Index
                    Li, Wentian (USA, 1959– )
                    and CA classes, 948
                    in Preface, xiii
                
                    Lichens
                    on Mars, 1180
                
Lichtenberg figures, 995
                    Lie groups
                    and additive systems, 953
                    and sphere packings, 987
                
                    Life
                    definition of, 557, 823, 1178
                    and definition of complexity, 1069
                    on Earth, 825
                    and history of complexity, 50
                    on Mars, 1179
                    origin of, 1179
                
                    Life, Game of
                    see Game of Life
                
Life force, 1178
                    Life insurance
                    and history of statistics, 1082
                
                    Lifeforms
                    alien, 825
                
                    LIFO (last-in first-out) stacks
                    and context-free languages, 939
                
                    Light
                    caustics in, 984
                    perception of, 577
                    and quantum history, 1056
                
Light bulb filaments, 842
                    Light cones, 519
                    for cellular automata, 949
                    differential geometry of, 1051
                    and random causal networks, 1052
                
                    Light levels
                    and object recognition, 1076
                
                    Lightning
                    and origin of life, 1179
                    pattern of from space, 1187
                    randomness in, 995
                    as source of radio emissions, 1187
                
                    Lights of cities
                    patterns of from space, 1187
                
Lily pads, 401
                    Limit cycles
                    for differential equations, 961
                    in iterated maps, 961
                    see also Repetitive behavior
                
Limit ordinals, 1162
                    Limitations of science, 6, 748, 846
                    and ultimate theory of physics, 471
                
Limited size systems, 255–260, 267
                    Limits
                    of cellular automaton rules, 948
                    and fractal dimensions, 933
                    of networks as space, 1030
                    undecidability of, 1138
                    see also Continuum limits
                
Lincoln cathedral, 873
Lincos language, 1189
                    Lindenmayer, Aristid (USA/Netherlands, 1925–1989)
                    and L systems, 893
                    and plant branching, 1005
                    in Preface, xiii
                
                    Lindgren, Kristian (Sweden, 1960– )
                    in Preface, xiii
                    and universal CAs, 1115
                
Line defects, 1045
                    Line-printer output
                    of my early cellular automata, 19
                
                    Linear algebra
                    and CA invariances, 1022, 1023
                    and dimensions of networks, 1031
                    and models of memory, 1101
                
                    Linear cellular automata
                    see also Additive cellular automata
                    see also Elementary cellular automata
                
Linear codes, 1101
                    Linear congruential generators, 318, 974
                    based on powers of 3, 903
                    and chaos on calculators, 920
                    cryptanalysis of, 1089
                    historical use of, 968
                    and randomized algorithms, 1085
                    as shift register analogs, 975
                
                    Linear differential equations
                    and time series, 1083
                
Linear differential operators, 953
                    Linear Diophantine equations, 944, 1164
                    and polynomial time, 1146
                
                    Linear equations, 940
                    as defining rationals, 916
                    and free field theories, 1061
                
                    Linear feedback shift registers
                    see Shift registers
                
                    Linear filters
                    in sound compression, 1080
                    and spectra, 1082
                    in visual perception, 1076
                
                    Linear models
                    and computational irreducibility, 1132
                    in statistics, 589
                
                    Linear predictive coding
                    in sound compression, 1080
                
                    Linear programming
                    NP completeness of integer, 1145
                    for optimizing designs, 1193
                
                    Linear recurrences, 891, 906
                    and additive CAs, 1018
                    and history of CAs, 878
                    and time series, 1083
                    see also Linear congruential generators
                
Linear stability analysis, 988
                    Linear systems
                    vs. nonlinear, 940
                
                    Linearity
                    compared to additivity, 952
                    in quantum mechanics, 541, 1060
                
                    LinearSolve
                    iterative algorithm for, 1141
                    and LFSR cryptanalysis, 1087
                    and linear systems, 940
                    and NC computations, 1149
                
                    Linguistics
                    see Languages (human)
                
                    Linial (Gulden), Samuel (USA, 1927–[2004])
                    and underivability of logic axioms, 1170
                
                    Linkages
                    in chaos toys, 1183
                    characteristic shapes of, 1183
                    and constructible reals, 1129
                    for randomness generation, 969
                
                    Linked lists
                    for Game of Life, 949
                
                    Linker
                    for register machines, 1114
                
Linnik's problem, 910
                    Linux
                    and creation of this book, 854
                
