FOLLOW BOREME
TAGS
<< Back to listing
Why is the sky dark at night?

Why is the sky dark at night?

(5:24) Olbers' paradox argues that in an infinite and static universe, the night sky should be as bright as day, because looking into the universe from Earth, your sight line will always end at the surface of a star. It's like standing in a forest of white trees. If the vision of the observer always ended on a tree, the observer would only see white. Because the night sky is not bright as day, this is one of the pieces of evidence for a non-static universe such as the current Big Bang model.

Share this post

You can comment as a guest, but registering gives you added benefits

Add your comment
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
glortman glortman (2602 days ago)
Si, and Timo, you are not listening carefully. At 2:37 he says that we know the universe is NOT infinitely old and uniformly distributed. London1, the problem with 'before' the big bang has to do with the nature of time and its relationship with matter. No 'time' = no 'before'. Furthermore, not all cosmologists believe there was 'nothing' before... many feel there was another state or even possibly other universes before the beginning of this one.
ReplyVote up (175)down (136)
Original comment
Si, and Timo, you are not listening carefully. At 2:37 he says that we know the universe is NOT infinitely old and uniformly distributed. London1, the problem with 'before' the big bang has to do with the nature of time and its relationship with matter. No 'time' = no 'before'. Furthermore, not all cosmologists believe there was 'nothing' before... many feel there was another state or even possibly other universes before the beginning of this one.
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: Si the Pi (2604 days ago)
This is scientifically wrong in so many ways. Firstly, the universe is not "infinitely old". Secondly, the film completely underestimates how far away stars are. And thirdly, light photons interact with their surroundings just like every other waveform in the physical universe. To put it simply, a torch shone from the moon onto the earth would send light photons to the earth, but would you be able to see it?
ReplyVote up (151)down (146)
Original comment
This is scientifically wrong in so many ways. Firstly, the universe is not "infinitely old". Secondly, the film completely underestimates how far away stars are. And thirdly, light photons interact with their surroundings just like every other waveform in the physical universe. To put it simply, a torch shone from the moon onto the earth would send light photons to the earth, but would you be able to see it?
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: Timo (2604 days ago)
Furthermore, I think the very fact that the universe is not totally light is a 'proof' that the universe is not infinite (neither infinitly old nor infinitly large). Which is infact, as I understand is, what this video says:" We know now that the universe is not infintely old and static"
ReplyVote up (167)down (159)
Original comment
Furthermore, I think the very fact that the universe is not totally light is a 'proof' that the universe is not infinite (neither infinitly old nor infinitly large). Which is infact, as I understand is, what this video says:" We know now that the universe is not infintely old and static"
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: Wibble. (2603 days ago)
It should also be noted that a sizable proportion of the 'missing' light is coming towards the Earth through gas and dust clouds. Like fog on Earth, this causes light to scatter so that the relatively few photons reaching us from that point in the sky make it look dark. The cloud though radiates in the infra red spectrum which we cannot see with the naked eye.
ReplyVote up (149)down (143)
Original comment
It should also be noted that a sizable proportion of the 'missing' light is coming towards the Earth through gas and dust clouds. Like fog on Earth, this causes light to scatter so that the relatively few photons reaching us from that point in the sky make it look dark. The cloud though radiates in the infra red spectrum which we cannot see with the naked eye.
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: (2601 days ago)
This is what science does so bad it takes some so obvius and makes it un obvious it is simple THE SKY IS DARK BECAUSE WE HAS GONE ROUND THE SUN FOR A DAY AND IT IS NOT BRIGHT DUH!!!!!!!!!!
ReplyVote up (141)down (137)
Original comment
This is what science does so bad it takes some so obvius and makes it un obvious it is simple THE SKY IS DARK BECAUSE WE HAS GONE ROUND THE SUN FOR A DAY AND IT IS NOT BRIGHT DUH!!!!!!!!!!
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: Timo (2600 days ago)
Latest comment: It takes 365 days to go around the sun you absolute cretin! Oh I'm sorry: it does while tooked a jesus to burn round the sun 365 days and he says balahHHAHAHKSBJAK. **** OFF SAM YOU ******* TWAT!
ReplyVote up (151)down (145)
Original comment
Latest comment: It takes 365 days to go around the sun you absolute cretin! Oh I'm sorry: it does while tooked a jesus to burn round the sun 365 days and he says balahHHAHAHKSBJAK. **** OFF SAM YOU ******* TWAT!
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
Guest: God (2603 days ago)
And don't forget all that dark matter out there which is not emitting and may be blocking visible light.
ReplyVote up (156)down (160)
Original comment
And don't forget all that dark matter out there which is not emitting and may be blocking visible light.
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
London1 London1 (2603 days ago)
I simply do not believe that there was nothing and then a big bang and then the universe started expanding. And as Si said, light waves can be bent and distorted so light from distant stars may become dissipated or directed away from us.
ReplyVote up (141)down (138)
Original comment
I simply do not believe that there was nothing and then a big bang and then the universe started expanding. And as Si said, light waves can be bent and distorted so light from distant stars may become dissipated or directed away from us.
Add your reply
Submit as guest (your name)

Copy code captcha


Submit as member (username / password)

CANCEL
RELATED POSTS
Scientists turn carbon dioxide into stone
Scientists turn carbon dioxide into stone
If we could, should we end ageing forever?
If we could, should we end ageing forever?
Another cool demonstration of inertia
Another cool demonstration of inertia
Will 2017 see the first successful human head transplant?
Will 2017 see the first successful human head transplant?
The science of wildfires
The science of wildfires