August Adolf Eduard Eberhard Kundt (; 18 November 183921 May 1894) was a

German German(s) may refer to: * Germany (of or related to) ** Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

Early life

Kundt was born at

Schwerin Schwerin (; Mecklenburgian Low German: ''Swerin''; Latin: ''Suerina'', ''Suerinum'') is the capital and second-largest city of the northeastern German state of Mecklenburg-Vorpommern as well as of the region of Mecklenburg, after Rostock. It ...

Mecklenburg Mecklenburg (; nds, label= Low German, Mękel(n)borg ) is a historical region in northern Germany comprising the western and larger part of the federal-state Mecklenburg-Western Pomerania. The largest cities of the region are Rostock, Schweri ...

. He began his scientific studies at

Leipzig Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as ...

, but afterwards went to

Berlin University Humboldt-Universität zu Berlin (german: Humboldt-Universität zu Berlin, abbreviated HU Berlin) is a German public research university in the central borough of Mitte in Berlin. It was established by Frederick William III on the initiative o ...

. At first he devoted himself to

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

, but coming under the influence of H. G. Magnus, he turned his attention to

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

, and graduated in 1864 with a thesis on the depolarization of light. In 1867 he became privatdozent in Berlin University, and in the following year was chosen professor of physics at the

Federal Polytechnic Institute (colloquially) , former_name = eidgenössische polytechnische Schule , image = ETHZ.JPG , image_size = , established = , type = Public , budget = CHF 1.896 billion (2021) , rector = Günther Dissertori , president = Joël Mesot , a ...

in Zurich, where he was the teacher of

Wilhelm Conrad Röntgen Wilhelm may refer to: People and fictional characters * William Charles John Pitcher, costume designer known professionally as "Wilhelm" * Wilhelm (name), a list of people and fictional characters with the given name or surname Other uses * Mount ...

; then, after a year or two at

Würzburg Würzburg (; Main-Franconian: ) is a city in the region of Franconia in the north of the German state of Bavaria. Würzburg is the administrative seat of the ''Regierungsbezirk'' Lower Franconia. It spans the banks of the Main River. Würzburg ...

, he was called in 1872 to Strasbourg, where he took a great part in the organization of the

new university In the UK, a post-1992 university, synonymous with new university or modern university, is a former polytechnic or central institution that was given university status through the Further and Higher Education Act 1992, or an institution that ...

, and was largely concerned in the erection of the Physical Institute. Finally in 1888 he went to Berlin as successor to

Hermann von Helmholtz Hermann Ludwig Ferdinand von Helmholtz (31 August 1821 – 8 September 1894) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Associatio ...

in the chair of experimental physics and directorship of the Berlin Physical Institute. He died after a protracted illness at Israelsdorf, near

Lübeck Lübeck (; Low German also ), officially the Hanseatic City of Lübeck (german: Hansestadt Lübeck), is a city in Northern Germany. With around 217,000 inhabitants, Lübeck is the second-largest city on the German Baltic coast and in the state ...

, on 21 May 1894.

Career

As an original worker, Kundt was especially successful in the domains of sound and light. In 1866, he developed a valuable method for the investigation of aerial waves within pipes, based on the fact that a finely divided powder,

lycopodium ''Lycopodium'' (from Greek ''lykos'', wolf and ''podion'', diminutive of ''pous'', foot) is a genus of clubmosses, also known as ground pines or creeping cedars, in the family Lycopodiaceae. Two very different circumscriptions of the genus are i ...

for example, when dusted over the interior of a tube in which is established a vibrating column of air, tends to collect in heaps at the nodes, the distance between which can thus be ascertained. An extension of the method renders possible the determination of the velocity of sound in different gases. This experimental apparatus is called a

Kundt's Tube Kundt's tube is an experimental acoustical apparatus invented in 1866 by German physicist August Kundt for the measurement of the speed of sound in a gas or a solid rod. The experiment is still taught today due to its ability to demonstrate l ...

. In 1876, at Strasbourg in collaboration with

Emil Warburg Emil Gabriel Warburg (; 9 March 1846 – 28 July 1931) was a German physicist who during his career was professor of physics at the Universities of Strassburg, Freiburg and Berlin. He was president of the Deutsche Physikalische Gesellschaft 1899� ...

, Kundt proved that mercury vapour is a

monatomic gas In physics and chemistry, "monatomic" is a combination of the words "mono" and "atomic", and means "single atom". It is usually applied to gases: a monatomic gas is a gas in which atoms are not bound to each other. Examples at standard conditions ...

.* In light, Kundt's name is widely known for his inquiries in anomalous dispersion, not only in liquids and vapours, but even in

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

s, which he obtained in very thin films by means of a laborious process of electrolytic deposition upon platinized glass. He also carried out many experiments in magneto-optics, and succeeded in showing what

Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic induction, ...

had failed to detect, the rotation under the influence of

magnetic force In physics (specifically in electromagnetism) the Lorentz force (or electromagnetic force) is the combination of electric and magnetic force on a point charge due to electromagnetic fields. A particle of charge moving with a velocity in an e ...

of the plane of polarization in certain gases and vapours. Work was performed by Kundt on plant physiology and chlorophyll light frequencies absorption (Kundt's rule), centred on wavelengths of 6800 Å. This work may or may not have been complementary to E. Warburg work and theories. It was subsequently refined and expanded by R. Houston and O. Biermacher and others.

Early life

Career

See also

References

Sources

Further reading