In Einstein's paper, "The Principle of Relativity and Its Consequences in Modern Physics" (1910), Einstein describes an electromagnetic ether.
"When it was realized that a profound analogy exists between the elastic vibrations of ponderable matter and the phenomena of interference and diffraction of light, it could not be doubted that light must be considered as a vibratory state of a special kind of matter. Since, moreover, light can propagate in places devoid of ponderable matter, one was forced to assume for the propagation of light a special kind of matter that is different from ponderable matter, and that was given the name "ether." (Einstein4, § 1).
"The introduction of the electromagnetic theory of light brought about a certain modification of the ether hypothesis. At first the physicists did not doubt that the electromagnetic phenomena must be reduced to the modes of motion of this medium. But as they gradually became convinced that none of the mechanical theories of ether provided a particularly impressive picture of electromagnetic phenomena, they got accustomed to considering the electric and magnetic fields as entities whose mechanical interpretation is superfluous. Thus, they have come to view theses fields in the vacuum as special states of the ether" (Einstein4, § 1).
Maxwell's electromagnetic field originates from Faraday's (Lenz) induction effect that is not luminous which is experimental proof Maxwell's electromagnetic field cannot be used to represent the electromagnetic ether.
"When it was realized that a profound analogy exists between the elastic vibrations of ponderable matter and the phenomena of interference and diffraction of light, it could not be doubted that light must be considered as a vibratory state of a special kind of matter. Since, moreover, light can propagate in places devoid of ponderable matter, one was forced to assume for the propagation of light a special kind of matter that is different from ponderable matter, and that was given the name "ether." (Einstein4, § 1).
"The introduction of the electromagnetic theory of light brought about a certain modification of the ether hypothesis. At first the physicists did not doubt that the electromagnetic phenomena must be reduced to the modes of motion of this medium. But as they gradually became convinced that none of the mechanical theories of ether provided a particularly impressive picture of electromagnetic phenomena, they got accustomed to considering the electric and magnetic fields as entities whose mechanical interpretation is superfluous. Thus, they have come to view theses fields in the vacuum as special states of the ether" (Einstein4, § 1).
Maxwell's electromagnetic field originates from Faraday's (Lenz) induction effect that is not luminous which is experimental proof Maxwell's electromagnetic field cannot be used to represent the electromagnetic ether.
