Number 173 (Story #1), April 12, 1994 by Phillip F. Schewe and Ben Stein COSMIC STRINGS are hypothetical defects in space/time resulting from the failure of the early expanding (and cooling) universe to pass over entirely from a symmetric phase, in which all the physical forces are comparable in strength, to an asymmetric phase in which the forces are unequal. Some cosmologists believe that cosmic strings might have acted as the seeds for the development of early galaxies. Now, scientists at the University of Lancaster in Britain have simulated this process in a container of superfluid helium-4. Their effort at "experimental cosmology" consisted of rapidly decreasing the pressure of the helium while maintaining constant temperature. The ensuing phase transition set up swirling vortices, with non-superfluid trapped inside and superfluid helium on the outside. Previously cosmic-string-like defects were observed in liquid crystals but, as W.H. Zurek of Los Alamos puts it in a commentary on the Lancaster results, liquid crystals are a "messy" system and do not exhibit the interesting rotation effects seen in the superfluid. (P.C. Hendry et al., Nature, 24 March 1994.)