Rock Doc

Hot enough for you? I’ve been thinking about heat lately, and not just because of the nation’s mostly torrid weather.

We all can easily verify that hot air rises – when you change a light bulb near the ceiling of your living room, you find the air up there is warmer than it is near the floor. Another fact about heat rests on a simple experiment. If you rub your palms together you’ll feel some warmth. Then, if you bear down on your hands, pressing them together hard, you’ll create quite a bit of heat.

Early scientists tried to understand the basic facts of heat with general theories. One such t...