Packard, Norman H. (USA, 1954– )
and CA classes, 948
as coauthor of paper, 882
in Preface, xiii

Painlevé, Paul (France, 1863–1933)
and Painlevé functions, 1092

Paley, Raymond E. A. C. (England/USA, 1907–1933)
and Walsh transforms, 1073

Paley, William (England, 1743–1805)
and natural theology, 861

Panini (India, ~500 BC)
and grammars, 875

Paris, Jeffrey B. (England, 1944– )
and unprovable statements, 1163

Pascal, Blaise (France, 1623–1662)
and arbitrary number bases, 902
and his calculator, 1107
and Pascal's triangle, 870

Paterson, Michael S. (England, 1942– )
and 2D Turing machines, 880, 930

Peacock, George (England, 1791–1858)
and generalization in math, 1168

Peano, Giuseppe (Italy, 1858–1932)
and axioms for arithmetic, 1152
and foundations of math, 1149
and math notation, 1182
and space-filling curves, 893

Peirce, Charles S. (USA, 1839–1914)
and axioms for logic, 1151
and Nand, 1173
and theories of communication, 1181

Penrose, Lionel S. (England, 1898–1972)
and mechanical self-reproduction, 1179

Penrose, Roger (England, 1931– )
and discreteness of space, 1027
and Penrose tiles, 932, 943
and polyomino tilings, 943
in Preface, xiii
and spin networks, 1055

Phelan, Robert J. (USA, 1933– )
and minimum area packings, 988

Piaget, Jean (Switzerland, 1896–1980)
and animism in children, 1195

Pingala (India, ~200 BC)
and Fibonacci numbers, 890

Pippenger, Nicholas J. (USA/Canada, 1947– )
and NC computations, 1149

Pitts, Walter H. (USA, 1923–1969)
and neural networks, 880, 1099
and universality, 1110

Planck, Max K. E. L. (Germany, 1858–1947)
and quantum theory, 1056

Plato (Greece, 427–347 BC)
and microcosm, 1196
and mimesis, 1178
and the nature of space, 1028
and primes, 909, 910
and purpose in nature, 1185

Plouffe, Simon (Canada, 1956– )
and computation of π, 912
in Preface, xiii

Podolsky, Boris (USA, 1896–1966)
and EPR experiment, 1058

Poincaré, J. Henri (France, 1854–1912)
and 3-body problem, 972
and cell complexes, 1050
and chaos theory, 971
and iterated maps, 918
and notion of complexity, 1068
and Poincaré recurrence, 1022

Politzer, H. David (USA, 1949– )
and particle masses, 1047
in Preface, xiv

Pollard, John M. (England, 1941– )
and integer factoring, 1090

Pólya, George (Hungary/Switzerland/USA, 1887–1985)
and zeta function zeros, 918

Pomeau, Yves (France, 1942– )
and cellular automaton fluids, 999
in Preface, xiii

Ponzano, Giorgio E. (Italy, 1939– )
and spin networks, 1055

Popper, Karl R. (Austria/New Zealand/England, 1902–1994)
and free will, 1135

Post, Emil L. (USA, 1897–1954)
and axiom systems in logic, 1170
and models of computation, 879
and models of math, 1150
and multivalued logic, 1175
and multiway systems, 938
and origins of universality, 1110
and Post Correspondence Problem, 1139
and tag systems, 879, 894
and truth tables, 1170
and undecidability, 1136
and undecidability of word problem, 1141
and underivability of logic axioms, 1170
and universality, 1125

Presburger, Mojzesz (Poland, 1904 – ~1943)
and axioms for arithmetic, 1152

Prigogine, Ilya (Belgium/USA, 1917–[2003])
in Preface, xiii
and reaction-diffusion, 1013

Prouhet, Eugène (France, 1817–1867)
and Thue–Morse sequence, 893

Prusinkiewicz, Przemyslaw (Poland/Canada, 1952– )
and branching in plants, 1005

Ptolemy (Egypt, ~100 – ~170 AD)
and math in science, 859
and models based on rules, 860

