Should humans be afraid of the future?

As we all know, the sun is a star and its mass is mainly composed of hydrogen and helium. About 4.5 billion years ago, when the hydrogen molecular cloud, the predecessor of the sun, collapsed and compressed the inner core to a temperature above 65.438+million degrees Celsius, hydrogen began to undergo nuclear fusion reaction, releasing huge energy.

Since then, this young star has entered its "youth", which is called the main sequence star stage in astronomy.

After entering the main sequence star stage, the sun becomes stable. The reason why the sun is "unchanged" is that it will take about10 billion years at this stage. Up to now, the sun has burned for 4.5 billion years, and it will burn for a long time. At the moment, the sun is in its heyday.

However, like other stars, the sun is not completely stable. As the video says at the beginning, the sun can not only give life to the earth, but also destroy it without blowing away dust.

As the core hydrogen decreases, the sun will gradually show fatigue. In the next 654.38 billion years, the temperature and density of the inner core of the sun will increase due to the collapse of the inner core, which will make its outer layer slowly expand and enhance radiation, becoming more dazzling and bright.

This change of the sun will make the earth face a serious "global warming" crisis, which is likely to evaporate all the water on the earth's surface and destroy the atmosphere.

If human beings want to survive, they must consider finding another planet home.

2018165438+1October 26th, the Mars probe Insight successfully landed on the surface of Mars, realizing the riskiest step in the Mars exploration mission. The reason why human beings are tirelessly developing probes to go to Mars is that when the earth is too hot to survive in the future, Mars will be a good place for immigrants.

Christopher Springob, assistant professor of research at the university of western Australia, pointed out that Mars is a planet very similar to the earth. For example, Mars Day is just over 24 hours, and its rotation axis tilts at roughly the same angle as the Earth. The most attractive thing is that research shows that there may have been liquid water on Mars in the past, and some scientists believe that Mars once had life.

So when the sun gets hotter and hotter, Mars, far away from the sun, will become livable enough for human beings to survive for hundreds of millions of years.

However, judging from the changing trend of the sun, Mars is not a place to stay for a long time. When the solar core runs out of hydrogen fuel, its temperature and density are enough for helium to fuse. The resulting heat is conducted to the outer layer, which will make the sun expand outward. This is what is mentioned in the video. The sun will become a huge red giant 5 billion years ago.

This means that the sun will enter the old age after about10 billion years of youth. By then, the sun will be big enough to devour Mercury and Venus in the inner orbit, and the earth will probably not be spared, and Mars, as the second home of mankind in the future, will also become purgatory.

If humans want to stay in the solar system, they can only choose to give up Mars and look for livable planets farther away from the sun. In this video, people turn their attention to Jupiter and Saturn, which are still frozen soil.

With the expansion of the sun, many of their satellites will be located in the livable zone for human survival. By then, Europa, Europa, Titan and other land satellites are likely to be the terminal of future human migration.

Europa was first discovered by Galileo. It is one of the seven known satellites with atmosphere in the solar system (Titan is one of them). At present, human beings have found that there are permanently frozen water resources on it, and its ice layer may be hundreds of kilometers thick.

20 18 in may, NASA and nature magazine confirmed that Galileo Jupiter probe found the evidence of liquid water on Europa in 1997, which made the hypothesis of life on Europa more supported.

Compared with Europa, Titan's migration conditions are even better than Europa's. Titan is Saturn's largest satellite and the second largest satellite in the solar system. Its atmosphere is thicker than the earth, and it also contains organic matter such as methane and ethane. These organic substances can be used as the basis for the formation of life or as a source of energy.

In an article about Titan "Titan: Facts about Saturn's largest satellite" on the American Astronomical News website (Space.com), NASA said:

"In many ways, Titan is one of the most Earth-like stars we have discovered so far. In many ways, Titan, Saturn's largest moon, is one of the most Earth-like planets we have discovered so far. )」

It is conceivable that when the sun turns into a red giant, as the ice melts, as the video says, humans can easily turn Titan into the second earth.

Even so, these small satellites are only temporary "peach blossoms" for future mankind.

About 8 billion years later, the sun, as a red giant, will also run out of helium in its core and collapse again. The expanding outer layer falls off to form a "planetary nebula" and floats into interstellar space, while the remaining core will collapse into a white dwarf.

A white dwarf is a star with a very high density, and its volume is roughly equivalent to that of the Earth. It will no longer generate energy, so during the cooling process, the white dwarf will gradually weaken its outward radiation, and in the final stage, it will stop emitting light and become a completely dim black dwarf.

At this time, the solar system will also ring the death knell of galaxy owners.

Of course, this process is so long. By then, if human beings are advanced enough, interstellar travel may have become a common occurrence, and human beings have already fled this galaxy that has exhausted the light of life.

Some scientists even predict that by then, silicon-based life will be a more powerful life form, or human life may no longer need material, but be maintained by information and data.

You may think this is a fable, but the significance of astronomy is not to make unfounded assumptions, but to let us know more about where human beings are in the universe.

The sun, like everything in the universe, is also going through the process of birth, aging, illness and death. The earth will eventually disappear with the decline of the sun. As for the future of mankind, it still depends on its own nature. After all, before the sun is enough to endanger mankind, climate change, nuclear war, infectious diseases, even artificial intelligence, and possible disasters on earth may destroy the fate of mankind.

1968, when American astronaut William Anders (William? Anders) flew to the moon by apollo 8. When he first photographed the whole picture of the earth, he said with emotion:

"The earth is the only color we see in space. We live on a speck of dust in the Milky Way galaxy, which is insignificant compared with the universe. The earth basically exists for us human beings, and it is a great pity to keep fighting for oil and territory. 」

Facing the ups and downs of the universe, the possible struggles and disasters on earth will be meaningless. Only by looking far can we truly cherish the present and love our home. This may be the greatest revelation that looking up at the sun brings to mankind.

Whether the future will be with the sun depends on human luck and courage.

So, should human beings be afraid of the less beautiful future of the solar system?

Or, in the face of the vast universe, what reason do we need to have the courage to pursue life?

An educational article about the sun, the official website, "Sun, why are you so violent?" Why are you so violent, my sun? It is pointed out that the energy produced by solar nuclear fusion is equivalent to the explosion of 6543.8+000 billion tons of explosives per second. However, the sun is only one of the most common stars in the Milky Way, which exceeds 654.38+000 billion.

These two numbers are so huge and similar that it is hard for the human brain to imagine. The vastness of the universe, on the one hand, makes human beings unable to cope with future changes, on the other hand, it also gives human beings a sense of sacredness and fear of seeing the mysteries of the universe.

Compared with naked fear, scientists experience more beauty of the universe in this sense of sacredness and fear. As physicist Yang Zhenning said, architects who plan to build Gothic churches should praise "sublime beauty, soul beauty, religious beauty and ultimate beauty". 」

This experience of the beauty of the universe is the source of courage for human beings to choose to see the ultimate fate of the universe. In addition to trying to figure out where mankind will go from here, we have placed a sincere wish on the chaotic space.

Martin rees, a British theoretical astronomer, in his book We Are All Scattered Stars, said emotionally when talking about the relationship between human beings and the universe:

"We look up at the stars with people who have lived, and eventually we will all become stardust. 」

Like all human beings who have lived, we have the same view on the stars. In the end, we are stardust ourselves. ? )?

Although eternity will disappear like the sun, we will eventually become stardust. So what?

At least, we have looked up at the vast starry sky overhead with the wisdom given by the universe. ■