Index
                    ⅇ (exponential constant)
                    continued fraction for, 144
                    digits of, 142
                    as not from rational integral, 916
                    and random networks, 963
                
                    e-commerce
                    use of randomness in, 1192
                
                    E8 (group) lattice
                    isotropy of, 980
                    and sphere packings, 987
                
Eanna temple, 873
                    Ear lobes
                    folding in formation of, 417
                
                    Early computers
                    and cellular automata, 45
                
                    Early universe
                    particles surviving from, 1047
                    and thermodynamics, 1021
                
                    Ears
                    operation of, 585, 1079
                    see also Auditory perception
                
                    Earth
                    conditions for life on, 1179
                    and extrasolar planets, 1179
                    formation of the, 1179
                    origin of life on, 1179
                    viewed from space, 835, 1187
                
Earth-Moon-Sun system, 313, 972
                    Earthquakes
                    1/f noise in, 969
                    and fracture, 374
                
                    Earthworks
                    as artifacts, 1184
                
Eastern philosophy, 1195, 1196
                    ECAD
                    multilevel logic in, 1096
                
                    Ecology
                    and complexity research, 863
                    of extraterrestrial colonization, 1191
                    iterated maps and models in, 918
                
                    Economics
                    applications to, 429–432
                    and complexity in science, 861
                    and computational irreducibility, 1132
                    and extraterrestrial trade, 1191
                    and free will, 1135
                    history of models from, 1015
                    iterated maps and models in, 918
                    and notion of purpose, 1185
                    and pragmatic theory of law, 1136
                    quantitative laws in, 1014
                    successes of math in, 859
                
                    ed (text editor)
                    and regular expressions, 958
                    and substitution systems, 894
                
                    Eddies
                    in fluid flow, 376
                
                    Eddington, Arthur S. (England, 1882–1944)
                    and models of the universe, 1025
                
Eddy viscosities, 996
                    Eden, Murray (USA, 1920– )
                    and aggregation systems, 978
                
                    Eden model, 331, 978
                    see also Aggregation systems
                
                    Edge detection in images, 1077
                    and scale invariance, 1076
                
                    Edgerton, Harold E. (USA, 1903–1990)
                    and splashes, 1000
                
                    Edison, Thomas A. (USA, 1847–1931)
                    and searching for materials, 1193
                
                    Education
                    and defining intelligence, 1178
                    and exact solutions, 1133
                    and recognizing intelligence, 825
                    and the science in this book, 855
                
                    EDVAC (computer)
                    and early CA, 1117
                
EEG, 1099
                    Eel
                    pigmentation pattern of, 426
                
                    Effective computability
                    see Decidability
                
Effectively computable sets, 1138
Efficiency of computations, 758
Efficient causes, 1185
Efficient Market Hypothesis, 432, 1015
                    Egg
                    randomness in fertilization of, 970
                
                    Egmont volcano
                    circular shape around, 1187
                
Egyptian art, 873
Egyptian fractions, 915
                    Egyptian mathematics, 1149
                    and evaluation chains, 1095
                    and π, 911
                
Egyptian pyramids, 874
                    Ehrlich, Paul (Germany, 1854–1915)
                    and chemotherapy, 1193
                
                    Eigenvalues
                    and dimension of networks, 1031
                    of distance matrices, 1031
                    and entropies of CAs, 958
                    and fractal dimensions for additive rules, 955
                    of nested systems, 1081
                    nesting in pattern of, 1130
                    of random matrices, 918, 977
                
Eikonal approximation, 1061
                    Einstein, Albert (Germany/Switzerland/USA, 1879–1955)
                    and EPR experiment, 1058
                    and general relativity, 1047
                    and math in science, 860
                    and particles as gravity, 1054
                    and quantum theory, 1056
                    and special relativity, 1041
                    and unified field theory, 1028
                
                    Einstein equations, 1052
                    exact solutions to, 1133
                    as examples of PDEs, 161, 923
                    history of, 1047
                    matter vs. space in, 1028
                    quantization of, 1054
                    specifying curvature of space, 531
                    vacuum solutions to, 1053
                
                    Einstein–Hilbert action
                    and spin networks, 1055
                
Einstein–Podolsky–Rosen (EPR) experiment, 1064
                    Elasticity theory
                    and fracture, 995
                
