Double-Trouble Dominoes

April 6, 2021

Thought this was a great video of geometric growth in action by @uoftphysics Prof. Stephen Morris Starting with a ~5mm domino you get to a one ~1 m in size in 13 domino topples. Overall, this chain reaction represents a 2 billion-fold amplification!

Dominoes are little toy rectangle tiles with dots on them. People like to stand them up on end in a long row, so when the first domino falls over, it knocks over the next domino, which knocks over the
next…pretty soon you have a rippling wave of falling dominoes. In this simple but amazing video, Stephen Morris shows that a little domino can knock over another one that’s 1 1/2 times as big in each direction. Then that one can tip over one that ‘s 1 1/2 times as big again. In this domino chain, the first one is only 1/4 inch tall, but the 13th domino weighs more than 100 pounds! If he kept going, the 29th domino would be as tall as the Empire State Building (1,454 feet). We’d all better get out of the way!