Paul Karl Ludwig Drude (; ; 12 July 1863 – 5 July 1906) was a German

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 ...

specializing in

optics Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of optical instruments, instruments that use or Photodetector, detect it. Optics usually describes t ...

. He was known for the Drude model.

Biography

Education

Born in

Braunschweig Braunschweig () or Brunswick ( ; from Low German , local dialect: ) is a List of cities and towns in Germany, city in Lower Saxony, Germany, north of the Harz Mountains at the farthest navigable point of the river Oker, which connects it to the ...

, Drude began his studies in

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 ...

, but later changed his major to

physics Physics is the scientific study of matter, its Elementary particle, 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 whi ...

. His dissertation covering the reflection and

diffraction Diffraction is the deviation of waves from straight-line propagation without any change in their energy due to an obstacle or through an aperture. The diffracting object or aperture effectively becomes a secondary source of the Wave propagation ...

of light in crystals was completed in 1887, under

Woldemar Voigt Woldemar Voigt (; 2 September 1850 – 13 December 1919) was a German mathematician and physicist. Biography Voigt was born in Leipzig, and died in Göttingen. He was a student of Franz Ernst Neumann. Voigt taught at the Georg August Universi ...

. Drude graduated the year

Heinrich Hertz Heinrich Rudolf Hertz (; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism. Biography Heinri ...

began publishing his findings from his experiments on the

electromagnetic In physics, electromagnetism is an interaction that occurs between particles with electric charge via electromagnetic fields. The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interacti ...

theories of

James Clerk Maxwell James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish physicist and mathematician who was responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism an ...

. Thus Drude began his professional career at the time Maxwell's theories were being introduced into Germany.

Career

In 1894, Drude became an extraordinarius professor at the

University of Leipzig Leipzig University (), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December 1409 by Frederick I, Electo ...

; in the same year he married Emilie Regelsberger, daughter of a Göttingen lawyer. They had four children. In 1900, he became the editor for ''

Annalen der Physik ''Annalen der Physik'' (English: ''Annals of Physics'') is one of the oldest scientific journals on physics; it has been published since 1799. The journal publishes original, peer-reviewed papers on experimental, theoretical, applied, and mathem ...

'', the most respected physics journal at that time. From 1901 to 1905, he was Ordinarius Professor of Physics at Giessen University. In 1905, he became the Director of the Physics Institute of the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

. In 1906, at the height of his career, he became a member of the

Prussian Academy of Sciences The Royal Prussian Academy of Sciences () was an academy established in Berlin, Germany on 11 July 1700, four years after the Prussian Academy of Arts, or "Arts Academy," to which "Berlin Academy" may also refer. In the 18th century, when Frenc ...

. A few days after his inauguration lecture, for inexplicable reasons, he committed suicide. Drude was survived by his wife and children.

Research

His first experiments were the determination of the

optical Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...

constants of various solids, measured to unprecedented levels of accuracy. He then worked to derive relationships between the optical and electrical constants and the physical structure of substances. In 1894 he was responsible for introducing the symbol "''c''" for the

speed of light The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time i ...

in a perfect

vacuum A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressur ...

. Toward the end of his tenure at Leipzig, Drude was invited to write a textbook on optics, which he accepted. The book, ''Lehrbuch der Optik'', published in 1900, brought together the formerly distinct subjects of

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

and

, which was cited by Drude as an “epoch-making advance in natural science.”Jungnickel, 1990b, p. 171. In 1900, he developed a powerful model to explain the thermal, electrical, and optical properties of matter. The Drude model would be further advanced in 1927 by

Arnold Sommerfeld Arnold Johannes Wilhelm Sommerfeld (; 5 December 1868 – 26 April 1951) was a German Theoretical physics, theoretical physicist who pioneered developments in Atomic physics, atomic and Quantum mechanics, quantum physics, and also educated and ...

into the Drude–Sommerfeld model.

Honors

* The crater

Drude In German folklore, a drude (, , pl. ''Druden'') is a kind of malevolent nocturnal spirit (an alp, kobold or hag) associated with nightmares, prevalent especially in Southern Germany. Druden were said to participate in the Wild Hunt and we ...

on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

is named after him. * The Paul Drude Institute, in Berlin, was named in his honor.

Books

* ''Lehrbuch der Optik'', Leipzig, 1906.

References

Other sources

* Jungnickel, Christa and Russell McCormmach. '' Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, Volume 1: The Torch of Mathematics, 1800 to 1870.'' University of Chicago Press, paper cover, 1990a. . * Jungnickel, Christa and Russell McCormmach. '' Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, Volume 2: The Now Mighty Theoretical Physics, 1870 to 1925.'' University of Chicago Press, Paper cover, 1990b. .

External links

Brief biography
{{DEFAULTSORT:Drude, Paul 1863 births 1906 suicides 19th-century German physicists Members of the Prussian Academy of Sciences Scientists from Braunschweig Scientists from the Duchy of Brunswick University of Göttingen alumni Academic staff of Leipzig University Academic staff of the University of Giessen Academic staff of the Humboldt University of Berlin Suicides in Germany 1906 deaths