A Domino The Size Of A Tic Tac Could Topple A Building
It won't come as a surprise that they fall just as a regular series of dominoes do, but things quickly start to take on a pretty massive scale.
Stephen Morris (who holds a PhD in geophysics and lists "the Physics of everyday phenomena" as a research interest) set up a series of 13 dominoes, each roughly one and a half times the size of the one knocking it over."As in all gravitational phenomena, the total mass of the object drops out of the equations, but not the mass distribution," a heady paper (by Leiden University's J. M. J. van Leeuwen) on the physics of "domino magnification" notes. Like Morris, Leeuwen has a funny label for this odd research interest: Curiosa.
A summarization of that paper by the MIT Technological Review explains that "the force required to topple the domino is smaller than the force it generates when it falls. It is this 'force amplification' that can be used to topple bigger dominoes." In fact, the kinetic energy exerted to push that first domino is just 2 billionths of that released by the last one as it comes loudly crashing down. Another important factor of domino physics is that they lean on one another as they fall. Since one falling domino is being weighed upon by its predecessor, its force is greater than if you or I had simply tipped it over. Van Leeuwen even proves that - with optimal spacing and no domino "slipping" - a domino series like this one could use dominoes that double in size from one to the next.But that's more theoretical than practical. In Morris's demonstration, you can clearly see that the dominoes slip back after they've fallen.
But fall they do. "That was 13 dominoes," Morris says. "If I had 29 dominoes, the last domino would be as tall as the Empire State Building."

At 6.40 meters, the purported world record for greatest domino toppled in this way gets a tiny bit closer to the Empire State Building's league, though the organizers may not have used Morris's 1.5x growth scale.
The answer - 18,446,744,073,709,551,615, or roughly 18 and a half quintillion - is much greater than most people would guess before doing the math.
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