Will relativistic heavy-ion colliders destroy our planet?

Experiments at the Brookhaven National Laboratory will study collisions bet ween gold nuclei at unprecedented energies. The concern has been voiced tha t "strangelets" - hypothetical products of these collisions - may trigger t he destruction of our planet. We show how naturally occurring heavy-ion col lisions can be used to derive a safe and stringent upper bound on the risk incurred in running these experiments. (C) 1999 Published by Elsevier Scien ce B.V. AII rights reserved.