We have two eyes. Some people think that aliens also have two eyes. We have four limbs and a head. Some people think that aliens also have limbs and heads. We communicate by radio, and some people want to send messages to aliens by radio. We live on the surface of the earth, and some people think that aliens also live on a planet. Others infer the existence of aliens from the living conditions of human beings. Humans can't live in high temperature, so which planet is too hot and there is no sign of life. People can't live without water, so they say that there is no water on the surface of any planet, so there is no sign of life. ..............................................................................................................................................
In fact, they may not use language to communicate. They don't have to be bound by three-dimensional space, and they can travel freely between the past and the future. Newton's gravity can't affect them (for example, the flying saucer's flight is not affected by the gravitational field). They look at us just like we look at ants and can't communicate. Their way of thinking is completely different from ours. They may also intend to promote peace in the universe. They may not be a combination of our body and spirit. Flat ... they may just be an "ideology". They may exist in a galaxy or a planet. It may have come to our earth long ago, but we haven't noticed it yet. They may be observing the earth. It may also be adsorbed on some people (a little scared, no, too scared). It may even be ... (Stop it, it's so scary and desperate)
In a word, we can't imagine their affairs with our thinking. ...............................................................................................................................................................
However, Hawking once said, "Don't talk to aliens.