That's where the above analogy doesn't really work. Without reading the paper, I'd guess that the crystal enters a different energy state. A bit like a jet of

That's where the above analogy doesn't really work. Without reading the paper, I'd guess that the crystal enters a different energy state. A bit like a jet of water that's been 'absorbed' by a sponge, rather than sloshing around in a hollow ball [1]. [1] I know that's a bad analogy but I can't think of anything better off the top of my head right now.