Friedrich Hasenöhrl

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Friedrich Hasenöhrl
Friedrich Hasenöhrl
Friedrich Hasenöhrl
Born November 30, 1874(1874-11-30)
Vienna, Austria-Hungary
Died October 7, 1915 (aged 40)
Tyrol, Austria-Hungary
Residence Austria-Hungary
Nationality Austro-Hungarian
Fields Physicist
Institutions University of Vienna
Alma mater University of Vienna
Doctoral advisor Franz S. Exner
Doctoral students Karl Herzfeld
Erwin Schrödinger
Known for Cavity radiation

Friedrich Hasenöhrl (November 30, 1874 - October 7, 1915), was an Austro-Hungarian physicist.

Friedrich Hasenöhrl was born in Vienna, Austria-Hungary in 1874. His father was a lawyer and his mother belonged to a prominent aristocratic family. After his elementary education, he studied natural science and mathematics at the University of Vienna under Stephan and Boltzmann. He worked under H. A. Lorentz in Leiden at the low temperature laboratory.

In 1907 he became Boltzmann's successor at the University of Vienna as the head of the Department of Theoretical Physics. He had a number of illustrious pupils there and had an especially significant impact on Erwin Schrödinger, who later won the Nobel Prize for Physics for his contributions to Quantum Mechanics.

When the war broke out in 1914, he volunteered at once into the Austria-Hungarian army. He fought as Oberleutnant against the Italians in Tyrol. He was wounded, recovered and returned to the front. He was then killed by a grenade in an attack on Mount Plaut on October 7, 1915 at the age of 40.

Contents

[edit] E = mc²

In 1904 and 1905 he published two papers on the inertia of a cavity containing radiation. This was an entirely classical derivation (no use of special relativity) and used Maxwell's equation for the pressure of light.

In the first paper, Hasenöhrl[1] specifically associated mass via inertia with the energy concept through an equation. Hasenöhrl first concluded that m = (8 / 3)E / c2. The same formula appeared on the page 363 in his paper [2]. The title of this paper, which in English is On the radiation of the bodies in motion, is very similar to the title of the Einstein's paper published a year later On the electrodynamics of the bodies in motion.

In the later paper[3] Hasenöhrl re-calculated this result and arrived at m = (4 / 3)E / c2. Hasenöhrl indicated that if the internal energy of a system consists of radiation, then, in general, the inertial mass of the system would depend upon that energy. Thus, this new Hasenöhrl calculation establishes that due to the radiant energy E contained in his system, to that inertial mass must be added an apparent mass m. Indeed, in 1914 Cunningham[4] showed that Hasenöhrl had made an error in that he did not include the shell. If he had included the shell in his calculations in a way consistent with relativity, the pre-factor would have been 1, so yielding m = E / c2. He could not have done this, since he did not have relativistic mechanics, with which he could model the shell.

[edit] See also

[edit] Notes and References

  1. ^ F. Hasenöhrl, Wien, Sitzungen IIA, 113, 1039 (1904)
  2. ^ F. Hasenöhrl, Annalen der Physik, Band 15, Heft 12, 344 (1904) [1] (the relevant part is marked on the page 363)
  3. ^ F. Hasenöhrl, Ann. Physik, 16, 589 (1905) [Received 26 Jan., presented 14 Mar.]
  4. ^ E. Cunningham, The Principle of Relativity, Cambridge University Press, 1914, p. 189

[edit] Further reading

  • Hasenöhrl,Friedrich, Berichte der Wiener Akademie, 113, 1039 (1904).
  • Hasenöhrl,Friedrich, Annalen der Physik, 16, 589 (1905).
  • Lenard, Philipp, Great Men of Science. Translated from the second German edition, G. Bell and sons, London (1950) ISBN 083691614X
  • Moore, Walter "Schrödinger: Life and Thought" University of Cambridge (1989) ISBN 0521437679.

[edit] External links


Persondata
NAME Hasenöhrl, Friedrich
ALTERNATIVE NAMES
SHORT DESCRIPTION Austrian physicist
DATE OF BIRTH November 30, 1874
PLACE OF BIRTH Vienna, Austria-Hungary
DATE OF DEATH October 7, 1915
PLACE OF DEATH Tyrol, Austria-Hungary