With thousands billions of stars in the universe, Why the nights are dark?

Answer 1

Even with all of those stars. The universe is filled with an infinite amount of nothing. Most of what's out there in space is just that EMPTY SPACE. Try going to a big wharehouse with a little flashlight and observe how, though the flashlight will light up your immediate vacinity, the brightness does eventually dissipate and fails to light the entire space. The distance between stars is often tens if not hundreds or thousands of light years. and that is just within galaxies where the stars are "close" together. The distance between galaxies is on the order of millions of light years. So again...even though there are many hundreds of billions of stars in the universe, there is MUCH MUCH MORE empty space. The effect is kind of like seeing cars on highway on a dark night from very far away. All you see is a little twinkle.

Answer 2

It is called Olbers' paradox and the question was first asked in the 1600s, then it was described in detail in the early 1800's by Olbers.
Regardless of how far and faint the distant stars are, if the universe was infinite, at every point of the sky there will be a star and the combined brightness if an infinite number of stars would make the sky as bright as a surface of a star itself. Obviously this is not the case.
The explanation-
1. The universe must not be infinite
2. Light travels at a finite speed. Light originating from a very far distance has not reached us yet.
3. The expanding universe causes red shift. The further the object is, the greater the shift to longer wavelengths, going beyond the spectrum of visible light. Total radiation in the sky is pretty consistent and high but a lot of it is not in the visible spectrum.

Answer 3

There could be several reason why you don't see stars at night.

It could be your location. I live in a congested city on the east coast of the U.S. So between all the street lights, high buildings, and pollution, I don't expect to see much unless we're having a REALLY clear night.

It also has to do with our atmosphere. We live on a gaseous ball of rock and water. Sometimes that can obscure visible light, making it harder to detect, and even harder to identify and learn about. (This is partly why Astronomers are now using telescopes in orbit, so that the view isn't so obstructed.)

It can also have to do with the location of our planet. As we move around our solar system, we get different glimpses of the space around us, and if we're facing ourward from the center of the Milky Way, then being located on outter part of one of the arms, we will only see a handful of stars and the empty black void between galaxies.

And finally, the nights are dark whether it's starry or not simply because of the mind-boggling size of our universe and the unimaginable distsances light of any type has to cross before we are able to observe it.

Answer 4

In fact, our nights are rather well lit up by the stars and Moon. What makes the nights darker is cloud cover and possible lack of a Full Moon due to the time of the month you might be considering.

On some nights you can walk in the countryside quite easily with the available light from the stars and Moon. This must occur after your eyes become adjusted to the lower light levels after sundown.

Answer 5

They really aren't. Put yourself in a closet on a moonless night for about 15 minutes till your eyes adjust. Then have someone lead you outside, making sure that the house is dark and light threw your eyelids doesn't mess up the experiment. Use a blindfold if you need too, making sure that there is no outside lighting. When you take off the blindfold or open your eyes, a moonless starry night will be a very bright thing.

Answer 6

Some light hasn't reached us yet from more distant stars and some are just so dim the light dosen't make it through the dirt in the atmosphere. The light from the moon or street lights can obscure a lot of dimmer stars as well. If you get out in the desert or wilderness away from any citys and street lights, and is it is clear, you can clearly see all the stars you want.

Answer 7

It all has to do with your proximity to the stars. As light travels out from a source like a star it's luminescence is spreading over the surface of a sphere, so in a relatively short distance the light of the start dissipates rather quickly.

Look at our own sun as an example the amount of light and heat and how it varies from Mercury to Pluto. It goes from really bright and hot to relatively dim and very cool.

Answer 8

First of all with all of spaceprobes, we can't even see light from the infinite universe, and the light we do see is/or can be billions of years old. Which just dawned me has nothing to do with the question. Without city light pollution, a clear sky , a starry night would light your way.

Answer 9

The night sky above large cities are probably very bright, but because of all the modern lights, the people on the city can not see them. Or maybe on a cloudy night anywhere it is hard to see all the stars.

Answer 10

The distance of the stars. It is like seeing a flashlight from 20 miles away. Very dim and you may not even see it at all.