X-RAY Wilhelm( German physicist, Nobel Prize in Physics, 1901)
Comments for X-RAY Wilhelm
Biography X-RAY Wilhelm
March 27, 1845, Mr.. - 10 February 1923
. German physicist Wilhelm Conrad Roentgen was born in Lennep, . a small town near Remscheid in Prussia, . and was the only child of a prosperous merchant of textiles Friedrich Conrad Roentgen and Constanta, Charlotte (nee Froveyn) X-ray,
. In 1848, Mr.. family moved to the Dutch city of Apeldoorn - home parents, Charlotte. Expeditions Committed R. in childhood in the dense forests in the vicinity of Apeldoorn, for life instilled in him a love for wildlife.
P. enrolled in technical school in Utrecht in 1862, but was expelled for refusing to name his friend, irreverently drawn a caricature of a disliked teacher. Without a formal certificate of completion of secondary school, he could not formally enter the university, but as an auditor completed several courses at the University of Utrecht. After passing the entrance exam P. in 1865. student was enrolled in the Federal Institute of Technology in Zurich, as intended to become a mechanical engineer, and in 1868. graduated. August Kundt, German physicist and a distinguished professor of physics at the Institute, drew attention to the brilliance P. and strongly advised him to study physics. He followed the advice of Kundt and a year later he defended his doctoral dissertation at University of Zurich, after which he was immediately appointed assistant to Kundt first in the laboratory.
. Receiving the Department of Physics, University of Wц?rzburg (Bavaria), Kundt took with him and his assistant
. Go to Wurzburg was for P. beginning 'intellectual odyssey'. In 1872, Mr.. he, together with Kundt moved to the University of Strasbourg in 1874,. there began his teaching career as a lecturer in physics. A year later, P. became a full (valid) Professor of Physics at the Agricultural Academy in Hohenheim (Germany), and in 1876, Mr.. returned to Strasbourg, where to begin reading course in theoretical physics.
Experimental studies conducted by P. in Strasbourg were related to different fields of physics, such as thermal conductivity and electromagnetic crystals rotate the plane of polarization of light in gases, and, according to his biographer Otto Glaser, won R. reputation 'fine classical experimental physicist'. In 1879, Mr.. R. was appointed professor of physics at the University of Hesse, where he remained until 1888, refused the offer to take the chair of physics at the universities of Jena consistently and Utrecht. In 1888. He returned to the University of Wц?rzburg, as professor of physics and director of the Physical Institute, where he continued to conduct experimental studies of a wide range of problems, t.ch. compressibility of water and electrical properties of quartz.
In 1894, when P. was elected rector of the university, he began experimental studies of electric discharge in a glass vacuum tubes. In this area, much has been done by other. In 1853, Mr.. French physicist Antoine Philibert Masson said, . that the high-voltage discharge between electrodes in a glass tube, . containing gas at very low pressure, . generates a reddish glow (such tubes were the first forerunners of modern neon tubes),
. When the other experimenters began to pump gas from the tube to a greater dilution, the glow started to break up a complicated sequence of individual luminous layers of color which depended on the gas.
. English physicist William Crookes using an improved vacuum pump has reached an even greater dilution and found that the glow disappeared, and the walls of the glass tube fluoresce green light
. Crookes showed, . that the rays emitted by the negative electrode (placed inside the tube cross-shaped object casts a shadow on the opposite wall) and that the rays consist of some substance, and bear a negative electrical charge (the blade of light striking the wheel, . rays led him into the rotation, . a bundle of rays deflected in the direction of the magnet, . corresponding negative charge),
. In 1878, Mr.. Crookes conjectured that the rays cause fluorescence when the bump on the glass walls. Since the negative electrode called the cathode, the radiation emitted by the walls is called cathode rays. German physicist Philipp von Lenard showed that cathode rays can penetrate through the window in the tube covered with a thin aluminum foil and ionize the air in the immediate vicinity of the window. Mystery solved later, in 1897, when the English physicist Dzh.Dzh. Thompson established the nature of the particles in cathode rays and they were called electrons.
