Scientists at the Lawrence Livermore Laboratory have made a thermonuclear fusion reactor that, they claim, can fit on a laboratory bench. The reactor consists of a femtosecond laser (femtosecond is a million-billionth of a second) that hits laser pulses at clusters of deuterium atoms. The cluster explodes because of the tremendous energy and some of the atoms undergo fusion. Though the process is not energy efficient, the scientists feel that because of the low costs, it could replace reactors and be used to study thermonuclear reactions ( Nature , Vol 398, p489).