[David_D]

quote:Our ancesters had much more hair than we do. In those days, when they became cold they would get goosebumps as a skin response which would raise the hairs on their body. ...

I've heard that humans have as many hairs as a chip, but our hair is much finer.

[lightarrow]

Why it's dark in the night?
(It was a serious question).

[Mjhavok]

Hairy chips yuk. I prefer mine with salt and vinegar. lol.

[science_guy]

Why it's dark in the night?
(It was a serious question).

I was taught that not as many photons reach the planet when the sun is on the other side.  The Earth's "night" side is not completely dark, because the light from the sun bounces off the moon and light shines from faraway stars.  More recently, though, light pollution from the lights in citys have made it harder to see stars.  The night sky is never completely dark.

That answer your question?

[lightarrow]

No.
The question is very simple: why in the night there is not as such ligh as in the daylight? (Or almost, or more?).
I'm not talking about complete dark, just the usual concept of dark we all have.
(The answer is not trivial).

[lightarrow]

No one have any idea?

[Heliotrope]

First of all define night. Then define dark.
Your answer will follow logically.

If not, I'll have a go at it when you have some definitions.

[lightarrow]

First of all define night. Then define dark.
Your answer will follow logically.
If not, I'll have a go at it when you have some definitions.

Night = the sun is behind the earth.
Dark = There is not enough light to play tennis or to read a book or to make precision work...

[ukmicky]

Its dark at night for us humans because we have evolved to do most of our survival work (hunting and gathering) during daylight conditions. And therefore we have not been equipt with enough light collecting cells in our eyes or specialist systems like cats have for us us to see well in low light conditions.

[lightarrow]

Its dark at night for us humans because we have evolved to do most of our survival work (hunting and gathering) during daylight conditions. And therefore we have not been equipt with enough light collecting cells in our eyes or specialist systems like cats have for us us to see well in low light conditions.

Interesting consideration, Michael.
But my question was different: why it is physically dark in the night? Why there is (almost) no light, or much less light in the night than during the day?
You shoudn't give anything for granted, believe me.

[kalimna]

And Im guessing that your answer has little to do with the fact  that of all the photons streaming from the sun (primary source of 'light' received by the earth), at night they are only interacting with the side facing the sun? And hence the side away from the sun is receiving only starlight (and reflected sunlight from the moon)....
Or am I missing something here?

[lightarrow]

And Im guessing that your answer has little to do with the fact  that of all the photons streaming from the sun (primary source of 'light' received by the earth), at night they are only interacting with the side facing the sun? And hence the side away from the sun is receiving only starlight (and reflected sunlight from the moon)....
Or am I missing something here?

You don't miss anything, the answer has nothing to do with that.

[kalimna]

Hmmm, well in that case, Im stumped! Unless the answer is one of those metaphysical philosophising answers. 'Why is it dark?' - 'Because it is not light'.......
Throw us a bone here

Adam

[lightarrow]

Hmmm, well in that case, Im stumped! Unless the answer is one of those metaphysical philosophising answers. 'Why is it dark?' - 'Because it is not light'.......
Throw us a bone here

Ok. The bonus is:
star's light.

[Soul Surfer]

Just latched on to this I think he is talking about "Olbers paradox"  If the universe was infinite every line of sight would end up on a star and it would be uniformly bright.  The fact that it is dark at night means that the universe is finite in space time or both.

It is also essential for life to work to have a heat flow so a uniform high temperature universe without light or dark bits would be boring and devoid of life.

[lightarrow]

A winner! At last! Cheers!

The Wiki explanation, however, is focused more on the universe's expansion, and the consequent Doppler redshift of light from distant stars (frequency and intensity becomes lower and lower with distance).

http://en.wikipedia.org/wiki/Olber%27s_paradox

So, folks, the night is dark Because of the Big Bang!

[jolly]

i guess its because as your skin gets cold it shrinks, as all things do, and as it shirks it makes little hills with air between them which helps them retain heat when used in conjuction with the bodies hairs, the bodies heat then has to travel up through these little hills as if theres extra skin there. so it could be like the body gives itself an extra two or three layers of skin slowing down heat loss; and keeping you warmer just long enought for you to find a jumper.lol best guess why is it?

[jolly]

sorry answered without realising it had finished.

[Mjhavok]

QUESTION: WHAT IS THE SPEED OF GRAVITY?

[lightarrow]

QUESTION: WHAT IS THE SPEED OF GRAVITY?

C