Técnica de cortar vidrios con tijeras

Spectrum Glass says that the trick does work, although if doesn't make a very clean cut. They quote from Scientific American to explain why holding the glass under waters aids the cutting process:
 
"Water causes glass to crack more easily because when a water molecule enters the crack, a reaction occurs in which a silicon-oxygen bond at the track and an oxygen-hydrogen bond in the water are cleaved, creating two hydroxyl groups attached to silicon. As a result, the length of the crack grows by the size of one bond rupture. The water reaction reduces the energy necessary to break the silicon-oxygen bonds, thus the crack grows faster. "


Fuente: http://blog.everything-stained-glass.com/cutting-glass-with-scissors/