Relativity: The Special and the General Theory, Einstein’s Own Guide for Non-Specialists
Albert Einstein (1879–1955) wrote this short book in 1916, shortly after he had completed the field equations of general relativity. His aim was to give as exact an idea as possible of the theory of relativity to readers who, without mastering the mathematics of theoretical physics, are interested in the theory from a general scientific or philosophical point of view.
Author: Albert Einstein (1879–1955)
Title: Relativity: The Special and the General Theory (German original 1916/1917)
Format: English paperback (Princeton University Press), 100th Anniversary Edition with commentary by Hanoch Gutfreund and Jürgen Renn
Scope: Einstein’s popular account of special and general relativity
Amazon: www.amazon.es/dp/0691191816 (ASIN 0691191816)
Relativity in Einstein’s Words
Einstein builds the theory step by step: the relativity of simultaneity, the constancy of the speed of light, the Lorentz transformation, then the leap to gravity and curved space-time. The mathematics is kept to the minimum, and his examples of trains, embankments and falling chests have become classics of scientific explanation.
A Carefully Edited Edition
The edition I read had been translated and thoroughly revised, and included an analytical index, an appendix with a simple derivation of the Lorentz transformation and a discussion of Minkowski’s four-dimensional formulation, as well as autobiographical notes by Einstein. The Princeton 100th Anniversary Edition linked here adds an introduction and a reading companion by Hanoch Gutfreund and Jürgen Renn that places the book in its historical context.
Written for Everyone, Almost
Einstein dated his preface December 1916, and the book appeared in German the following year as Über die spezielle und die allgemeine Relativitätstheorie, with the subtitle Gemeinverständlich, "generally understandable". The first English translation, by Robert W. Lawson, followed in 1920, just after the solar eclipse expedition of 1919 led by Arthur Eddington had measured the bending of starlight by the Sun and turned Einstein into a world celebrity overnight. Einstein revised and extended the book several times, adding appendices on the experimental evidence and, in 1952, on the problem of space.
The Thought Experiments
The reader’s companion through the book is a railway carriage moving along an embankment. With it Einstein shows that two lightning flashes that are simultaneous for someone on the embankment are not simultaneous for a passenger on the train, the key step towards special relativity. Later, a man in a closed chest pulled upwards through space cannot tell whether he is being accelerated or standing in a gravitational field: the principle of equivalence, which leads to general relativity. These images are so clear that they have been reused by teachers ever since.
Why the Commentary Helps
The Princeton anniversary edition adds an essay by the historians of science Hanoch Gutfreund and Jürgen Renn, who explain how the book came to be written, how it was received and what has changed since. It is a useful bridge for modern readers: it places Einstein’s explanations within the physics of his day and shows where later developments, from black holes to gravitational waves, grew out of them. Einstein’s Nobel Prize of 1921, incidentally, was awarded for his work on the photoelectric effect, not for relativity.
Companions
Readers who find parts of it hard can pair it with a modern guide, such as Persiguiendo a Einstein or Hawking’s anthology A Stubbornly Persistent Illusion, both reviewed on this blog.
How to Read It
Read slowly, with a pencil, and do not skip the short chapters on coordinates: everything later depends on them.
Who Should Read It
Do not expect it to be easy: Einstein’s idea of ’popular’ still asks for patience and some school algebra. But there is nothing quite like hearing the theory explained by the person who discovered it.
As an Amazon Associate, this site earns from qualifying purchases.
Part of the reading recommendations featured on books.sapiensverbum.com.
