Science!

[dvandom]

Well, more like science, not SCIENCE!. But still. Back in grad school I worked out an explanation of the Coriolis force that didn't require using all sorts of complicated principles. It had holes, and I found a better explanation. That has stood until recently, when a guy in Germany started emailing me about a problem with it. I'm still not totally sure what he's getting at, but clearly it's time for another revision. And here it is! The part I need to re-explain in the most depth isn't done yet, I'm still building the props.

Edit: I borrowed a basketball from the lab equipment room and used it and some micro-Gundam figures to finish up my explanation.

Comments

[foomf.livejournal.com]

OK, so on your stationary sphere you add point C, at some arbitrary distance, say, 1/4 of a diameter from A and B, because otherwise the shape of the triangle adds confusion. There's still no rotation, so still no preferred directions.

The shortest distance between these points is defined by the plane intersecting them, and is a triangle; it can be projected onto the sphere and the lines will curve in the process.
If viewed from the 'overhead' defined by the line between the center of the triangle and the sphere, and projected down onto the common plane, the lines will indeed appear to be curved away from the center.

If C watches this intercontinental spitball fight, and if A were using an intercontinental mole-machine spitball, the straight-line distance from C to the spitball would decrease until the right-angle, then increase again.
The straight-line distance to the intercontinental ballistic spitball gets away from simple right-angles. There's an added component from the projection. Without deriving this component I can't tell if the distance would actually increase to the top of the arc or simply decrease less.