Wilhelm Wien

Wilhelm Carl Werner Otto Fritz Franz Wien (German: [ˈviːn]; 13 January 1864 – 30 August 1928) was a German physicist who, in 1893, used theories about heat and electromagnetism to deduce Wien's displacement law, which calculates the emission of a blackbody at any temperature from the emission at any one reference temperature.

He also formulated an expression for the black-body radiation, which is correct in the photon-gas limit. His arguments were based on the notion of adiabatic invariance, and were instrumental for the formulation of quantum mechanics. Wien received the 1911 Nobel Prize for his work on heat radiation.

He was a cousin of Max Wien, inventor of the Wien bridge.

Wilhelm Wien
Wilhelm Wien 1911
Born
Wilhelm Carl Werner Otto Fritz Franz Wien

13 January 1864
Died30 August 1928 (aged 64)
NationalityGerman
Alma materUniversity of Göttingen
University of Berlin
Known forBlackbody radiation
Wien's displacement law
Spouse(s)Luise Mehler (1898)
AwardsNobel Prize for Physics (1911)
Scientific career
FieldsPhysics
InstitutionsUniversity of Giessen
University of Würzburg
University of Munich
RWTH Aachen
Doctoral advisorHermann von Helmholtz
Doctoral studentsKarl Hartmann
Gabriel Holtsmark
Eduard Rüchardt

Biography

Early years

Wien was born at Gaffken near Fischhausen, Province of Prussia (now Primorsk, Russia) as the son of landowner Carl Wien. In 1866, his family moved to Drachstein near Rastenburg (now Kętrzyn, Poland).

In 1879, Wien went to school in Rastenburg and from 1880-1882 he attended the city school of Heidelberg. In 1882 he attended the University of Göttingen and the University of Berlin. From 1883-85, he worked in the laboratory of Hermann von Helmholtz and, in 1886, he received his Ph.D. with a thesis on the diffraction of light upon metals and on the influence of various materials upon the color of refracted light. From 1896 to 1899, Wien lectured at RWTH Aachen University. He became twice successor of Wilhelm Conrad Röntgen, in 1900 at the University of Würzburg and in 1919 at the University of Munich. Wien was very active in science politics representing conservative and nationalistic positions though being not as extreme as sharing the attitude of those going to develop the "Deutsche Physik". He appreciated both Albert Einstein and relativity.[1]

Career

In 1896 Wien empirically determined a distribution law of blackbody radiation,[2] later named after him: Wien's law. Max Planck, who was a colleague of Wien's, did not believe in empirical laws, so using electromagnetism and thermodynamics, he proposed a theoretical basis for Wien's law, which became the Wien-Planck law. However, Wien's law was only valid at high frequencies, and underestimated the radiancy at low frequencies. Planck corrected the theory and proposed what is now called Planck's law, which led to the development of quantum theory. However, Wien's other empirical formulation , called Wien's displacement law, is still very useful, as it relates the peak wavelength emitted by a body (λmax), to the temperature of the body (T). In 1900 (following the work of George Frederick Charles Searle), he assumed that the entire mass of matter is of electromagnetic origin and proposed the formula for the relation between electromagnetic mass and electromagnetic energy.

Wien developed the Wien filter (also known as velocity selector) in 1898 for the study of anode rays. It is a device consisting of perpendicular electric and magnetic fields that can be used as a velocity filter for charged particles, for example in electron microscopes and spectrometers. It is used in accelerator mass spectrometry to select particles based on their speed. The device is composed of orthogonal electric and magnetic fields, such that particles with the correct speed will be unaffected while other particles will be deflected. It can be configured as a charged particle energy analyzer, monochromator, or mass spectrometer.

While studying streams of ionized gas, Wien, in 1898, identified a positive particle equal in mass to the hydrogen atom. Wien, with this work, laid the foundation of mass spectrometry. J. J. Thomson refined Wien's apparatus and conducted further experiments in 1913 then, after work by Ernest Rutherford in 1919, Wien's particle was accepted and named the proton.

In 1911, Wien was awarded the Nobel Prize in Physics "for his discoveries regarding the laws governing the radiation of heat".[3]

See also

Publications

References

  1. ^ Wolff, Stefan L. (2017-07-30). "Physiker im "Krieg der Geister"" (PDF).
  2. ^ Kragh, H. (2002). Quantum Generations: A History of Physics in the Twentieth Century. Princeton University Press. p. 58. ISBN 978-0-691-09552-3.
  3. ^ "The Nobel Prize in Physics 1911". The Nobel Foundation. Retrieved 2014-08-09.

