Integration, 115, 117 International Atomic Scale (TAI), 70 International Date Line, 93–94 International Geophysical Year, 76 Ionosphere, 75, 79–80, 81 Ionospheric (sky) wave radio signals, 80–81
Feedback systems, 37, 42, 43, 144 Flamstead, John, 62 “Flicker" noise, 36 Flying clocks, 72 Foliot, 26, 49 Fourier, J. B. J., 146–148 Frequency, 9, 13, 36, 41; ammonia molecule, 42;
atomic, 41; electric power and, 100; measure- ment, 9, 157; phase and, 100; photon, 165;
radio signals, 78, 79; sine waves, 146–149 Frequency diversity, 84 Frequency division multiplexing, 103 Frequency-energy relationship, 128-129, 130 Frequency standard, 54-55, 66, 69, 97 Fusee, 12
Jeweled bearings, 50, 51 Josephson, Brian, 157 Josephson effect, 157 Josephson junction, 157
Kelvin, Lord, 135 Kinetic Energy, 39 Knots (nautical), defined, 26 Krypton atom, 95, 158
Galileo, 27, 113, 115, 116–117 Gamma-ray resonator, 165 Gamma rays, 164 “G” constant, 130 Geodesy, 5 Geological time, 7, 154 Geometry, 114 Gravitation, law of, 121 Gravitational clocks, see Pendulum clocks Gravitational ("G") constant, 130 Gravitational pull, 121, 125, 130 Gravitational second, see Ephemeris second Gravitational time, 130–131 Greenwich, England, 19, 20, 93 Ground wave radio signals, 80–81
Lagrange, Louis, 122 Latitude, 18 Leap second, 66 Leap year, 66 Lee, T. D., 132, 133 Leibnitz, Gottfried Wilhelm von, 121 Left-hand, right-hand symmetry, 133 Longitude, 19, 20 Loran-C navigation system, 80, 84, 105, 161-163 Low-frequency (LF) broadcast systems, 80 Low-frequency navigation systems, 77 Low-Q resonator, 31, 33–34
Halley, Edmund, 62 Hamilton, William, 122 Harrison, John, 20 Harrison, William, 20 Hayward, R. W., 133 Henlein, Robert, 49 Hertz, 12-13, 34; definition, 13 Hertz, Heinrich, 13 High frequency (HF) radio systems, 81 High message rate communication systems, 103,
156, 160 High-Q gamma rays, 165 High-Q resonators, 32-37; feedback system, 37,
42 Hooke, Robert, 27, 49 Hoppes, D.D., 133 Hubble, Edwin, 136 Hudson, R. P., 133 Huygens, Christian, 27, 50 Hydrogen atom, 12, 42, 47, 12 Hydrogen maser, 46–47, 128
Magnetization, 44, 52; cesium atom, 43-44 Marrison, Warren A., 40 Maser, hydrogen, 47 Master clock (NBS), 82 Mathematics, 113, 115, 122, 132, 166 Mechanical clocks, 16, 26, 39, 40 Medicine Wheel, Wyoming, 7 Medium frequency (MF) radio signals, 81 Mesons, 153 Microsecond, 9 Microwave Amplification by Stimulated Emissic
of Radiation (MASER), 47 Microwave radio signals, 42, 43, 44, 46, 47 Molecules, 41; ammonia, 42 Morse, Samuel F. B., 72 Mossbauer, R. L., 164 Mullard Radio Observatory, Cambridge Univer-
sity, 137 Muons, 153 Musical instruments, 108
Quality (“Q") factor, 31, 33, 35, 45; cesium
resonator, 45, 47, 48, 129; gamma rays, 164; hydrogen atom, 47; limitation, 37; rubidium
oscillator, 46; watches, 52 Quantum mechanics, 41, 42, 47, 122, 123, 128, 130 Quartz-crystal clock, 14, 40, 52 Quartz-crystal oscillators, 12, 14, 40, 42, 43; cost,
54 Quartz-crystal resonator, 40, 52 Quartz-crystal watches, 52–53; accuracy, 53
73, 84, 97, 133; Boulder, Colorado, 55, 85; Fort Collins, Colorado, 85; Gaithersburg, Maryland,