                    Liquid crystals
                    as components in technology, 1195
                    phase transitions in, 981
                    topological defects in, 1045
                
Liquid-gas phase transitions, 981
                    Liquids
                    flow of, 376
                    see also Fluid flow
                
                    Lisp (computer language)
                    grammar of, 1104
                    and network systems, 936
                    representing expressions in, 897
                    theorems about, 1158, 1168
                
Lissajous figures, 917
                    List manipulation
                    examples of in Mathematica, 853
                
                    Listable
                    and implementing CAs, 866
                
                    ListConvolve
                    and aggregation systems, 978
                    and autocorrelation, 1080
                    basic example of, 853
                    and CellularAutomaton, 886
                    and elementary CAs, 865
                    and fast evolution rules, 1094
                    and general CAs, 886
                    and hexagonal CAs, 992
                    and image processing, 1077
                    and integer multiplication, 1093
                    and Ising model, 981
                    and multidimensional CAs, 927
                    recursive algorithm for, 1142
                    in sandpile models, 989
                    and Sierpiński pattern, 931
                    and visual perception, 1076
                
                    ListCorrelate
                    and additive CAs, 870, 952
                    and visual feature extraction, 1077
                
                    ListPlay
                    and sound output, 1080
                
                    Lists
                    encoded as integers, 1120, 1127
                    see also Sequences
                
Lithic analysis, 1183
Little group (spacetime symmetries), 1046
                    Littlewood, John E. (England, 1885–1977)
                    and chaos theory, 971
                    and Goldbach's Conjecture, 911
                    and iterated maps, 919
                    and numbers of primes, 910
                
Livermore (Lawrence Radiation Laboratory), 864
                    Lizards
                    pigmentation patterns of, 426
                
                    Local conservation laws, 1023
                    see also Conservation laws
                
Local minima, 346
                    Localization
                    in class 1 and 2, 252
                    as origin of repetition, 355
                
                    Localization (of eigenstates)
                    and randomness tests, 1085
                
                    Localized structures
                    and 3n+1 problem, 904
                    in class 4 systems, 281–296
                    in code 20 CA, 285
                    in code 357 CA, 286
                    in code 1329 CA, 287
                    in continuous CAs, 160, 244
                    as engineering components, 678
                    finding in 2D CAs, 965
                    and long-range communication, 252
                    in network evolution, 525
                    origins of, 990
                    and particles in physics, 525
                    in PDEs, 164, 1129
                    in presence of randomness, 526
                    in QCD, 1061
                    from random initial conditions, 228
                    in reversible CAs, 440
                    in rule 30 CA, 700
                    in rule 37R CA, 455
                    in rule 45 CA, 701
                    and rule 110 axiom system, 1168
                    in rule 110 CA, 31, 292, 964
                    same in different 2D rules, 949
                    in three dimensions, 949
                    in turbulent fluids, 997
                    in Turing machines, 888
                    and universality, 692
                    see also Gliders
                
Locomotion in animals, 1011
                    Log (logarithm)
                    algebraic independence of, 1164
                    computation of nth digits in, 912
                    and computational reducibility, 744, 747
                    continued fractions for, 144
                    digits of, 141
                    leading digits in, 914
                    randomness in digits of, 967
                    as source of randomness, 968
                    uniform distribution mod 1, 904
                    and Weber's law, 1014
                
Log-periodic antennas, 1183
                    Logarithmic growth
                    of number representations, 1070
                
                    Logarithmic law
                    for leading digits, 914
                
Logarithmic series, 1134
Logarithmic spiral, 418
                    Logging
                    and messages to Moon, 1189
                    regular patterns of, 1187
                
                    Logic
                    as applied to math, 780
                    axioms for, 773, 808
                    and combinators, 711, 898
                    and communication, 1181
                    and computational irreducibility, 1196
                    and defining intelligence, 1178
                    difficult notation in, 1104
                    and discreteness in programs, 976
                    as example of lattice theory, 1153
                    as example of rules, 875
                    and finite set theory, 1171
                    as foundation of math, 1176
                    history of, 1097, 1099, 1151
                    history of notation for, 1182
                    and history of universality, 1109
                    in human languages, 1173
                    in human thinking, 627
                    implications for, 1197
                    interesting theorems in, 816
                    lengths of proofs in, 1175
                    machines for doing, 1107
                    multilayer, 1096
                    multivalued, 814, 1175
                    and natural science, 860
                    non-universality of basic, 784
                    as not mainstream math, 859
                    possible models of, 805
                    in practical computers, 1108
                    and quantum mechanics, 1058
                    reversible, 1097
                    shortest And, Or axioms for, 1174
                    shortest Nand axioms for, 808
                    ternary, 814
                    and Thue on substitution systems, 893
                    see also Predicate logic
                