Putnam, Hilary W. (USA, 1926–[2016])
and Diophantine equations, 1161

Pythagoras (Italy, ~560 – ~480 BC)
and math in science, 859, 860
and perfect numbers, 911
and rules in music, 875

Radó, Tibor (Hungary/USA, 1895–1965)
and Busy Beaver Problem, 889

Ramanujan, Srinivasa A. (India/England, 1887–1920)
and almost integers, 915
and divisor sequences, 910, 911
and experimental math, 899

Rankine, William J. M. (Scotland, 1820–1872)
and vortices in ether, 1044

Raup, David M. (USA, 1933–[2015])
and shapes of shells, 1008

Ray, John (England, 1627–1705)
and natural theology, 861

Regge, Tullio E. (Italy, 1931–[2014])
and discrete spacetime, 1054
and spin networks, 1055

Reif, Frederick (USA, 1927– )
and inspirational book cover, 864

Rényi, Alfréd (Hungary, 1921–1970)
and generalized entropies, 959

Reynolds, Osborne (Ireland/England, 1842–1912)
and Reynolds numbers, 996

Rice, Henry G. (USA, 1920–[2003])
and Rice's theorem, 1137

Richardson, Lewis F. (England/Scotland, 1881–1953)
and fluid turbulence, 997

Ricker, William E. (Canada, 1908–2001)
and iterated map for fish populations, 918

Riemann, G. F. Bernhard (Germany, 1826–1866)
and discrete space, 1027
and distribution of primes, 918
and nested curves, 934
and Riemann tensor, 1049

Riesz, Frigyes (Hungary, 1880–1956)
and Riesz products, 1081

Robbins, Herbert E. (USA, 1915–2001)
and axioms for logic, 1151

Robinson, Abraham (England/Israel/USA, 1918–1974)
and non-standard analysis, 1172

Robinson, J. Alan (USA, 1930–[2016])
and resolution theorem proving, 1157

Robinson, Julia B. (USA, 1919–1985)
and axioms for arithmetic, 1152
and Diophantine equations, 1161
and encodings of arithmetic, 1163
in Preface, xiii
and undecidability of field theory, 1160

Robinson, Raphael M. (USA, 1911–1995)
and axioms for arithmetic, 1152
and non-periodic tilings, 943
in Preface, xiii

Rogozhin, Yurii (Moldova, 1949–[2014])
and Turing machines, 1119

Rosen, Nathan (USA/Israel, 1909–1995)
and EPR experiment, 1058

Rosenblatt, Frank (USA, 1928–1971)
and perceptrons, 1099

Rosenblueth, Arturo (Mexico, 1900–1970)
and reaction-diffusion, 1013

Roth, Klaus F. (England, 1925–[2015])
and rational approximations, 915

Rucker, Rudy v. B. (USA, 1946– )
and 2D Turing machines, 930
in Preface, xiii

Russell, Bertrand A. W. (England, 1872–1970)
and axioms for logic, 1151
and character of math, 1176
and foundations of math, 1149
and paradoxes in set theory, 1154
and Principia Mathematica, 894
and theory of types, 898

Russell, John Scott (Scotland, 1808–1882)
and solitons, 899

Rutherford, Ernest (New Zealand/Canada, 1871–1937)
and atomic nuclei, 1044

Rytin, Maxim (Russia, 1975– )
and concatenation sequences, 913

Sagan, Carl E. (USA, 1934–1996)
and Pioneer 10 plaque, 1189

Salem, James (USA, 1962– )
as coauthor of paper, 882
in Preface, xiii

Sander, Leonard M. (USA, 1941– )
and diffusion-limited aggregation, 994
in Preface, xiii

Saussure, Ferdinand de (Switzerland, 1857–1913)
and concept of language, 1181

Schickard, Wilhelm (Germany, 1592–1635)
and origin of computers, 1107

Scholes, Myron S. (USA, 1941– )
and options pricing, 1015

Schönfinkel, Moses I. (Germany/Russia, 1889 – ~1942)
and combinators, 879, 1121
and origins of universality, 1110
and symbolic systems, 898

