Number 112 (Story #2), January 28, 1993 by Phillip F. Schewe and Ben Stein THE RACE IS ON TO ACHIEVE BOSE CONDENSATION , a state of matter in which an ensemble of bosons collapses to a single quantum state at very low temperature. According to Carl Wieman of the University of Colorado (303-492-6963), Bose condensation represents the lowest possible energy state for matter. Daniel Kleppner of MIT (617-253-4876) is trying to achieve Bose condensation in a cloud of atomic hydrogen supercooled by liquid helium. He further cools and condenses the atoms through the process of "evaporative cooling," in which the atoms are held in a magnetic field where only the hottest atoms have enough energy to escape. Only the coldest atoms remain, clumping together in the trap as a result of their lethargy. Wieman is also trying to apply evaporative cooling to his setup of laser-cooled cesium atoms, but has not achieved a density of atoms sufficiently high to trigger the process. He plans to design a "magnetic lens" that would increase the density to desired levels. Kleppner is adjusting his experiment to better monitor the trapped hydrogen atoms and thereby pinpoint the conditions that would optimize their density and temperature. Both groups and those at other labs are optimistic about achieving Bose condensation in the near future. (Discover, February 1993.)