Sandworms.

[Gawdzilla Sama]

Wanna sound brainy? In Dune the sand worms slither through the ... wait for it ... SAND. People be sayin' this is crazy. Actually EVERYBODY has seen something similar. Chunks of ice turn into clouds of frozen death during an avalanche, in a process called "particularization", meaning little bits bouncing off other little bits at speed. This simulates a fluid. Scale up, you say? Pyroclastic flow? Not enough? Avalanches of rock do the same thing, when they get going it's one rock bouncing off every other rock at speed.

BTW, that has been bugging me since I read the book the year it came out.

So now you know. Go verbally beat up your friends doing the high dudgeon thing.

Seen recently: "I don't care about the Third World War, that's the Third World's problem."