                    Electric breakdown, 302, 995
                    see also Lightning
                
                    Electric fields
                    particle production in, 1062
                
Electric light bulb filaments, 1193
                    Electricity
                    as defining feature of life, 1178
                
                    Electromagnetic fields
                    and gauge invariance, 1045
                    quantization of, 1056
                    and radioactive randomness, 970
                    and relativistic invariance, 1041
                    theories of based on space, 1028
                    as ultimate constituents, 1024
                    and virtual photons, 1060
                
                    Electromagnetic radiation
                    and information transmission, 1069
                
                    Electromagnetic signals
                    see Radio signals
                
                    Electromechanical machines
                    as computers, 1107
                    and finite automata, 958
                
                    Electron diffraction
                    and visualizing fracture, 995
                
                    Electron levels
                    in nested potentials, 1081
                
Electron-photon scattering, 1060
                    Electronic computers
                    and Church's Thesis, 1125
                    history of, 1107
                    and history of universality, 1110
                    numbers in history of, 902
                    and proofs of universality, 1117
                
                    Electronic design
                    and Boolean formulas, 1097
                
                    Electronic noise, 302, 968
                    randomness from, 969
                
                    Electronics
                    making reliable, 981
                    and studying complexity, 862
                
                    Electrons
                    discovery of, 1024, 1044
                    as initiators of randomness, 303
                    lack of intuition about, 537
                    limits on sizes of, 1044
                    magnetic moment of in QED, 1060
                    mass of, 1046
                    in practical computers, 1108
                    theories of structure of, 1044
                    wave-particle duality of, 1056
                
                    Elegant theorem
                    definition of, 1176
                
                    Element
                    in set theory, 1155
                
                    Elementary cellular automata, 53, 883
                    emulation of rules by, 705
                    legal rules for, 948
                    my first pictures of, 19, 864
                    with random initial conditions, 232, 424
                    rule equivalences, 883
                    table of Boolean forms for, 884
                    uniqueness of patterns from, 956
                    as universal logic functions, 1174
                    see also Cellular automata
                    see also Rule 30, Rule 90, etc.
                
                    Elementary functions
                    difficulty of evaluating, 1134
                    and math impossibilities, 1137
                    numbers generated from, 916
                    vs. special functions, 1092
                
                    Elementary particles, 525–530
                    decays and time quantization, 1032
                    detection of, 969
                    discovery dates of, 1043
                    as dual to black holes, 1045
                    enumerating in networks, 1045
                    interactions between, 539
                    known types of, 1043
                    and limit of networks, 1030
                    masses of, 528, 1046
                    motion of, 528
                    motion of along geodesics, 531
                    motion of through network, 536
                    quantum threads between, 544
                    searching for additional, 1047
                    spin of, 1046
                    in unified field theory, 1028
                    upper limits on mass of, 1047
                
                    Elephants
                    communication by, 1181
                
                    Elkies, Noam D. (USA, 1966– )
                    and nearby powers, 1166
                    in Preface, xiii
                
                    Elliott 903 computer
                    my use of, 854, 864
                
                    Elliptic curves
                    and Diophantine equations, 1164, 1165
                    and Fermat's Last Theorem, 1166
                
Elliptic equations (PDEs), 923, 940
                    Elliptic functions
                    and background for PDE, 924
                    difficulty of evaluating, 1134
                    and logistic map formulas, 1098
                
                    EllipticK (elliptic integral)
                    in 2D Ising model, 982, 1133
                
                    EllipticTheta (elliptic theta functions)
                    and algebraic equations, 1092
                    as generating function, 1092
                    nested patterns from, 1093
                    and quintic equations, 945, 1133
                    and runs of digits, 914
                
Embeddings of networks, 193, 476, 1031
                    Embryos
                    development of, 417, 419, 1009
                    history of study of, 1004, 1010
                    pigmentation precursors in, 425
                    randomness in, 970
                
                    Emergence
                    of order from randomness, 223
                
                    Emergent behavior
                    general theory of, 3
                
                    Emotions
                    and learning, 1102
                
                    Empirical mathematics
                    see Experimental mathematics
                
                    Empiricism
                    and theories of communication, 1181
                    and visual perception, 1076
                
