Why did this farthest flying aircraft make mankind despair?

In 1977, the United States launched an unmanned outer solar system space probe, named "Voyager I". At present, this probe has been in operation for more than 4 years and is still flying in the universe. By last year, voyager 1 was 21.1 billion kilometers away from the sun, making it the farthest man-made probe.

However, it is precisely because of this that human beings sadly discover that they may be "imprisoned" in the earth. The earth is not safe

We know that the earth's environment does not mean absolute safety. Although it is still suitable for human survival at present, the earth's environment is never static, but will undergo various changes, including changes in oxygen content, temperature and air composition, and each drastic change will lead to a large number of biological extinction. In the history of the earth, such things have happened countless times, including five mass extinctions that almost led to the extinction of the earth's creatures.

according to scientists' prediction, the earth's environment may no longer be suitable for human survival after 1 million years, because the earth will usher in the Great Ice Age every once in a while, and the Great Ice Age will lead to the death of plants in pieces, so that the energy that organisms can use will be less, so the larger creatures with greater demand for energy will be extinct first.

in fact, if the earth encounters another asteroid collision 65 million years ago, it is possible that human beings will not survive on the earth for 1 million years.

It can be seen that finding another planet suitable for human habitation is very important for the continuation of human beings.

However, we know that human beings have very high requirements for a livable planet, at least to meet: the planet is located in the livable zone of galaxies, and it has liquid water, ozone layer and global magnetic field; On the outer side of the planet, there is a guardian of a larger planet, etc.

Under such harsh conditions, there are not many alien planets that can satisfy human migration, and most of them are very far away from the earth. What is even more desperate is that with the help of human detectors, it is very likely that people will not be able to immigrate to other planets for the rest of their lives, because the universe is too big. The earth's "cage"

According to the statistics of scientists, the average distance between stellar systems in the Milky Way is about 3 light years. If you drive at a speed of 12km/h, you will have to drive for 2.7 million years without eating or sleeping.

even if you fly at the speed of Voyager-1, it will take tens of thousands or even hundreds of thousands of years to fly to the next star system. In the science fiction novel "Three-body", Liu Cixin described three-body people with highly developed science and technology. Their galaxy is 4.2 light years away from the Earth, and their spacecraft reached 1% of the speed of light, and it took more than 4 years to reach the Earth.

Not to mention that at present, our technology can't make the speed of spacecraft reach 1%. Just talking about the food and fresh water of pilots in these 4 years has decided that we can't emigrate to other galaxies.

as we know, the life span of human beings is less than 1 years, and the flying time of 4 years means that we have to relay for at least 5-8 generations to get there. However, the space of the spacecraft is limited, so not only can it not hold so much food, but even the safety of pregnant women on the spacecraft can not be guaranteed.

What is even more desperate is that this is only the distance between the earth and proxima centauri, and proxima centauri belongs to Trinary star system, which means it has three suns, so proxima centauri is not livable. To find a planet suitable for human habitation, human beings may have to look further, even beyond the Milky Way.

The diameter of the Milky Way is over 1, light years. If we cross the Milky Way at a speed of 12km/s, it will take at least 9 billion years. Even if we reach the speed of light, it will take 1, years. Such a long time, human beings can't cross it at all, so that human beings are almost trapped on the earth forever. Why explore the universe?

since human beings may not be able to emigrate to other planets for the rest of their lives, why should they explore other planets?

Actually, the more people know about the universe, the more they can find a way out for human beings. In the past, we thought that the earth was the center of the universe, and the life on earth was created by God. What it was like in the past is what it is now.

but now we know that the earth is not special in the universe, and the life on earth is not created by God, but naturally produced, and will evolve with the change of environment.

since the earth is not special in the universe, and living things can be spontaneously generated, we are curious whether there are other planets in the universe that have given birth to life and even civilization like the earth.

In addition, although humans can't cross the Milky Way, they can't find the next livable planet. However, human beings can develop science and technology and transform their own planet. Just as The Wandering Earth described, when the solar system becomes uninhabitable, we can take the earth to wander and find the next livable galaxy.

Although everything is at the stage of speculation at present, with the exploration of the universe by human beings, we can answer our doubts one by one, which may contain the answer to how human beings continue to survive.