John Herapath

John Herapath

John Herapath (May 30, 1790 - February 24, 1868) was an English physicist who gave a partial account of the kinetic theory of gases in 1820 though it was neglected by the scientific community at the time.

Herapath's scientific interests started with an attempt to provide a mechanistic explanation for gravity. Motivated by his search for a mechanical explanation of gravitation, he started to consider how a system of colliding particles could give rise to "action at a distance". In considering the effect of the high temperatures near the Sun on his "gravific particles" he was led to a relationship between temperature and particle velocity.

Herapath postulated that the momentum of a particle in a gas is a measure of the absolute temperature of the gas. He used momentum, rather than the kinetic energy on which the later established theory is based, as it seemed to him to avoid some difficulties around whether elastic collisions were possible between indivisible atoms. Apparently ignorant of Daniel Bernoulli's work, he was led to the incorrect, but suggestive, relationship that expresses the product of pressure "P" and volume "V" as proportional to the square of his "true temperature". The correct relationship is proportional to the absolute temperature, not its square, the error arising from his identification of momentum, rather than energy, with temperature.

He submitted his ideas in a paper to the Royal Society in 1820 where it was peer reviewed by Sir Humphry Davy. Davy had already sympathised with the view that heat was associated with molecular motion rather than with Joseph Black's caloric theory of heat but he rejected Herapath's paper with some coolness, uncomfortable with the implication that there was an absolute zero of temperature at which all motion ceased. Davy may also have had some distaste for the mechanistic Newtonian picture, influenced as he was by the more holistic philosophy of the Romantic movement.

In 1821, Herapath managed to have his paper published in the "Annals of Philosophy", a well-read journal that counted Michael Faraday among its regular contributors. However, the paper seems to have attracted little attention other than from James Prescott Joule who presented a short account of the work in 1848, again to little reaction. Meanwhile, Herapath maintained a campaign against Davy and the Royal Society in the correspondence pages of "The Times" newspaper.

He discovered the Great Comet of 1831 on January 7, 1831.

In 1835 Herapath became editor of "The Railway Magazine" (which became " Railway Gazette", and is not to be confused with "The Railway Magazine" which commenced publication in 1897 - see notes in discussion page), which gave him some limited opportunity to publish his scientific ideas. In 1836, he published a calculation of the mean molecular speed in a gas based on his kinetic theory and hence the speed of sound. Joule reproduced his results but is usually incorrectly credited as the originator.

He revised his theories in the 1840s, largely based on the experimental work of Thomas Graham and Henri Victor Regnault, and published it in his two-volume "Mathematical Physics" (1847).

References

Further reading

*
*

External links

* [http://www.math.umd.edu/~lvrmr/History/Neglected.html Neglected Pioneers: John Herapath]


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • John Herapath — (* 30. Mai 1790; † 24. Februar 1868) war ein englischer Physiker und Astronom, der teilweise die kinetische Gastheorie vorwegnahm, was aber von seinen Zeitgenossen kaum beachtet wurde. Herapaths wissenschaftliche Arbeiten begannen mit dem Versuch …   Deutsch Wikipedia

  • Herapath — John Herapath (* 30. Mai 1790 † 24. Februar 1868) war ein englischer Physiker und Astronom, der teilweise die kinetische Gastheorie vorwegnahm, was aber von seinen Zeitgenossen kaum beachtet wurde. Herapaths wissenschaftliche Arbeiten begannen… …   Deutsch Wikipedia

  • John James Waterston — (1811 June 18, 1883) was a Scottish physicist, a neglected pioneer of the kinetic theory of gases.Early lifeWaterston s father, George, was an Edinburgh sealing wax manufacturer and stationer, a relative of the family of Robert and George… …   Wikipedia

  • John James Waterston — (* 1811; † 18. Juni 1883) war ein schottischer Physiker. Er gilt als Pionier der kinetischen Gastheorie. Inhaltsverzeichnis 1 Leben und Ausbildung 2 Kinetische Gastheorie 3 Letzte Stationen …   Deutsch Wikipedia

  • John James Waterston — (1811 18 de junio de 1883) fue un químico escocés, que realizó trabajos pioneros sobre la teoría cinética de los gases. Después de que su trabajo fuese rechazado por la Royal Society en 1845 se volvió huraño y esquivo con los demás miembros de la …   Wikipedia Español

  • Kinetic theory — [ temperature of an ideal monatomic gas is a measure related to the average kinetic energy of its atoms as they move. In this animation, the size of helium atoms relative to their spacing is shown to scale under 1950 atmospheres of pressure.… …   Wikipedia

  • atom — /at euhm/, n. 1. Physics. a. the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical… …   Universalium

  • Liste der Biografien/Hep–Her — Biografien: A B C D E F G H I J K L M N O P Q …   Deutsch Wikipedia

  • James Clerk Maxwell — Pour les articles homonymes, voir Maxwell. James Clerk Maxwell James Clerk Maxwell Naissance 13 …   Wikipédia en Français

  • Gastheorie — Die Kinetische Gastheorie (früher auch dynamische Gastheorie) ist ein Teilgebiet der statistischen Mechanik. Die kinetische Gastheorie erklärt die Gasgesetze und die Eigenschaften von Gasen durch Bewegungsvorgänge ihrer Teilchen. Die Kinetische… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”