 0.999r and how much data is required to encode 1?

This is why I never got on with maths at school, and indeed mathematics in general, its assumptions just don't make sense to me.
 
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