Comment by liquid-handsoap on 16/01/2024 at 19:27 UTC

-34 upvotes, 2 direct replies (showing 2)

View submission: Is sand a liquid???

View parent comment

That just sounds like surface tension. Like a droplet wont flat itself out either

Replies

Comment by LordGeni at 16/01/2024 at 19:29 UTC

34 upvotes, 1 direct replies

Surface tension is due to link between particles on the outside surface. This is due to friction between all the particles and the ones below them.

Comment by agate_ at 16/01/2024 at 22:41 UTC

2 upvotes, 1 direct replies

Maybe I'm moving the goalposts, but surface tension is an example of liquids being not exactly perfectly liquid. Still, the static strength of granular materials comes from the *friction* between the grain particles, not their surface tension, so they behave very differently. One way that plays out is that you can build a pile of sand as tall as you like, so long as it's not too steep, but surface tension will never let you make a blob of water more than a few millimeters tall (in Earth's gravity). And on the other hand, you can never make a "drop" of sand that holds together as it falls.