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!)
Crystallinesolids
Can you slow a liquid down without it crystallizing?
WaterHoney
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 1023 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
