 That's a great word. The word expanse is used in the book of Genesis even, which means it was used of a piece of metal that was hammered out. And the more you hammer on it, of course, it expands. It gets thinner, but it stretches outward, and it gets larger. Metalworkers know all about this. You heat the metal up, you hit it with a hammer, and it just expands. About everything you hit with a hammer will do that if it doesn't break.