What's the matter with human falling into a black hole? Is a black hole a hole? The first black hole photo in human history has been released simultaneously in many places around the world. Yuan Feng, deputy director of Shanghai Observatory of Chinese Academy of Sciences, said that at present, this photo has verified Einstein's general theory of relativity. The news aroused widespread concern. So what's interesting about black holes?
Black holes are not 'holes': they are celestial bodies
First of all, black holes are not 'holes', but a class of celestial bodies. They are astonishingly old, almost hundreds of millions of years old. At that time, it was Einstein's general theory of relativity that deduced the existence of black holes.
After calculating Einstein's gravitational field equation, German astronomer Karl & middot; Schwarzschild got a solution: if more than a certain amount of matter can be concentrated at a certain point in space, there will be a 'horizon' around the 'point', and once it enters it, light cannot escape.
Sun Zhengfan, a doctor of Astrophysics and a popular science writer, said in an exclusive interview with China news. Com that for various reasons, some astronomers are dubious about this mysterious celestial body and even refuse to believe its existence. It was only later that the existence of black holes was observed and confirmed by scientific and technological means.
At a meeting in New York, American physicist John ackebard Wheeler used the word 'black hole' when he expounded Einstein's theory and the discovery, which spread.
Sun Zhengfan explained that when evaluating a black hole, there are generally three indicators, namely mass, angular momentum and electric charge. "The information inside the black hole is still difficult to understand for the time being.".
Fall into a black hole, may 'nobody survive'?
In the universe, black hole is one of many mysterious celestial bodies. People often have big brain holes in all kinds of literary works. "Star Trek" has such a plot: astronauts fall into the black hole after still alive, but also found something from it.
'what happens when a person falls into a black hole, how he scores. Sun Zhengfan explained that some black holes themselves are not very big. Their gravitational field is as steep as a cliff, so that people may be pulled as thin as noodles before they fall in.
But if the black hole is big enough and the gravitational field is gentle, people will be relatively safe just like sliding down a slope. Sun Zhengfan said, but even if they can enter the black hole and are still alive, it is difficult to pass the information back to people outside the black hole.
More than 200 scientists around the world have jointly completed a major astronomical achievement - the first picture of human black hole, which was released in many places around the world on the evening of April 10, Beijing time. Photo provided by event horizon telescope
'physicists can build models to guess what's inside a black hole. But now we can only speculate from the mathematical point of view, and how to verify it is still impossible. Sun Zhengfan explained that with the current scientific and technological means, it is impossible to get too close to the black hole, which is similar to that people can't get close to the sun.
Those interesting little knowledge
"The composition of matter in the universe is similar to that around us. It is composed of neutrons, atoms and electrons. Sun Zhengfan explained that the so-called 'astrophysics' is to apply the physical knowledge and laws we obtained from the laboratory to the study of astronomical phenomena. If the conditions are met, some laws applicable to the earth can also be used to study the matter in the universe.
But in the vast universe, there are many extreme cases. Sun Zhengfan said, for example, the temperature of some places is close to the lowest zero, while the familiar sun's surface temperature is more than 6000 degrees, which seems' not too hot ', but its atmosphere has a high temperature of more than one million degrees, which is higher than that of the body that generates heat. This phenomenon has not been solved up to now.
In addition, there are also descriptions of wormholes in some films, TV dramas and novels, which can connect two different regions of space and time in the universe. Sun Zhengfan said that at present, wormhole is just a science fiction concept.
There are also white holes that are described as "just spitting but not eating" for energy and matter. At present, they are only mathematical structures, not physical ones. Sun Zhengfan believes that with the existing knowledge of physics, wormholes and white holes actually violate some basic physical principles.