For the Love of Physics
Page 32
You might also be interested in knowing that Newton believed that the average density of the Earth was between 5,000 and 6,000 kilograms per cubic meter. This was not based on any astronomical information; it was completely independent of any of his laws. It was his best “educated” guess. The average density of the Earth is, in fact, 5,540 kilograms per cubic meter. If you allow me to write Newton’s guess as 5,500 ± 500 kilograms per cubic meter, his uncertainty was only 10 percent (amazing!).
I do not know if Newton’s guess was ever taken seriously in his day, but suppose it was. Since Earth’s radius was well known in the seventeenth century, its mass could have been calculated to an accuracy of 10 percent (mass is volume times density). Equation 7 could then be used to calculate G also to an accuracy of 10 percent. I am telling you this because it intrigues me that, accepting Newton’s guess for the mean density of the Earth, at the end of the seventeenth century the gravitational constant, G, could already have been known to an accuracy of 10 percent!
INDEX
absorption lines, 237–39
Academic Earth, x
Academy of Sciences, Bavaria, 155
Academy of Sciences, St. Petersburg, 146
Academy of Sciences, Soviet, 253
accretion disk, 231, 245
adenosine triphosphate (ATP), 169
“Aerodynamic Lift, Bernoulli Effect, Reaction Lift” (Johnson), 74
air, weight of, 60–61
air drag, 43, 51
maglev trains and, 164
pendulums and, 52
Air Force Cambridge Research Laboratories (AFCRE), 193–94
air pressure, 59–65, 71
barometer and, 63, 66–67
on Earth’s surface, 63–64
measuring, 61–63
wind and, 64
Albee, Edward, 123
alpha decay, 183
alternating current (AC), 158, 161
aluminum, 151
Amazon Star (Bellatrix), 237
amber, 126
American Physical Society, 213
American Science and Engineering (ASE), 17, 193–94
Ampère, André-Marie, 138, 154, 166
ampere (amp), 138, 141
Ampère’s law, 166
amplitude, 118
energy and, 105
of pendulums, 52–54, 106
of sound waves, 104–6
of tuning fork, 106
AM radio band, 191–92
Andromeda galaxy, 4, 28
Cepheids and, 33
distance of, 33–34, 35
angular momentum, 224
Annis, Martin, 17, 193
antimatter, 187
antisolar point, 84, 89, 97
Apollo 15 mission, 42
Ara (constellation), 195
arc second, 29–30
Aristotle, 42, 79, 218
art, 262–68
author’s collaborations in, 263, 264–67
author’s collection of, 262
pioneers of, 267–68
astronauts, 24–25, 44, 58, 65
artificial gravity and, 56
free fall and, 47–48
Astronomical Netherlands Satellite (ANS), 248
astronomy, 2–3, 50, 189
error box and, 195
gravitational potential energy and, 172–73, 174
measurements and, 27–28
telescopes and, 190
women in, 32n
see also specific kinds of astronomy
Astrophysical Journal Letters, 215
Atmospheric Optics, 85
atmospheric pressure, 63–64, 66–68
atomic bomb, 184
atoms, 6, 238
electricity in, 130
nucleus of, 130
positive and negative charges in, 130–31
size of, 130
X-rays and, 192
ATP (adenosine triphosphate), 169
audiometer, 106
aurora australis (southern lights), 153–54
aurora borealis (northern lights), 10, 153–54, 245
Australia, 186, 202–5, 209
Baade, Walter, 197, 217
Babylonians, 115
banjo, 112
barometer, 63, 66–67
bass fiddle, 113
bassoon, 120
battery, 138, 158, 161, 181
making, 170
Bavarian Academy of Sciences, 155
Becquerel, Antoine Henri, 268
Belian, R. D., 248
Bell, Jocelyn, 32n, 198, 224–25
Bellatrix (Amazon Star), 237
Bernoulli, Daniel, 73–74
Bernoulli’s principle, 73–74
Bessel, Friedrich Wilhelm, 236–37
Betelgeuse (star), 237
Bevis, John, 196
Bible, 80
big bang, theory of, 9, 19, 35–36, 188, 223, 270
sound of, 107, 108–9
wavelength of, 108–9
birds, magnetism and, 152
bismuth, 151
blackbody radiation, 192, 237, 246
in X-ray bursts, 250–51
black holes, xiv, 192, 225–34
accretion disk of, 231, 245
animations and recreations of, 225, 229
calculating size of, 228
in core-collapse supernova, 223
creation of, 220–21
Doppler effect and, 232–33
escape velocity of, 227–28
evaporation of, 230
event horizon of, see event horizon
falling into, 231–34
general relativity and, 228
gravity well of, 226, 227–28
Hawking radiation of, 231
LHC and creation of, 229–30
matter swallowed up by, 225–26
micro, 229–31
in Milky Way galaxy, 226, 245
in Perseus cluster, 108
singularity of, 228–29, 233–34
