robert ammann

Robert Ammann (October 1, 1946-May, 1994) was an amateur mathematician who made several significant and groundbreaking contributions to the theory of quasicrystals and aperiodic tilings. Ammann attended Brandeis University, but generally did not go to classes, and left after three years. He worked as a software programmer for Honeywell. After ten years, his position was eliminated as part of a routine cutback, and Ammann ended up working as a mail sorter for the post office. In 1975, Ammann read an announcement by Martin Gardner of new work by Roger Penrose. Penrose had discovered two simple sets of aperiodic tiles, each consisting of just two quadrilaterals. Since Penrose was taking out a patent, he wasn't ready to publish them, and Gardner's description was rather vague. Ammann wrote a letter to Gardner, describing his own work, which duplicated one of Penrose's sets, plus a foursome of "golden rhombohedra" that formed aperiodic tilings in space. More letters followed, and Ammann became a correspondent with many of the professional researchers. He discovered several new aperiodic tilings, including the first simple examples that did not involve the golden ratio. He also showed how to generate tilings using lines in the plane as guides for lines marked on the tiles, now called "Ammann bars". The discovery of quasicrystals in 1982 elevated the status of aperiodic tilings, and Ammann's work, from mere recreational mathematics to an important application. After more than ten years of coaxing, he agreed to meet various professionals in person, and eventually even went to two conferences and delivered a lecture at each. Afterwards, Ammann dropped out of sight, and died a few years later. News of his death did not reach the research community for a few more years.

Robert Ammann

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