Wigner Hilbert Zhang Shousheng

Wigner, 89, recalls seeing Hilbert for the first time in Göttingen in 1927, curled up in a lounge chair on a balcony, his shadow stretched long in the setting sun. Wigner's first feeling was that Heshe was getting old. The person who listened to the story next to him reminded, wait, Hilbert was only 65 years old. Wigner replied, yes, the people of that era must have aged faster.

People of different generations have different feelings about the time of birth, old age, illness and death. People who live longer feel that those who live shorter get older, and those who enjoy old age feel that those who cannot enjoy old age get older faster.

Wigner met Hilbert at a time when Göttingen was in full swing, Heisenberg, Born, and Jordan had just completed the matrix expression of epoch-making quantum mechanics, Born had just explained the significance of the probability wave of Schrödinger's equation, von Carmen was keen on new technologies such as airplanes and airships, "what a glorious place," and Wigner lamented that this was the "scientific center of the world, not only in mathematics and physics, but also in aeronautics and aerodynamics." "And all this brilliance is not as attractive as a god-like being," and the most exciting thing was the opportunity to work closely with Hilbert. Hilbert was perhaps the greatest mathematician since Gauss. He had a superb mind and a rough and inspiring way of dealing with people. "Wigner came to work as a physics assistant to Hilbert, and he was in urgent need of a mentor to give him confidence and work hard, so he was full of expectations.

Unfortunately, Hilbert was ill and had just been diagnosed with pernicious anemia, which was an incurable disease at the time. The symptoms of this disease for the average person are aging, premature aging. But there was a more brutal wound to Hilbert—the loss of an active mind. Wigner said he was visibly very tired. We already know something is wrong, and Hilbert has only half a life left. He couldn't keep up with the math and couldn't keep up with the latest advances in physics.

Hilbert suddenly looked old. This old reflection under the brilliant brilliance of Göttingen is particularly bleak and desolate. Hilbert grew old at an alarming rate, and his premature aging erased the old man's brilliance. His wide range of interests was almost lost, and with it was the charm that had earned him so many disciples. ”

Wigner felt that the brilliance of the old man should be like Einstein's "more like a philosopher." Still extremely friendly and imaginative, with a deep interest in philosophy and politics, he continued to help other physicists, still worthy of the admiration of his contemporaries, but he no longer changed physics. "Although it no longer has the splendor of the past, the fading twilight light also has its own charm. Unfortunately, Hilbert is no longer like this, no longer the original Hilbert, and no longer the appearance that everyone thinks of him as great. He was tormented by illness like a mallet, his heart was like ashes, no thoughts, no thoughts, boring and boring. Like a black hole of great honor collapsing into a closed door, it withered quietly out of sight of everyone. It was the last shred of dignity he could do.

But what exactly is the dignity of old age? Bohr has a funny theory, he said, what is the value of the elderly who have stopped doing good work? Why do they continue to live? They should live so that those who are not so old feel that they are still younger. Eighty-year-olds continue to live, and sixty-year-olds feel that they are not very old. Being young is just a person feeling that the old age line is moving backwards. Value is dignity. Wigner lamented Hilbert because he was alive and uninteresting, lost the value of old age, could not benefit the younger generations, and could not make the latecomers feel young.

What is more cruel than aging is that it is longer than friends and peers. Hilbert still lived another 16 years, during which time his Göttingen was wiped out by Nazi anti-Semitism, and many of his protégés were sent to concentration camps without their whereabouts. The reporter told him this, and he said expressionlessly, I don't remember, forgetfulness is good.

Hilbert died in 1943 at the age of 81 and was buried in a cemetery by the Göttingen River, next to Gauss, Klein, etc. The tombstone is only engraved with name and date, and the stele is engraved with two sentences "We must know, we will know" - these are the last two sentences in Hilbert's retirement, the hometown of Königsberg, the last two sentences of his thank-you speech, and the two sentences he said when he recalled his youth and believed that "knowing nature and life is our noblest mission".

For Wigner's generation of young people who were close to Hilbert, Hilbert's life was over at the age of 65, and the rest of the time was only a continuation of death. This is the next generation of people who are very close in time to the previous generation, the previous generation has not yet had time to become an idol or spiritual symbol, and the next generation also hopes that the previous generation can play a "useful" value. If you get nothing, you will naturally be resentful. Seeing Hilbert five times a year, Wigener soon left Göttingen. Until he was old, he did not forgive Hilbert, and he was still grumpy about a small matter: once he explained a new theorem to Hilbert, and Hilbert coldly said, learn what to do. It was clear that Hilbert didn't want to seek new knowledge anymore.

40 years later, a Chinese student who came to Göttingen for a tour said that Göttingen was a holy place, and even more sacred was the cemetery of Göttingen. He wandered through the Göttingen cemetery, saw the words on Hilbert's tombstone, and suddenly there was light in the darkness, and felt that this epitaph embodied a firm determination, in Chinese's words, that is, "death is not blind", because when Hilbert died, although some of his 23 problems had been solved, many of them did not have answers. This made him feel that the meaning of life was to leave some information that could be preserved forever.

That year, Zhang Shousheng was 20 years old, went to college at the age of 15 in the name of genius, and obtained a master's degree at the age of 20, and like all young people, the graduation season was wandering, and he did not know how to go on the road of life. At Hilbert's tomb in Göttingen, he learned an important lesson in life: the highest pursuit in life should be to leave some knowledge you have created. From then on, he was determined to be a physicist without thinking about how he would make money to support himself in the future.

The same Hilbert, for Zhang Shousheng's generation, his death masked the embarrassment of realistic aging, extracted the purity of spiritual symbols, and was a clue to recall the spirit of that great era. The distance in time makes the "useful value" of life into a "pure meaning", or in Wigner's words, there is a subtle joy of death, the joy of getting rid of a little vulgar element from the past years.

Hilbert was born in 1862, Zhang Shousheng was born in 1963, Hilbert was 65 years old and aged rapidly, and Zhang Shousheng was said to have committed suicide at the age of 55, who was deeply troubled by depression.

The fragility of life, separated by a hundred years, is just as evident.

Hilbert incidentally studied quantum, providing "Hilbert space" for quantum mechanics; Zhang Shousheng specialized in quantum research, discovering topological insulators, quantum spin Hall effects, angel particles, and so on. They all know that particles decay, with long and short half-lives, like human life. Glashow visited the proton decay experiment, the proton's expected half-life is 200 trillion years, the current age of the universe is much shorter and shorter than a blink of an eye, and the probability of discovering proton decay is much slimmer, much slimmer. But human beings are so strange, hope is almost nothing, but they still have hope. Glashow left a message in the visitor booklet:

If the protons had come back, I would have decayed long ago.

Whether Wigner is 93 years old, Hilbert is 81 years old, zhang Shousheng is 55 years old, in the face of protons, the slight difference in the length of human life is meaningless. What's the point of that? It lies in being able to perceive death, to perceive the spirit and joy behind death. Just as the recording of the last part of Hilbert's Königsberg speech has survived, when he said:

We must know, we must know.

If you listen closely, you can hear his laughter.