, which further encourages the prediction of the existence of black holes. At first, Bell and her mentor Anthony Hervish thought that they might have made contact with alien civilizations in our galaxy! I do remember that at the seminar where they announced their discovery, they called the four earliest discovered sources LG M1-4, and LGM stands for "Little Green Man". However, in the end, they and everyone else came to a less romantic conclusion. These objects called pulsars are actually rotating neutron stars. When the concept of black holes was first put forward, * * * had two light theories: one was Newton's theory of light particles; The other is the wave theory of light. We now know that, in fact, both are correct. Due to the wave-particle duality of quantum mechanics, light can be considered as both a wave and a particle. In the wave theory of light, it is not clear how light responds to gravity. But if light is composed of particles, people can expect that they are affected by gravity just like shells, rockets and planets. At first, people thought that light particles move infinitely fast, so gravity can't slow them down, but Luo Mai's discovery about the limited speed of light shows that gravity can have an important effect on it.
roger penrose's research between 1965 and 197 pointed out that according to the general theory of relativity, there must be infinite density and singularity of space-time curvature in a black hole. This is quite similar to the Big Bang at the beginning of time, except that it is the end of time for a collapsing object and astronauts. At this singularity, the laws of science and the ability to predict the future fail. However, any observer who stays outside the black hole will not be affected by the failure of predictability, because neither light nor any other signal from the singularity can arrive. This amazing fact led roger penrose to put forward the cosmic censorship conjecture, which can be translated as: "God hates naked singularity." In other words, the singularity caused by gravitational collapse can only occur in places like black holes, where it is covered by the event horizon and is not seen by the outside world. Strictly speaking, this is the so-called weak cosmic censorship conjecture: it protects the observer who stays outside the black hole from the failure of predictability at the singularity, but it is helpless to the poor astronaut who unfortunately falls into the black hole. There are some solutions to the general relativity equations, which make it possible for our astronauts to see naked singularity. He may be able to avoid hitting the singularity and go through a "wormhole" to another part of the universe. It seems that this provides great possibilities for space-time travel. But unfortunately, all these solutions seem to be very unstable; The smallest disturbance, such as the existence of an astronaut, will change it, so that he can't see this singularity, so he crashes into it and ends his time. In other words, singularities always happen in his future, but never in the past. Strong cosmic censorship guess means that in a realistic solution, the singularity always exists in the future (such as the singularity of gravitational collapse) or in the past (such as the Big Bang). Because it is possible to travel to the past near naked singularity, some form of cosmic censorship's conjecture is promising.
when a star collapses to form a black hole, it moves much faster, so the energy is taken away at a much higher rate. So it won't take too long to reach the same state. People will think that it will depend on all the complex characteristics of the star that forms a black hole-not only its mass and rotation speed, but also the different densities of different parts of the star and the complex movement of gas in the star. If black holes are as changeable as the original objects that collapsed to form them, generally speaking, it will be very difficult to make any prediction about them.
However, in 1967, Canadian scientist Nai israel completely changed the study of black holes. He pointed out that according to the general theory of relativity, non-rotating black holes must be very simple and perfect spheres; Its size depends only on their mass, and any two such black holes with the same mass must be equal. In fact, they can be described by Einstein's special solution, which was discovered by Karl Schwartz Schild in 1917 shortly after the discovery of general relativity. At first, many people (including israel himself) thought that since a black hole must be perfectly spherical, a black hole can only be formed by the collapse of a perfectly spherical object. Therefore, any actual star is never a perfect sphere, but only collapses to form a naked singularity.
However, some people, especially roger penrose and john wheeler, advocate a different interpretation of israel's results. They argue that the rapid movement involving the collapse of a star shows that the gravitational waves released by it make it closer and closer to a sphere, and when it finally becomes static, it becomes an accurate sphere. According to this view, any non-rotating star, no matter how complicated its shape and internal structure, will end up in a perfect spherical black hole after gravitational collapse, and its size depends only on its mass. This view was further supported by calculation and soon accepted by everyone.