P. repeated some of the earlier experiments, in particular showing that coming from the window Lenard Cathode rays (then still unknown) cause fluorescence of the screen covered with barium tsianoplatinitom. One day (this happened on Nov. 8, 1895) P., to facilitate monitoring, darkened room and turned up Crookes (without window Lenard) dense opaque black paper. To his surprise, he saw on the screen, standing nearby, covered with tsianoplatinitom barium fluorescence band. Thoroughly analyze and remove possible causes of errors, . he established, . that the fluorescence appeared every time, . when it included the receiver, . that the source of radiation is precisely the tube, . and not some other part of the chain and that the screen fluoresce even at a distance of nearly two meters from the tube, . far surpasses the capabilities of short-cathode rays.,
. The next seven weeks he spent investigating the phenomenon, which he called the X-rays (ie
. unknown rays). The shade, which cast on fluorescent screen guide from the induction coil, to create the required high voltage electricity, turned the P. the idea of studying the penetrating power of X-rays in various materials. He found that X-rays can penetrate almost all the objects at various depths, depending on the thickness of the object and the density of matter. Holding a small lead disc between the discharge tube and the screen, P. noticed that the lead is impervious to X-rays, and then made a startling discovery: the bones of his hands cast on the screen darker shade, surrounded by a lighter shade of soft tissue.
. Soon he discovered that X-rays are not only the glow of the screen covered with tsianoplatinitom barium, but darkening of photographic plates (after development) in those places where X-rays fall on the photographic emulsion
. Since P. became the world's first radiologist. In honor of his X-rays became known as X-rays. Widespread fame made P. X-ray picture (radiograph) brush of his wife. It, . as negative, . clearly visible in the bone (white, . as more dense bone retards the X-rays, . not letting them get on a photographic plate) against the darker images of soft tissues (delay x-rays to a lesser extent), and white stripes of the rings on his fingers.,
. In 1893, Mr.
. German physiologist and physicist Hermann von Helmholtz had predicted that the radiation like light, but with a sufficiently short wavelengths could penetrate solid materials. While such radiation was not known. After the opening of P. German physicist Max von Laue made the brilliant suggestion that the short-wave nature of X-rays could be proved, using as a diffraction grating is a regular arrangement of atoms in a crystal. The diffraction grating consists of a series of strokes, held at the same (small) distance from each other on the surface of glass or metal plates.
. In the scattering of light on such plates arises from a complex pattern of bright and dark spots, whose form depends on the wavelength of light incident on the grating
. But optical diffraction gratings have been too rude to them could happen diffraction of radiation with such short wavelengths, such as those expected in the case of X-rays. In 1913, Mr.. experiment, proposed by von Laue, was raised by Walter Friedrich and Paul Knipping. For example, opening a previously unknown radiation, R. made a significant contribution to that revolution in physics, which took place at the beginning of XX century.
Starting R. his research, published in the local scientific journal in late 1895, has generated enormous interest in scientific circles, and the general public. 'We soon found out - he wrote P., - that all bodies are transparent to these rays, though in very different degrees of'. Experiments P. were immediately confirmed by other scientists. R. published two articles on X-rays in 1896 and 1897. but then his interests shifted to other areas.
Doctors immediately recognized the importance of X-rays to diagnose. At the same time, X-rays have become a sensation, which trumpeted around the world newspapers and magazines, often handing materials hysterical note, or with a comic touch. R. annoyed suddenly fallen on his fame, breaks away from him precious time and hamper the further experimental studies. For this reason, he was rarely speak with the publication of articles, while not stop do it all: for my life P. 58 articles written. In 1921, when he was 76 years old, he published an article on the electrical conductivity of crystals.
In 1899, shortly after the closure of the department of physics at Leipzig University, P. became professor of physics and director of the Physics Institute at the University of Munich. While in Munich, P. learned that it was the first (1901) Nobel Prize in Physics "in recognition of unusually important service to science, epitomized by the opening of the remarkable rays subsequently named in his honor '. When presenting the winner K.T. Odhner, a member of the Royal Swedish Academy of Sciences, said: 'There is no doubt how much success will reach physical science, when the previously unknown form of energy will be sufficient to investigate'. Then Odhner reminded the audience that the X-rays have already found many practical applications in medicine.
In 1872, Mr.. R. married Anna Bertha Ludwig, daughter of the owner of the guesthouse, he had met in Zurich, where he studied at the Federal Institute of Technology. Not having their own children, spouses in 1881. adopted by a six-year old Bertha, the daughter of his brother R.
Modest, shy P. Deeply resentful of the idea that his person may attract attention. He liked being outdoors, many times visited during holidays Veylhaym, where the ascent to the neighboring Bavarian Alps, and was hunting with friends. He resigned from their posts in Munich in 1920, shortly after the death of his wife. He died three years later from cancer of internal organs.
Although P. was quite satisfied with the knowledge that his discovery is of great importance for medicine, he never dreamed of any of the patent, nor the financial remuneration. He has received many awards, . in addition to the Nobel Prize, . including the Rumford medal of the Royal Society of London, . Barnard's gold medal for outstanding services to science at Columbia University, . and was an honorary member and a corresponding member of scientific societies of many countries.,