17; Washington, D.C., 73, 133 National Frequency Standard, 85 Navigation, 5, 18–19, 97 Navigation systems, 6, 9, 18, 77, 104; electronic,
104, 167; Loran-C, 80, 84, 105, 161-163; low- frequency, 77; Omega, 105; radio, 104; satel-
lite, 105-106, stellar, 18-19, 104 NBS atomic frequency standards, 54-55, 66, 69,
77, 89; cost, 55 NBS Time and Frequency Division, 73 NBS time and frequency service, 55, 73 Neutron stars, 137, 138 Newcomb, Simon, 62 Newgrange, 6 Newton, Issac, 3, 41, 114; laws of gravitation,
121, 130; laws of motion, 65, 115, 124, 138 Nitrogen atom, 42 Noise, additive, 83; definition of, 83; diversity,
83; 'Aicker," 36; multiplicative, 83; satellites,
82 North Pole, 18, 19, 62 North Sar, 18, 19, 20 Nuclear force, 164
Pallets, 26 Parity ("P") invariance, 133; violation of, 133 Pendulum, 14, 147-148; atomic, 43; free-swing-
ing, 11; spring-wound, 12, 28 Pendulum clock, 11, 20, 27, 39, 129, 130-131;
two-pendulum, 28, 39, 40 Pendulum clock time, 131 Phase and frequency, 100-101 Photographic zenith tube, 70 Photography, 70, 107, 116, 128 Photon, 47, 165 Physical constants, 130 Physics, 124, 132, 164, 166 Piesoelectric effect, 40 “P" invariance, 133; violation of, 133 Plank's (“h”) constant, 130 Portable cesium standard, 72 Potential energy, 39 Power companies, 12, 99–102, 107 Power distribution system, 102 Pulsar rates, 139 Pulsars, 138 Pulsed signals, 80
Radar, 42, 144, 145; narrow-beam, 145; wide-
beam, 145 Radar echo signals, 148 Radar tracking system, 42, 144, 145–146 Radioactive dating, 7, 135, 154, 164 Radio astronomy, 135, 137, 140 Radio beacons, 104 Radio broadcast time systems, 72, 73; accuracy,
74; ambiguity, 77; coverage, 76; NBS, 73, 74, 97; percent of time available, 77; receiver cost, 77; regulation, 97; reliability, 76; time and frequency, 100, 161; uniform, 73; USNO,
73, 97 Radio navigation system, 74, 104 Radio signal frequency, 43 Radio signals, 43, 44, 46, 47, 73; ammonia mole-
cule, 43; aviation, 160; cesium atom, 44; maser, 47; radar, 145; rubidium atom, 46;
satellite, 106, stellar, 137 Radio spectrum, 42, 43 Radio-star signals, 141 Radio telescopes, 140 Radio time signals, 72–74; accuracy, 74–75; con-
tinuous, 80; pulsed, 80 Railroads and time, 51, 72, 89–91 Relativity, 122, 124, 125, 135 Relativity, General Theory of, 123, 125–126 Relativity, Special Theory of, 125-126 Resolution, 140 Resonance curve, 32-37, 148; ammonia molecule,
43 Resonant frequencies, 32, 36; ammonia molecule,
42; atomic, 41-42; cesium atom, 44-45, 129;
quartz crystal, 40; rubidium, 46; watches, 52 Resonators, 29, 31; accuracy, 32; ammonia, 42-
43; atomic, 41-42, 129; cesium, 45, 46, 47, 48, 129; high-Q, 32, 33, 34, 35, 36, 37; hydrogen, 47; quartz crystal, 40, 52; rubidium, 46;
stability, 32; watches, 49-50, 52 Rubber seconds, 65 Rubidium atom, 13, 14, 46 Rubidium oscillators, 46 Rubidium resonant frequencies, 46 Rubidium resonator, 46 Rutherford, Ernest T., 41
Sand clock, 26 Satellite, navigation, 105-106; noise, 82; time
broadcasts, 74, 75, 82, 141-142, 163; tracking,
5; Transit, 105 Second, atomic, 45, 66, 95, 130, 157; ephemeris,