Black hole is one of the rare cases in the history of science. Without any observed evidence to prove that its theory is correct, it has been developed to a very detailed level as a mathematical model. Indeed, this is often the main argument against black holes: how can you trust an object whose basis is only a calculation based on questionable general relativity? However, in 1963, maarten schmidt, an astronomer at the Paloma Observatory in California, measured the redshift of a faint quasar in the direction of a radio source called 3C273 (No.273 in the third category of the Cambridge Radio Source Catalogue). He found that the gravitational field could not cause such a big redshift-if it is a gravitational redshift, such a star must have such a large mass and be so close to the earth that it would interfere with the orbits of planets in the solar system. This implies that this redshift is caused by the expansion of the universe, which further indicates that this object is very far from the earth. Since it can be observed at such a long distance, it must be very bright, which means it must radiate a lot of energy. People will think that the only mechanism that produces so much energy seems to be not just a star, but the gravitational collapse of the entire central region of a galaxy. Many other quasars have been found, all of which have great red shifts. But they are all too far away from the earth, so it is too difficult to observe them.
experts study black hole plasma in Germany.
researchers from Max Planck Institute of Nuclear Physics in Germany and Berlin Center in Helmholtz successfully produced plasma around the black hole in the laboratory using the Berlin Synchrotron (BESSY Ⅱ). Through this research, astrophysical experiments that were previously only carried out by satellites in space can also be carried out on the ground, and many astrophysical problems are expected to be solved. The gravity of a black hole is so great that it will absorb everything. After entering a black hole, nothing can escape from the boundary of the black hole. With the rising temperature of the inhaled object, high-temperature plasma will be produced, in which the nucleus and electrons are separated.
The black hole adsorbs substances to produce X-rays, which in turn stimulate a large number of chemical elements in it to emit X-rays with unique lines (colors). Analyzing these lines can help scientists learn more about the density, velocity and composition of plasma near black holes.
in this process, iron plays a very key role. Although iron is not as abundant in the universe as lighter hydrogen and helium, it can better absorb and re-emit X-rays, and the emitted photons therefore have higher energy and shorter wavelength than those emitted by other lighter atoms (making them have different colors).
the x-rays emitted by iron will also be absorbed when passing through the medium around the black hole. In this so-called photoionization process, iron atoms usually undergo ionization several times, and more than half of the 26 electrons contained in them will be removed, eventually producing charged ions, which will gather into plasma. Now, researchers have recreated this process in the laboratory.
The core of the experiment is the electron beam ion trap designed by Max Planck Institute of Nuclear Physics. In this ion trap, iron atoms are heated by a strong electron beam and thus ionized 14 times. The experimental process is as follows: a mass of iron ions (only a few centimeters long and as thin as hair) is suspended in an ultra-high vacuum under the action of magnetic and electric fields, and the photon energy of X-rays emitted by the synchrotron is selected by an ultra-high precision monochromator and applied to the iron ions as a thin but concentrated beam.
the spectral lines measured in the laboratory match the results observed by Chandra X-ray Observatory and Newton X-ray telescope. In other words, researchers artificially created black hole plasma in space in the ground laboratory.
this novel method combines the ion trap of charged ions with the synchrotron radiation source, so that people can better understand the plasma around the black hole or the active galactic nuclei. Researchers hope that the combination of EBIT spectroscope and clearer third-generation (synchrotron radiation source PETRAⅢ) and fourth-generation (X-ray free electron laser XFEL)X-ray sources will bring more fresh vitality to this research field. On March 18th, 25, the Guardian reported that Horatie Nastasi, a physics professor at Brown University in the United States, created the first "artificial black hole" on the earth. The Brookhaven Laboratory in new york, USA, built the world's largest particle accelerator seven years ago, which collided gold ions at nearly the speed of light to produce high-density substances. Although this black hole is small, it has many characteristics of a real black hole. Nastasi said that the relatively heavy ion collider in Brookhaven National Laboratory in new york can collide large atomic nucleons (such as gold nucleons) with each other at a speed close to the speed of light, generating heat energy equivalent to 3 million times the surface temperature of the sun. The glowing fireball made by Nastasi in Brookhaven National Laboratory, new york, based on the principle of atomic impact, has the remarkable characteristics of celestial black holes. For example, a fireball can absorb particles 1 times its own mass around it, which is more than the number of particles that all fireballs can absorb at present.
