We’re all familiar with Indiana Jones, replete with adventure-beaten fedora, leather jacket, and of course, the trademark bullwhip. Bullwhips, of course, aren’t the typical tool of adventurers, fictional or otherwise. Rather, the tool is used for livestock control — quite literally, the whip helps cattle ranchers move cattle and other animals around in open land expanses. Many who use the tool in modern times assert that the bullwhip was rarely used to strike cattle; rather, the loud, snapping sound the whip makes did the job fine.
But how does the a bullwhip make a loud sound if it doesn’t hit anything? Easy: it breaks the sound barrier.
That’s right — the end of the whip, called the “cracker,” moves faster than speed of sound (about 786 miles per hour). The sound a bullwhip makes is actually a miniature sonic boom. (The Wikipedia entry on sonic booms explains some of the physics, if you’re interested.)
Bullwhips may have been in existence since the second or third century — because they degrade over time, there is no way to tell for sure. It is quite likely that man has been breaking the sound barrier for over a thousand years, and did not even realize it.
Related: A replica Indiana Jones hat and whip set — for kids. Probably can’t be used to make sonic booms.