How long will it take for humans to feel after the sun stops nuclear fusion? Scientists: tens of thousands of years

We all know that the importance of the sun to our earth and human beings is self-evident. It can be said that in the entire solar system, all energy comes from the sun, and the reason why the earth can give birth to life is mainly nourished by the energy of the sun. Essentially, without the birth of the sun, the solar system would not exist, let alone us humans and all creatures on the earth.

It is precisely because of the characteristics of the sun's light and heat that human beings have long recognized the role of the sun for us, and at the same time began to monitor the sun very early. In the ancient times of our country, there were even special departments to observe the changes of the sun. In ancient Chinese astronomical data, the records of the sun occupy more than half of the space, and with the continuous development of science and technology, people have a clearer understanding of the sun.

For a long time in the past, human beings have not understood the secret of the sun's combustion, because everyone knows that in a vacuum environment, ordinary chemical fuels cannot burn like this at all, until Einstein proposed the mass-energy equation , let everyone understand that the conversion relationship between mass and energy, we only understand the way the sun burns, which is completed through hydrogen nuclear fusion.

We all know that the main constituent elements of the sun are hydrogen and helium, of which 71% are hydrogen, and under the action of ultra-high temperature, hydrogen nuclear fusion will occur, thereby producing helium and a large amount of energy, that is to say, the sun In essence, it is a huge nuclear fusion reactor. The main principle is that because of the huge mass of the sun, the core area of ​​the sun has caused a lot of pressure, resulting in ultra-high temperature, and hydrogen nucleation occurs when it interacts with hydrogen. fusion.

After hydrogen nuclear fusion, a large amount of light and heat will be generated, slowly moving from the center of the sun to the surface of the sun, and then photons will begin to be released into the universe. Of course, this nuclear fusion is naturally impossible to continue. Going forward, although the mass of the sun is very large, the hydrogen itself is still limited. Only when the hydrogen element is consumed, the nuclear fusion of the sun will stop, so that it will not be able to release energy towards the universe.

So if the sun stopped nuclear fusion, how long would it take for humans on Earth to perceive it? Many people think that it is 8 minutes, which is calculated according to the speed of light, because it really only takes 8 minutes to travel from the sun to the earth at the speed of light, but we must know that the sun does not mean that nuclear fusion has stopped, so it cannot emit light at all. It's hot, and the sun itself doesn't disappear in an instant.

From stopping hydrogen nuclear fusion to stopping the release of energy, this itself is a long process. As we said above, the energy is mainly released from the central area of ​​the sun. If you follow the normal speed, from the center of the sun to the surface, at the speed of light For example, it only takes less than 3 seconds, but in fact, these energies and photons want to reach the surface of the sun, but it is not so smooth.

This is because there are a large number of atoms and electrons in the interior of the sun, and when photons move toward the surface of the sun, they will collide with these atoms and electrons. The speed of photon movement, you must know that the sun itself is also very large, so a photon is likely to encounter countless photons in the process of movement. In this case, the photon wants to reach the surface of the sun, at least It takes thousands of years.

That is to say, after the sun stops hydrogen nuclear fusion, it will take at least tens of thousands of years for the last photon to leave the sun. For the universe, this time is negligible, but for human civilization, it is extremely long. , Of course, for us humans, it is basically impossible to see the time when the sun stops hydrogen nuclear fusion. On the one hand, we cannot be sure that human civilization can develop to that time.

You know, the sun can still burn for at least 5 billion years, and on the other hand, when the sun stops nuclear fusion, the earth has long ceased to exist, although the sun can still burn for 5 billion years, but in the last 10 years of the sun In hundreds of millions of years, it will gradually expand and eventually become a red giant star. At this time, the earth has already been swallowed up by the sun. After becoming a red giant star for a period of time, most of the energy of the sun is exhausted.

Becoming a white dwarf, of course, white dwarfs can also emit light and heat, but this energy is very small, resulting in very low temperature, but at this time the sun already has a solid surface, and we can even successfully land on the sun , but in fact, this is just the last afterglow of the sun, but after the sun consumes the last energy, it will completely become a black dwarf star, completely unable to shine!