Galilean NON-Invariance: UNIZOR.COM - Relativity 4 All - Galilean View
Channel: Zor Shekhtman on UNIZOR Education
Date: 2023-06-15

UNIZOR.COM - Physics through a Looking Glass of Mathematician
Read full text of notes for this lecture on UNIZOR.COM - Relativity 4 All - Galilean View - Galilean NON-Invariance
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Galilean NON-Invariance


Clouds on the Horizon

At the end of the 19th century physicists were generally of a positive opinion about the state of Physics.

Newton's mechanics and theory of gravitation, Coulomb's laws of electrostatic were pretty much in good shape.

The properties of electromagnetic field were well described by Maxwell equations.

The theory of aether as a medium for electromagnetic waves, while not being absolutely satisfactory for physicists, was the only one available to explain the observable wave character of light and its constant speed that depends only on medium's characteristics of electric permittivity and magnetic permeability.

All was not bad... except a couple of "small" things.

First, the experiment of Michelson-Morley in 1887 attempted to detect aether and showed negative result, as was confirmed by many other experiments afterwards.

The aether was supposed to have too many contradictory properties to satisfy all the experimental data, and physicists became more and more skeptical about this theory.

Second, the Newtonian laws of mechanics an gravitation, as well as Coulomb's law of electrostatics showed the invariance relative to Galilean transformation of coordinates between two inertial frames, but the laws related to electromagnetism and, in particular, Lorentz force and Maxwell equations showed that these laws and equations are not invariant, if we use Galilean transformations.
Their expression in one inertial reference frame, transformed into another frame using the Galilean transformation, took a different form than in the original frame.

[Full text of notes for this lecture are at UNIZOR.COM - Relativity 4 All - Galilean View - Galilean NON-Invariance]