The new ether of Einstein

[Giovanni R.]

The New Ether of Einstein

(From the book - Einstein and the ether - of L. Kostro)

The belief that Einstein in his theory of relativity has definitively eliminated the concept of ether by modern physics is very widespread. This opinion is contained in the physics and philosophy handbooks, encyclopedias, textbooks and scientific publications.
However, this description does not reflect at all the historical truth, rather in a major way deforms it.
Einstein primarily considered superfluous the concept of luminiferous ether postulated by Maxwell and also adopted by Poincaré, and all the previous models.
In this sense it is true that until the end of his days he denied the existence of the ether as it was conceived in the nineteenth century.
But after General Relativity, Einstein introduced a new version of relativistic ether, then expressed in three models.
Therefore, the historical truth is that Einstein denied the existence of the ether for eleven years, from 1905 to 1916. Unfortunately this is not said in the University and it's not written in textbooks.

For example, in 1919 he wrote:
"It would have been more correct if in my first publications I were limited me to point out the impossibility of measuring the speed of the ether, instead of mainly support its non-existence. Now I understand that with the word ether we just intend the need to represent space as a carrier of physical properties. >>
(Albert Einstein, in a letter to A. H. Lorentz, 1919)

And in 1920:
"Even if in 1905 I thought physics could be absolutely no talk of ether, this judgment was too radical, as we can see with the next considerations of general relativity. It is then allowed to assume a means colmante in space if one refers to the electromagnetic field and therefore also to the matter. However it is not allowed to attribute to this means a state of motion at each point in analogy with ponderable matter. This ether can not be conceived as consisting of particles. >>
(Albert Einstein, Grundgedanken und Methoden der Relativitätstheorie in ihrer Entwicklung dargestellt, § 13, 1920)

And at University of Leiden, 5 May 1920:
Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of ligh...

The word ether has very old origins, derived from the Greek aither, descending from Sanskrit aidh, and has changed its meaning many times in the development of science. In the nineteenth century were in use simultaneously fourteen different models of ether.
What E. called ether is no longer a separate medium from the space, contained within the space, as were the previous models, but it is precisely the space that, with its - geometrodynamic property - determines the inertial and gravitational behavior of matter.

The speech continues in the site ricercaetereperduto
in Google.

Goodbye
Giovanni R.