Do Cathedral Window glasses flow? The importance of glass North Rose Window, Cathedral of Chartre
Can glass flow at room temperature? Are glasses liquids or solids?
What does it mean to be a: Solid Liquid Gas Are glasses liquids or solids?
Gas: Widely spaced Non-interacting Fast moving
Liquid: Closely, randomly packed Interacting slowly moving (flowing)
Crystalline solid: Densely packed Well ordered Not moving (still vibrating!)
Crystalline solids
Can you slow a liquid down without it crystallizing? Water Honey
Temperature IS molecular motion
A GLASS is just a really, really slow liquid How slow? Can it flow on human timescales?
Zanotto, Am. J. Phys., Vol. 66, No. 5, May 1998 Calculations of flow rates predict the relaxation time for glass: 2 x years A million billion billion years!
So why are windows warped? Making Crown glass:
Other glasses: beyond windows Plastics Metals
Other glasses: beyond windows Biology: Hibernation
Other glasses: beyond windows Medical drugs Bioavailability Storage