From the day human beings were born, they began to look up at the starry sky and think: What does this world in the sky look like? Do we hope to go to see it? It is this kind of human exploration genes that are deeply imprinted in the bones that have allowed humans to develop very fast after entering the era of civilization. In just over 5,000 years, we have embarked on the road of technological development.
With the advent of the age of science and technology, our dream of flying to the sky has finally become possible. In the 1950s, mankind finally walked out of the earth and saw the vast universe of stars. With the continuous development of human science and technology, we are constantly exploring the history of the earth and exploring the mystery of life. In the process of exploring the history of the earth and the evolution of life, scientists have discovered a fact that we have to face, that is, the earth’s There is a cycle of life.
The earth has a history of 4.6 billion years, and the earliest life was born 3.8 billion years ago. Is this long life history and evolutionary path smooth? Of course not. In fact, the evolution of life on the earth is not smooth at all. In the past billions of years, the earth’s ecology has undergone many great changes, countless small great changes, and every ecological change will give life to evolution. Survival poses a huge threat.
We all know that although the earth’s life history is 3.8 billion years old, it wasn’t until 500 million years ago that life ushered in a major explosion, and a large number of complex and advanced life began to emerge. In the previous 3.3 billion years, life has been unable to develop due to various ecological constraints, which shows how difficult the evolutionary path of life is.
Even though the explosion of life ushered in 500 million years ago, in the following hundreds of millions of years, the ecological environment did not make the evolution of life smooth sailing, but also brought about five great changes in survival, triggering five The secondary biological extinction, the most serious one, the life of the earth was extinct by 96%, almost completely ending life and restarting.
Through these research findings, we understand that the earth’s ecology will undergo tremendous changes in the future, and the sixth mass extinction will also come. If human beings have stayed on the earth, then what awaits us may be the same fate as dinosaurs, and to get rid of the fate of dinosaurs, then humans must go out and find other new homes suitable for human survival.
Therefore, after human beings walked out of the earth, they started to explore the solar system. On the left and right are Venus and Mars, which are in the same habitable zone as the earth. They have many similarities with the earth. However, later detection results found that Venus is a purgatory planet with a surface temperature of 460 degrees Celsius, and various environments are very harsh, not suitable for life and human survival.
Although the situation of Mars is better than that of Venus, it is also not a planet that is naturally suitable for human survival. After transformation, Mars can allow some humans to live and live, but it is not the ultimate new home for humans. To find a new home, we still need to focus on other galaxies outside the solar system, so scientists launched Voyager 1 in 1977. It is an extrasolar probe with the ultimate goal of flying out of the solar system and towards The vast universe.
Voyager 1 passed the acceleration of Jupiter and Saturn twice, reaching a speed of 17 kilometers per second, which is a super fast speed in our opinion. At this speed, Voyager 1 passed through on August 25, 2012. The heliosphere became the first vehicle to cross the solar circle into interstellar space.
Today, Voyager 1 has reached the starry sky 21.6 billion kilometers away. This is a pride of mankind and a starry sky that has never been set foot in the history of mankind. While we were proud of Voyager 1, it also brought a pessimistic result for mankind: unable to fly out of the solar system. Yes, although the speed of Voyager 1 is very fast, reaching 17 kilometers per second, it cannot fly out of the solar system at this speed.
In the eyes of many people, the range of the solar system is the heliosphere, which is the top of the heliosphere. As long as it passes through the heliosphere, it is out of the solar system. This is the cognition of early scientists, but with the continuous improvement of human observation technology, we observed that there is a larger nebula structure outside the solar system-the Oort Cloud, which is a light-year thick. The nebula layer contains a large number of celestial bodies and dust.
After Voyager 1 crossed the solar circle, it also got the same result. In theory, the matter in the galaxy is larger than the interstellar space, which is actually well understood. The matter in the universe mainly gathers near massive celestial bodies, while galaxies are the basic unit of the universe. A large amount of matter is concentrated in the galaxy, and a large amount of matter in the Milky Way is gathered in the star system except for gathering towards the center. .
In the interstellar space between star systems, matter is relatively small. Only when we are sure that the observed interstellar matter is significantly less than that in the galaxy, can it be considered that it has flown out of the solar system. However, after Voyager 1 passed through the heliosphere, the result of monitoring is that the density of matter outside the heliosphere is much higher than that at the edge of the solar system. This shows that Voyager 1 may not have really gone out of the solar system. It just crossed the solar circle.
If the range of the solar system includes the Oort Cloud, the diameter is at least 2 light-years, and the distance traveled by Voyager 1 is only a fraction of a fraction. It will take at least 15,700 years to fly out of the solar system at this speed. . This time is extremely long for human civilization.
So what kind of speed do humans need to get out of the solar system at least? According to the research of scientists, according to the new scope of the solar system, we must at least achieve sub-light speed to get out of the solar system. It takes 400 years to travel through the solar system at 1% of the speed of light, and 40 years to travel at 10% of the speed of light. Coupled with the relatively short life span of human beings, it is unlikely that we will spend 400 years out of the solar system. The complex and harsh environment of the universe only allows us to get out of the solar system in a short time.
Therefore, if it takes 40 years to get out of the solar system, human beings can barely accept it. In this case, the speed of the spacecraft must reach at least 10% of the speed of light. Of course, this speed is only able to get us out of the solar system, but it is far from enough to explore the star system closest to us. It takes 4.2 light years to know that the star system closest to the earth.
Therefore, humans want to explore the galaxies near the solar system in a short period of time and find a second home suitable for human survival. Then the speed of the spacecraft must achieve at least 30% of the speed of light. There are many terrestrial planets in the universe that are similar to the Earth. Scientists have discovered many terrestrial planets within thousands of light-years through astronomical telescopes. Some of them are very similar to the Earth. It is speculated that they may be suitable for human survival.
However, these Earth-like planets that we are optimistic about are all more than a hundred light-years away, and to reach at least a stronger sub-light speed, for example, a light speed of more than 90%. For galaxies that are more distant, they need to fly faster than the speed of light, which is too far away for us.
The ecological deterioration of the earth is accelerating. We can’t go too far to find a second home, we can only look for it near the solar system. However, it is not an easy task to achieve a 30% speed of light. At least it requires a qualitative change in human energy technology and the emergence of a more powerful energy. Controllable nuclear fusion may be able to meet the requirements initially, but to realize this technology, scientists cannot give a specific time. It may be 50 years, 100 years, or it may take hundreds of years.
In any case, going out of the earth and out of the solar system to find a second homeland is the guarantee for the continued survival of mankind. No matter how difficult the front is, we have to overcome them one by one.