Do aliens exist?

There must be. But it is not easy to find.

Far away. There are more than 200 billion sun-like stars in our galaxy alone. They carry countless planets. It's hard to believe that none of them are suitable for biological growth. Now people find that the adaptability of life is far wider than previously known. It has been found that living things can survive in an environment without water at all. So it can be considered that there is not only life on other planets in the universe. And there should be quite a few. Of course, if there is life, it may also develop into intelligent life, that is, "aliens."

Having said that. But it is not easy to find them. Because the distance between celestial bodies is far away. Only a handful of dozens of light years away from us. It is unlikely that there will be aliens there. Others are hundreds of thousands of light years away. In this way, it takes twice as long for the radio signal to go back and forth. And the universe is full of all kinds of chaotic radio signals. It is difficult to screen out artificial signals. So it is not easy to find them.

As far as the scientific knowledge we have at present is concerned, it is very difficult to communicate with them. But their science and technology may be much more advanced than ours. It's hard to say whether they can contact us actively. But I'm afraid this is not a good thing. Because the wisdom gap is too big. In their eyes, we are like inferior creatures. This may be a human nightmare.