In the movie 2001 a black cuboid with side ratios 1:4:9 detected on the Moon through its anomalous magnetic properties sends a radio pulse in response to sunlight.

My papers The primary papers that I published about cellular automata and other issues related to this book were (the dates indicate when I finished my work on each paper; the papers were actually published 6-12 months later): • "Statistical mechanics of cellular automata" (June 1982) (introducing 1D cellular automata and studying many of their properties) • "Algebraic properties of cellular automata" (with Olivier Martin and Andrew Odlyzko ) (February 1983) (analyzing additive cellular automata such as rule 90) • "Universality and complexity in cellular automata" (April 1983) (classifying cellular automaton behavior) • "Computation theory of cellular automata" (November 1983) (characterizing behavior using formal language theory) • "Two-dimensional cellular automata" (with Norman Packard ) (October 1984) (extending results to two dimensions) • "Undecidability and intractability in theoretical physics" (October 1984) (introducing computational irreducibility) • "Origins of randomness in physical systems" (February 1985) (introducing intrinsic randomness generation) • "Random sequence generation by cellular automata" (July 1985) (a detailed study of rule 30) • "Thermodynamics and hydrodynamics of cellular automata" (with James Salem ) (November 1985) (continuum behavior from cellular automata) • "Approaches to complexity engineering" (December 1985) (finding systems that achieve specified goals) • "Cellular automaton fluids: Basic theory" (March 1986) (deriving the Navier–Stokes equations from cellular automata) The ideas in the first five and the very last of these papers have been reasonably well absorbed over the past fifteen or so years.

With 6 states, a machine is known that takes about 3.002 × 10 1730 steps to halt, and leaves about 1.29 ×10 865 black cells.

Already in 1882 George FitzGerald and Hendrik Lorentz noted that if there was a contraction in length by a factor Sqrt[1 - v 2 /c 2 ] in any object moving at speed v (with c being the speed of light) then this would explain the result.

But there is evidence that a widespread fractal structure develops—with a correlation function of the form r -1.8 —in the distribution of stars in our galaxy, galaxies in clusters and clusters in superclusters, perhaps suggesting the existence of general overall laws for self-gravitating systems.

(The narrowest lines come from natural masers and have widths around 1 kHz.)

And what effectively happens is that the amount of mixing differs by about 0.1% in the positive and negative time directions.

Then in the 1970s work in quantum field theory encouraged the use of gauge theories and by the late 1970s the so-called Standard Model had emerged, with the Weinberg–Salam SU(2) ⊗ U(1) gauge theory for weak interactions and electromagnetism, and the QCD SU(3) gauge theory for strong interactions.

If one computes the product of Exp[  (j 1 + j 2 - j 3 )] for all triangles, then it turns out for example that this quantity is extremized exactly when the whole surface is flat. … The SixJSymbol[{j 1 , j 2 , j 3 }, {j 4 , j 5 , j 6 }] are slightly esoteric objects that correspond to recoupling coefficients for the 3D rotation group SO(3), and that arose in 1940s studies of combinations of three angular momenta in atomic physics—and were often represented graphically as networks.

If one considers all 2 n possible sequences (say of 0's and 1's) of length n then it is straightforward to see that most of them must be more or less algorithmically random.