Penrose Tiles to Trapdoor Ciphers: And the Return of Dr Matrix (Spectrum)
Martin Gardner
Language: English
Pages: 330
ISBN: 0883855216
Format: PDF / Kindle (mobi) / ePub
Here is another collection drawn from Martin Gardner's 'Mathematical Games' column in Scientific American. Each chapter explores a different theme, for example fractals, surreal numbers, the sculptures of Berrocal, tiling the plane, Ramsey theory and code breaking, all combining to create a rich diet of recreational mathematics. Most chapters can be readily understood by the uninitiated: at each turn there are challenges for the reader and a wealth of references for further reading. Gardner's clarity of style and ability systematically to simplify the complex make this an excellent vehicle in which to start or continue an interest in recreational mathematics.
The New York Times (21 September 2015)
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Bock from the Klondike ond Other Problems 75 north. To eliminate this solution Loyd later changed the 8 to 1. I don't know why he changed the other cell from 2 to 3. Perhaps the 2 allowed still another unintended solution. Virginia F. Walters, Octave Levenspiel and Mrs. M. Reynolds lowered the record for a transfer of six marbles on the order-4 Chinese checkers board from 18 to 17 moves. On these smaller boards you are not, of course, allowed to use holes beyond the borders if you are working
Dudeney. Dover, 1958. The Best Mathematical Puules of Sam Loyd. Dover, 1959. More Mathematical Puules of Sam Loyd. Dover, 1960. "The No-Three-in-Line Problem." Richard K. Guy and Patrick A. Kelly, in Canadian Mathematics Bulletin, l l , 1968, pp. 527-531. "Some Thoughts on the No-Three-in-Line Problem." Michael A. Adena, Derek A. Holton and Patrick A. Kelly, in Combinatorial Mathematics: Proceedings of the Second Australian Conference, edited by Derek A. Holton, 403 of Lecture Notes in
prime numbers. Rivest obtained his doctorate in computer science from Stanford University in 1973 and is now an associate professor at M.I.T. Once he had hit on the brilliant idea of using primes for a public cipher system, he and his two collaborators had little difficulty finding a simple way to do it. Their work, supported by grants from the NSF and the Office of Naval Research, appears in A Method of Obtaining Digital Signatures and Public-Key Cryptosystems (Technical Memo 82, April 1977),
a fast way of proving that a number is composite. Moreover, if an odd number passes the Fermat test with a certain number of random a's, it is almost certainly prime. This is not the place to go into more details about computer algorithms for testing primality, which are extremely fast, or algorithms for factoring composites, all of which are infuriatingly slow. I content myself with the following facts, provided by Rivest. They dramatize the staggering gap in the required computer time between
quasicrystals maintain that all these alternative interpretations of the micrographs have been eliminated and that true nonperiodicity is the simplest explanation. It could be that in a few years empirical studies will disconfirm this, and quasicrystals may go the ill-fated way of polywater; but if the nonperiodic interpretation holds, it will be a sensational turning point in crystallography. Assuming quasicrystals are real, the next few years should see increasingly efficient techniques for