Light Switches Crystal Without Heating
A stack of playing cards lies still. You can slide the top card with your finger: that's crude intervention. Or you can blow so that the whole stack momentarily changes shape, but the cards don't scatter. That's roughly how light, in a new experiment, rearranges a crystal of tin selenide (SnSe).
Usually, to change the structure of a solid, you heat it or pass a current through it.