Index
                    Fabric
                    wrinkling of, 996
                
                    Face-centered cubic (fcc)
                    lattice, 930
                    sphere packing, 986
                    Voronoi diagram, 987
                
                    Faces (geometrical)
                    in deformable packings, 988
                    and discrete spaces, 1051
                    in planar networks, 1038
                
                    Faces (human)
                    development of bones in, 1010
                    parametrization of, 1010
                    random variations in, 1192
                    recognition of, 626
                
Faceted crystal growth, 370
                    Factor (polynomial factorization)
                    analog for Boolean formulas, 1095
                    and cycles in shift rules, 963
                    and quadratic congruential generators, 975
                    randomized algorithm for, 1192
                    and shift register periods, 975
                
                    Factorial (n!)
                    encoded as integer equation, 1160
                    and examples of universality, 1110
                    and hypersphere volume, 1050
                    leading digits in, 914
                    and number of reversible block cellular automata, 1023
                    number with digits at, 914
                    and QED perturbation series, 1060
                    as recursive sequence, 906
                    and transcendental numbers, 914
                    see also Gamma
                
                    Factorial2 (double factorial)
                    and isotropic tensors, 980
                
                    Factories
                    and self-reproducing systems, 876
                
                    FactorInteger (integer factorization)
                    and arithmetic system encoding, 1115
                    basic methods for, 1090
                    difficulty of evaluating, 1134
                    and Fermat's Last Theorem, 1166
                    and multiplicative digit sequences, 902
                    and MultiplicativeOrder, 1147
                    and NP completeness, 1146
                    and number of commutative groups, 1172
                    and quantum computers, 1148
                    running times for, 1090
                    unique domains for, 915
                
                    Factorization
                    of cellular automata, 956
                
                    False
                    definition from And and Not, 817
                
Falsifiability of models, 365
Faltings theorem (Mordell conjecture), 1164
                    Family trees
                    and substitution systems, 893
                
                    Fano, Robert M. (USA, 1917–[2016])
                    and data compression, 1069
                
Farey sequences, 916
                    Farm animals
                    growth of, 1010
                
Fast algorithms, 1141
                    Fast Fourier transform (FFT)
                    recursive algorithm for, 1142
                    see also Fourier
                
Fast Walsh transform, 1073
Fastest programs, 760
                    Fate
                    vs. randomness, 967, 1135
                
                    Fax
                    data compression in, 1070
                
                    fcc (face-centered cubic)
                    lattice, 930
                    sphere packing, 986
                    Voronoi diagram, 987
                
                    Feasible computations, 1143
                    see also Polynomial time
                
                    Feathers
                    coloration of, 1012
                
                    Feature detection
                    as basis for perception, 549
                    in human visual system, 577
                
                    Fedorov, Evgraf S. (Russia, 1853–1919)
                    and shapes of 3D domains, 929
                
                    Feedback
                    control and cybernetics, 862
                    in growth of bones, 1010
                    in visual system, 1075
                
                    Feedback shift registers, 974
                    see also Shift registers
                
                    Feigenbaum, Mitchell J. (USA, 1944–[2019])
                    and computer experiments, 899
                    and iterated maps, 921
                    in Preface, xiii
                
Feigenbaum's constant, 913
                    Fejes Tóth, László (Hungary, 1915–[2005])
                    and circle packing, 985
                
                    Fermat, Pierre de (France, 1601–1665)
                    and Fermat's Last Theorem, 1166
                    and primes, 909
                
                    Fermat primes conjecture
                    as unsolved problem, 1166
                
                    Fermat's Last Theorem, 1166
                    and Diophantine equations, 1164
                    as having long proof, 779
                    and number theory history, 910
                    and sparse solutions, 945
                
Fermat's little theorem, 909
Fermat's principle (in optics), 1061
                    Fermi, Enrico (Italy/USA, 1901–1954)
                    and computer experiments, 879, 899
                    and extraterrestrial contact, 1191
                    and statistical mechanics, 1020
                
Fermi–Pasta–Ulam experiment, 1020
                    Fermilab
                    circular shape of, 1187
                
                    Fermions
                    and basic quantum effects, 1059
                    and classical limits, 1059
                    spin-statistics of, 1046
                
                    Ferns
                    branching in, 401, 1004
                    and iterated function systems, 1005
                
Ferrite core memory, 864
                    Ferrites
                    as components in technology, 1195
                
                    Ferrofluids
                    maze-like patterns in, 1013
                    phyllotaxis-like patterns in, 1007
                
                    Ferromagnetic materials
                    Ising model for, 981
                    phase transitions in, 981
                
