Domino Chain Reaction (short version): geometric growth in action

A domino can knock over another domino about larger than itself. A chain of dominos of increasing size makes a kind of mechanical chain reaction that starts with a tiny push and knocks down an impressively large domino. Original idea by Lorne Whitehead, American Journal of Physics, Vol. 51, page 182 (1983). See and for sophisticated discussions of the physics. This video is the root of a zillion memes via As seen on QI in the “kinetic“ episode. I was contacted by those Elves. A typo in the credits has been blurred out.