Emil Wiechert

Emil Wiechert ( born December 26, 1861 in Tilsit, East Prussia, † March 19, 1928 in Göttingen, also: Johann Emil Wiechert ) was a German physicist and seismologist.

Life

Emil Wiechert was the only child of Tilsit merchant Johann Wiechert and his wife Emilie. After the early death of his father, he grew up in Königsberg, where he attended the grammar school and studied after high school in 1881 at the University of Königsberg Albertina physics. In 1889 he earned his doctorate under Paul Volkmann ( 1856-1938 ) and his habilitation in the following year for physics. His research in Königsberg dealt with the structure of matter, experimenting with cathode rays and theoretical work on electricity. Little known is that there succeeded one of the first rules of the ratio of charge to mass of the electron.

He discovered about the same time as Joseph John Thomson ( commonly termed as the discoverer and the Nobel Prize), the particle that today "electron" is called. In April 1896, he has pointed out in a lecture to the Konigsberg Physical- Economic Society on the existence of a particle whose mass must be much smaller than that of the hydrogen atom. On January 7, 1897, he reported in a lecture to the same society that he had detected the particle and determine its mass than about 2000 to 4000 times smaller than that of the hydrogen atom experimentally. In September 1897, he gave a more accurate value known: the mass of the particle is about 1 / (1500 ± 500 ) of the mass of the hydrogen atom ( current value is 1/ 1838). Thomson's lecture to the Royal Society was held on 30 April 1897.

Wiechert introduced independently by Alfred -Marie Liénard (1898 ) in an essay in 1900, named after two Liénard -Wiechert potentials of a moving charge a.

After Göttingen physicist Emil Wiechert on became aware, he worked from 1897 at the University of Göttingen, where he received in 1898, the reputation of the world's first chair of geophysics. After completion of the newly established Institute for Geophysics at the grove hill above Göttingen Wiechert began in 1901 with the construction of there today still operating Wiechert earthquake observatory. The construction of the air- damped Wiechertschen seismograph with high magnification, which should be the model for most of the instruments used in the seismic stations around the world for decades, the first time allowed a continuous record of global earthquake activity. The data recorded by this seismograph charts of ground motion propagation of the seismic waves and the structure of the Earth's interior have been explored. In addition, air and geomagnetic electrical phenomena have been studied. In 1902, a geophysical observatory was founded in Samoa on Wiechert operation, which was operated until after the First World War from Göttingen. Behind this was the realization that the answers to the great questions of geophysics requires a global observation network. 1903 Emil Wiechert one of the founders of the International Association of Seismology, from which today's International Association of Seismology and Physics of the Earth 's Interior ( IASPEI ) has emerged.

Many of Emil Wiechert Göttingen students have become important later geophysicist and have branches of science, decisive progress has, such as Beno Gutenberg and Ludger Mintrop and Hans Haalck. Wiechert itself has received numerous honors, was in constant exchange with the leading physicists of his time ( such as Arnold Sommerfeld, Hendrik Antoon Lorentz, Albert Einstein, Max Planck ) and took an active interest in the rapid developments in many fields of physics, including the development of theory of relativity. This was, among others, in his contributions to the subject of ether in physics to express what Wilfried Schroeder brought a compilation, which also published the correspondence Sommerfeld and Wiechert Lorentz -Wiechert. However, his main area of ​​work remained seismology, he drove forward constantly on practical and theoretical field. Consequently, he gave in 1922 led to the founding of the German Seismological Society, whose first chairman was elected in Leipzig. 1924 was the German Geophysical Society resulting ( DGG ), which has named its highest award for outstanding work in the field of geophysics by Emil Wiechert.

Several calls to prestigious professorships refused Emil Wiechert. In 1908 he had married Helene Ziebarth, the daughter of a prominent jurists Göttingen; The marriage remained childless. With her and his mother, he lived quietly and very focused on his scientific work, which he continued unabated until just before his death in 1928 at the age of 66 years.

Emil Wiechert is also internationally recognized as the founding father of the field of geophysics. Even today he is considered one of the most important seismologists in Germany, if not the world. He founded seismic observatory in Göttingen is a monument to science today with the historical instruments operation. It is the only facility, such as the San Francisco 1906 enables a direct comparison of large earthquakes of the past with today's earthquake.

After Emil Wiechert, a crater is named on the reverse side of the moon.

On 10 November 2011, the German post office issued a special stamp made ​​to mark the 150th birthday of Emil Wiechert (worth 90 cents) out.

Quote

"Remote client brings you the fluctuating rock Explain the sign! "