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Why is the sky dark at night?
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It lost me after about 40 seconds....
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I tried really hard, but he was throwing too many new things at me, and my brain got a little confuddled around the chain plug border bit...so is the night dark because it is the left over water from VC's fathers bath?I'm only here cos I got on the wrong bus.
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Now, I'm a scientist with 13 years post-grad experience and I thought he was going fast!
Still, from that I got:
1) In theory the sky looks blue in the day because of the sun's light scattering through the earth's atmosphere. Without atmosphere, the sky would be dark day or night.
2) If you looked in any direction with infinite vision, you would, in theory, see stars in all directions, meaning that the sky *shouldn't* be dark at any time! But...
3) Stars are moving away from us as the universe expands. The Doppler effect (don't ask) means that the further away the stars, the further into the infrared they become and so the more invisible. So...
4) We see the stars which are closest or are bigger. We don't see further away stars because they are in the infrared spectrum and so are invisible.
Do I get a prize????? Or a headache tablet?
ETA: I'm a Biologist, not a Physicist. Couldn't deal of those equation thingies. They're evil!!Last edited by SlugLobber; 09-10-2012, 04:07 PM.
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Yeah, obvious, innit ? I knew all that...
Scarily, I did. I do need to get out more, don't I ?
In defence, can I just say that normally when I see this sort of article (or anything mentioning the word "quantum", which is total brainsprain) in New Scientist, I turn the pages until I come to something easier !
So really, Lobber's points 3 and 4 are the story in a nutshell, he could have talked at half that speed...
Now, can someone tell me how two particles that have never actually existed, can become quantumly entangled so that each knows instantaneously what the other one is doing...'cos supposedly some clever bod has done it.There's no point reading history if you don't use the lessons it teaches.
Head-hunted member of the Nutter's Club - can I get my cranium back please ?
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Originally posted by SlugLobber View PostThe Doppler effect (don't ask) means that the further away the stars, the further into the infrared they become and so the more invisible.Granny on the Game in Sheffield
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Originally posted by cardiffsteve View PostYe canna change the laws of physics.
So if stars are flying away from us are supposed to be red shifted, why do they look silver?
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