In presenting this translation to the English-reading public, it is hardly necessary for me to enlarge on the Author's prefatory remarks, except to draw attention to those additions to the book which do not appear in the original.
At my request, Professor Einstein kindly supplied me with a portrait of himself, by one of Germany's most celebrated artists. [appendix:III]Appendix III, on "The Experimental Confirmation of the General Theory of Relativity," has been written specially for this translation. Apart from these valuable additions to the book, I have included a biographical note on the Author, and, at the end of the book, an Index and a list of English references to the subject. This list, which is more suggestive than exhaustive, is intended as a guide to those readers who wish to pursue the subject farther.
I desire to tender my best thanks to my colleagues Professor S. R. Milner, D.Sc., and Mr. W. E. Curtis, A.R.C.Sc., F.R.A.S., also to my friend Dr. Arthur Holmes, A.R.C.Sc., F.G.S., of the Imperial College, for their kindness in reading through the manuscript,
for helpful criticism, and for numerous suggestions. I owe an expression of thanks also to Messrs. Methuen for their ready counsel and advice, and for the care they have bestowed on the work during the course of its publication.
ROBERT W. LAWSON
Physics Laboratory The University of Sheffield 3June 12, 1920
CONTENTS
PART I
THE SPECIAL THEORY OF RELATIVITY
PAGE
I. Physical Meaning of Geometrical Propositions . 1 II. The System of Co-ordinates . 5 III. Space and Time in Classical Mechanics . . 9 IV. The Galileian System of Co-ordinates . .11 V. The Principle of Relativity (in the Restricted Sense) . . . . . .12 VI. The Theorem of the Addition of Velocities employed in Classical Mechanics . . 16 VII. The Apparent Incompatibility of the Law of Propagation of Light with the Principle of Relativity . . . . 17
VIII. On the Idea of Time in Physics . . .21 IX. The Relativity of Simultaneity . . .25 X. On the Relativity of the Conception of Distance 28 XI. The Lorentz Transformation . . .30 XII. The Behaviour of Measuring-Rods and Clocks in Motion . . . . 35
XIII. Theorem of the Addition of Velocities. The Experiment of Fizeau . . 3 XIV. The Heuristic Value of the Theory of Relativity 4 XV. General Results of the Theory . . .4, XVI. Experience and the Special Theory of Relativity 4 XVII. Minkowski's Four-dimensional Space . . 5;