2017년 9월 3일 일요일

Why is the night sky dark?

Why is the night sky dark?

Simple, but long troubled mankind. There is a problem that has come to the right answer since it came to modern science.



Why is the night sky dark?

For our modern people who have forgotten this night, this sounds like an absurd question.

2017년 9월 2일 토요일

observable universe


 According to modern cosmology based on the big bang theory, about 13.7 billion years ago, the universe was created by a big bang in a space without any reason. A space without anything can easily be said to be a point, without space concept, no time concept. If we ask why the big bang occurred and the universe was created, we can not answer it right away.
 But what is clear is that this universe was born for some reason and we are present. The universe can be divided into a "universe" and an "observable universe." The universe literally talks about the entire universe, and the "observable universe" refers to the area in the universe where human beings are observable. Since no one knows what is in the universe beyond observable, we will consider only the observable universe.