218
INDEX
- Perihelia of planets, motions of, 123
- Permanence of matter, 196
- Permanent identity, 40, 193
- Permanent perceptual world, 141, 198
- Poincaré, 9
- Point-event, 45, 186
- Potentials, 80; Galilean values, 83
- Potentials, electromagnetic, 172
- Principe, eclipse expedition to, 114
- Principle of Equivalence, 76, 131, 212
- Principle of Least Action, 149, 178
- Principle of Relativity (restricted), 20
- Probability, a pure number, 178
- Projectile, Jules Verne's, 65
- Propagation of Gravitation, 94, 147
- Proper-length, 11
- Proper-time, 71
- Pucker in space-time, 85
- Quanta, 60, 177, 182, 200
- Radiation-pressure, 110
- Real world of physics, 37, 181
- Receding velocities of B-type stars, 135; of spiral nebulae, 161
- Reflection by moving mirror, 22
- Refracting medium equivalent to gravitational field, 109
- Refraction of light in corona, 121
- Relativity of force, 43, 76; of length and duration, 34; of motion, 38; of rotation, 152, 155; of size, 33
- Relativity, Newtonian, 40; restricted Principle of, 20; standpoint of, 28
- Repulsion of light proceeding radially, 102, 108
- Retardation of time, 24, 55; in centrifugal field, 129; in spherical world, 160
- Ricci, 89
- Riemann, 2, 89, 167
- Riemann-Christoffel tensor, 89
- Riemannian, or non-Euclidean, geometry, 6, 73, 84, 90
- Rigid scale, definition of, 3
- Rotation, absolute, 152, 164, 194
- Rotation of a continuous ring, 194
- Russell, 14, 197
- St John, 130
- Semi-Euclidean geometry, 47
- Simultaneity, 12, 51
- de Sitter, 134, 159, 179
- Sobral, eclipse expedition to, 117
- Space, conventional, 9; kinds of, 81; meaning of, 3, 8, 15; relativity of, 34
- Space-like intervals, 60, 187
- Space-time, 45; due to Minkowski, 212; partitions of, 54
- Spherical space-time, 159
- Standard metre, comparison with, 168
- Stresses in continuous matter, 193
- Structure opposed to content, 197, 200
- Structure, geodesic, absolute character of, 155, 164; acceleration of, 195; behaviour at infinity, 157
- Super-observer, Newton's, 68
- Synthesis of appearances, 31, 182
- Tensors, 89, 189
- Thomson, J. J., 61
- Time, absolute, 163; depends on observer's track, 38, 57; for moving observer, 24; imaginary, 48; measurement of, 13; past and future, 51; "standing still," 26, 160
- Time-like intervals, 60, 187
- Tracks, natural, 70
- Vacuum, defined by law of gravitation, 190
- Vector, non-integrable on Weyl's theory, 174
- Velocity, addition-law, 59; definition of, 193; static character, 194
- Velocity of gravitation, 94, 147
- Velocity of light, importance of, 60; in gravitational field, 108; system moving with, 26, 56
- Warping of space, 8, 126
- Wave-front, slewing of, 108
- Weight, of light, 107, 111; of radio-active energy, 111; proportional to inertia, 137; vanishes inside free projectile, 65
- Weyl, 174
- World, 186, 187
- World-line, 87
