The recent announcement of the 2016 Nobel Prize in physics seems to have left many people perplexed. Three physicists — Michael Kosterlitz, David Thouless and Duncan Haldane — received the prize for work on "topological phase transitions and topological states of matter." Scientists at the awards press conference vaguely implied it had something to do with the holes in bagels and pretzels, and with topology, an arcane branch of mathematics.
And yet, the work isn't as obscure as it may seem. It's one more step in the study of ordinary matter that has been going on for centuries.
Substances often change form; make some water cold enough, and it will abruptly freeze. The water molecules don't change, only their organization does: the molecules that moved freely in the liquid at the higher temperature, when they had more energy, suddenly get locked in place, making a solid. Physicists call this a phase transition, and similar transformations of organization happen everywhere — in crystals, magnetic materials, superconductors, you name it. Making anything from good steel alloys to tasty chocolate requires careful control over such organizational changes.