I think there was also an article about it on The Old New Thing, but I can't seem to find it anymore.
Find modern examples by Googling "menu safe triangle." Here's one from 5 days ago https://www.framer.com/blog/cursor-trajectory/
> I asked the Framer Agent to fix it, and within minutes it had built and applied what I now call trajectory-based menu aim
How is this different from the observation that, say, a non-magnetic iron ball may have more than one possible velocity in a given gravitional field, depending on whether it was recently thrown upward or dropped from above?