Esther Inglis-Arkell — Anyone who's seen enough old Sesame Street episodes or been to enough Renaissance Fairs knows that when glass gets hot enough, it turns to liquid. Applied heat pumps energy into the solid pieces of glass, getting their molecules jiggling. As the heat dissipates, the glass becomes cool and solidifies again.
Most of the time, not many interesting things happen once a substance gets below the temperature required for solification. Its atoms are bound to one another, and without the indroduction of some kind of energy, they'll stay that way. Glass, it turns out, is the exception. Once it gets close to absolute zero, it melts again.
But what could make that happen? The atoms in glass chilled to near-absolute zero have almost no energy, so they can't be jiggling fast enough to tear apart from each other. And yet, on paper and in computer simulations, glass returned to a liquid form when brought close enough to absolute zero.
The wild card turned out to be quantum mechanics. Once the atoms of glass became still enough, they stopped acting like particles and instead acted like waves. The wave-like atoms now were able to flow, moving through spaces too small for particles to get through. This motion, and this ability to fit through small spaces, causes ultra-cold glass to melt into a liquid. No word yet if this works on the T-1000.
Sunday, 20 February 2011
Awesome discovery of the week: Glass melts when it gets too cold