# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Revealing Uncertainties in Computer Models," by Barry Cipra, *Science,* 11 February 2000, pages 960-961.

The Department of Defense has a "stockpile stewardship" program, which aims to maintain the reliability of nuclear weapons in part through computer simulations and virtual testing. But what happens if the simulations for the detonators no longer work after 50 years? This example illustrates the theme of this article, which is the need to quantify uncertainty in computer models. As these models have become more prevalent and more complex, researchers are coming to understand the importance of quantifying exactly how reliable the models are.

*--- Allyn Jackson*