Evidence for Free-Flowing Supersolid Slipping Away? -- Cho 329 (5987): 20 -- Science - "Six years ago, frigid solid helium set the world of condensed-matterphysics afire when one team found that at temperatures nearabsolute zero the stuff appears to flow like a liquid withoutany viscosity (Science, 1 July 2005, p. 38). Physicists havesince debated how such "supersolidity" might come about, orwhether it even exists. Now, an experiment calls into questionthe first, best evidence for supersolidity. What physiciststook as a sign of resistance-free flow at very low temperaturesis in fact a manifestation of an odd softening of the solidat slightly higher temperatures, says John Reppy of CornellUniversity."