Fortune-telling neutrino

In the dark and silent universe, the brightest is the star. A star is a giant sphere composed of luminous plasma, and its core is always in motion, and nuclear fusion is taking place at any time, producing amazing energy, which is why we can still see the shining star from far away. Most of the stars we can see with the naked eye are located in the same galaxy-the Milky Way.

As early as in ancient times, when there was no modern technology, people began to observe the existence of stars. In ancient Egypt, Sirius was observed to predict the flood of rivers. In China, since the Shang Dynasty, the state has specially sent people to observe galaxies. With the research of ancient astronomers, they thought that the position of constant stars was fixed, so for a long time, they combined the obvious stars into constellations or galaxies and applied them in various fields, such as creating calendars, judging directions, fortune telling and so on.

With the development of science and technology, people have a deeper understanding of the stars in the sky, realizing that these are the lights from distant stars a long time ago, and even breaking the view that the sun is the brightest thing in the world.

In fact, many stars in the universe are brighter than the sun, such as the star R 136c, which is even 5.62 million times brighter than the sun. However, because it is too far away from the earth, with160,000 light years, human eyes can't find it at all. Only through telescopes can we be lucky enough to see this magical star in the southern hemisphere.

The star NGC2363-V 1 is brighter than R 136c, and its brightness is 6.3 million times that of the sun, but it is also farther away, about1060,000 light years, and the brightness of star WR-25 is almost 6.3 million times that of the sun, but it is located in the Milky Way and is the brightest star found in the Milky Way at present.

At the same time, there are stars MK34 and R 136a 1, which are about160,000 light years away from the solar system. The former is 7.08 million times brighter than the sun, and the latter is more powerful. It is the brightest star in the universe discovered by astronomers so far. It is located in the large Magellanic galaxy, and its mass is also very large, ranking first in the universe for the time being, with higher brightness.

In addition to the star with exaggerated brightness, there is another star in our sky, Betelgeuse, which ranks tenth or even ninth occasionally except the sun in the whole day. It is the fourth star of Betelgeuse, also known as the alpha star of Orion, but it is the second brightest star of Orion. Looking up in the cold winter, Alpha Orion at night usually forms a triangle with Sirius and Nanhesan-known as the winter triangle. It is very easy to be seen by people's eyes, so in ancient China, people classified it as a resident in Seven Nights of the Western White Tiger.

Betelgeuse is one of the largest and brightest stars discovered so far, which is 700 million times larger than the sun. If placed in the solar system, it would be a "disaster", which is equivalent to the sun suddenly changing from an ordinary human into a huge Kuafu, even crowding out the earth, occupying the thrones of Mercury, Venus and Mars, and perhaps eyeing the position of Jupiter, which is likely to drive Jupiter away.

Since the last century, human beings have been exploring this bright red Betelgeuse in Supergiant star. Its light variation range is very large, and its distance estimation fluctuates greatly, as small as 180ly and as large as 1300ly. Now the distance of Betelgeuse is estimated to be 724ly, but it is also because the distance cannot be accurately measured, which also leads to the radius of Betelgeuse.

Betelgeuse is considered to have a growth time of only tens of millions of years, and it is still "immature", but it grows rapidly because of its large mass. At night, Betelgeuse glows orange. In March, except for some places in the Antarctic, other places are extremely easy to see. May is more "shy" and will not go out easily. Only when the sun goes down can you see "Yan Fang" from the west coast.

As we all know, stars are constantly evolving in the universe. From the beginning, the gas and dust of nebulae or molecular clouds collapsed, creating conditions for the birth of stars. After a long and short time compared with the universe, the main sequence stars began to appear. They constantly generated energy, expanded outward from the core, and fused hydrogen into helium at each layer. With the development of time, the star gradually becomes subgiant, and then becomes a red giant. Betelgeuse is in the late stage of the development of red giant.

At this time, the stars with smaller mass can convert hydrogen in the fusion core into helium, thus obtaining the required energy, while the stars with heavier mass can also produce heavier elements for development. However, a star like Betelgeuse, which is much bigger than the sun, will collapse into a neutron star or a mysterious black hole due to the lack of sufficient power and vitality to maintain the operation of the whole planet, and will form an explosion and eventually become a supernova.

20 19 12 A paper on the "Decline of Betelgeuse" caused a wide discussion on social media, and the light curve of Betelgeuse published by an American association specializing in observing galaxies further confirmed that Betelgeuse became darker by an order of magnitude, even darker than Betelgeuse. However, Betelgeuse, as a late red Supergiant star, is very close to the earth. If it explodes, it will become the closest star to the solar system and become a supernova. These changes are enough to cause "earthquakes" in astronomy.