                    Fertilization
                    randomness in, 970
                
                    Feynman, Carl R. (USA, 1962– )
                    and cryptanalysis of rule 30, 1087
                    in Preface, xiii
                
                    Feynman, Richard P. (USA, 1918–1988)
                    and cryptanalysis of rule 30, 1087
                    and discrete quantum models, 1060
                    and discreteness of space, 1027
                    and path integrals, 1057
                    and physics and computation, 1126
                    in Preface, xii, xiii, xiv
                
                    Feynman diagrams, 1060
                    exact calculations of, 1133
                    history of, 1057
                    Monte Carlo methods in, 1192
                    not as mechanistic model, 1026
                    in QCD, 1061
                    for quantum gravity, 1054
                    and random networks, 1039
                    vs. space networks, 1040
                    and spin networks, 1055
                
                    FFT (fast Fourier transform)
                    digit reversal sequences in, 905
                    implementation of, 1074
                    multiplication using, 1093
                    recursive algorithm for, 1142
                    see also Fourier
                
                    Fiber bundles
                    and continuum limits of networks, 1030
                    and gauge theories, 1045
                
                    Fiber optics
                    vs. broadcasting, 1188
                
                    Fibers (biological)
                    and folding of tissue, 417
                
                    Fibonacci, Leonardo (Pisano) (Italy, ~1170 – ~1250)
                    and digital numbers, 902
                    and Fibonacci numbers, 891
                    and rabbit populations, 1002
                    and tables of primes, 910
                    and trees, 893
                
                    Fibonacci (Fibonacci sequence)
                    difficulty of making with CAs, 1186
                    and entropy in rule 32, 958
                    generalized, 891
                    generalized for randomness generation, 975
                    generating function for, 1091
                    as initial condition for rule 60, 1091
                    leading digits in, 914
                    and multiway system states, 205
                    and multiway systems based on numbers, 939
                    number with digits at, 914, 1070
                    in ordering of math constructs, 1177
                    and plant phyllotaxis, 1006
                    and polyominoes, 943
                    as precursors to my work, 878
                    properties of, 890
                    and prosody, 875
                    and randomness generators, 975
                    and recursion history, 907
                    as recursive sequence, 128
                    and rule 150 pattern, 885
                    as solution to Diophantine equation, 1161
                    and spectral maxima, 1081
                    and substitution systems, 82, 890
                    as term in continued fraction, 913
                    uniform distribution mod 1, 904
                    as values of polynomial, 1161
                
Fibonacci multiway system, 205
                    Fibonacci number representation, 560, 1070
                    and multicolor encodings, 1111
                    as non-power base, 902
                    and substitution systems, 892
                
                    Fibonacci substitution system, 83
                    and cyclic tag system, 895
                    and cyclic tag systems, 96
                    in music, 875
                    and Penrose tilings, 932
                    properties of, 890
                    and sine curves, 147
                    spectrum of, 586, 1081
                    two-dimensional, 932
                
Field Museum of Natural History, 1011
                    Field operators
                    measurement of, 1065
                
                    Field theory (in abstract algebra), 1153
                    axioms for, 773
                    decidability with ordering predicates, 1159
                    and generalizing numbers, 1168
                    universality of, 1159
                    see also Finite fields
                
                    Field theory (physics)
                    history of, 1024
                    nonlinear PDE as, 923
                    quantum, 1061
                    see also Quantum field theory
                
                    Fields (agricultural)
                    patterns of from space, 1187
                
                    Fifths (musical chords)
                    curves of, 146
                    perfect, 1079
                
Fig leaves, 1005
Figurate numbers, 911
                    Filters (for data)
                    cellular automata as, 225
                    in visual perception, 1076
                
Filters in posets, 1040
Final cause, 1185
                    Final theory
                    see Ultimate theory of physics
                
                    Financial systems
                    applications to, 429–432
                    data from as source of randomness, 969
                    history of models of, 1015
                    meaning of random data in, 1183
                    simulations of, 968
                    using randomness to verify contracts in, 968
                
                    FindMinimum
                    and network layouts, 1031
                
                    FindRoot
                    difficulty of evaluating, 1134
                    iterative algorithm for, 1141
                
                    Fine structure constant (alpha)
                    numerology for, 1025
                    and perturbation theory, 1057
                
                    Fine tuning
                    and self-organized criticality, 989
                
                    Fingerprints
                    origin of patterns in, 1013
                    randomness in, 1014
                
                    Fingers
                    formation of human, 419
                
                    Finite automata
                    and attractors for CAs, 277
                    and Boolean functions, 1097
                    and CA encodings, 1119
                    and defining complexity, 1069
                    and formulas for nesting, 608
                    and groups, 1141
                    history of, 958
                    lower bounds in, 1143
                    minimization of, 957
                    as networks, 957
                    probabilistic, 1084
                    and regular languages, 939
                    and semigroups, 1153
                    and soundex system, 1100
                    spectra of, 1081
                    and substitution systems, 891, 931, 1091
                    total number of, 957
                
