Existential blow for ghostly quantum supersolids - New Scientist: ...they sealed the glass with a thin layer of epoxy resin and inserted the helium through a very thin tube. This meant only a tiny fraction of the helium could become a bulk solid – and so any speeding up due to quantum plasticity would be negligible.
Chan and Duk Kim found that this set-up completely eliminated the changes in oscillation rate that they had originally observed. "We didn't see anything at all," says Chan. That suggests that all of the speeding up in the original experiment must have been due to bulk helium forming a quantum plastic, not supersolidity as originally claimed in 2004.