The Einstein Theory of Relativity

The Einstein Theory of Relativity

Project Gutenberg's The Einstein Theory of Relativity, by H.A. Lorentz
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Title: The Einstein Theory of Relativity
Author: H.A. Lorentz
Release Date: February 27, 2004 [EBook #11335]
Language: English
Character set encoding: ASCII
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The Einstein Theory of Relativity
A Concise Statement
by
Prof. H.A. Lorentz of the University of Leyden

NOTE
Whether it is true or not that not more than twelve persons in all the
world are able to understand Einstein's Theory, it is nevertheless a fact
that there is a constant demand for information about this
much-debated topic of relativity. The books published on the subject
are so technical that only a person trained in pure physics and higher
mathematics is able to fully understand them. In order to make a
popular explanation of this far-reaching theory available, the present
book is published.
Professor Lorentz is credited by Einstein with sharing the development
of his theory. He is doubtless better able than any other man--except the
author himself--to explain this scientific discovery.
The publishers wish to acknowledge their indebtedness to the New
York Times, The Review of Reviews and The Athenaeum for
courteous permission to reprint articles from their pages. Professor
Lorentz's article appeared originally in The Nieuwe Rotterdamsche
Courant of November 19, 1919.

INTRODUCTION
The action of the Royal Society at its meeting in London on November
6, in recognizing Dr. Albert Einstein's "theory of relativity" has caused
a great stir in scientific circles on both sides of the Atlantic. Dr.
Einstein propounded his theory nearly fifteen years ago. The present
revival of interest in it is due to the remarkable confirmation which it
received in the report of the observations made during the sun's eclipse
of last May to determine whether rays of light passing close to the sun
are deflected from their course.
The actual deflection of the rays that was discovered by the
astronomers was precisely what had been predicted theoretically by
Einstein many years since. This striking confirmation has led certain
German scientists to assert that no scientific discovery of such
importance has been made since Newton's theory of gravitation was
promulgated. This suggestion, however, was put aside by Dr. Einstein
himself when he was interviewed by a correspondent of the New York
Times at his home in Berlin. To this correspondent he expressed the
difference between his conception and the law of gravitation in the
following terms:

"Please imagine the earth removed, and in its place suspended a box as
big as a room or a whole house, and inside a man naturally floating in
the center, there being no force whatever pulling him. Imagine, further,
this box being, by a rope or other contrivance, suddenly jerked to one
side, which is scientifically termed 'difform motion', as opposed to
'uniform motion.' The person would then naturally reach bottom on the
opposite side. The result would consequently be the same as if he
obeyed Newton's law of gravitation, while, in fact, there is no
gravitation exerted whatever, which proves that difform motion will in
every case produce the same effects as gravitation.
"I have applied this new idea to every kind of difform motion and have
thus developed mathematical formulas which I am convinced give
more precise results than those based on Newton's theory. Newton's
formulas, however, are such close approximations that it was difficult
to find by observation any obvious disagreement with experience."
Dr. Einstein, it must be remembered, is a physicist and not an
astronomer. He developed his theory as a mathematical formula. The
confirmation of it came from the astronomers. As he himself says, the
crucial test was supplied by the last total solar eclipse. Observations
then proved that the rays of fixed stars, having to pass close to the sun
to reach the earth, were deflected the exact amount demanded by
Einstein's formulas. The deflection was also in the direction predicted
by him.
The question must have occurred to many, what has all this to do with
relativity? When this query was propounded by the Times
correspondent to Dr. Einstein he replied as follows:
"The term relativity refers to time and space. According to Galileo and
Newton, time and space were absolute entities, and the moving systems
of the universe were dependent on this absolute time and space. On this
conception was built the science of mechanics. The resulting formulas
sufficed for all motions of a slow