Tuesday, February 23, 2010

Why isn't the clear night sky one huge bright blanket of stars,since there are trillions of them???

How come so few shine through???...tom scienceWhy isn't the clear night sky one huge bright blanket of stars,since there are trillions of them???
An excellent question. You've touched on what is called Olbers' paradox. There are several reasons on resolving the paradox. One can be you have two stars in line with your eye. You only see one star.





Another is that stars and galaxies are not smoothly distributed across the universe so it is likely that there will be gaps. Also the visible universe is not infinite in depth so gaps will not be filled by farther stars.





Another is that stars are smaller and fainter as they are farther from your eye. The result is that they can end up being too small and too faint for your eye to resolve.





Another is that a star that may be able to fill a gap in your blanket exists but it is so far away that its light has yet to reach this planet.





Pick any and all with my compliments.Why isn't the clear night sky one huge bright blanket of stars,since there are trillions of them???
A lot of crazy answers coming through, I see.





Basically, we live in a sparse area of the galaxy - in the outer edges of one of the spiral arms. If our sun was in the central region the sky would be alive with stars, and if it was in a globular cluster, there would never be night.





The fact is that we owe our existence to being in this sparse region, because in a densely starred region there would be a much greater incidence of supernova. Life would have been repeatedly extinguished at every blast, and would have to keep starting again (if it could), meaning it would never get a chance to develop far.





There are still millions of stars in our region, but at the same time there are awesome stretches of space. With the naked eye, we can only see stars down to a certain level. You start using scopes with larger light capture, and the number of stars you can see increases dramatically. Even with a good pair binoculars you can see hundreds of times as many stars.





Try it.





PS - the previous repondant who said you can see trillions from the desert is talking garbage. yes, you see a great deal more than from polluted cities, but there are still only several thousand stars visible to the naked eye at any one time. The count for the whole sky is about 8000, but half the sky is not visible.





With a pair 8x50 binoculars, you may see a third of a million. Magnification is not the issue, it is the 50mm objective lens that captures all the light. In fact if you want to view lots of stars, binoculars are the way, as they present a much larger field of view than a telescope, and magnification does nothing for stars.
Because they are so far away. Trillions of kilometers. Do you know these Hubble-Pictures on which you kann see hundreds of galaxies on one picture? Fascinating, isn`t it?
they're too far away for the human eyeballs to see but a telescope will helpO.O
The expansion of the universe.
it proves that there is a beginning to the universe....we can only see stars that are within , lets say 15 billion light years from us, bc according to science the universe is only 15 billion years old...also as the distance of a star increases, its brightness decreases, so an infinitely far star will also be infinitely dim and therefore we wouldnt be blinded by all the stars so far away.
Yes, the stars are very numerous, but they are very sparsely distributed in a very, very vast space. If stars were molecules of water, there would be only two or three of them in an olympic swimming pool.





Also the further they are from us, the dimmer they appear.





It has nothing to do with light pollution, though light pollution is a very bad thing. I think many people are afraid to look at the night sky, for fear God will be able to see them, or some such reason.





But even with no light pollution (as in the middle of the Pacific Ocean), the naked eye sees only a couple of thousand stars. Add the light gathering power of even a small telescope, and you multiply that by hundreds.





The answers to this question demonstrate the wide range of intelligence and knowledge base found on the internet. Lots of poorly informed kooks out there, and some very decent, intelligent folks.
Interstellar gas and dust absorb some of the starlight, so not all of the original light reaches us.
Usually light pollution even if you dont realize it. The reasons are : Light pollution - resolution of the eye, time of year, or even not really slowing down to look at them. There may be more.


Light Polution - even in the back yard and only a few porch lights can damper the viewing of the sky. Have you seen when they show seeing through night goggles and all of a sudden you see a light source? Your eyes act the same way, in the dark, even a small porch light some feet away will cause the eye to close up. Time of year - Summer skies have the most, winter skies have the prettiest. Summer the air is turbulent due to heat, the milky way virtually overhead. Winter not so many stars and the milky way is close to horizon. The air is still from being cold so the twinkle isnt interfereing with what you are seeing.





Eye resolution and time - your eye is like a camera. It takes time for it to gather light to see. Lay on your back and look up on a clear night . Wait.....you will see more and more
Because of light pollution. If you go to the desert where there are not many lights, like only two street lamps in a village, you will see more than trillions, go. You will see, it is wonderful. All we see here is the North Star, and in a country village in England, maybe on a clear night, pollution rid, you can see the plough, and the milky way and all that, but you have to go to a desert......you will be gob smacked
Because we live on one of the arms of the galaxy, far from the center where we would see them in a blanket. Also, there is a lot of dust particles that block out most of the light from the galaxy. Our knowledge of the true nature of the galaxy comes from huge radio telescopes and our eyes cannot detect radio waves.
Light pollution. All the bright lights here on earth dim the stars. If you wanna see a LOT of stars go out in the middle of no where in the middle of the night. The stars can be pretty breathtaking. If you can't go out in the middle of no where you can still see a lot of stars as long as you aren't in a big city. Just turn out all the lights.
Several reasons....I'll let someone else give you a good explanation.
Never been to the High Sierra at night have you?
The damn city lights make it to bright to see the lights in the night.





Plus the atomsphere is filled with smog and pollution making it cloudy














I got your back Stephanie
our street lights or lights in gerneral create a reflection that blocks out the stars. the darker the better. also our polution has a lot to do with it.

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