Finite axiomatizability, 1176
                    Finite complement languages, 941
                    2D generalizations, 959
                    and excluded blocks, 958
                    and repetition in 1D CAs, 954
                
                    Finite differences
                    and CA diffusion, 1024
                    and continuous CAs, 921
                    explicit schemes and sequential cellular automata, 1035
                    and history of CAs, 876
                    isotropy in, 980
                    methods based on, 940
                    neighborhood compared to cellular automata, 928
                    for PDEs, 924
                    and reaction-diffusion, 1013
                
Finite element methods, 940
                    Finite fields
                    as not universal, 1160
                    see also Additive cellular automata
                    see also Field theory (in abstract algebra)
                
                    Finite groups
                    axioms for, 1176
                    Cayley graphs of, 1032
                    as extraterrestrial messages, 1190
                    rules for, 938
                
                    Finite impulse response
                    and sequential CAs, 1035
                
                    Finite-size scaling
                    in Ising models, 983
                
Finite-size systems, 255–260, 961
                    Finite state machines
                    see Finite automata
                
                    Finitely presented groups
                    see Groups
                
Finitistic mathematics, 1158
                    Finkelstein, David R. (USA, 1929–[2016])
                    and discreteness of space, 1027
                    in Preface, xiii
                
                    Finnish
                    logic operations in, 1173
                
                    Fins (heat exchanger)
                    characteristic shapes of, 1183
                
                    Fire
                    as artifact, 1183
                    as basis for universe, 1125
                    as visible from space, 1187
                
                    Firing of neurons
                    in neural networks, 1102
                    repeatable randomness in, 976
                
Firing squad problem (in cellular automata), 876, 1035
                    First digits, 914
                    of powers, 903
                
First Law of Thermodynamics, 1019
First-order phase transitions, 981
                    Fisher, Ronald A. (England, 1890–1962)
                    and random number tables, 968
                
Fisher–Tippett distribution, 977
                    Fishes
                    color vision in, 1075
                    iterated maps for populations of, 918
                    pigmentation patterns of, 389, 426
                    shapes of related by transformations, 1010
                
                    Fishhooks
                    characteristic shapes of, 1183
                
                    Fit (least-squares fit), 1083
                
                    Fitness
                    optimization of in biology, 386
                    and purpose, 1185
                
                    Fitting of clothes
                    and allometry, 1010
                
                    FitzGerald, George F. (Ireland, 1851–1901)
                    and relativity theory, 1041
                
FitzGerald–Lorentz contraction, 1041
Five-body problem, 1130
                    Five-fold symmetry
                    in biology, 1007
                    cellular automata with, 930
                    and Penrose tilings, 932, 943
                    in quasicrystals, 994
                
Five-neighbor rules (in CAs), 927
                    Fixed points
                    in 1D cellular automata, 224, 954
                    in 2D cellular automata, 954
                    as attractors, 276
                    of blocking transformations, 270, 955
                    in combinator evolution, 712, 1122
                    for differential equations, 961
                    in Game of Life, 964
                    in iterated maps, 955, 961
                    in Mathematica, 1137
                    of pigmentation patterns, 427
                    in recursive evaluation, 906
                    of sandpile model, 989
                    and satisfying constraints, 348
                    in symbolic systems, 897
                    undecidability of, 1138
                
                    FixedPoint
                    and gradient descent, 985
                    undecidability in, 1138
                
                    FixedPointList
                    and length prefixed numbers, 1070
                    and prime implicants, 1095
                
                    Flagellated microorganisms
                    random motion of, 970
                
                    Flames
                    as self-organizing systems, 824
                    as self-reproducing, 1178
                
                    Flash photography
                    and forms of splashes, 1000
                
                    Flat (associative)
                    and associative CAs, 886, 956
                    and Boolean functions, 1173
                    and confluence property, 1037
                    and fast evolution rules, 1094
                    and generalized additivity, 952
                    and sequential substitution systems, 894
                
Flat spectra, 1081
                    Flatness (geometry)
                    of growing sheets of tissue, 1007
                
                    Flatten
                    basic examples of, 853
                    and correspondence systems, 1139
                    generalized to 2D, 931, 1073
                    generalized to any dimension, 932
                    and sequence equations, 944, 1141
                
                    Flatworm
                    pigmentation pattern on, 426
                
                    Flicker noise, 969
                    see also 1/f noise
                
Flint arrowheads, 1183
