On this day, 67 years ago, February 1, 1958 (December 13, 1957 in the lunar calendar), American physicist Davidson passed away. American physicist Davidson was one of the experimental discoverers of electron diffraction. Born on October 22, 1881 in Bloomington, Illinois, he died on February 1, 1958 in Charlottesville, Virginia, at the age of 77. Entered the University of Chicago in 1902. He dropped out of school the following year and temporarily worked as an assistant professor at Bertu University. In 1908, Davidson obtained a bachelor's degree from the University of Chicago, and in 1911, he obtained a doctorate in philosophy from Princeton University with a thesis entitled "Thermal Emission of Cationations from Alkali Metal Salts." After 1925 he became a physicist at the Bell Telephone Laboratory. In cooperation with others, he completed the first experiment on the diffraction effect of crystals on electrons in 1927, demonstrating the idea of electron wave diffraction. In 1930, Davidson continued his research on electronic waves, especially crystal physics and electron microscopy applications, and developed electron focusing technology. The 1937 Nobel Prize in Physics was awarded to both Davidson and G. P. Thomson. Retired in 1954. Davidson is also a member of the National Academy of Sciences, a fellow at the American Academy of Arts and Sciences, and a member of the American Philosophical Society. In addition to receiving the Nobel Prize, he also received the Cresson Medal from the Franklin Institute in 1931 and the Comstock Prize from the National Academy of Sciences in 1928. The Royal Society also awarded him the Hughes Medal in 1935. Extended reading: Davidson's "lucky luck" proves the matter wave hypothesis Extended reading: Davidson's "lucky luck" proves the matter wave hypothesis Name: Davidson There is an old saying in China: If you lose in the east, you will reap the benefits. This sentence is the most appropriate way to describe some scientific invention processes. There are many scientific discoveries that are so-called lucky ones. Scientists accidentally achieved another unexpected goal while doing experiments or thinking. Other people may have encountered similar situations, but only a very small number of people noticed and thought deeply, so they got unexpected new gains. Davidson proved the matter wave hypothesis and won the Nobel Prize is such an example. Davidson was a researcher at the Bell Telephone Laboratory in the United States at the time. He and his assistants had long been engaged in the experiment of electrons bombarding metals. They tried to use experimental research to knock electron currents out of nickel plates in high vacuum. One day, Davidson and his assistant were doing experiments as usual. The two of them were concentrating on checking the data when suddenly there was a loud noise in their ears. They were scared and rushed to see what was going on. They saw a bottle used to hold liquid air. It fell to the ground and broke. Immediately, the air inside began to evaporate and escape, filling the laboratory. Davidson secretly cried in his heart: "Shit!" It turned out that the metal targets they used in their experiments were placed in a vacuum environment to prevent oxidation. This time, air penetrated into the vacuum system. They saw that the originally good metal target blunt nickel plates were suddenly oxidized. An oxide film formed on their surfaces, so that they could no longer be used as targets. They looked at each other and smiled bitterly at each other. They had to work overtime all night to replace the oxidized nickel plate and heat it for a long time. Then they washed it with great effort. It took great effort to clean all the oxide film, and then put the nickel plate back into the vacuum system. The next day, they went to work and began to do experiments again. The assistant was responsible for adjusting the angle of the nickel plate. Davidson flipped the switch and sent current to the nickel plate. However, for some reason, today's electron beam was very disobedient and unstable. Davidson found that the intensity of the electron beam changes with the orientation of the nickel plate, a phenomenon much like the diffraction of a wave around an obstacle. But how can electrons be particles have wave properties? This is unbelievable. Davidson wondered for a long time, then did this experiment several times, but the results were still the same. They didn't care about this matter anymore and put it on hold for two years. Once Davidson visited Britain and met the famous physicist Born. Born told him that the French physicist de Broglie had proposed the "matter wave" hypothesis that electrons have wave properties, but no one had verified it yet. This theory is still just a hypothesis. Davidson thought that the diffraction pattern in his experiment was also produced by electrons, and diffraction was the characteristic of waves. He hurriedly bid farewell to his friends and returned to the United States. Without even having time to pack his luggage, he ran to the laboratory to redo the experiment that had been suspended for two years. He found that the results of the experiment were completely consistent with de Broglie's prediction. In this way, de Broglie's "matter wave" hypothesis was experimentally confirmed. The rupture of the liquid gas container made him a "blessing in disguise." After heating the nickel plate, the internal structure of the nickel changed, from countless small crystals to large crystals. Any wave passing through the crystal will produce periodic changes. However, since the surface of the nickel plate had not changed at all, Davidson and the others had never paid attention. Davidson won the 1937 Nobel Prize in Physics.