sound waves of, 108
spaghettification in, 233–34
speed of light and, 232
tidal forces and, 233–34
in X-ray binaries, 241–42, 244
X-ray bursts and, 257
Bloksma-Lewin, Bea, 11, 14
blue jet lightning, 148
blueshift, 233, 237, 238–39
see also Doppler effect
body heat, 176–77, 179
Bohr, Niels, 268
Boijmans van Beuningen Museum, 266
Bolton, Tom, 241–42
bottlenecks, 121–22
Boyle, Robert, 126
Brahe, Tycho, 126, 189, 190, 281
Brancusi, Constantin, 268
brass instruments, 120–21
bremsstrahlung emissions, 192, 194
Brewster, David, 93
Brewster angle, 93
brightness, luminosity and, 32–33
Brocken spectres (glories), 97–98
Broglie, Louis de, 268
Brooklyn Bridge, 124
Broughton Suspension Bridge, 124
Bruno, Giordano, 189
BTUs, 177
Buddha’s light, 98
Busza, Wit, 158
calculus, 38, 261
calorie, 174
defined, 177
capacitor, 155
carbon, 6, 169, 219
carbon dioxide, 169
Cassini, Giovanni, 281
cello, 112
Centaurus (constellation), 196, 213, 243
Center for Advanced Visual Studies, 263
Centralian Advocate, 211
centrifugal force, 57
centripetal force, 56–57, 136, 280
Cen X-1 (X-ray source), 196
Cen X-2 (X-ray source), 213, 215, 255
Cen X-3 (X-ray source), 243
Cepheid variables, 32, 36
luminosity-period relationship of, 32–34
Type II, 33
CERN (European Organization for Nuclear Research), 229
Cézanne, Paul, 268
Chadwick, James, 217
Chandrasekhar, S., 215
Chandrasekhar limit, 219
Chandra X-Ray Observatory, 198, 222
Chernobyl disaster, 185
China, ancient, 150, 151, 183
China, People’s Republic of, 98, 185
Chladni plates, 118–19
chromium oxide, 151
Chu, Steven, 181
clarinet, 119
Clark, Alvan, 237
Clark, George, 2, 18, 198, 199, 200, 208, 213, 214
classroom and home demonstrations:
of air column, 121–22
of air flow, 73–75
of air pressure, 59–60, 64–65, 71
of artificial gravity, 55–58
of building a motor, 158–61
of conservation of energy, 168–69, 173–74
creating fogbows, 96–97
of drinking with a straw, 75–77
of electrical potential, 140–41
of electromagnetism, 156
of energy conversion, 170
of Fiestaware, 183–84
of glassbows, 100–102
of high-frequency sound, 106
of homemade rainbow, 86–88, 87
of hydrostatic pressure, 67–70
of liquid magnet, 151
of magnetic levitation, 161–62, 164
of making a battery, 170
of measurement, 23–24
of pendulums, 52–55
of shattered wineglass, 118
of sounding board, 114
of sparks, 139–40
of static electricity, 127–28, 132–36
of weightlessness, 47–48
cobalt, 151
color (timbre), 112
comets, 10
Cominsky, Lynn, 255
commutator, 159
co-moving distance, 35
compact fluorescent lights (CFL), 186
Compact Stellar X-Ray Sources (Lewin, et al., eds.), 259
complete field theory, 165
conductors, conduction, 128–29, 131–32, 136
skin effect and, 145–46
Conner, J. P., 248
conservation of electric charge, law of, 128
constructive interference, 95
Copernicus, Nicolaus, 189
copper, 151, 156–57
Córdova, France, 259
core-collapse supernova, 217–20, 226
black hole formed in, 223
burning cycles of, 218–19
Chandra limit in, 219
elements created in, 223
energy emitted by, 221
iron core in, 219
neutrinos in, 221–22
neutron star in, 217, 219–21
protons in, 220–21
remnant of, 221
corona discharge, 145
in X-ray ballooning, 206–7
cosmic distance ladder, 34
cosmic microwave background (CMB) radiation, 9, 199
cosmic rays, 230
cosmology, 19, 187–88, 270
Coulomb, Charles-Augustin de, 133
coulomb (unit of charge), 133
Coulomb’s law, 133–34
Crab Nebula (M-1), 192, 196–97, 221, 242
changing shape of, 222
Moon in occultation of, 197–98
pulsar in, 224–25
crux (constellation), 213
Crux X-1 (X-ray source), 213
Curie, Marie, 268
Curie temperature, 152
cyclotron, 7
Cyg X-1 (X-ray source), 196, 212–13, 234, 240–42, 245
Cyg X-2 (X-ray source), 196
Cyngus (constellation), 196
Dalibard, Thomas-François, 146
Dalton, John, 174
dark energy, 6, 36
dark matter, 6, 36, 51
Darwin, Charles, 34
decibels, 105
deCordova Museum, 99, 101
defibrillators, 142
Degas, Edgar, 267
degenerate neutron matter, 220
Dekkers, Daniel, 265
Delft University of Technology, 1, 10–11
Democritus, 189
Derain, André, 268
Descartes, René, 79, 126
destructive interference, 95
deuterium, 6, 187
diamagnetic materials, 151
didgeredoo (musical instrument), 120
diffraction (interference), 95–96
dipoles, 165–66
Dirac, Paul, 269
direct current (DC), 158
Doppler effect, 232–33
