How can we see the past?

The dream of man is still to travel through time or to have the ability to see the past or go into a future, but he does not fully realize that he is actually seeing the past literally every day. "When you look at the night sky, you look at the past, but how far can we see the past, for example, would you be able to see the first stars and galaxies with the help of a large enough telescope, or see the light from the flash of the big bang?" In itself? ".

Our vision of stars and planets in the sky is a vision of what it was like before, when you look at the night sky, you look at the past at different levels. Between us and the celestial bodies enormous distances closest to the moon and beyond. A galaxy 13.1 billion light years away, the moon's light has been off the surface for nearly two years, and the light from the bright star called the Vega Eagle has been left for about 26 years. The light from the Andromeda galaxy began its journey toward our telescopes almost two million years ago, while the light coming from the most distant galaxy takes 13 billion years. Hence our vision of the moon is not now but two seconds before the moment of vision. 13 billion years ago, and may have disappeared in water time after its release, a light that is still coming, or is still traveling in space. So we can watch what happened a few tens, hundreds, thousands, or billions of years ago, and when we look at space, we do not see what happens, but what happened and ended. It's already travel through time, according to Sky News.

In the year 2016, an international scientific team discovered the first evidence of gravitational waves a century after Einstein predicted it. Two LIGO observatories in the United States have detected two black holes collided before a billion Year, an event that resulted in the emission of gravity energy equivalent to 3 times the mass of the sun, working to change the form of time and space in the universe, and was enabled not only observatory observatory but converted to sounds, the first time to monitor the sounds coming from the silent space so far.

"The most fundamental of astrophysics is knowing that everything we look at is in the past and that the farther the body moves away from us, the more distant it is in the past," says Ali Alam in a tweet on Twitter. The deeper you get into space, the closer you are to the beginning of creation, and the stars and the quasars will reach a point that has not yet reached the Earth ... these are the limits of the visible universe.