Comment by petripooper on 16/01/2024 at 17:55 UTC

11 upvotes, 1 direct replies (showing 1)

View submission: Is sand a liquid???

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Is there a clear line between granular material and liquid? or is it a continuous transition?

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Comment by agate_ at 17/01/2024 at 05:41 UTC

13 upvotes, 1 direct replies

It’s interesting and complicated, because the same material — say, sand grains in air — can transition from behaving like a fluid to a solid depending on the density of sand particles and the forces driving the flow.

There’s a sudden transition called the “jamming transition”: as you add more sand to air, it behaves like a more viscous fluid until suddenly the grains lock together and form a strong network that doesn’t move at all.

https://physics.aps.org/articles/v4/86

https://en.m.wikipedia.org/wiki/Granular_material