Liquid Glass?

I thought glass was already a liquid.

Me too.

It is liquid - very heavy large glass doors are known to "melt" due to gravity over several years: proof lies in measuring sections of top and bottom of glass plate. However a spray is probably new - not sure who awarded that patent, though, as it's sure to get challenged by the fiberglass manufacturers among others. Saarbruecken University is of course in Germany but patents awarded in Turkey (as the linked article claims) probably have no automatic protection under EU intellectual property law - and btw Turkey is even worse than Israel in patent law enforcement.

It's not just heavy glass constructions. Ordinary window panes flow as well--it's just exceedingly slow, and does not become noticeable for many decades, perhaps a century. It can be seen, though, and i've seen it myself in really old houses.

On a tour around Beacon Hill in Boston with a visiting friend, the guide said he understood that window pane thing to be a myth (at least in terms of the Beacon Hill houses). He suggested that the panes were nearly impossible to get even in olden times and that they'd put the heavy/thicker end downward as would seem a common sense practice.

I heard something similar about early glass making technology. Italian window panes, or some such. Anyhow, the process was such that the glass was thicker around the edges before it was cut into panes.

venetian glass, via wiki -
http://en.wikipedia.org/wiki/Venetian_glass#History_of_Murano_Glassmaking