We can never leave the earth. Are oxygen and speed the limiting factors?

In many sci-fi movies and TV works, humans leave the earth by spaceship, which can not only come and go freely in the Milky Way, but also reach the other side of the universe through wormholes. What's more, in Liu's The Wandering Earth, human beings built thousands of propellers on the earth's surface, and left the Tianyang system with the earth for proxima centauri, 4.2 light years away.

However, in reality, it is difficult for human beings to leave the earth, even in the nearest proxima centauri. As mentioned above, according to the current flight speed of human beings, it will take about 6.5438+0.7 million years to reach a distance of 4.2 light years. What is the life span of human beings? One hundred years at most, that is to say, human beings have just left the earth and have already died.

Not to mention arriving in proxima centauri, today's human beings are inseparable from the solar system. Although we have been talking about Martian immigration since the last century, no other country sent astronauts to land on any planet except the United States in the 1960s. Even for many countries, it is very difficult to launch a planetary probe.

Although human beings were born on the earth for more than 5 million years, more than 4 million of them were used for evolution. Simply put, they were all used to learn to walk upright from ancient apes, and then they became apes. Now they have become modern human beings, and the real scientific and technological development of human beings is only 300 years. This time is placed in the time span of the earth, as if it happened just a minute ago.

At the same time, there is a very main reason why humans can't leave the earth. We can't live without oxygen. Suitable temperature and sufficient water resources are actually easy to find in the universe. At present, scientists have discovered potential livable planets on many exoplanets through exploration. However, they have no oxygen.

In fact, in the early days of the birth of the earth, there was no oxygen on the earth. Until 3.5 billion to 4,654.38 billion years ago, cyanobacteria appeared on the earth and injected oxygen into the earth through photosynthesis. Since then, various plants have gradually appeared on the earth, and the earth's atmosphere has begun to be dominated by oxygen. However, there is no oxygen on other planets. Take Mars as an example. The most critical step in the human plan to transform Mars is to make oxygen on Mars.

Humans can't live without oxygen, so they need to carry a lot of oxygen equipment when they leave the earth, which is not only huge, but also not a long-term solution. Therefore, oxygen has become one of the keys to lock human beings on the earth. Some people think that it may be that alien civilization has bound human development with oxygen, so we can't leave the earth so far.

At the same time, speed is also. Einstein said that the speed of light is the fastest in the universe, but human beings can never reach it. Of course, the sub-light speed of human beings is also feasible, and it can also take us years or even longer to reach another galaxy. However, since the development of mankind, we are still as slow as turtles. So some people think that speed may also be one of the means for alien civilization to balance human beings.

Of course, we have never found alien life in the universe, which means that there is not necessarily an alien civilization. What mankind should do now is to develop science and technology vigorously first, and then find the key to prolong human life, so that we are not bound by time in the long interstellar voyage. In addition, we need to get as close as possible to the speed of light and find another way for us to sail in the universe with oxygen. A long way to go, let's wait and see!