1On September 8th, 895, Roentgen was doing a cathode ray experiment. Cathode rays consist of an electron beam. When there is a high voltage between the electrodes located at the two ends of an almost completely vacuum closed glass tube, an electron flow will occur. The penetration of cathode rays is not particularly strong, and even air with a thickness of several centimeters is difficult to pass through. This time, Roentgen completely covered the cathode ray with thick black paper, so that even if there was current passing through, the light from the glass tube could not be seen. However, when Roentgen turned on the circuit of the cathode ray tube, he was surprised to find that a fluorescent screen (coated with a fluorescent substance, cyanoplatinum barium) on the nearby workbench began to glow, just like being excited by the induction of a lamp. He cut off the current of the cathode ray tube and the screen stopped emitting light. As the cathode ray tube was completely covered, Roentgen soon realized that when the current was switched on, there must be some invisible radiation emitted from the cathode. Because of the mysterious nature of this radiation, he called it "X-ray"-X is usually used to represent an unknown number in mathematics.

Because of this accidental discovery, Roentgen was so excited that he gave up other research work and concentrated on the nature of X-rays. After several weeks of intense work, he discovered the following facts. (1)X-rays can not only make barium cyanoplatinum fluoresce, but also make many other chemicals fluoresce. (2)X-rays can penetrate many substances that ordinary light cannot penetrate; In particular, it can directly penetrate muscles but not bones. Roentgen put his hand between the cathode ray tube and the screen, and you can see his hand bone on the screen. (3)X-rays run in a straight line. Unlike charged particles, x-rays are not cancelled by magnetic fields.

1895 65438+ In February, Roentgen wrote his first X-ray paper, which immediately aroused great interest and excitement. In just a few months, hundreds of scientists are studying X-rays and publish about 1000 papers a year! Antoine henry beck Rael is one of the scientists who studied under the direct inspiration of the invention of Roentgen. Although Bekkerel was interested in X-ray research, he accidentally discovered a more important radiation phenomenon.

Under normal circumstances, whenever an object is bombarded by high-energy electrons, it will produce X-rays. X-rays themselves are not made of electrons, but of electromagnetic waves. So this kind of radiation is basically similar to visible light radiation (that is, light waves), but the wavelength is much shorter.

Of course, the most famous application of X-ray is in medical (including oral) diagnosis. Another application is radiotherapy, in which X-rays are used to eliminate malignant tumors or inhibit their growth. X-ray also has many applications in industry, for example, it can be used to measure the thickness of certain substances or detect potential defects. X-rays are also used in many scientific research fields, from biology to astronomy, especially providing scientists with a lot of information about the structure of atoms and molecules.

All the honors for discovering X-rays belong to Roentgen. He studied alone, and his discovery was unexpected. He made an excellent follow-up study on this, and his findings played an important role in promoting Bekkerel and other researchers.

However, people should not overestimate the importance of roentgen. The application of X-ray is of course very beneficial, but we can't think that it has changed our whole technology like the discovery of Faraday electromagnetic induction. Nor can we think that the invention of X-ray has its real significance in scientific theory. For nearly a century, people have known ultraviolet (shorter wavelength than visible light). X-ray is similar to ultraviolet ray, but its wavelength is shorter than ultraviolet ray, and its existence is completely consistent with the viewpoint of classical physics. In a word, I think there is every reason to put Roentgen behind Bekkerel, because Bekkerel's discovery is more significant.

Roentgen has no children, but he and his wife adopted a daughter. Roentgen won the Nobel Prize in Physics with 190 1, and was the first person to win the prize. He died in Munich, Germany on 1923.