External links

1864

1864 (MDCCCLXIV)

was a leap year starting on Friday of the Gregorian calendar and a leap year starting on Wednesday of the Julian calendar, the 1864th year of the Common Era (CE) and Anno Domini (AD) designations, the 864th year of the 2nd millennium, the 64th year of the 19th century, and the 5th year of the 1860s decade. As of the start of 1864, the Gregorian calendar was

12 days ahead of the Julian calendar, which remained in localized use until 1923.

1928 in Germany

Events in the year 1928 in Germany.

Anode ray

An anode ray (also positive ray or canal ray) is a beam of positive ions that is created by certain types of gas-discharge tubes. They were first observed in Crookes tubes during experiments by the German scientist Eugen Goldstein, in 1886. Later work on anode rays by Wilhelm Wien and J. J. Thomson led to the development of mass spectrometry.

Eduard Rüchardt

Eduard Rüchardt (March 29, 1888 – March 7, 1962) was a German physicist. In modern times Rüchardt is mainly noted for the experiment named after him. However, Rüchardt's chief topic was the study of canal rays. This work started under the supervision of Wilhelm Wien and continued later in collaborations with Walther Gerlach.

Karl Wien

Karl ("Carlo") Wien (10 September 1906 – c. 14 June 1937) was a German mountaineer.

Born in Würzburg, Wien was the son of university professor Wilhelm Wien, and became a lecturer himself in the geography department of Munich University. His mountaineering career began in the Alps, where with Willi Welzenbach he made the first ascent of the north face of the Grossglockner. Outside Europe he made a number of visits to Africa and the Himalaya, including Paul Bauer's 1931 attempt on Kangchenjunga, and a 1936 expedition to Sikkim during which he made the first ascent of Siniolchu.In 1937. Karl Wien was chosen to lead a German expedition to Nanga Parbat, the first since ten climbers had died on the mountain in 1934. Some time between 14 and 16 June, Wien was camped with fifteen other climbers at Camp IV, below Rakhiot Peak, when it was overwhelmed by a massive avalanche. All sixteen men were killed in what remains the worst single disaster ever to occur on an eight thousand metre peak.He is memorialized in Munich's Waldfriedhof. (http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=wien&GSmid=47782179&GRid=140121273&)

Kurd von Mosengeil

Kurd Friedrich Rudolf von Mosengeil, also Curd Friedrich Rudolf von Mosengeil (* 7 March 1884 in Bonn; † 5 September 1906 at Wildgall in Rieserfernergruppe), was a German physicist.

Kurd von Mosengeil was a student of Max Planck. In 1905, the latter became the most prominent early advocate of the theory of special relativity of Albert Einstein. In the subsequent years, Planck published several works, in which he explained further consequences of Einstein's theory. He conveyed his enthusiasm to his assistant Max von Laue and his student Kurd of Mosengeil, who became the first physicists to habilitate and graduate, respectively, in relativity-related subjects.

Tragically, Kurd von Mosengeil died in a mountaineering accident in Tyrol in September 1906, as he was completing his doctoral dissertation. Planck and Wilhelm Wien edited his draft for publication in the Annalen der Physik in 1907. The resulting posthumous paper (Theorie der stationären Strahlung in einem gleichförmig bewegten Hohlraum, en:Theory of stationary radiation in a uniformly moving cavity) contains the correct relativistic expression for the temperature of a moving body among other equations of relativistic thermodynamics and a statement of the mass-energy equivalence inspired by the work of Friedrich Hasenöhrl (1904). Planck vouched personally for the scientific content of von Mosengeil's dissertation and believed in its lasting value. Von Mosengeil's results help break new ground in further researches by Planck (1907) and Einstein (1908).

Kętrzyn

Kętrzyn [ˈkɛntʂɨn] (listen) (German: Rastenburg (listen); former Polish name: Rastembork), is a town in northeastern Poland with 28,351 inhabitants (2004). Situated in the Warmian-Masurian Voivodeship (since 1999), Kętrzyn was previously in Olsztyn Voivodeship (1975–1998). It is the capital of Kętrzyn County. The city was named after Wojciech Kętrzyński in 1946.

Lars Vegard

Lars Vegard (3 February 1880 – 21 December 1963) was a Norwegian physicist, especially known as an aurora borealis researcher.

