why universe appears dark?

Answer 1

no light radiation.

Answer 2

I can think of a very simple and fairly easy to understand reason for this.

Shine a flashlight at night. Do you see the beam of the flashlight? Under "normal" gasless and cloudless circumstances, you do not see a beam of light coming out of the flashlight, but rather the matter around the beam of light that we cannot see illuminates because the particles absorb the light. When you shine the flashlight on a very foggy night straight ahead of you, though, you can see a beam of light protruding from the flashlight and going on for some ways until it either hits something or is simply no longer visable. This is because the fog is, in fact, illuminating from the absorbed light and you are seeing the illumination of the fog. The universe works in this exact same way.

Space is a vacuum. That means that no regular matter is present in almost all parts of space. As light passes through this vacuum, there is no matter to absorb and become illuminated by the light. This is why we do not see anything! And since we do not see any particles or matter illuminate, we see black/darkness, which is sort of the same as virtual "nothingness."

I hope that this answer had made this concept simple and easy to understand!

Answer 3

This question is called Olber's Paradox, and was actually first published hundreds of years ago. The explanation is that the universe had a beginning about 13.5 billion years ago.

At the time Olber posed the question, it was assumed that the universe was infinite in size and ageless. If this were true, then no matter where you looked in the sky, you should see light from a star.

This doesn't happen for several reasons:

1. The universe hasn't been around long enough for it to completely fill with stars.

2. Light from all stars hasn't had time to reach us yet. Light has a speed limit of 186,000 miles per second (300,000 km per second).

3. Stars have finite lifetimes -- they're born from gas clouds, and then burn out in various ways depending on their mass.

There could well be other factors involved as well, but I think those are the main ones.

Answer 4

The universe only appears dark in visible light.

In radio waves, the sky is glowing in all directions. That's called the Cosmic Microwave Background Radiation. In the past, shortly after the Big Bang, that radiation was visible light, and every direction was bright, as light as the surface of the Sun. (This is about a half-million years after the Big Bang.) As the Universe expanded, this light was redshifted to longer and longer wavelengths, and is now the Cosmic Microwave Background.


So one answer is that the Universe appears dark because it is expanding.

Answer 5

it's a very nice a question and there is a very simple answer to it.

For you to say any object, that object has to give light; either by reflecting it from a luminous source or by being itself that luminous source. If you got the idea your fine; if not read what's next:

Take as an example a tree in a garden. The sun (self-luminous object) sends light to the tree. The tree will reflect in all directions and the part that comes to your eyes makes you see the tree. Same thing applies to the universe except their is nothing to reflect the ligh. In other words, light exists but their is nothing that reflects it to your eyes so you do not see anything.

(with a figure it is much more easier to understand)

By the way, David M's answer is wrong. In fact it is not wrong, but it has nothing to do with the universe being black.

Answer 6

It is an interesting question.
Light comes from the starts and other cosmos' explosions, but with the distance traveled, it will vanish. Our outer space is so big that the predominant factor is the darkness. To think about what this mean could be scary and agoraphobic. Light is a physical substance or matter, it travels long distances, but dissipates in our infinite universe until disappear.

Answer 7

You can have darkness in both ways by having light or not having light unless there is the same amount of brightness in every single space, one area has to be brighter for another area to be darker.

Answer 8

In physical cosmology, dark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure.[1] According to the theory of relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales. Invoking such an effect is currently the most popular method for explaining recent observations that the universe appears to be expanding at an accelerating rate, as well as accounting for a significant portion of the missing mass in the universe.

Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously,[2] and quintessence, a dynamic field whose energy density can vary in time and space. Distinguishing between the alternatives requires high-precision measurements of the expansion of the universe to understand how the speed of the expansion changes over time. The rate of expansion is parameterized by the cosmological equation of state. Measuring the equation of state of dark energy is one of the biggest efforts in observational cosmology today.

Adding a cosmological constant to the standard theory of cosmology (i.e. the FLRW metric) has led to a model for cosmology known as the Lambda-CDM model. This model agrees closely with established cosmological observations

Answer 9

you stand in a dessert with your friend standing about 1000 feet away and he is shining a torch at you what do you see?? you will see the light from the torch. if you look up into the sky what will you see first? you will see the stars. the first thing you see in both cases is the light... so why the f@#k do you think the universe is dark for ????????????????????

Answer 10

its extremely simple. theres nothing for light to reflect off of and hit our eys. and if three is an edge where light can bounce off, by the time it gets you us, we will be gone.

Answer 11

Cause It aint full yet
substance is light
not enough substance on
Earth yet either