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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

J

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

K

G

Kelvin, Lord, 135
Kinetic Energy, 39
Knots (nautical), defined, 26
Krypton atom, 95, 158

L

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

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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

N

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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

R

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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

S

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

U

T

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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