1987, humans were fortunate to observe the formation of Magellanic cloud supernova. The dangerous Betelgeuse may experience an explosion and collapse at any time, either now or tens of thousands of years later. Its own hydrogen fuel consumption is only100000 years. Only after the explosion of Nirvana will Betelgeuse become a supernova and be reborn.

From 1836, someone described the photometric change of Betelgeuse, which is the first time in human history. According to these data, the period of Betelgeuse's luminosity sometimes does not change much every few years. Generally, there will be a brightness peak every few years, but there is basically no change law, and even the brightest time is 2.5 times that of its darkest period.

On record, Betelgeuse began to dim at the end of 20 19, and reached the lowest brightness in 2020. However, it began to light up after a while. Astronomers speculate that this may be because Betelgeuse is entering the stage of collapse, just like the recent sun. When the sun is in the late stage, its brightness will also be reduced by helium flash. However, if Betelgeuse collapses, the mass of the outer shell will collide with the inner core at a speed of 70,000 kilometers per second, leading to a type II supernova explosion, which is likely to become a neutron star.

Some scientists believe that if there is a problem with the core of Betelgeuse, its change cycle will be extremely long and will not be detected by human beings in a very short time as in 2020. They believe that the photons produced by Betelgeuse's core do not go straight out, but collide with the substances in it. Just like in the sun, it takes a long time for photons produced by nuclear fusion to reach the surface of the sun, even more than 654.38+ million years, unlike neutrinos, which can be rushed out in just a few seconds.

Although Betelgeuse has a low density of charged particles, the "maze adventure" of photons in it is not as bumpy as in the sun, but it will take tens of thousands of years. Therefore, if the brightness of Betelgeuse core changes, it will take us more than 10 thousand years to see it dim, and it will take another 10 thousand years to find it bright again.

So what caused Betelgeuse to change so dramatically? Astronomers have also analyzed this, thinking that it is because Betelgeuse spewed a lot of gas and dust hundreds or thousands of years ago, which blocked the light after cooling, thus making people feel that the brightness of Betelgeuse has changed. And the back is bright, because these substances are scattered and the shelter disappears.

When will Betelgeuse explode? At present, it depends on the degree of integration of its core. If its core is burning helium, it will take us 654.38 million+years to see Betelgeuse explode, even if it burns carbon, it will take thousands of years. Once there is no substance that can provide fusion, the core is only iron, nickel and cobalt, then Betelgeuse will officially start a supernova explosion.

It happened that Australian scientists thought that Betelgeuse might still be in the early stage of helium burning, which also showed that we didn't have a chance to see Betelgeuse explode.

Betelgeuse is 700 million times the size and 8 times the mass of the sun, so if it explodes, what impact will it have on us? Generally speaking, supernova explosions usually have four ways to release energy. The first wave, headed by neutrinos, is close to the speed of light and has strong penetration. Even because it will not be blocked by the material inside the supernova, it will come to the earth faster than photons, just like the supernova explosion in the Large Magellanic Cloud. It takes three hours for neutrinos to travel through the earth before photons arrive late.

Fortunately, neutrinos do no harm to human body. In fact, the earth and human body are traversed by 10 trillion neutrinos every second. It is difficult to react with other substances, which has no effect on us at all.

The second wave is the gamma ray that has the greatest impact on the earth. It will release ozone and destroy biological DNA, which is a great threat to life. Scientists found that it led to the extinction of life in the long history of the earth.

In fact, however, supernova explosions more than 50 light-years away from the earth will not affect the earth. Both gamma rays and the subsequent third and fourth waves will endanger the existence of the earth because they are too far away. And because of the angle, Betelgeuse's jet angle will not rush to the earth, so we can rest assured.

Although the luminosity change of Betelgeuse is only a false alarm, there are still many people looking forward to its outbreak. But we still let them down. We had to bury the ashes underground, and waited for a long time before the neutrinos from Betelgeuse exploded through our bodies.

The infinite change of the universe is not just a supernova explosion. There are still many mysterious phenomena waiting for human beings to discover. Our present technology can't explore the mysteries of the universe deeply, and we can only observe even nine Niu Yi hairs superficially. We can't even reach Mars, let alone explore the universe. We also need to vigorously develop science and technology, not only to seek the truth of the universe, but also to strengthen the country, promote the arrival of the space age and gain a foothold in new fields in the future.