Alvy Ray Smith


1971, Scientific American, All Rights Reserved.

Martin Gardner published John Conway's Game of Life in October 1970 in his column "Mathematical Recreations" in Scientific American magazine. I called him immediately when I finished reading it to let him know that the Game of Life was just one example of a whole class of mathematical objects, called cellular automata (CA), on which I had just written my PhD thesis at Stanford. The topic was the most popular ever published by the magazine, whose editor decided on a second issue, with a cover story this time. Gardner - intrigued by my references to von Neumann, Stanislaw Ulam, self-reproducing machines, and the Garden of Eden - spent the day with me at NYU learning about the larger field of study. This daylong conversation became his column in the February 1971 issue, which I proofread for him.

The editor asked several of us to submit cover design ideas. Gardner submitted some Ulam designs. I had just published a theorem on recognition of palindromes by one-dimensional CA, so I drew up a spacetime diagram for the proof, using the palindrome "TOOHOTTOHOOT" as the example, with the letters encoded in colors. I had learned this palindrome from a New York Times crossword puzzle. The clue, for which this palindrome is the answer, is "Why owls don't live in the tropics". My design was selected because the publisher of Scientific American was a palindrome aficionado! See the masthead of this issue for details about the picture.

Created in New York City in 1970.