“I too have many reasons to believe that the present quantum theory, in spite of its many successes, is far from the truth. This theory reminds me a little of the system of delusion of an exceedingly intelligent paranoiac concocted of incoherent elements of thought.”
Albert Einstein, (1879–1955)
Letter to Daniel M. Lipkin, July 5, 1952
July 1887 as Hertz was busy with his investigations, two American scientists, Albert A. Michelson (1852–1931) and Edward W. Morley (1838–1923) decided to measure the velocity of the Earth with respect to the æther [[i]]. They constructed the interferometer of Figure 5.1, guiding a beam of light back and forth along the diagonals of a rotating square platform. They reasoned that the flow of æther through their apparatus would help or hinder the propagation of light, an effect they could detect to an accuracy better than one wavelength by making the electromagnetic waves in one direction interfere with the waves propagating in the other.

Much to their surprise, no matter how they rotated the device, Michelson and Morley saw no difference in the electromagnetic wave fringes large enough to correspond to the Earth’s supposed motion through the æther. Extending upon the 1889 observation by Oliver Heaviside (1850–1925) that a moving electrified sphere would contract along the axis of motion [[v]], George Francis FitzGerald (1851–1901) [[vi]] speculated that the length of the interferometer might contract in the direction of motion.

The implications of electrodynamics for moving bodies held further surprises. In 1900, for instance, Joseph Larmor (1857–1942) suggested that time for rapidly moving objects might dilate relative to a rest frame [[vii]].
Writing on electrodynamics in 1904 [[viii]], Hendrik Lorentz (1853–1928) offered eleven ad hoc hypotheses including the correct coordinate transformations for moving frames of reference (the “Lorentz Transforms”) and the principle of length contraction [[ix]].
Also in a 1904 lecture, Henri Poincaré (1854–1912) coined the term the “principle of relativity,” and described “a new mechanics, where, the inertia increasing with the velocity, the velocity of light would become a limit that could not be exceeded” [[x]]. These scientists and others applied and extended upon Maxwell’s theory to work out how electromagnetism works at different velocities. This bottom-up method of exploring electrodynamics would soon be overshadowed by a more Platonic top-down approach.
Next time: 5.1 Positivism & Physics
Enjoyed the article, but maybe not quite enough to spring for a paid subscription?
Then click on the button below to buy me a coffee. Thanks!
Full Table of Contents [click here]
Follow Online:
You may follow me online in other places as well:
Telegram: 𝔸𝕖𝕥𝕙𝕖𝕣𝕔𝕫𝕒𝕣'𝕤 𝔸𝕖𝕥𝕙𝕖𝕣𝕤𝕥𝕣𝕖𝕒𝕞
Gab: @aetherczar
Twitter: @aetherczar
Amazon: Hans G. Schantz
References
[[i]] Michelson, Albert A. and Edward W. Morley, “On the Relative Motion of the Earth and the Luminiferous Ether,” The American Journal of Science, vol. CXXXIV, no. 203, November 1887, pp. 333 - .
[[ii]] Fig. 3 from “On the Relative Motion of the Earth and the Luminiferous Ether.”
[[iii]] https://commons.wikimedia.org/wiki/File:Albert_Abraham_Michelson2.jpg
[[iv]] https://commons.wikimedia.org/wiki/File:Edward_Williams_Morley2.jpg
[[v]] Heaviside, Oliver, “On the Electromagnetic Effects due to the Motion of Electrification through a Dielectric,” Phil Mag, May 1889 p. 324, collected in Electrical Papers, vol. 2, p. 514.
[[vi]] FitzGerald, George Francis, “The Ether and the Earth’s Atmosphere,” Science, vol. XIII, no. 328, 1889, p. 390.
[[vii]] Larmor, Joseph, “On a Dynamical Theory of the Electric and Luminiferous Medium, Part 3, Relations with Material Media,” Philosophical Transactions of the Royal Society, vol. 190, 1897, pp. 205–300.
[[viii]] Lorentz, H.A., Proc. Acad. Sci. Amsterdam 6, 1904, p. 809.
[[ix]] Holton, Gerald, “On the Origins of the Special Theory of Relativity,” American Journal of Physics, 28(7), 1960, pp. 627–636. doi:10.1119/1.1935922 .
[[x]] Poincaré, Henri, “The Principles of Mathematical Physics,” The Monist, Vol. XV, no. 1, January 1905: a speech originally presented at the International Congress of Arts and Science, St. Louis, September, 1904.
[[xi]] Jospeh Larmor. See: https://en.wikipedia.org/wiki/Joseph_Larmor#/media/File:Joseph_Larmor.jpeg
[[xii]] Photo de le mathématicien français Henri Poincaré. See: https://upload.wikimedia.org/wikipedia/commons/4/45/Henri_Poincar%C3%A9-2.jpg
Well researched and written, thank you.
What do you mean by (Einstein’s) more ‘Platonic top-down’ approach? Do you mean more qualitative rather than quantitative? Theoretical rather than empirical?
This Plato guy, whoever he is, has got to be stopped!