Nothing for me proves the ubiquity of physics more than this article I came across in the LA Times.
Yes, that's right; on top of just being tasty, popcorn is a great demonstration of several physics concepts such as thermodynamics.
First off, food chemists have determined the ideal moisture content of a kernel to be around 14%, and since the 1950s, plant breeders have apparently fixed that annoying unpopped kernel problem by 75%. So there's evidently a lot of people with some passions for this stuff, and it follows that researchers have looked into the physics here.
Most people know that kernels are consistent of water, which when heated expands and pops the corn. But it's slightly more complicated. Only a specific type of corn can actually pop; when the popcorn is heated to 100 degrees Celsius, the water inside turns to steam, which forces its way into a protein matrix called the endosperm. This apparently creates a molten mass similar to bread dough, and this starch mass soon solidifies into a light spongy treat that we all know and love.