Place a bar of ivory soap into the microwave. After two minutes on high heat, watch what comes out, it doesn’t resemble a bar of soap in the slightest. This is a result of what’s called the Charles’ Law, aka the law of volumes, which deals with the relationship of pressure, volume, and temperature of gas. What this mean is, a gas will expand as it’s temperature rises. When this bar of soap is put in the microwave, the molecules of air inside it will expand. The end result is something that resembles a wild Soufflé!