He was born in Vegårshei as a son of farmer Nils Gundersen Grasaasen (1840–1886) and Anne Grundesdatter Espeland (1839–1930). He attended middle school in Risør and took the examen artium in Kristiania in 1899. He enrolled at the Royal Frederick University and graduated with the cand.real. degree in 1905. He worked as an assistant under Kristian Birkeland from 1906, and studied under J. J. Thomson from 1908 to 1910 and under Wilhelm Wien from 1911 to 1912. He was a research fellow in physics from 1908 to 1910 and amanuensis from 1910 to 1913, both at the Royal Frederick University. In 1912 he published “Über die Lichterzeugung in Glimmlicht und Kanalstrahlen” in Annalen der Physik, and this earned him the dr.philos. degree in 1913. He continued advancing at the University, and worked as a docent from 1913 to 1918 and professor from 1918 to 1952. He was also the dean of the Faculty of Mathematics and Natural Sciences from 1937 to 1941.In 1939 he proved hydrogen emissions in aurora borealis, and in 1948 he pointed out the doppler effect in hydrogen lines of aurora borealis. He penned about 100 academic publications, and was a board chairman of Det norske institutt for kosmisk fysikk from 1928 to 1935 and 1939 to 1955. He was a member of the Norwegian Academy of Science and Letters from 1914, vice president of the International Union of Physics from 1932 to 1940, and a Commander of the Royal Norwegian Order of St. Olav.Vegard also had a political career, representing the Liberal Party in Aker municipal council from 1938 to 1945. He was married to consul's daughter Inger Hervora Petersen (1886–1961) from November 1915. He died in December 1963 in Oslo.

List of Ludwig Maximilian University of Munich people

This is a list of people associated with Ludwig Maximilians University of Munich in Germany.

List of RWTH Aachen University people

This is a list of people associated with RWTH Aachen University in Germany.

List of scientific constants named after people

This is a list of physical and mathematical constants named after people.Eponymous constants and their influence on scientific citations have been discussed in the literature.

  • Reduced Planck constant or Dirac constant (-bar, ħ) – Max Planck, Paul Dirac
List of scientists whose names are used in physical constants

Some of the constants used in science are named after great scientists. By this convention, their names are immortalised. Below is the list of the scientists whose names are used in physical constants.

Max Bernhard Weinstein

Max Bernhard Weinstein (1 September 1852 in Kaunas, Vilna Governorate – 25 March 1918) was a German physicist and philosopher. He is best known as an opponent of Albert Einstein's Theory of Relativity, and for having written a broad examination of the theological theory of Pandeism.

The Russian-born Weinstein translated James Clerk Maxwell's Treatise on Electricity and Magnetism into German in 1883, and taught courses on electrodynamics at the University of Berlin.While teaching at the Institute of Physics in the University of Berlin, Weinstein associated with Max Planck, Emil du Bois-Reymond, Hermann von Helmholtz, Ernst Pringsheim, Sr., Wilhelm Wien, Carl A. Paalzow of the Technische Hochschule in Berlin Charlottenburg, August Kundt, Werner von Siemens, theologian Adolph von Siemens, historian Theodor Mommsen, and Germanic philologist Wilhelm Scherer.

Max Wien

Max Karl Werner Wien (German pronunciation: [ˈviːn]; 25 December 1866 – 22 February 1938) was a German physicist and the director of the Institute of Physics at the University of Jena. He was born in Königsberg, Prussia (now Kaliningrad, Russia). He was a cousin of Nobel laureate Wilhelm Wien.

Wien studied in Konigsberg, Freiburg, and Berlin under Hermann von Helmholtz and August Kundt, receiving his PhD under Helmholtz in 1888. In 1892 he worked with Wilhelm Röntgen in Wurtzburg, where in 1893 he received the habilitation, qualifying him to be a professor. He moved to the Technical High School of Aachen in 1898 where he became Extraordinary Professor in 1899. In 1904 he became full Professor at the Technical High School of Danzig (now Gdansk, Poland). From 1911 to 1935 he was Professor at University of Jena, in Jena, Germany, where he died in 1938.Wien's scientific research were in the areas of high frequency electronics, acoustics, and electrolyte conductance. He is known for the invention of the Wien bridge in 1891, a type of AC measurement circuit similar to the Wheatstone bridge which was used to measure the impedance of capacitors and inductors. From 1906 to 1909 he did research into the efficiency of early radio transmitters, called spark gap transmitters, which used an electric spark to generate radio waves. In existing transmitters the spark damped the oscillation in the tuned circuit, creating highly damped waves, in which the radio energy was spread over a wide bandwidth, limiting their range. In 1906 Wien invented a new type of spark gap, called a "quenched gap", that extinguished the spark immediately after energy had been transferred to the tuned circuit. This transmitter produced very lightly damped waves, which had a narrower bandwidth and thus greater range, and also produced an easy to identify musical tone in the receiver headphones. Wien "singing spark" or quenched-spark transmitters ("Löschfunkensender") were widely used until the end of the spark era around 1920. At Jena he studied the conductance of electrolyte solutions when high fields and high frequencies, discovering what is now called Wien's law.The Wien bridge oscillator is so named because it uses a Wien bridge as a feedback network, but it was not invented by Wien. William Hewlett, co-founder of Hewlett-Packard, was the first to use a Wien bridge as a feedback network around a vacuum tube amplifier to create an oscillator in 1939.

