Hidden flaws have been discovered in the random number generators used to simulate complex phenomena such as the interactions of subatomic particles. The problem has sent scientists scrambling to check established results and has highlighted how difficult it is to distinguish between genuinely random numbers and sequences of numbers with hidden patterns.
David Landau, a physicist at the University of Georgia, and two colleagues discovered the problem while attempting to simulate the way some materials suddenly flip into a magnetic state when cooled below a critical temperature. Landau found that his computer model was consistently predicting the wrong temperature for the transition. He tracked down the flaw and found that it lay not in the simulation algorithm but in the random numbers the algorithm relied on.
'We thought the random number generators which we had were pretty good,' says Landau. 'Unfortunately, it turns out that ostensibly high-quality random number generators ...
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