Is Glass a Liquid or a Solid ?
You may have heard the claim that glass is actually a liquid, flowing ever so slowly over time. While it’s a fascinating idea, the truth is more complex.
Glass isn’t a traditional solid, but it’s not a liquid either. It’s something in between, known as an amorphous solid.
Unlike crystalline solids, where atoms are arranged in an orderly, repeating structure, glass has a disordered atomic arrangement more like a liquid.
However, it doesn’t flow like a liquid – at least not in any way we can observe.
The myth likely comes from old cathedral windows, where the glass is sometimes thicker at the bottom. But that’s not because it flowed downward over centuries.
Early glassmaking techniques simply produced uneven panes, and they were often installed with the heavier side down.
So, while glass isn’t a liquid in the traditional sense, it also doesn’t behave like a true solid.
It exists in a unique, frozen-in-place state – a rigid material with the randomness of a liquid.
Science is full of weird in-betweens, and glass is one of the most fascinating!
Is glass liquid or solid?
[Physics FAQ] - [Copyright] Updated by Dan Watts, 2021. Original by Philip Gibbs, 1996 Thanks to the many who contributed their knowledge and references. Is glass liquid or solid? It's sometimes said that glass in very old churches is thicker at the bottom
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