by Lee Smolin
lack of “senior” leaders, 272, 274–75, 285
Maldacena conjecture as unproved, 282–83
messianic tendencies, 275–77, 284
monolithic approach to problems, 272, 284
narrowing of research agenda, 273–75
pathologies in methodology, 267–68
sense of entitlement, 270–71, 284
split between string and nonstring theorists, xvii–xix, xx–xxi, 271–72, 284, 351
tribal tendency, 352
uniformity of views, 273, 284
See also string theory, assessment of
Solomon, Jacques, 85–86
Sorkin, Rafael D., 243, 313
space
as entity, 41
Euclidean geometry and, 41, 44, 81
geometry of, 41–42, 44, 81
space/time relational theory (Barbour), 321
spacecraft trajectory, 213–14
space dimensions
Euclidean geometry and, 41
in Kaluza-Klein theory, 46–47, 46, 48
negative dark energy and, 142
Nordstrom and, 39, 43, 44, 46, 47
saddle-shaped, 142, 143
superstring theory/revolution (second), 141–42, 144
verification of extra, 172–74
spacetime
curved path of, 42, 257
Euclidean geometry and, 42
experiment on, 43–44
general relativity and, ix, 4, 43, 81–82, 93, 151
geometry of, 42–43
gravitational field and, 43
partial unification, 42, 55, 67
symmetry, 92–93
unification of (Einstein), 36, 41–44
spacetime bounce, 251
special relativity
DSR theory and, 227, 229, 236
Einstein’s solving of, 36, 37, 38
gravity and, 54–55
and invention of string theory, 104–5, 107–8
observers and, 55, 58–59
postulates of, 226–27
predictions for elementary particles, 219
space as continuous, 55
spacetime (partial) unification, 42, 55, 67
speed of light and, 55, 219, 224, 226, 227–28
symmetry and, 219
special relativity (possible breakdown)
background-dependent/-independent approach, 236–37
cosmic ray studies, 221–22, 225–26
DSR (deformed/doubly special relativity) theory, 227, 229, 236
effects on string theory, 223, 236, 237
gamma-ray bursts and, 223–24, 225–26
Jacobson and, 314–15
motion, rest, and, 226
Planck-length paradox, 227, 228–29
possible meanings of, 223, 226, 236
results for, 315, 316
speed, 14, 228
speed of light
changes (possible) in, 215–17
cosmological constant and, 209
quasar study of, 216–17
special relativity, 55, 219, 224, 226, 227–28
spin network, 248
spontaneous symmetry breaking
combining with gauge principle, 61
description/examples, 56, 59–61
Higgs boson and, 61
standard model and, 56, 59–62
supersymmetry, 68, 75
squarks, 74, 75
standard model (of elementary-particle physics)
description, 12
free-constants problem and, 12–16, 191
discovery of quarks and, 56
gauge principle and, 56–59, 61, 62, 239
importance of, 62
instabilities and, 65
neutrinos’ mass and, 66
noncommutative geometry and, 247
pragmatic style of physics and, 312
proton decay problem and, 63–65
QCD and, 62
quarks changing into electrons/neutrinos and, 63–64
spontaneous symmetry principle and, 56, 59–62
string theory vs., 182–83
SU(5) symmetry problem and, 63, 64–65
symmetry and, 63
Weinberg-Salam model and, 62
Weyl and, 45
work on in last thirty years, xiii
Yang-Mills theories, 317
standard model of cosmology, 16
Stanford group
cosmological constant/stability work, 156–57, 197
number of string theories and, 157–60, 161
Stanford Linear Accelerator Center (SLAC), 56, 173
Stelle, Kellogg, 97
string coupling constant, 108, 131
strings
breaking and joining of, 108
propagation of, 109
string tension, 108
string theory
craftspeople vs. seers, 313–14
dark-energy problem of, 149–50
description, xii–xiv
dominance of, xx, xxi, xxii
duality of strings and fields, 110–11
eleven-dimensional supersymmetric theories, 274
finiteness issue, 117, 186–88, 187, 278–79, 280, 281, 367 n14, 368 n15
fundamental unification problem, 176
generic features of, 172, 176
higher-dimension stability, 154–59
history of, 102–13
inducing strings to become bigger, 171–72
observation and, 149–50
particles in, 102
prediction of photons’ speed with, 223
prediction problem summary, 170–71, 179
scientists’ relation to, 147–48
Stanford group’s theories, 157–60
supersymmetry and, 68
time and money invested in, 176, 177
unifying gravity with other forces, 106, 107, 112, 176
verification problem, 171–72
Weyl’s unification attempts and, 45–46
See also superstring theory/revolution (first); superstring theory/revolution (second)
string theory, assessment of
background-dependent problem, 83, 146–47, 184–86, 191, 198, 239, 255, 271
basic groups of theory, 193
as “beautiful,” 194
conjectured-theories problems, 181–82
cosmological constant problems, 153–60, 180, 189
dark matter-dark energy problems, 191–92
derivation of general relativity from, 185–86
experimental difficulties and, 178, 203
finiteness issue, 117, 186–88, 187, 278–79, 280, 281, 367 n14, 368 n15
and foundational problems of quantum mechanics, 192
by Friedan, 193–94
future research, 198–99
higher-dimensions problem, 196–97
human intuition problem, 188
impacts if correct/incorrect, xvii
instabilities(tachyons), 185, 186
on key physics problems, 183–92
knowledge deficiencies, 179–81
landscape theories problem, xiv, 197, 198
mathematical developments from, 194–96, 197
M-theory and, 181, 182, 183, 196–97, 198
as not a fundamental theory, 182, 183
as not a theory, xvi
and observation, experiment, 179, 181, 193, 196–97, 198
overview, xiv–xv, xvi–xvii, 177–78, 192–93, 257, 349, 352
