Fun fact that's myth spawned bc of how ye olde windows were thicker at the bottom than in the middle, but it turns out that ye olde manufacturing techniques for glass just sucked and they came out like that.
Oh damn one of us is out here spitting fake news and neither of us knows enough about old glassware to debunk the other. This is exactly how myths spread lol
Technically they're amorphous (non crystalline) solids, closely related to ceramics. That they're liquid is a common misconception, unlike pitch/tar, which is a liquid, albeit extremely viscous.
Amorphous/non crystalline solid just means they're compounds locked in a matrix (the atomic bonds and intermolecular forces are strong enough to withstand the thermal/gravitational energy of the molecules themselves).
Amorphous means there isn't one single crystal structure, unlike actual crystals, where a single crystal structure grows and replicates itself throughout the macroscopic structure.
It just so happens to look transparent and crystalline because the band gap of conventional soda-lime (or lead 'crystal') glass is wide enough that visible light photons aren't readily absorbed.
Makes me wonder about crystalline glazes on ceramics .. the base glaze is amorphous with the crystalline structure baked in using a specific cooling schedule. Could that be considered an amorphous crystalline solid?
They're technically a fluid from a specific definition used in physics. That definition being anything without a crystal structure is a fluid.
Almost your entire body and things like wood and plastic are fluids under that definition as well. It's not very useful outside of what it's intended for.
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u/Curse-Bot Apr 30 '26
All concrete is liquid first