sleep

[vinaya]

why does sleep refresh us?
i mean, v do perform many actions like respiration, circulation etc even during sleep
v would be dead if v didnt do that, right......

[Mastermind]

The traditional answer--that we sleep to refresh the brain--is implied by the definition of "sleep" in the 1989 edition of the Oxford English Dictionary: "the unconscious state or condition regularly and naturally assumed by man and animals, during which the activity of the nervous system is almost or entirely suspended, and recuperation of its powers takes place."

But sleep can refresh the body as well as the mind.

Sleep is controlled by a body clock in the brain that scientists call the circadian clock. The internal clock is named "circadian" from the Latin circa, which means "about" and dies, which means "day." The first clock was the Earth, making one "tick" or revolution, every 24 hours

[Mjhavok]

You are also moving less when you sleep which maybe rests your body, but when you lie down you can still feel tired. I dislike having to sleep. To evolve without the need to sleep would be great for a species. Most people sleep for 1/4 - 1/3 of there lifetime.

[iri_black]

I agree, it would be great to have no need to sleep....so many things you could do
Unfortunatly it's impossible

[February Beetle]

I've heard something a teacher did where I think he was a professor. He stayed very small room and didn't sleep for I forget how many days (took caffeine pills to stay awake) and his students watched to make sure he was okay and he recorded what was happening to him. It was pretty interesting if you could find something on that it might help you understand why we need sleep! He was hallucinating after not too long of a time. He was going crazy because when you sleep your brain sorts your information out to what is important or not (like, what to remember about a day?) I don't remember too many details, sorry. It was interesting, though.

[iri_black]

http://www.galactic-guide.com/articles/2R24.html
http://www.dolfzine.com/page161.htm

[vinaya]

thanx
that was really very interesting.
now for a good night's sleep
good night, all

[Fried Zygote Sandwich]

I wonder if lower organisms sleep? For example single celled creatures, do they sleep?

It's probably a lot to do with our central nervous system. Need time for our mind to catch up with the imput. Sort things out (like was previously mentioned) and start fresh.

[baikuza]

in the book i have read

men (A)who have enough time to spend for sleep can life much longger than men(B) who do not consider to keep the time to rest for his/her body at enough value(time).

nutrition...

[iri_black]

I wonder if lower organisms sleep? For example single celled creatures, do they sleep?

I think they don't have time to sleep

[victor]

in the book i have read

men (A)who have enough time to spend for sleep can life much longger than men(B) who do not consider to keep the time to rest for his/her body at enough value(time).

nutrition...

It depends on how many hours do men [A] sleep. If men [A] spend more than 12 hours only for sleep, then it's wasting time...
I've read one book and it said that, the minimal hours for night sleep is between 4-5 hours...because our refreshment begins in the 4th hour...

[MrMistery]

How much sleep do we need?
20 hours/day- newborn baby
10 hours/day - kids and adolescents
8 hours/day - adults
6-7 hours/day - old people

4-5 hours is to little time for sleep.