RWTH Aachen Faculty of Mathematics, Computer science, and Natural sciences

The Faculty of Mathematics, Computer science, and Natural sciences is one of nine faculties at the RWTH Aachen University. It comprises five sections for mathematics, computer science, physics, chemistry and biology. The Faculty was founded in 1880 and produced several notable individuals like Arnold Sommerfeld and Nobel laureates Philipp Lenard, Wilhelm Wien, Johannes Stark or Karl Ziegler. Peter Debye studied Physics at the RWTH Aachen and won the Nobel Prize in 1936. Furthermore, Helmut Zahn and his team of the Institute for textile chemistry were the first who synthesised Insulin.

The faculty cooperates with Forschungszentrum Jülich and the 4 Fraunhofer Institutes in Aachen. Several projects are assisted by the Deutsche Forschungsgemeinschaft and the European Union. Approximately 6,100 students are enrolled in the faculty.

University of Würzburg

The Julius Maximilian University of Würzburg (also referred to as the University of Würzburg, in German Julius-Maximilians-Universität Würzburg) is a public research university in Würzburg, Germany. The University of Würzburg is one of the oldest institutions of higher learning in Germany, having been founded in 1402. The university initially had a brief run and was closed in 1415. It was reopened in 1582 on the initiative of Julius Echter von Mespelbrunn. Today, the university is named for Julius Echter von Mespelbrunn and Maximilian Joseph.

The University of Würzburg is part of the U15 group of research-intensive German universities. The university is also a member of the Coimbra Group.Adolf-Wuerth-Center for the History of Psychology is a scientific institution of the University

Wien's displacement law
Not to be confused with Wien distribution law.

Wien's displacement law states that the black-body radiation curve for different temperature peaks at a wavelength is inversely proportional to the temperature. The shift of that peak is a direct consequence of the Planck radiation law, which describes the spectral brightness of black-body radiation as a function of wavelength at any given temperature. However, it had been discovered by Wilhelm Wien several years before Max Planck developed that more general equation, and describes the entire shift of the spectrum of black-body radiation toward shorter wavelengths as temperature increases.

Formally, Wien's displacement law states that the spectral radiance of black-body radiation per unit wavelength, peaks at the wavelength λmax given by:

where T is the absolute temperature in kelvins. b is a constant of proportionality called Wien's displacement constant, equal to 2.8977729(17)×10−3 m⋅K, or to obtain wavelength in micrometers, b ≈ 2900 μm⋅K. If one is considering the peak of black body emission per unit frequency or per proportional bandwidth, one must use a different proportionality constant. However, the form of the law remains the same: the peak wavelength is inversely proportional to temperature, and the peak frequency is directly proportional to temperature.

Wien's displacement law may be referred to as "Wien's law", a term which is also used for the Wien approximation.

Wien approximation

Wien's approximation (also sometimes called Wien's law or the Wien distribution law) is a law of physics used to describe the spectrum of thermal radiation (frequently called the blackbody function). This law was first derived by Wilhelm Wien in 1896. The equation does accurately describe the short wavelength (high frequency) spectrum of thermal emission from objects, but it fails to accurately fit the experimental data for long wavelengths (low frequency) emission.

Wien filter

A Wien filter also known as velocity selector is a device consisting of perpendicular electric and magnetic fields that can be used as a velocity filter for charged particles, for example in electron microscopes and spectrometers. It is used in accelerator mass spectrometry to select particles based on their speed. The device is composed of orthogonal electric and magnetic fields, such that particles with the correct speed will be unaffected while other particles will be deflected. It is named for Wilhelm Wien who developed it in 1898 for the study of anode rays. It can be configured as a charged particle energy analyzer, monochromator, or mass spectrometer.

1901–1925
1926–1950
1951–1975
1976–2000
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present
Physical constants

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