Page:Eddington A. Space Time and Gravitation. 1920.djvu/233

Rh * Identities connecting $$G_{\mu\nu}$$, 141
 * Identity permanent, 40, 193
 * Imaginary intervals, 150, 187
 * Imaginary time, 48, 181
 * Inertia, compared with force, 137; electrical theory of, 61; in regions at infinity, 157; infinite, 56; Mach's views, 164; of light, 110; relativity theory of, 139
 * Inertia-gravitation, 137
 * Inertial frame, 156
 * Infinity, conditions at, 157
 * Integrability of length and direction, 174
 * Interval, 46, 150, 187; general expression for, 82; practical measurement of, 58, 75
 * Interval-length, geometrical significance essential, 127; identified with proper time, 71; tracks of maximum, 70, 150; zero for velocity of light, 71
 * Invariant mass, 145; of light, 148


 * Jupiter, deflection of light by, 133


 * Kaufmann's experiment, 62, 146
 * Kinds of space, 81


 * Laplace's equation, 96, 140
 * Larmor, 19, 211
 * Length, definition of, 2; effect of motion on, 19; relativity of, 34
 * Le Verrier, 124
 * Levi-Civita, 89
 * Lift, accelerated, 64
 * Light, bending of, 107, 112, 118, 207; coordinate velocity of, 107; mass of, 62, 110, 148; voyage round the world, 161; weight of, 111
 * Light, velocity of, an absolute velocity, 59; importance of, 60; system moving with, 26, 56
 * Lobatchewsky, 1, 9
 * Lodge, 32, 125, 211
 * Longest tracks, 70
 * Lorentz, 19, 211


 * Mach's philosophy, 163
 * Macroscopic equations, 92, 139; interval, 187
 * Map of sun's gravitational field, 99
 * Mass, conservation of, 141, 195; electrical theory of, 61; gravitational, 98; identified with energy, 146; invariant, 145; of light, 62, 110, 148; variation with velocity, 145
 * Mathematics, Russell's description of, 14
 * Matter, continuous, 91; definition of a particle, 98; extensional relations of, 8; gravitational equations in, 141; perception of, 190; physical and psychological aspects, 192
 * Mercury, perihelion of, 123, 125
 * Mesh-systems, 77; irrelevance to laws of nature, 87
 * Michelson-Morley experiment, 18
 * Minkowski, 30, 212
 * Mirror, distortion by moving, 22
 * Momentum, conservation of, 141; re-definition of, 144; of light, 111
 * Moon, motion of, 93, 134
 * Motion, insufficiency of kinematical conception, 194; Newton's first law, 136


 * Natural frame, 155
 * Natural gauge, 176
 * Natural geometry, 2
 * Natural tracks, 70
 * Nebulae, atomic vibrations in, 161
 * Newton, absolute rotation, 41; bending of light, 110; law of gravitation, 93; law of motion, 136; relativity for uniform motion, 40; super-observer, 68
 * Non-Euclidean geometry, 6, 73, 84, 90
 * Non-Riemannian geometry, 169


 * Observer, an unsymmetrical object, 57
 * Observer and observed, 30
 * Orbits under Einstein's law, 123
 * Order and dimensions, 14, 186
 * Ordering of events in external world, 35, 54, 184


 * Past, absolute, 50
 * Perceptions, as crude measures, 10, 15, 31