Shulou(Shulou.com)11/24 Report--

Only people with a holistic view, such as saints, lunatics or mysterious people, can help us crack the code of the composition of the universe.

Born into a Jewish family in Frankfurt, Germany, on October 9, 1873, Karl Schwarzschild was interested in astronomy and subjects such as music and fine arts from an early age. At the age of 16, he wrote his first research paper by virtue of his outstanding ability. This is an article on the binary orbit theory of celestial mechanics, published in the oldest astronomical journal, Astonomische Nachrichten (Astronomical Notes), in 1890.

He received his doctorate from the University of Munich, during which he studied Henry Poincare's theory of the stable configuration of the body of rotation and the influence of the moon on tidal deformation. From 1901 to 1905, he worked as a professor at a well-known institute in Gottingen and had the opportunity to work with many famous mathematicians such as Felix Klein, David Hilbert and Herman Minkowski. He then moved to Potsdam, where he served as director of the Astronomical Observatory and made achievements in the field of spectroscopy.

Sir Arthur Eddington said of him: "for a man like him who has a wide range of interests in all branches of mathematics and physics, the surrounding environment must be interesting."

After the outbreak of World War I in 1914, Schwarzschild, 40, still volunteered for military service, working as a weather station in Belgium and in the French Artillery Corps, helping to calculate the trajectory of artillery shells.

I didn't always believe in heaven. My interest is never limited by things on the moon or beyond the sky, but to follow the clues woven by the human soul into the dark space to reach where the new light of science shines.

Carl Schwarzschild

While on the eastern front, Schwarzschild got a volume of the Proceedings of the Royal Prussian Academy of Sciences and learned about Einstein's theory of general relativity.

During his stay in Russia, he wrote papers on Einstein's theory and Planck's quantum theory. the latter part includes the explanation of the Stark effect (the phenomenon that the spectral line of the hydrogen atom moves under an external electric field) and the proof that this effect is based on the quantum theory hypothesis.

In order to really appreciate Schwarzschild's work, the first exact solution of Einstein's field equation must understand some history of physics.

On December 22, 1915, Albert Einstein received a letter from the trenches of World War I. The old, wrinkled envelope was covered with dust, and the sender's name was covered with a large piece of blood. When he opened it, he saw the genius's name: Carl Schwarzschild.

As you can see, the war is gentle to me, although fierce gunshots can be heard at a short distance, please allow me to carry out this exploration in the garden of your thoughts.

Einstein was completely shocked by the letter, which contained the first exact solution of the mid-field equation of general relativity, which perfectly described the geometry or distortion of space-time around a mass object.

The reason for Einstein's shock was that only a month after his theory was published, Schwarzschild was able to find the exact solutions of these complex and highly nonlinear partial differential equations, and as the author of the theory, it's just a mathematical skill to find an approximate solution. Schwarzschild did this as a miracle in a battlefield full of explosions and gas.

A slight adjustment to Schwarzschild's result yields a famous solution named after him, the Schwarzschild Metric (Schwarzschild metric).

Nowadays, physicists and mathematicians usually use powerful computers and numerical techniques to solve these thorny and complex equations.

Einstein was very satisfied because he knew that such a powerful result was enough to spark interest in general relativity in the physics community.

He replied to the letter and promised to present the work at a meeting of the Prussian Society:

I read your letter with the greatest interest. I had no hope that anyone would get an accurate solution to the problem in such a concise way. I like your mathematical treatment of this problem very much.

The explanation of Schwarzschild solution Schwarzschild adopts a simple assumption, considering an ideal case of vacuum, spherical symmetry, no charge and no rotation, and then uses the field equation to determine the space deformation caused by the central mass of the celestial body, similar to the deformation of a projectile on a plastic plate.

General relativity equations without cosmological constants can be written:

Among them

It's a Ricky curvature tensor, and R is a Ritchie scalar.

Is a metric tensor.

For the stress-energy-momentum tensor, by assuming vacuum conditions, Schwarzschild can

Take zero. The Schwarzschild metric is as follows:

Where r and M represent the radius and mass of the centrosome respectively.

Gravity behaves as predicted by Newton at a long distance from the sphere, but if it is close to an object with a strong gravitational mass, the results of general relativity will deviate from Newton's classical description.

Schwarzschild's exact solution has a wide range of applications today, such as tracking the trajectories of celestial bodies, planetary orbits, and the deflection of light as it passes through a strong gravitational body.

The Schwarzschild point, as predicted by Einstein, is in good agreement with the standard star, and the bending of the surrounding space is limited, but this solution leaves some very strange problems.

A complex situation occurs when a huge celestial body runs out of fuel and begins to collapse due to its own gravity, with the central mass concentrated in a small area.

