Why is the sky black?

"Space remains dark despite numerous stars due to Olbers’ paradox, involving great distances, a young universe, and the Doppler effect, which shifts distant starlight to invisible wavelengths."(ScitechDaily, Stars Are Everywhere, So Why Is the Sky Still Dark?

We see that stars are everywhere. But the sky is black. Why is that thing so? Sometimes is introduced that light has no time to travel all around and fill the universe. There is one part true in that answer. The expansion of the universe has something to do with that phenomenon. When the universe expands the wavelength of the wave movement, or radiation, turns out from the visible areas. When the distance of the particles grows. Wave movement echo or reflection from the particle turns longer. 

That is called redshift or Doppler shift. So when the distance between particles grows the redshift turns the reflecting waves to the red side of the electromagnetic spectrum. If the wave movement's wavelength is near the infrared area that wave movement slips to that area. Same way if the particle comes towards another particle the reflecting wavelength from the particle turns shorter. That thing is called blueshift. 

If the speed of the particle that comes to the observer is high enough, it can press all those waves to the ultraviolet areas. That Doppler effect means that fast-moving particles can turn the electromagnetic radiation into another form. And theoretically, the Doppler effect can turn the gamma rays into visible light. The fast-moving particles can also turn visible light into gamma- or X-rays. 

Most of the radiation is invisible to us. 

The thing is that the dark energy that is the dominating force in the universe can theoretically turn into the "visible energy" if something affects its wavelength. But there is no idea if should researchers press or pull that energy. The dark energy is wave movement. But its wavelength or source is unknown. Sometimes researchers introduce that dark energy is like string that kinks over some other wave field. 

That means dark energy could be like a tornado that surrounds regular or visible energy strings. In some other models, the dark energy source is in the cutting superstrings. Or maybe. It's in the wormholes or black holes that vaporize. When the wormholes cut they release energy that is stored in them. But that theory requires the existence of wormholes. 

"The universe is expanding, and that expansion stretches light traveling through space in a phenomenon known as cosmological redshift. The greater the redshift, the greater the distance the light has traveled. As a result, telescopes with infrared detectors are needed to see light from the first, most distant galaxies. Credit: NASA, ESA, AND L. Hustak (STSci)" (ScitechDaily, Stars Are Everywhere, So Why Is the Sky Still Dark?

We know that dark energy affects the material. But we don't know where it actually affects. The dark energy can have an effect on the material itself or some field around it. If we think that dark energy is like wind and quantum fields including gravity fields are like soap bubbles around the objects, the dark energy can blow that bubble. 

When there is asymmetry in that bubble there forms that low pressure in that bubble. That causes an effect where the particle moves into the lower pressure area in that bubble. That could be one reason why we cannot see dark energy. But when we think about things like wormholes the channels through the Higgs field. It's possible. That the so-called white holes are the reason for the dark energy. 

The white hole is not a white version of a black hole. It's the point where energy comes out from the wormhole. That means energy or wave movement that comes out from a wormhole makes it impossible to go into a wormhole from that point. The wormhole's entrance is the black hole hole. The white hole is the term that means the anti-black hole. 

When energy comes out of the wormhole it pushes a wave field around it. If a wormhole exists the light travels inside it faster than outside the wormhole. When wave movement comes out from a wormhole it releases its energy to fields around it. That means the wormhole can cause an effect that the wavelength of that wave movement turns so short that we cannot detect it. 

One of the explanations for dark energy can be the Hawking radiation. Nobody has seen that radiation yet. But it's possible that Hawking radiation wavelength is so short, that the Hawking radiation waves seem straight. And that makes them hard to see. 

When we think about the wave movement we always think that we see the wave movement itself. The fact is that we see the changes in the fields of wave movement. So if the wavelength of wave movement or radiation is short enough that thing seems straight. And it's hard to see straight waves. That is one way to understand the wave movement. 

Same way when a particle's energy level rises. It starts to send energy waves more and more often. The size of the particle turns smaller. Then sooner or later the particle starts to send radiation impulses so often that we cannot see it. If we move that model to the macro-environment, that means the black holes can also send radiation. 

The radiation called Hawking radiation could have so short wavelength that the observers cannot see that radiation because its waves seem straight. So it's possible. That the strange dark energy can at least partially be the same as Hawking radiation. But that is only a hypothesis. 

https://scitechdaily.com/stars-are-everywhere-so-why-is-the-sky-still-dark/