Paradox of interstellar migration

Scientist: There are at least 300 million Earth-like galaxies, which are only 20 light-years away from the Earth recently.

At present, the universe is still mysterious to us human beings. Although with the development of science and technology, we have a clearer understanding of the universe, but questions are also increasing, especially in the process of looking for alien civilization, there have been a lot of questions, such as whether there are aliens or other planets, whether they are suitable for human habitation, and whether human beings can carry out interstellar migration in the future.

At present, there are two main views on alien civilization. One is that there are no aliens, and human beings are unique in the universe. Even put forward a paradox, if there are aliens, then the earth civilization should have been discovered by them long ago. Why have aliens been discovered until now? Therefore, it is considered that there are no aliens at all, and human exploration of the universe is redundant.

Of course, this view is indeed too pessimistic, but the mainstream view in astronomy still believes that there are alien civilizations in the universe, at least there are alien creatures. This is mainly because with the continuous development of aerospace and observation technology, human beings have realized the vastness of the universe, and at the same time, in the study of life, they also believe that the synthesis of the most basic life will not be very complicated. In this respect, human beings cannot be a special case in the universe.

Human exploration of extraterrestrial life naturally begins from the inner solar system. Of course, our current technology can only support this, but after a long period of exploration, human beings are still disappointed. The current detection results show that there is no intelligent civilization in all celestial bodies in the solar system except the earth. Of course, whether there is life needs further study. After all, intelligent creatures and creatures are very different, even on Mars.

In fact, before the last century, human beings always thought that the Milky Way was the whole universe, but with the appearance of Hubble telescope, human beings learned more about the whole universe and discovered that the Milky Way was only the most common galaxy in the universe. According to the current observation results, humans have discovered a total of 200 million galaxies in Hubble's volume of 93 billion light years, and the number is huge, far larger than the Milky Way.

In the Milky Way alone, there are hundreds of billions of stars. Assuming that every star has two planets, the number of planets will reach hundreds of billions or more. With such huge observation data and so many stars and planets, it is conceivable that human beings will never be lonely, and even have the concept of 100%, thinking that there are other intelligent civilizations in the universe, unless human beings are really special, such as human beings are very advanced.

Because planets can't shine, it is actually a very difficult moment to find planets in the dark universe, which can only be detected through the transit of planets. Therefore, it was not until the 1990s that humans detected the first planet outside the solar system, which was located in the Pegasus solar system. With the appearance of Kepler telescope dedicated to finding planets, today, humans have discovered more than 4,000 planets in the Milky Way.

According to the relevant planetary observation data, there are at least nearly 2,700 planets with liquid water on them, and the atmospheric environment is similar to that of the earth as a whole, so these planets are theoretically suitable for life. According to this ratio, there are at least 300 million Earth-like planets in the Milky Way, and the latest one is only 20 light years.

Of course, as far as the distance in the universe is concerned, 20 light-years is not too far, but for humans, it will take several times to reach, and as far as these planets are concerned, it is only theoretically feasible. Whether they are really suitable for human habitation requires specific testing, which is very difficult for human beings.

Even the transformation of planets of the solar system is much less difficult than the detection of these planets. For human beings, even if the future development encounters bottlenecks, the resources in the solar system can fully support the development of human civilization. For human beings, exoplanets are actually a way to explore extraterrestrial civilization, trying to prove that human beings are not alone.

In a word, the universe is vast, even if the diameter of Hubble volume reaches 93 billion light years, it is only a small part of the whole universe. In such a vast universe, the probability of the existence of extraterrestrial civilization reaches 100%, and human beings cannot be lonely in the universe!