Schwarzschild's calculation predicts that in this case, the space-time structure will not only bend, but will be completely torn, the huge gravity will cause the collapse to continue, and the density of the stars will continue to increase until the space has infinite curvature and will eventually be isolated from the world forever. into an inescapable hole. This is called the Schwarzschild singularity, also known as the "black hole".

The simplified diagram of a black hole because physics had not yet accepted infinite meaning (infinity had no physical meaning at that time), Schwarzschild at first thought that his solution was just a special mathematical result, an abstract idea that there would never be a natural entity. He thought that the singularity in the equation was just an unreasonable mistake.

The physical interpretation of Schwarzschild not only violates common sense, but also violates Einstein's theory and even shakes the foundation of physics, because in the singularity, the concept of space-time no longer exists.

Schwarzschild began to work on removing singularities, thinking that the difference might be due to the introduction of an ideal hypothesis, but there is no such perfect uncharged sphere in reality.

In doing this, he used up three notebooks and deduced that each object contains a singularity, which occurs when matter is fully compressed to a specific radius. For the sun, the radius is 3 kilometers; for the earth, it is 8 millimeters.

There is a barrier beyond the singularity, which is a sign that you cannot "turn back". Once an object crosses this line, it will be trapped forever. Decades later, this critical limit was named the Schwarzschild radius.

Doesn't anyone know what's in the singularity? The Schwarzschild metric predicts that time and space will change roles: space will flow like time (one way points to the singularity), while time will unfold like space (past, present and future cannot be distinguished).

Such a reversal would violate the law of causality: in the hypothesis, if a person can cross the gully, he can receive light signals from the future, so he can foresee events that have not happened. If he can avoid gravitational shredding and reach the center, he can tell the future evolution of the universe from the past in an instant.

The Flash seems to involve such a bizarre science fiction plot.

Mercury's perihelion precession, if nothing else, the Schwarzschild rule recognizes general relativity because it perfectly describes the long-term abnormal behavior of Mercury's orbit (Mercury perihelion precession).

It is known that the planets move around the sun in an elliptical orbit. The mass of each planet will have a slight effect on the orbits of other planets, and the orbits of other planets will be affected to produce precession around the sun. All planets except Mercury are slightly affected, which can be explained by Newton's law of gravity.

On the other hand, an obvious precession has been observed in Mercury's orbit, which is not consistent with the results calculated by Newtonian mechanics. At first, it was thought that this was due to the fact that there was another planet between the Sun and Mercury, known as the "Zhu Rong Star", which had never been observed.

Schwarzschild calculated the solution of Mercury's orbit and showed that relativity causes the orbit to precede itself, which supports general relativity rather than Newton's law of gravity.

Mercury's incurable illness on the same day that he shared the results with Einstein, Schwarzschild wrote a letter to his wife from Russia complaining about unusual feelings in his body. It wasn't long before the disease spread to his whole body.

I don't know how to describe it, but it has an uncontrollable force that obscures all my thoughts. It is a void without shape and dimension, an invisible shadow that consumes all my soul.

At the war zone hospital, military doctors diagnosed him with a rare and incurable skin disease, pemphigus vulgaris, in which the body was unable to distinguish its own cells, causing the immune system to strongly attack the skin. At first, there were only two blisters on his face, and they soon covered his whole body.

Doctors believe that gas attacks on the battlefield may have caused his illness, and Schwarzschild described the attacks in his diary:

"the moon quickly crossed the sky as if it had speeded up. The soldiers were all equipped and waiting for the password to attack, but the scene was strange and disturbing, like an ominous sign, and I could see the fear in their eyes."

Because of illness, Schwarzschild returned to Gottingen from the front in March 1916. He died of illness two months later at the age of 42 and was buried in the family graveyard of Gottingen.

The asteroid 837 Schwarzschilda was named after Schwarzschild. It orbits the sun in 3.48 years and is 2.21-2.39 AU (astronomical units) from the sun. It was first discovered by German astronomer Max Wolf at an observatory in Heidelberg a few months after Schwarzenegger's death.

In his name, the German Astronomical Society set up an award, the Karl Schwarzschild Medal, for outstanding astronomers and astrophysicists. The first winner of the medal was Martin Martin Schwarzschild, son of Schwarzschild.

At his funeral, Einstein read the eulogy to the people and paid tribute to him:

He confronts the problems evaded by others, he loves to explore the connections between all aspects of nature, and what leads him to find the unknown motivation is happiness, the pleasure felt by artists, and the imagination of dreamers who care about the future.

Author: Areeba Merriam

Translation: zhenni

Revision: Tibetan idiots

This article comes from the official account of Wechat: Institute of Physics, Chinese Academy of Sciences (ID:cas-iop), author: Areeba Merriam

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