Index



0L systems, 82-85, 893
     see also Substitution systems
Sqrt[163]
     and almost integers, 915
17-gons
     and constructible reals, 1129
1/f noise
     in electronic systems, 969
     and limits to randomization, 970
     in radioactive decay, 970
     and self-organized criticality, 989
1/f^2 noise, 1082
     see also Random walks
1L systems, 85-88, 893
     see also Substitution systems
1/n expansion, 1040
Sqrt[2]
     continued fraction for, 144
     digits of, 142
     in musical chords, 917
     and sine curves, 146
     and substitution systems, 892, 904
2001: A Space Odyssey
     extraterrestrial artifacts in, 1183
     extraterrestrial contact in, 1190
21 cm line
     on Pioneer 10 plaque, 1190
     and water hole, 1189
24 dimensions
     isotropy of lattices in, 980
     sphere packing in, 987
2SAT (2-satisfiability problem), 1146
3
     powers of, 119, 903
Sqrt[3], and substitution systems, 904
3-regular graphs
     see Networks, trivalent
3/2
     powers of, 121, 903
3n+1 problem, 904
     cellular automaton for, 904
     as precursor to my work, 879
     and register machines, 100
     and Turing machine 600720, 1145
     see also Arithmetic systems
3SAT (3-satisfiability problem), 1146
4-color theorem
     see Four-Color Theorem
4 dimensions
     isotropy of lattices in, 980
     lattices in, 930
     and spacetime, 481-486
     see also Four manifolds
411 services
     name lookups in, 1100
5 dimensions
     and Kaluza-Klein theory, 1028
5-fold symmetry
     CA patterns with, 930
5/2
     multiplication system, 123
5D hypercubes
     and Penrose tilings, 932
60 (base)
     of Babylonian numbers, 902
6j symbols
     and spin networks, 1055
8 dimensions
     isotropy of lattices in, 980
     sphere packing in, 986