why is the universe always dark?

Question

in pictures of earth from space earth is bright on one side and dark on the other but universe is totaly dark. how?

Answer 1

It is because the brightness of the Earth overwhelms the much dimmer stars. Basic photography knowledge there. You cannot correctly expose a very bright object and expect to see very dim objects in the same picture.

In the case of the Earth, it is also bright enough to overwhelm human vision. Astronauts likewise cannot see stars in the sky while the Earth is visible. Same thing on the surface of the moon...the landscape is far too bright to see or photograph stars in the sky. (Which Apollo hoax believers are far too stupid to figure out for themselves.)

Answer 2

WEll the earth is bright on one side because the sun is hitting it from (relatively) not too far away. A small 93 million miles (on average). Space between galaxies are many light years apart. Light waves do still travel between these galaxies (obviously since you can see them :o) however they disperse. Take a flashlight and shine it on an object far away. if it is a powerful flastlight you will see it hit the object and if you were the object it was being shined at obviously you'd see it. Now imagine being right in front of it, but at an angle...it would still be pretty bright. If you stood much further away it would be dimmer.

On to the reason the "background" of space looks dark though. I have heard several things before, but the most common I hear is that what we are seeing is the background radiation, remains of the big bang. Other theories include that it is "dark matter" which supposedly accounts for 90% of the mass of the universe.

Answer 3

This is a great question. If you think about it, if the universe is infinite, with an infinite number of stars, then for every point in space there should be a point of light that reaches the eye. So, in theory, regardless of the distance to the stars, every point in space should be as bright as the sun. So... why is the sky dark at night?

The theory that is most widely accepted is that the universe is finite but expanding. The reason that the sky is dark is because
1) there are not an infinite number of stars, and
2) the edge of the universe is expanding at a rate nearly at the speed of light, and so the cosmic materials that emit heat/light at that distance and at that speed reach us as light waves that are shifted into the infra-red/radio wave spectrum, similar to the Doppler effect of sound. Something traveling toward you is shifted into a shorter wave pattern, and something traveling away from you is shifted into a longer wave pattern. We can't see the "light" because it is shifted out of our visual light spectrum.

If you were to see the night sky through the "eyes" of a radio telescope, it should be very bright indeed.

Answer 4

Who mentioned the universe is darkish? you assert the earth has days (vivid) and nights. The earth is contained in the universe. And there are various many many many different stars brighter than our sunlight. It does not advise that no longer something is exterior the universe, yet we dont be attentive to what's exterior the universe. ok if the universe is a black hollow, how can it have black holes. So the universe isn't a black hollow. A Vacuum planet? No, the universe isn't a planet. The Universe is that has each little thing, which includes us. Dont get perplexed :)

Answer 5

Light has speed of 3 lacs KM per sec Our concept of today universe begain about 12 to 20 billion years from now & the star are finet in number
this therory is supported by your question if unverse was infinate & star counts are infainate & and unverse had no begainng (it was always there) then hower for stars & infinate number of star should light all sky becuase they have suffient time reach us & ther number infinate so light intesnsity will infinate but that is not case as star count is finate unverse begian at pertcular point of time light from distant star has limited time to reach us unverse is dark
But our sun is just 8 light miniutes away so on side of sun there brightness but opposite side is open to rest of unverse which finete so it is dark

Answer 6

Earth is bright on one side because, Sun's light falls on it. Sun has his limit of spreading light up to some crores of kilometers and beyond that he would be seen but there would be no significant effect of Sun over there. And its similar to all stars. You know that Universe is much bigger than all stars combine together. About 95% of Universe is empty....means it is all dark.

Answer 7

light rays refract in our atmosphere due to the dust and also due to air molecules that is why we can see the spreading of sun light. but in the outer space there is nothing but vaccum so refraction of light does not take place. light rays needs medium to refract, but it can travel without any medium. so light rays will be travelling in their way without refracting in the space. so, the universe looks darker.
in the case of earth wherever the sun's rays is falling the surface of the earth looks brighter i.e., those areas will be having daytime. like that the darker side of the earth will be having night time.

Answer 8

The earth being bright on one side and dark on the other obviously is because it is rotating and whichever side is not facing the sun is going to be dark...

Answer 9

Space is a continuous void. There is nothing to refract the light. Our atmosphere is loaded with light refracters, most notably dust particles. Did you sleep through school?

Answer 10

because of being devoid of matter,no light gets reflected from space and since no light reaches our eyes from the SPACE,we feel it as dark.