                    Emulation
                    between cellular automata, 1118
                    by universal CA, 652
                    and computational irreducibility, 742
                    rates of, 765
                    and universality, 642
                    see also entries for specific systems
                
                    Encoding
                    arithmetic, 1071
                    of arithmetic by set theory, 1160
                    block, 563
                    dictionary-based, 565
                    Huffman, 564
                    in mathematics, 815
                    pointer-based, 565
                    run-length, 560
                    theory of cellular automaton, 1118
                    of three colors by two, 655, 1111
                    in universal CA, 652
                    and universality proofs, 1126
                
                    Encryption
                    see Cryptography
                
                    Encyclopedia Britannica
                    leaf shapes in first edition of, 1005
                
                    Endogenous randomness
                    see Intrinsic randomness generation
                
                    Endomorphisms
                    cellular automata as, 959
                    and generalized additivity, 952
                
Endpapers in this book, 851
                    Energy
                    and advanced technology, 1191
                    in gravity theory, 537
                    heat as form of, 1019
                
                    Energy conditions
                    and general relativity, 1053
                
                    Energy conservation
                    in cellular automata, 458
                    in Einstein equations, 1052
                    in Ising model CAs, 982
                    in network evolution, 529
                    in PDE, 923
                    in physics, 1022
                    and thermodynamics, 445
                    in three-body problem, 972
                
                    Energy levels
                    in nested potentials, 1081
                
                    Energy minimization
                    and adaptation, 823
                    in chemistry, 1194
                    and NP completeness, 1146
                    in proteins, 988, 1003
                    and purpose, 831
                    and quasicrystals, 994
                
                    Energy-momentum tensor
                    in Einstein equations, 1052
                
                    Engineering
                    avoiding complexity in, 723
                    vs. biological evolution, 393
                    vs. biological forms, 1004, 1180
                    and computational reducibility, 829
                    correctness proofs in, 1157
                    fracture as issue in, 995
                    future of, 840
                    historical forms in, 828, 1183
                    and history of complexity, 862
                    intuition from, 40
                    optimization of designs in, 1193
                    of universal systems, 678
                    and universality proofs, 698
                    used in building computers, 822
                
                    English
                    and cryptanalysis, 599
                    frequency of letters in, 1069
                    hashing of words in, 1100
                    logic operations in, 1173
                    redundancy of, 1086
                
                    ENIAC (computer)
                    and digits of π, 911
                    and history of computing, 1107
                
Enigma rotor machine, 1085
                    Ensembles
                    evolution of in CAs, 278
                    in Ising model, 982
                    in rule 37R, 457
                    in statistical mechanics, 1020
                    in statistics, 593
                
                    Entanglement (in quantum theory), 544
                    as basic quantum effect, 1059
                    and Bell's inequalities, 1064
                
                    Entrails of goats
                    and fortune-telling, 968
                
                    Entropy
                    as algebraic number in CA, 958
                    analogy of to amount of computation, 1133
                    vs. biological complexity, 1003
                    in block encoding, 1071
                    in cellular automata, 958
                    as defining CA classes, 960
                    and definition of life, 1178
                    estimation of, 959, 1084
                    history of, 1019
                    and Lyapunov exponents, 960
                    measure, 959
                    origins of increasing, 441–457
                    of particles in box, 1022
                    and redundancy of text, 1086
                    and repetitive CA behavior, 954
                    of rule 30 mapping, 1087
                    and self-organization, 948
                    spacetime, 960
                    temporal, 960
                    in thermodynamic systems, 448
                    undecidability of in CAs, 958, 1138
                    see also Second Law of Thermodynamics
                
Entscheidungsproblem (decision problem), 1110
                    Enumeration of
                    alkanes, 1194
                    balanced parenthesis strings, 989
                    CA periodic points, 954
                    CAs to find doubling rules, 832
                    cases in proofs, 1177
                    commutative monoids, 952
                    cycles in shift rules, 963
                    finite automata, 957
                    programs, 758
                    reachable states in CAs, 958
                    string constraints, 1140
                    surjective cellular automata, 959
                    tiling configurations, 959
                    Turing machines, 888, 1120
                
                    Envelopes
                    masking patterns on, 1077
                
                    Environmental sciences
                    math morphology in, 1077
                    and systems theory, 862
                