64, 130; leap, 166; measurement, 9, 17; rub-
ber, 65; standard, 66; universal time, 65 Shortt, William Hamilton, 39, 42 Shortwave radio transmissions, 72, 75, 84, 85;
accuracy, 74; reliability, 77 Sidereal (stellar) day, 61 Sidereal year, 67, 68 Sine waves, 146–149 Sky wave, 80–81, 82 Solar day, 61 Solar year, 60 South Pole, 19 Space travel, 125–126 Speed and direction, 116, 118-121 Stability, 35, 36 Standardized time system, 91 Standard time, 89–91, 93, 97, 167 Standard Time Act (1918), 91 Standard time interval, 94 Standard time zones, 89, 97 Standard units, 17 Standards laboratories, 97 Star time, 89,
123 "Steady-state” theory, 137 Stellar clocks, 137 Stellar day, 61 Stellar radio signals, 137 Stonehenge, 7 Summer solstice, 8 Sun spots, 75, 76 Sun time, 89, 167 Super “CPT" principle, 134 Super-symmetry principle, 134 Symmetries in nature, 132 Synchronization, 6, 94-95, 124, 151; comunica-
tion, 104; radio signals, 78, 85, 140, 141; satel-
lite, 142; television signals, 85 Synchronization pulses, 85, 104, 157 System magnification (gain), 145 System-response time, 144
star signals, 141; radio stations, 72; receiver cost, 77; reliability, 76; standards, 72, 81, 82,
97; transportation systems, 104 Time and length standard, 158, 165 Time control systems, 143-144; closed-loop, 144,
150; open-loop, 143, 150 Time, definition, 5 Time direction, 126–127, 132 Time dissemination systems, 72, 76, 77, 161-162 Time/distance ratio, 117–118, 136 Time diversity, 84 Time division multiplexing, 103 Time information broadcasts, 72–78 Time information recording, 141 Time information storage, 141, 156 Time information transmittal, 108, 153, 156, 161 Time interval, 6, 94, 97, 108, 151, 153; and fre-
quency 13, 158; measurement, 17, 157, 158 Time invariance (“T”) symmetry, 134 Timekeepers, 8, 25, 66, 68, 152; historic, 14, 68;
international, 70, 72; United States, 69 Timekeeping devices 8, 11, 97, 167; cost, 53 Time measurement, 9, 17, 59, 63, 127–128; limita-
tions, 127-131; standards, 17; synchronization,
6 Time regulation, 96–97 Time reversal, 133 Time's arrow, 132 Time signals, 162–163 Time ("T") invariance, 133 Time zones, 91, 97; international, 93; United
States, 91 "T" symmetry, 134 Townes, Charles H., 47 Transfer standard technique, 85 Transistorization, 52 Transit satellite, 105 Transportation and time, 104 Tropical year, 64, 67 Two-pendulum clock, 28, 39, 40 Tuning fork, 12, 52
Uniform Time Act (1966), 93; Amendment
(1972), 93 Universal Time (UT), 63, 64, 65, 66, 69; UTO,
63; UTI, 63, 66; UT2, 63, 65 UTC (Coordinated Universal Time), 65, 66, 69,
72 U.S. Naval Observatory (USNO), 13, 69, 73, 74,
85, 97 Usher, Archbishop (Ireland), 135
Tachyons, 166 Telegraph, 72 Telephone companies, 12 Television, 102, 156-157; time broadcasts, 77, 82,
85; time measurement, 9, 13 Time and frequency technology, 55, 106-107;
accuracy, 74; ambiguity, 77; communication systems, 102–104; consumer surveys, 107; cov- erage, 76; electric power, 100-101; percent of time available, 77; radio signals, 74; radio-
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