The distorted room was named after ophthalmologist Adelbert Ames, who invented the optical illusion in 1934. The floor, ceiling and side walls of the room are trapezoidal in shape but when viewed from a specific fixed point it appears to be rectangular.
Transformation of a supersaturated solution into solid crystals
It just takes one small nudge to spark the transformation of a seemingly stable liquid into a solid. The liquid – a supersaturated solution of sodium acetate – consists of water with more dissolved sodium acetate salt than can be stably sustained. Drop in a salt crystal and provide the kick needed to start the transformation into the more thermodynamically favourable solid state.
But if the solid state is more thermodynamically stable, why does it exist as a liquid at all? It’s to do with scale: the solution is only better off as a solid at the macroscopic scale – the scale of the whole solution. On a microscopic scale, the individual crystals are not thermodynamically favourable, so until you start it off with a salt crystal (which is, relatively, a huge disturbance), the transformation won’t begin.