in binary systems, 237, 238–39
black holes and, 232–33
stellar distances and, 34–35
X-ray binaries and, 237–39, 241, 243
double-dutch (game), 110
Draw the Lightning Down: Benjamin Franklin and Electrical Technology in the Age of Enlightenment (Schiffer), 146
driven oscillator, 110
Duchamp, Marcel, 268
dynamo effect, 153
Earth, 28, 49, 50–51, 55, 187, 227, 236, 244, 279
age of, 36
average radius of, 283
calculating distances to Moon from, 282–83
calculating mass of, 282–83, 284
core of, 152–53, 183
density of, 284
gravitational acceleration and, 41–42
magnetic field of, 9, 152–53, 154
mass of, 45
neutrino strikes on, 222
Sun’s distance from, 181, 281–82
surface air pressure of, 63–64, 66–67
thunderstorms on, 143
tidal forces on, 233
voltage of, 137
e-Astronomer (blog), 195
ecliptic plane, 29
Eco, Umberto, 266
eddy currents, 161
Einstein, Albert, 9, 19, 21, 38, 165, 166, 167, 226–27, 228, 268, 269–70
electricity, 125–48, 261
in ancient Greece, 126
in atoms, 130
attraction and repulsion and, 128, 132–36
chemical reactions and, 129–30
conductors and conduction in, 128–29, 132, 136
corona discharge and, 145, 206–7
Coulomb’s law and, 133–34
early scientific study of, 126
as fluid, 128
Franklin’s experiments in, 128–29, 146–47
Gauss’s law for, 165
healing stimulation and, 142
in human body, 129
induction process and, 133–35
insulators and, 128–29, 131–32, 136
lethality of, 142–43
in lightning, see lightning
naming of, 126
pervasiveness of, 129–30
positive and negative charges and, 130–31
short circuits and, 142–43
static, 125–28, 132–36
torture and, 141
triboelectric effect and, 127, 132, 135, 140
electrodynamic suspension (EDS), 163
electromagnetic suspension (EMS), 163–64
electromagnetism, 36, 39, 166, 167, 227, 232
electrons, 6, 40, 116, 153, 155, 245
in core-collapse supernova, 220–21
electric current and, 131–32
electric field and, 40
in magnetic materials, 151
negative charge of, 131
”quantized,” 238
size of, 8
sparks and, 138
electroscope, 155
Elegant Universe, The (Greene), 23
elements, 6–7, 19
absorption lines of, 237–38
nuclear decay of, 7–8
supernova and creation of, 223
Elizabeth I, Queen of England, 152
energy, 6, 9, 168–88
amplitude and, 105
ATP and, 169
in bod
y cells, 169
chemical, 169–70
in everyday life, 180
food, 176–79
global warming crisis and, 185–87
gravitational potential, see gravitational potential energy
heat as form of, 174–75
household use of, 180–81
kinetic (KE), 154, 170, 171–72, 173, 176, 179, 221, 246
of lightning stroke, 144–45
mechanical, 173
motion and, see motion, converting energy into
nuclear, 183–85
nuclear fusion and, 186–87
physical activity and, 177–79
potential, 173
from Rapid Bursters, 256–57
solar, 181–82
from stars, 218
Sun’s radiation of, 192, 218
units for, 177
voltage and, 137
wind power and, 182–83
in X-ray bursts, 249
of X-rays, 191–92
energy, conservation of, 181
classroom demonstrations of, 168–69, 173–74
energy, conversion of, 169–88
classroom demonstrations of, 170
gravitational potential energy and, 171–72
Joule’s discovery of, 174–75
in nuclear reactors, 170
England, 127
equatorial coordinate system, 250
ergs, 177
error box, 195
escape velocity, 227
Evans, W. D., 248
event horizon, 226, 228–29, 231, 232–34
radius of, 228
Everest, Mount, 64
everything, theory of, 167
evolution, 34
Faraday, Michael, 156–57, 166
Faraday’s law, 161, 166
Fermi, Enrico, 269
ferromagnetic material, 156
ferromagnetism, 150–51
Fiestaware, 183, 262
firewood, 180
Fisher, Philip, 212–13
flavors, of quarks, 9
flight, 73–75
Bernoulli principle and, 73–74
reaction lift and, 74–75
flute, 119
fogbows, 96–99, 102
food, 169
food energy, 176–79
Fortran (computer language), 208
fossil fuel, 170, 181, 182, 185
France, 127
nuclear power in, 185
Franklin, Benjamin, 128, 130–31, 155
Franklin, Rosalind, 32n
frequency:
of big bang, 108–9
fundamental, 110–11
harmonics and, 114–15
of sound waves, 104, 105–6
of tuning fork, 106, 109–10
friction, 39
mechanical energy and, 173
see also air drag
Friedman, Herbert, 195, 197–98, 212, 213
galaxies, 28, 51
and expansion of space, 18–19
Great Wall of, 5
jets emitted from, 199
mapping projects of, 108
Perseus cluster of, 108
plasma in, 107
Galileo Galilei, 25–26, 27, 42, 43, 50, 51, 66, 126, 172, 189, 278, 282