Дэвид Сингмастер: Математик и популяризатор кубика Рубика

British mathematician (1938–2023)

David Breyer Singmaster (14 December 1938 – 13 February 2023) was an American British mathematician who was emeritus professor of mathematics at London South Bank University, England. He had a huge personal collection of mechanical puzzles and books of brain teasers. He was most famous for being an early adopter and enthusiastic promoter of the Rubik's Cube. His Notes on Rubik's "Magic Cube" which he began compiling in 1979 provided the first mathematical analysis of the Cube as well as providing one of the first published solutions. The book contained his cube notation which allowed the recording of Rubik's Cube moves, and which quickly became the standard. Singmaster was both a puzzle historian and a composer of puzzles, and many of his puzzles were published in newspapers and magazines. In combinatorial number theory, Singmaster's conjecture states that there is an upper bound on the number of times a number other than 1 can appear in Pascal's triangle.

David Singmaster was a student at the California Institute of Technology in the late 1950s. His intention was to become a civil engineer, but he became interested in chemistry and then physics. However he was thrown out of college in his third year for "lack of academic ability". He taught at the American University of Beirut, and then lived for a while in Cyprus. Singmaster moved to London in 1970. The "Polytechnic of the South Bank" had been created from a merger of institutions in 1970, and Singmaster became a lecturer in the Department of Mathematical Sciences. He went off course one day and noticed a timber sticking up out of the sand. This led to the discovery of the Marsala Punic Ship. He was designated emeritus at London South Bank University in 2020. Some other mathematicians at the conference, including John Conway and Roger Penrose, already had one. He devised his notation for recording moves (now known as the Singmaster notation) in December 1978. In June 1979 he wrote one of the first articles about the Cube in The Observer newspaper. In October 1979, he self published his Notes on the "Magic Cube". The booklet contained his mathematical analysis of Rubik's Cube, allowing a solution to be constructed using basic group theory. In August 1980 he published an expanded 5th edition of the book retitled as Notes on Rubik's "Magic Cube". In 1981, at the height of the Rubik's Cube craze, the book was republished by Penguin Books, with a US edition by Enslow Publishers. In September 1981 he was said to be devoting "almost 100%" of his time to promoting, reporting, marketing and analysing the Cube. He soon began publishing a quarterly newsletter called the Cubic Circular which was published between 1981 and 1985. In 1996 he reported that the collection contained over 4700 works. He also collected books on cartoons, humour, and language. However the venture lost him "a fair amount of money" and led to prolonged tax negotiations. He referred to this period of his life as "a massive overdose of cubism". He published a collection of his puzzles in his 2016 book Problems for Metagrobologists. He was instrumental in the re discovery of one of the world's oldest books on puzzles and magic illusions when he came across a reference to the work in a 19th century manuscript. The recovered text, De viribus quantitatis was penned by Luca Pacioli, a Franciscan friar who lived around 1500.

In combinatorial number theory, Singmaster's conjecture states that there is a finite upper bound on the number of times a number other than 1 can appear in Pascal's triangle. Paul Erdős suspected that the conjecture is true, but thought it would probably be very difficult to prove. The empirical evidence is consistent with the proposition that the smallest upper bound is 8.

In November 1981, Singmaster appeared on the scifi themed BBC puzzle show The Adventure Game.

Chronology of Recreational Mathematics by David Singmaster. 1996. (Available online at anduin. eldar. org)
Chronology of Computing by David Singmaster. 2000. (Available online at the University of Applied Sciences, Darmstadt)
Sources in Recreational Mathematics: An Annotated Bibliography, David Singmaster. 8th preliminary edition. South Bank University. 2004. (Available online at the Puzzle Museum)
Mathematical Gazetteer of the British Isles, by David Singmaster. The British Society for the History of Mathematics. 2012. (Available online at the Internet Archive)