physics

Wilhelm Wien

Wilhelm Wien is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Wilhelm Wien rather than just read about it. In short: Wilhelm Carl Werner Otto Fritz Franz Wien (German: [ˈvɪlhɛlm ˈviːn] ; 13 January 1864 – 30 August 1928) was a German physicist who 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. Wien also formulated an expression for the black-body radiation, which is correct in the ph…

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Reference excerpt

Wilhelm Carl Werner Otto Fritz Franz Wien (German: [ˈvɪlhɛlm ˈviːn] ; 13 January 1864 – 30 August 1928) was a German physicist who 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. Wien 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 Nobel Prize in Physics in 1911 for his work on heat radiation. He was a cousin of Max Wien, inventor of the Wien bridge.

Early life and education Wien was born on 13 January 1864 in Gaffken (now Parusnoye, Russia), Prussia, the son of landowner Carl Wien. In 1866, his family moved to Drachenstein (now Smokowo, Poland). In 1879, Wien went to school in Rastenburg (now Kętrzyn, Poland) and from 1880 to 1882 he attended the city school of Heidelberg. In 1882, he attended the University of Göttingen and the University of Berlin. From 1883 to 1885, 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 Röntgen, in 1900 at the University of Würzburg and in 1920 at the Ludwig-Maximilians-Universität München. 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.

Career In 1896, Wien empirically determined a distribution law of blackbody radiation, 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 λ m a x T = c o n s t a n t {\displaystyle \lambda _{\mathrm {max} }T=\mathrm {constant} } , 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 m = ( 4 / 3 ) E / c 2 {\displaystyle m=(4/3)E/c^{2}} 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". He delivered the Ernest Kempton Adams Lecture at Columbia University in 1913.

See also History of special relativity Mass–energy equivalence

Publications

—— (1898). "Ueber die Fragen, welche die translatorische Bewegung des Lichtäthers betreffen" . Annalen der Physik. 301 (3): 1–18. Bibcode:1898AnP...301....1D. doi:10.1002/andp.18983010502. —— (1900). Lehrbuch der Hydrodynamik. S. Hirzel. ISBN 978-0-691-21419-1. OCLC 557663670. OL 16968004M. {{cite book}}: ISBN / Date incompatibility (help) —— (1900). "Über die Möglichkeit einer elektromagnetischen Begründung der Mechanik" . Annalen der Physik. 310 (7): 501–513. Bibcode:1901AnP...310..501W. doi:10.1002/andp.19013100703. —— (1904a). "Über die Differentialgleichungen der Elektrodynamik für bewegte Körper. I" . Annalen der Physik. 318 (4): 641–662. Bibcode:1904AnP...318..641W. doi:10.1002/andp.18943180402. —— (1904b). "Über die Differentialgleichungen der Elektrodynamik für bewegte Körper. II" . Annalen der Physik. 318 (4): 663–668. Bibcode:1904AnP...318..663W. doi:10.1002/andp.18943180403. —— (1904c). "Erwiderung auf die Kritik des Hrn. M. Abraham" . Annalen der Physik. 319 (8): 635–637. Bibcode:1904AnP...319..635W. doi:10.1002/andp.19043190817. —— (1904d). "Zur Elektronentheorie" . Physikalische Zeitschrift. 5 (14): 393–395. —— (1930). Aus dem Leben und Wirken eines Physikers. Johann Ambrosius Barth. ISBN 978-0-691-21419-1. OCLC 249831418. {{cite book}}: ISBN / Date incompatibility (help) —— (1913). Neuere Probleme der theoretischen Physik (in German). B. G. Teubner. LCCN 14005571. OL 6565621M.

References Rüchardt, E. (1936). "Zur Entdeckung der Kanalstrahlen vor fünfzig Jahren". Naturwissenschaften. 24 (30): 57–62. Bibcode:1936NW.....24..465R. doi:10.1007/BF01473963. S2CID 33211480. Rüchardt, E. (1955). "Zur Erinnerung an Wilhelm Wien bei der 25. Wiederkehr seines Todestages". Naturwissenschaften. 42 (3): 57–62. Bibcode:1955NW.....42...57R. doi:10.1007/BF00589524. S2CID 42482780.

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Illustrations

Worked examples

Example 1 — a first encounter with Wilhelm Wien

Start with the simplest possible case. Write down what Wilhelm Wien claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Wilhelm Wien before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Wilhelm Wien ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Wilhelm Wien

In research: Wilhelm Wien appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Wilhelm Wien in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Wilhelm Wien is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1864 births, 1928 deaths, 19th-century German physicists, so understanding it makes those chapters shorter.
In everyday life: Look for Wilhelm Wien outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Wilhelm Wien in 20 minutes

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Frequently asked questions

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Why does Wilhelm Wien matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Wilhelm Wien?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

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It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Wilhelm Wien.