John Trowbridge (physicist)

John Trowbridge (August 5, 1843 – February 18, 1923) was an American physicist, innovator in science education, and, from 1888 to 1910, holder of Harvard University's Rumford Chair of Physics. He was elected in 1878 to the United States National Academy of Sciences and in 1896 to the American Philosophical Society. From 1908 to 1916, he served as president of the American Academy of Arts and Sciences.

Quotes

In order to make measurements of force, it is essential that the field of force should be uniform—that is, the lines of force should be straight, and the pull or push along them should be the same at any point in the field. If the lines of force are not straight, a pendulum in swinging across these curved lines of force would not be uniformly acted upon by equal parallel forces. It would move under the influence of one force in one direction, and at another time under the influence of another in a different direction. There could be no uniformity in its motion in different parts of such a curved field of force. In all our experiments, therefore, we endeavor to make our measurements in fields of uniform force, whether these fields be gravitational fields, magnetic, or electrical fields.
- The New Physics. D. Appleton & Company. 1884. p. 154.

It is an interesting question to ask if Tyndall were living today, and if a publisher should ask him to bring his book up to date, what title would he give to it? He certainly would not retain the title Heat as a Mode of Motion nor would he, in view of the all-embracing nature of electricity, term it Electricity, a Mode of Motion. The extension of our views of energy would require for its popularization all his power as an eloquent expounder. We have made an astonishing advance since his time: the subject of physics has broken away from comparatively narrow limits and has made even chemistry and biology a part of it. The physicist has discovered that all the life of the world depends upon electromagnetic waves of energy which come from the sun.
- The Advance in Electricity Since the Time of Franklin. Harvard University Press. 1922. p. 6. (183 pages)

In the tradition of Joule, Helmholtz, and their followers, Trowbridge argued that because electrical and magnetic energy were convertible into heat, and heat had its equivalent in mechanical work, then electricity and magnetism were reducible to the purely mechanical properties of underlying atoms.
- Albert E. Moyer (1945–2000), American Physics in Transition: A History of Conceptual Change in the Late Nineteenth Century. Volume 3 of History of Modern Physics and Astronomy. Springer Science & Business Media. 1983. pp. 48–49. ISBN 9780938228066. (218 pages)