Do you want a civilization from other places to exist?

Extraterrestrial civilization is not something you wish you didn't have.

Judging from the size of the universe we know at present, extraterrestrial civilization certainly exists.

If you don't match the picture, you may have no idea how big the universe is.

When we were in primary school, the known diameter of the universe was 65.438+0.4 billion light years. And now, it's been 20 years, and now it's 93 billion light years. Note that this is not getting bigger. With the progress of human science and technology, the ability of exploration and discovery has become stronger, and we know that the universe is more than 65.438+0.4 billion light years.

The discovery of human electromagnetic waves is about 200 years. The speed of electromagnetic waves is equal to the speed of light, that is to say, the range of electromagnetic waves emitted by human beings is centered on the earth, forming a sphere, and then the radius of this sphere is 200 light years. At present, the diameter of the Milky Way is 654.38+ million light years. Therefore, at present, our electromagnetic waves can't fly out of the Milky Way at all. Still in the galaxy. On a very small scale. In other words, even if there are aliens, we can't be detected, of course, in terms of our human technology. We can't detect the existence of aliens.

Every galaxy has countless star systems like the solar system. There may be more than a dozen planets in each solar system. And the number of stars in this light map may all exceed/kloc-0 100000000000000.

As far as mathematical algorithms are concerned, there must be aliens in this universe. Moreover, it's not just the existence of one or two alien planets! There should be hundreds of millions of planets.