Schoute, Johannes C. (Netherlands, 1877–1942)
and phyllotaxis, 1007

Schröder, F. W. K. Ernst (Germany, 1841–1902)
and axioms of logic, 1151

Schrödinger, Erwin R. J. A. (Austria/Switzerland/Germany/Ireland, 1887–1961)
and quantum mechanics, 1056

Schwarzschild, Karl (Germany, 1873–1916)
and Einstein equations, 1053

Séguier, Jean-Armand de (France, 1862–1937)
and semigroups, 1153

Sejnowski, Terrence J. (USA, 1947– )
and neural networks, 1100
in Preface, xiii

Sekerka, Robert F. (USA, 1937– )
and dendritic growth, 993

Shallit, Jeffrey O. (USA/Canada, 1957– )
and continued fractions, 914

Shannon, Claude E. (USA, 1916–2001)
and analog computers, 1129
and Boolean algebra, 1097
and coding theory, 1069
and cryptography, 1086
and information theory, 1071, 1181
and statistical mechanics, 1020
and Turing machines, 1119

Shaw, Robert S. (USA, 1946– )
and chaos theory, 971
in Preface, xiii

Sheffer, Henry M. (USA, 1883–1964)
and axioms for logic, 1151, 1175
and Nand, 1173

Shepherdson, John C. (England, 1926–[2015])
and register machines, 896

Shor, Peter W. (USA, 1959– )
in Preface, xiii
and quantum computing, 1148

Shub, Michael I. (USA, 1943– )
and quadratic pseudorandom generators, 1090

Sierpiński, Waclaw (Poland, 1882–1969)
and nested curves, 934

Silverman, Brian (Canada, 1957– )
in Preface, xiii
and WireWorld CA, 1117

Simon, Herbert A. (USA, 1916–2001)
and automated proofs, 1157

Sinai, Yakov G. (Russia/USA 1935– )
and ergodicity of billiards, 1022

Sitnikov, Kirill A. (Russia, 1926– )
and 3-body problem, 973

Skolem, A. Thoralf (Norway, 1887–1963)
and non-standard arithmetic, 1169
and set theory, 1154

Smale, Stephen (USA, 1930– )
and chaos theory, 971
in Preface, xiii

Smith, Alvy Ray, III (USA, 1943– )
and branching in plants, 1005
and L systems, 893
in Preface, xiii
and universal CAs, 1115

Smith, Cyril S. (USA, 1903–1992)
and cellular structures, 1039

Smullyan, Raymond M. (USA, 1919–[2017])
and combinators, 898

Socrates (Greece, ~470–399 BC)
and purpose in nature, 1185

Solomonoff, Ray J. (USA, 1926–[2009])
and algorithmic randomness, 1068

Spearman, Charles E. (England, 1863–1945)
and defining intelligence, 1178

Spencer Brown, George (England/USA, 1923–[2016])
and axioms for logic, 1175
and Laws of Form, 1173

Staffelbach, Othmar J. (Switzerland, 1952– )
and cryptanalysis of rule 30, 1087

Stein, Paul R. (USA, 1924–1990)
and iterated maps, 918

Stevens, Peter S. (USA, 1936– )
and patterns in nature, 967

Stokes, George G. (England, 1819–1903)
and fluid flow past a sphere, 998

Stoneham, Richard G. (USA, 1920–1996)
and normal numbers, 912

Sturgis, Howard E. (USA, 1936–1990)
and register machines, 896

Sundman, Karl F. (Finland, 1873–1949)
and three-body problem, 972

Swindale, Nicholas V. (England/Canada, 1951– )
and pigmentation patterns, 1012

Szmielew, Wanda M. (Poland/USA, 1918–1976)
and commutative groups, 1160

Szudzik, Matthew P. (USA, 1973– )
and axioms for logic, 1151
in Preface, xii