A universal cellular automaton is a cellular automaton which, like a Turing machine, exhibits universality.
von Neumann proved that an automaton consisting of cells with four orthogonal neighbors
and 29 possible states would be capable of simulating a Turing
machine for some configuration of about cells (Gardner 1983, p. 227).

The outlines of a proof that the two-dimensional game of lifeouter-totalistic cellular
automaton is universal were given by Berlekamp, Conway, and Guy (1982) and independently
by Gosper (Gardner 1983, pp. 250-253). Around 2000, a Turing
machine was explicitly implemented in life by P. Rendell (Rendell, Adamatzky
2001). While Rendell's machine can be made into a "true" universal computer
simply by making his tape infinite, he neither noted this fact nor provided an actual
construction of a universal Turing machine.
Subsequently, on November 11, 2002, P. Chapman constructed a game
of life pattern that implements the actions of a universalregister machine, thus explicitly proving the game of life to be universal.

More amazingly still, even one-dimensional cellular automata can be universal. Wolfram (2002, pp. 644-656)
gave an example of a 19-color universal one-dimensional next-nearest neighbor cellular
automaton in which a block of 20 cells is used to represent each single cell in the
cellular automaton being emulated. The examples above show the first few steps of
the 19-color universal automaton emulating rule 90 and
rule 30, respectively (Wolfram 2002, pp. 646-647).

Smith (1971) showed that 18 colors and nearest-neighbor 1-dimensional rules could be universal, and Lindgren and Nordahl (1990) constructed a 7-color nearest-neighbor
universal cellular automaton. And most amazingly of all, as shown by Wolfram (2002,
pp. 675-691), two colors and nearest neighbor rules are sufficient for
producing universality in a 1-dimensional cellular
automaton. In particular, although it is anything but straightforward to prove, the
rule 110elementary
cellular automaton is universal (Cook 2004).

Gacs (2001) has proven that there exist fault-tolerant universal cellular automata, whose ability to simulate other cellular automata is not hindered by random perturbations provided that such perturbations are sufficiently sparse.

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in Winning
Ways for Your Mathematical Plays, Vol. 2: Games in Particular. London:
Academic Press, 1982.Chapman, P. "Life Universal Computer."
http://www.igblan.com/ca/.Cook,
M. "Universality in Elementary Cellular Automata." Complex Systems15,
1-40, 2004.Gacs, P. "Reliable Cellular Automata with Self-Organization."
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Game of Life, Parts I-III." Chs. 20-22 in Wheels,
Life, and other Mathematical Amusements. New York: W. H. Freeman, 1983.Gray,
L. "A Mathematician Looks at Wolfram's New Kind of Science." Not. Amer.
Math. Soc.50, 200-211, 2003.Lindgren, K. and Nordahl, M. G.
"Universal Computation in Simple One-Dimensional Cellular Automata." Complex
Systems4, 299-318, 1990.Rendell, P. "This Is a Turing
Machine Implemented in Conway's Game of Life." http://www.rendell.uk.co/gol/tm.htm.Smith,
A. R. III. "Simple Computation-Universal Cellular Spaces." J. Assoc.
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