> and certainly don't move in the direction it appears to be moving.

I hereby dub this the Ridley Scott's Prometheus Rule

It's not just for falling objects. In ship navigation this is known as Constant Bearing, Decreasing Range.

https://en.wikipedia.org/wiki/Constant_bearing,_decreasing_r...

And in aviation. Aircraft tracking across your canopy/windscreen? Usually NBD. Aircraft staying in the same spot on your canopy/windscreen? Potentially a Very Bad Thing.

And on the racetrack: car in front of you out of control? Drive to where it is, because it won't be there for long.

Ha! yup, heard that a looong time ago, but not from any racer. Having qualified for racing licenses and won championships in several types of racing including road racing, it's actually more complicated than that; you're looking at what direction the wheels are pointing, which wheels are on/off the pavement/grass and what'll hook-up or break-loose in the next seconds... e.g., if someone in front of you is two wheels off on the left side, and starts to turn back onto the track, he'll probably loop straight across the track in front of you and pound the right-side wall or sail across the right-side glass. I have pics of me absolutely threshold braking for exactly that situation, which looks like "huh?" in the first pic, then the next pic, I would have absolutely t-boned the guy if I hadn't braked so hard (and no, driving to where he was, half in the grass, wasn't an option).

So, if you don't have any clues, and have a half second to make your choice, I suppose it's better than no rule of thumb, but I wouldn't rely on it as a primary technique.

For illustration, a midair collision[1], where the "same spot"s were regrettably obscured for both pilots.

[1] https://www.youtube.com/watch?v=mT1omo5jBqs&t=116s

Wow - great illustration indeed!

Yup! Also applies to cars on intersecting roads especially at odd angles; if it's staying in the same spot in the windshield/side window, one of you needs to change speeds or you'll have an unscheduled rapid disassembly at the intersection.

It's also a real problem for certain intersection angles where vehicles or bicycles with unfortunate timing will be obscured behind the A-Pillar until nearly too late. There was an article (iirc) on HN years ago about just such an intersection repeatedly injuring/killing bicyclists. I once had to seriously threshold brake at an off-angle intersection to avoid a fire truck running a red light, when the timing/speed/distance/angle all lined up to hide the entire truck behind the A-Pillar for a few seconds approaching the intersection.