Friedrich Hasenöhrl
From Wikipedia, the free encyclopedia
 Friedrich Hasenöhrl |
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| Born | November 30, 1874 Vienna, Austria |
|---|---|
| Died | October 7, 1915 South Tyrol, Italy |
| Residence | Austria |
| Nationality | Austrian |
| Field | Physicist |
| Institution | University of Vienna |
| Alma Mater | University of Vienna |
| Notable Students | Karl Herzfeld, Erwin Schrödinger |
| Known for | Cavity radiation |
Friedrich Hasenöhrl (November 30, 1874 - October 7, 1915), was an Austrian scientist.
Friedrich Hasenöhrl was born in Vienna, Austria 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 the South Tyrol. He was wounded, recovered and returned to the front. He was then killed by a grenade in an attack on Mount Plaut in the South Tyrol on October 7, 1915 at the age of 40.
[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/c^2.
In the later paper[2], Hasenöhrl re-calculated this result and arrived at m = (4/3)E/c^2. 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. This would be in accordance with his calculation. 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[3] showed that Hasenöhrl had made a slight error in that he did not include the shell. If he had included the shell in his calculations, the factor would have been 1 or m = E/c^2.
[edit] References
- Hasenöhrl,Friedrich, Berichte der Wiener Akadamie, 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.
