SITE VISIT: Pick a Number From 1 to 232

See allHide authors and affiliations

Science  07 Jul 2000:
Vol. 289, Issue 5476, pp. 7b
DOI: 10.1126/science.289.5476.7b

From encrypting e-mail messages to simulating the collapse of stars, many scientific procedures require random numbers. But generating truly random numbers with a computer is impossible. Computers can only follow algorithms, and no matter how convoluted, an algorithm tells you how to get the next number from all the preceding ones. Mother Nature, however, is less predictable, and three Web sites rely on quirky physical processes to provide the truly random bits you crave.

To catch the randomness blowing in the wind, tunes a radio to an unused frequency, listens to the static generated by the churning of the atmosphere, and converts the fluctuations into numbers. In contrast, Hotbits tracks the time between clicks of a Geiger counter as it measures the radioactive decay of krypton-85, also a random process. And if you want retrohip unpredictability, try Lavarand. The site scrambles digital snapshots of six lava lamps to extract cool randomness from the groovy undulations of hot goo.

All three sites readily spit out kilobytes of numbers, and and Lavarand let you download megabytes of previously generated numbers. But don't use these to encode your deepest secrets: Hackers may be able to read the bits as you download them.

Navigate This Article