is this true?the universe is dark because the light can not reach the very distant corners of the universe?

This is true. The "visible universe" is the only things we can observe - and will ever be able to observe. As the universe expands, this "visible univese" will become smaller as galaxies spiral out of view. However, the Universe is increasing in size exponentially, and there are no true corners of the Universe, only what we can see of it.

Bowser's answer is pretty close.

According to Olber's paradox, the universe can't be infinite because if it were, the night sky would be as bright as the sun. What Olber didn't know is that space is expanding everywhere in the universe. If the expansion is uniform and constant, there is a distance called the Hubble limit beyond which the expansion puts new space between us and distant galaxies faster than the speed of light. Therefore, we can only see a finite portion of the universe, and most of its is black.

The Hubble limit is the speed of light divided by rate of expansion. At the present rate of expansion, that is about 13.7 billion light years. Recent observations of type 1a supernovas hints that the expansion may be accelerating, and faster expansion means a smaller Hubble limit. So the visible universe may be shrinking because the expansion of the whole universe is accelerating.

None of this proves that the universe is infinite, but it disproves one of the favorite arguments against an infinite universe. Olber's paradox is dead, but like Jason of Friday the 13th, it refuses to stay burried.

No...

Actually, our Universe is pretty "lit up" right now...

They believe this might be the "firework show" before the explosion fizzles out, like a 4th of July fireworks show, except on a very long time scale...

"Dark Matter" makes up most of the Universe, but the only reason we call it "Dark," is because we can't see it...

I think gravity has something to do with it. Notice that the earth we have the gravitational pull and its lighted when the sun is around. But in space, there is not light, because there is no gravity.... that is my thinking, but I have to education on space and science further than highschool, so Im not sure.... just my average joe thinking.

It's so dark because space is empty, there's nothing in space to absorb the light except planets, meteors etc. they are the only things visible.

the universe does not have corners

WHAT!!!The universe is not really dark it just depends were you at.

not true, the universe has no end

No. It is endless. it is dark because except for celestial objects (stars, planets etc.) it is a vacuum that contains no matter we can see.

No, someone just shut the door.