Jeopardy! category: MAY THE FORCE BE WITH YOU (04-11-2015)
$1200 clue: In the northern hemisphere, a projectile moving north outraces Earth’s rotation, so it will appear to be deflected to the right, thanks to this force named for a 19th century Frenchman
The gist: But it has nothing to do with toilets. Really. The Coriolis effect (or, sometimes, the Coriolis force) refers to the observed tendency of a projectile to veer from a straight path thanks when traveling between inertial and non-inertial reference points – in other words, if the target is moving at a different velocity than the origin point. To borrow an excellent example from How Stuff Works, imagine you’re standing in the centre of a clockwise-rotating platform, like a carousel, where you’re not changing location (you’re just spinning around in one spot). Your friend is standing on the edge of the platform, and is changing location pretty quickly. If you throw a ball to your friend, it will appear, from your inertial (non-moving) perspective, to veer to the right to “catch up” with your friend who’s moving faster than you. While not a force in the sense of friction or gravity, the Coriolis effect is sometimes referred to as one because it appears to be altering the velocity (that is, speed combined with direction) of the projectile, even if it’s only doing so from certain perspectives. When scaled up to the size of the Earth, the Coriolis effect can have serious consequences for things like hurricanes and intercontinental ballistic missiles, but not on little things like a toilet bowl or even a tornado.
By the way, the Frenchman is the clue was Gaspard-Gustave de Coriolis, an early 19th century mathematician and engineer. He was interested in codifying certain mechanical laws to make them applicable to industry – in fact, he first described his eponymous effect as it related to waterwheels. His name wouldn’t be applied to it until the beginning of the 20th century, however, more than 50 years after his death.
The clue: Many will be familiar with the Coriolis effect from the Simpsons episode where Bart calls Australia to find out which way their toilet bowls drain (although, as I said, if Australian toilet bowls do drain counter-clockwise, it’s not because of the Coriolis effect). Talk of hemispheres and rotation, even without toilet bowls, ought to bring up the Coriolis effect, but it’s not the best known physics-y thing and its name is sort of hard to remember, so it’s well-placed at $1200.
In Jeopardy!: M. Coriolis has 12 clues in the J!Archive. Six deal with winds (or hurricanes and the like). Three deal with water – two about drains (ugh…) and one about ocean currents. Five mention rotations, and three are about projectiles or moving bodies. One gives the name and definition of the effect, and asks for the Shakespeare tragedy about a Roman general that sounds like it.