parameter values of standard model and, 191
prediction problems, xiv, 180, 183, 193, 197, 199, 352
and quantum gravity, 83, 184–88, 191, 197–98
quantum gravity and Maldacena’s proposal, 188–89, 191
standard model vs., 182–83
style of scientists, 263, 264
supersymmetry problem, 180–81, 183–84, 185, 186, 187, 188, 189, 190–91, 193, 194, 196, 197, 198
as theory in crisis and, 178
and unification of particles and forces, 182, 183�
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See also sociology of physics, string theory
string theory, invention of
bosons, 105, 106, 112
closed/open strings, 106–8, 108, 109
constants, 108–9
dimensions of space, 105–6
distance between quarks, 104
fermions, 105, 106, 111, 112
field lines, 110–11
forces/particles of standard model and, 107, 112
as fundamental theory, 106–7, 112–13
gauge fields, 112
gravitons, 106, 112
“law of bubbles”/minimizing area, 109–10, 113, 184
massless particles, 105, 106
naming of, 104
pioneers, 103–4, 105, 106, 110, 111–13
problem-solving attempts, 105–6
puzzles solved by (summary), 112
quantum theory and, 104–5, 107–8
requirements of theory, 104–5
rubber-band comparison, 103, 104
as scientific revolution, 102–3
special relativity, 104–5, 107–8
strongly interacting particles experiments, 103
supersymmetric string (superstring) theory, 105–6, 112
supersymmetry discovery with, 105
tachyons, 105, 106
unification of motion and forces, 107–8, 112
Strominger, Andrew
and special black holes, 138, 283
and string theory, 122–23, 124, 138, 158, 273
strong nuclear force
description, x
gauge principle/theory and, 58, 62
quantum field theory, 55–56
unification of electromagnetic/weak fields and, 11
Structure of Scientific Revolutions, The (Kuhn), 115
SU(5) symmetry, 63, 64–65
Sundrum, Raman, 173–74
supergravity, 91–98
calculations for, 94–95, 96–97
dimensions of space and, 105–6
failure of, 97–98
N = 8 theory, 94, 97
quantum gravity theory, 91–98
supergeometry and, 96
Witten and, 135
supermembrane theory, 135
superpartners, 67, 74–75
superstring theory/revolution (first)
academic conferences on, 116
anomalies and, 114, 115
background-dependence/-independence, 119, 126–27
biology comparisons, 127
bosonic strings and, 117
Calabi-Yau spaces and, 122–24
constants and, 117–18, 119–21
discouragement with, 128
experimenting and, 116–17, 128
extra particles/forces problem, 121–22
fermions, 117
finiteness, 117
hidden extra dimensions, 119–20,
120, 122, 122, 123–24
instabilities and, 119, 123, 124
mathematics and, 116–17
as meta-theory, 126–27
multiple theories with, 117, 129, 160
“package deal” problems with, 118–19
“postmodern physics” and, 116–17
predictions and, 124, 128
problem of infinite forces, 123
problems of space dimensions, 118–21, 121–22, 134–36, 136
scientists split on, 116, 124–25, 128
slowing of progress on, 127–28
standard model reproduction, 122–23
supersymmetry problems, 118–19, 122–23
tachyons and, 117, 118
timing of, 114
tipping point, 114–15
and unification of particles and forces, 118, 120–21
unifying physics and, 115, 116, 117–18, 127
superstring theory/revolution (second)
black holes and, 145
dualities of theories and, 130–33, 135–36
impacts of discoveries, 129–30
information from, 145–46
instabilities and, 145
and Maldacena’s proposal, 142–45, 180, 189, 282–83
matrix model and, 147
M-theory, 136, 146–47
problem of background independence, 146–47
scientists’ split over, 133
space dimensions and, 141–42, 143, 144
string theory-gauge theory duality, 141–45
string theory unification and, 129, 134–36, 136
supersymmetry and, 142–43, 145
timing of, 129
vibrations of strings, 131, 183–84
See also maximally super theory
supersymmetry
current focus on, 66–67
description, 364 n1 (ch. 12)
electromagnetism and, 68
free constants problem with, 75–76, 78
inadequacies of, 78–79
LHC and, 69–70, 76–77, 78, 79
method to prove, 77
minimally supersymmetric standard model (MSSM) and, 75–76, 78
problems with, 69–70, 74–76, 77–78, 174–76
selectrons and, 68–69
Soviet Union/Western physicists and, 68
spontaneous symmetry breaking and, 68, 75
string theory and, 68
supergravity and, 92–93, 135
superpartners with, 67, 74
and superstring theory/revolution (second), 142–43, 145
and unification of particles and forces, 67
unifying bosons, fermions with, 67–68
WIMPs and, 175
Susskind, Leonard
anthropic principle/solution, 161–62, 163, 369 n5 (ch. 17)
and beginnings of string theory, 103–4
Cosmic Landscape, The, 276
matrix theory, 147
Stanford group and, 156
symmetry
circle shape, 218
gauge principle/theory and, 56–57, 138
importance to physicists, 218–19
laws and opportunities example, 59
of space and time, 92–93
stability and, 60
theories of relativity and, 219
See also spontaneous symmetry breaking; supersymmetry
tachyons
description, 105
instabilities and, 185, 186
superstring theory/revolution, 117, 118
Taubes, Gary, 338–39
T-duality, 130–31, 130, 135–36
Technicolor force, 73
Technicolor theories, 77
techniquarks, 73
Tegmark, Max, 170
TeV (tera-electron volt), 70
theory
characteristics of “right,” 256
definition, xvi
as falsifiable, xiii
as mathematically consistent, 112
multiple solutions for, 126
predictions and, xvi
and string theory, xvi