                    Logic circuits
                    emulated by CAs, 662, 1112
                    emulated by Game of Life, 1117
                    and universality, 1119
                
                    Logic expressions
                    see Boolean expressions
                
                    Logic minimization, 1095
                    compared to searching, 1193
                
Logic programming languages, 1158
Logic Theory Machine, 1157
                    Logical depth
                    and defining complexity, 1069
                    for Turing machines, 1144
                
                    Logical functions
                    see Boolean functions
                
                    Logical positivism
                    and theories of communication, 1181
                
                    Logical rules
                    see Rules
                
                    Logicism
                    as foundation of math, 1176
                
                    LogIntegral (logarithmic integral li)
                    and distribution of primes, 133, 909
                    and Zeta, 918
                
                    Logistic differential equation
                    and iterated maps, 918
                
                    Logistic map, 920
                    closed forms for iterates of, 1098
                    and continuous CAs, 922
                    and history of chaos theory, 971
                    see also Iterated maps
                
                    Logistics
                    and causal networks, 1033
                    and complex systems, 862
                
                    Lognormal distribution
                    for human weights, 977, 1003
                    and multiplicative processes, 977
                
                    Logo (computer language)
                    and 2D TMs, 930, 931
                
Long division, 139
Long-term memory, 1102
                    Long-time tails
                    in molecular dynamics, 999
                    and shaking, 969
                
                    Longest paths
                    and NP completeness, 1146
                
                    Looms
                    and history of computer, 1107
                
Loop general relativity, 1048
                    Loop quantum gravity, 1054
                    and spin networks, 1055
                
                    Loop switching method
                    and network layout, 1031
                
                    Lorentz, Hendrik A. (Netherlands, 1853–1928)
                    and relativity theory, 1041
                
Lorentz contraction, 1041
Lorentz gas, 1022
Lorentz transformations, 1041, 1042
Lorentzian spaces, 1051
                    Lorenz, Edward N. (USA, 1917–[2008])
                    and chaos theory, 971
                    and complex ODE, 879
                    and experimental math, 899
                    and fluid turbulence, 998
                    in Preface, xiii
                
                    Lorenz equations
                    as giving strange attractor, 922
                    and history of chaos theory, 971
                    and Lissajous figures, 917
                    and weather prediction, 1178
                
                    Los Alamos
                    and history of CAs, 877
                    and my work on CAs, xiii, 880
                
Lossless data compression, 560
Lossy data compression, 572
                    Lotka, Alfred J. (USA, 1880–1949)
                    and oscillatory chemical reactions, 1013
                
Lotteries, 969
                    Lovelace, A. Ada (Byron) K. (England, 1815–1852)
                    and universality, 1110
                
                    Low-level languages
                    and practical computing, 1109
                    and register machines, 101
                
Löwenheim–Skolem theorem, 1172
                    Lower bounds
                    on computations, 761, 1143
                    on parity, 1096
                    on sorting algorithms, 1142
                
                    LPC
                    in sound compression, 1080
                
                    Lucas, F. Edouard A. (France, 1842–1891)
                    and binomials mod k, 870
                
                    Lucas–Lehmer test
                    for primes, 911
                
Lucas numbers, 891
                    Lucian (Greece, 120 – ~180 AD)
                    and inhabitants of Moon, 1190
                
                    Lucretius, Titus Carus (Italy, ~95 – ~55 BC)
                    and atomism, 876
                    and models based on rules, 860
                
                    Łukasiewicz, Jan (Poland, 1878–1956)
                    and axioms for logic, 1151
                    and multivalued logic, 1175
                
Łukasiewicz representation, 896
                    Lunes
                    and ornamental art, 872
                    theory of, 873
                
                    Lungs
                    branching in, 1008
                
                    Lyapunov exponents
                    in cellular automata, 950
                    and entropies, 960
                    in iterated maps, 921
                    probabilistic estimates of, 953