Science News has a great, deep article about the myriad uses of random numbers–from e-commerce to protein folding–and why computers have such a hard time generating true randomness.
Now, physicists and computer scientists are figuring out ways to pull true randomness out of the physical world. One Web site, for instance, generates random numbers from the noise of a radio tuned between stations. And a commercial device put on the market last March harnesses nature’s ultimate source of randomness: quantum physics, which Albert Einstein famously described as God playing dice….
Although computers are expert at spewing out numbers, a computer program can’t by itself produce random ones. Computers are engineered to behave deterministically, obeying the will of their users. “If a computer does something unpredictable, then we call it broken,” says Landon Noll, a cryptographer at the computer security firm SystemExperts in Sudbury, Mass.