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

Temperature IS molecular motion

http://www.falstad.com/gas/

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