The idea of an artificial black hole was first put forward by Professor William Anlu of the University of British Columbia in Canada in the 198s. He thinks that the performance of sound waves in a fluid is very similar to that of light in a black hole. If the speed of a fluid exceeds the speed of sound, an artificial black hole has actually been established in the fluid. However, the artificial black holes that Dr. Leonhardt intends to build are unable to "swallow everything around them" like real black holes except light because they lack enough gravity. However, the artificial black hole made by Professor Nastasi can already absorb some other substances. Therefore, this is considered as a major breakthrough in the field of black hole research. European "Artificial Black Hole" On September 1th, 28, with the first proton beam running through the collider, the European Large Hadron Collider was officially launched. Some people once worried that the world's largest' Large Hadron Collider' built in Geneva, Europe, would create a black hole to devour life on earth (it was reported in the news that an Indian girl committed suicide because she was worried that the European Large Hadron Collider would create a black hole to destroy the earth). Although European scientists have repeatedly explained that this will not pose a threat to the earth, the Large Hadron Collider is equivalent to an' artificial black hole' manufacturing machine.
The European Large Hadron Collider (LHC) is the largest particle accelerator with the highest energy in the world. It is a kind of high-energy physical equipment to accelerate the collision of protons. It is located in the particle accelerator and collider of CERN, the European Organization for Nuclear Research, in the suburb of Geneva, Switzerland, for international high-energy physics research. The first person in charge of the system is lyn evans, a famous British physicist, who first conceived and led the manufacture of the Large Hadron Collider. Dr Evans is the child of a miner in Wales, England. When he was a child, he promised to do something earth-shattering. Sure enough, he was responsible for building the world's most powerful machine, the Large Hadron Collider, which attracted worldwide attention. For this reason, he was called "Evans Atomic Energy" by the outside world.
when a specific star larger than our sun explodes in the last stage of life, a black hole will be formed in nature. They concentrate a lot of substances in a very small space. Suppose that tiny black holes are formed during the collision of protons in the Large Hadron Collider, and each proton has the same energy as a flying mosquito. Astronomical black holes are heavier than anything that the Large Hadron Collider can produce. According to the gravity property described by Einstein's theory of relativity, it is impossible to produce tiny black holes in the Large Hadron Collider. However, some pure theories predict that the Large Hadron Collider can produce this particle product. All these theories predict that such particles produced by the Large Hadron Collider will decompose immediately. Therefore, the black hole it produces will have no time to concentrate matter and produce visible results. China's artificial electromagnetic black hole Scientists in China have created the first "artificial electromagnetic black hole"
It has the name of "black hole". Although it is "mini" in size, it is impossible for any passing electromagnetic wave or light to escape its gravity. On October 15th, 29, Science magazine announced that the world's first microwave artificial black hole capable of absorbing electromagnetic waves was born in the laboratory of China Southeast University.
However, this small "black hole" will not only destroy the world, but also help people absorb solar energy better.
in the universe, black holes devour everything, even light. People are willing to talk about this celestial body because it is mysterious and "temperamental": it is in the darkest place in the universe, and no one can directly observe it, and anything close to it will be ruthlessly dragged into its abyss, including asteroids, stardust, light waves and time.
People are curious about black holes, but they never want any black holes near themselves or our planet. Now, however, some scientists have created a "mini" black hole in their own laboratory.
On October 15th, 29, Science magazine suggested that people could put this kind of "artificial black hole" in their coat pockets.
It is a research group of Southeast University in China that created the "artificial black hole", among which Professor Cui Tiejun and Professor Cheng Qiang are the two most important researchers.
"In fact, the black hole we made is not strict.