Stacking Dominoes to the Limit
Dominoes stacked according to the harmonic series can create an arbitrarily large overhang. The blue dot shows the center of gravity.
Dominoes stacked with successive overhangs determined by the elements of the harmonic series will balance and not fall.
Based on ideas of Stan Wagon in Mathematica in Action, 2nd ed., New York: Springer-Verlag, 1999.