The tick-tick sound comes from the movement of gears and parts inside the clock. In mechanical clocks, a part called the escapement mechanism controls this sound.

You know that sound an engine, or anything really hot makes when it cools down? What exactly is making the "ticking" sound you hear? Molecules bumping into each other as they contract? Just seems ...

Jonathan Larson, author and composer of "tick, tick ... BOOM!" is better known for his later musical "Rent," for which he won a Pulitzer Prize and four Tony Awards. He never knew of this remarkable ...