Experimental Blog # 169

Quotations from "Einstein's Mistakes" - The Human Failings of Genius by Hans C. Ohanian

"Einstein's theories of relativity rest on foundations first laid by Galileo - the special theory rests on Galileo's discovery of the  relativity of motion, and the general theory rests on Galileo's discovery of the equal rates of acceleration of freely falling bodies. Furthermore, both the special and the general theories incorporate and extend Newton's laws, and both incorporate Maxwell's equations."

   "In 1861, Maxwell finished assembling all the laws of electricity and magnetism in a system of four equations, Maxwell's equations. He discovered that these equations imply the existence of electromagnetic waves consisting of oscillating electric and magnetic fields that are created by oscillating electric charges."

"Einstein was not the discoverer of E=mc{squared}. The equation was known several years before Einstein < > The equation played only a marginal role in the discovery of nuclear fission and the development of the atomic bomb. < > The first complete proof of E=mcc was not found by Einstein, in 1905 or at any other time. It was found by Max von Laue, in 1911."

   "Einstein's mistakes did not affect his rank because they did not prevent him from making his groundbreaking discoveries."
"How much of an advantage did Einstein gain over his colleagues by his mistakes? Typically, about ten or twenty years. < > other physicists would have discovered the theory of general relativity some twenty years later, via a path originating in relativistic quantum mechanics."
" ...if Einstein had not discovered his equations for the gravitational field in 1915, then quantum theorists would certainly have discovered them in the mid-1930s, some twenty years later."
"In the absence of Einstein, all these discoveries would have been made somewhat later - mostly by an entirely different path - and physics today would have been pretty much the same as it is."

Experimental Blog # 168

Quotation from "Relativity" - The Special and General Theory by Albert Einstein, translated by Robert W. Lawson, Introduction by Roger Penrose, Commentary by Robert Geroch, and a Historical Essay by David C. Cassidy

Quotations from the commentary by Robert Geroch:

"There are many other methods to measure "the length of a moving rod."
"There is considerably less reason to believe that these various methods must all agree in this realm. In fact, according to relativity theory they do not. For each different method there will be a factor - which can be calculated within special relativity .. . For one method ... might always yield precisely the rest-length of the rod; and for some other method ... the rod ... would be deemed to have lengthened rather than shortened.
   Thus "moving objects contract" is not a very good summary of what is predicted by special relativity."

   "Similar remarks apply to "time dilation." There are numerous experiments the results of which deserve to be called the "elapsed time" between two events; and different experiments will generally yield different answers. Einstein's time dilation refers to one particular choice of an experiment."