One falling domino knocks down two, which in turn knock down three, etc. Use it to model cascade signaling.
How it works:
Twenty five rows of dominoes are set up in front of the first domino. Each successive row is comprised of one additional domino, e.g. the 2nd row has two, the 3rd row three, ... the 25th row has twenty five. A total of 325 dominoes get knocked down in a couple of seconds after the 1st one falls.
The action can be contrasted to a second board which has 11 rows of 30 tiles each, for a total of...