When Mac application icons are bouncing in the dock, does their velocity = 0 at their highest point? Here's what it looks like when you open a new application for Mac if you're not familiar. Another way I'm thinking about it: What if you have a strip of LED lights and its on a chase pattern going back and forth. Would the velocity of the 'whatever' going back and forth drop to 0 when it switched direction? And isnt that essentially what the app icon is? LEDs lighting up/down? One answer I've gotten in discussion: "So lets say you capture every frame of the icon moving up and down. You flip through them one at a time. You may or may not see two identical frames where the icon stays put. But if you could render at an infinite frame rate, eventually you would find two identical frames where the icon hadn't moved. I think the simplest answer is graph velocity vs time. When moving up you have a positive velocity and when moving down you have a negative velocity. Move your finger along that graph from the positive to the negative and never cross through zero. Good luck with that."