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Prime Numbers.

From K2C Inspired by "The Times" Wednesday's supplement "Interface"11/9/96 re Prime Numbers.

Amateur mathematicians across the world are joining forces to beat the professionals in the numbers game. Last week the pros, Paul Gage and David Slowinski of The Cray Research Unit, discovered the biggest Prime Number to date - comprising of 378,632 digits! Using a Cray T94 super computer - one of the most powerful computers in existence - they took only 6 hours to check that the number could not be written as the product of two smaller numbers. Now they are being challenged by programmer George Woltman in Florida, armed only with a Pentium PC, access to Internet and a little help from his friends. Woltman believes that the combined forces of hundreds of PCs co-ordinated via the Internet can claim the prize for the next largest Prime. Since January he has co-ordinated via his Web site a growing army of PCs which now number 430. "There is no way a lone computer can compete with supercomputers, but if we work as a team we can accomplish a great deal", he says. To calculate Gage and Slowinski's Prime Number, you should multiply 2 by itself 1,257,787 times and subtract 1. You can see the result at Web site:-


- but be warned, it would take 12 pages of "The Times" to print it out! Finding such huge numbers may sound like an obscure mathematical curiosity, but Silicon Graphics' Cray Research Unit regards it as a rigorous way to test the performance of its computers before they are sent out to deal with real world problems. "This acts as a real torture test for a computer" says Slowinski, "There aren't many practical uses for Formula One race cars but some of the things engineers do to make these cars perform better eventually find their way into the cars that you and I drive." Anyone who would like to test their own computer by joining Woltman's call to go forth and multiply in search of an even bigger Prime Number should visit his Web site at:-


The author of this report is Dr. Marcus de Sautoy who is a Royal Society University Research Fellow at the Department of Pure Mathematics in Cambridge.
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