The MythBusters The MythBusters

MythBusters Episode 12: Break Step Bridge, Toothbrush Surprise, Rowing Water Skier

Premier Date: January 25, 2004

Soldiers marching in unison can cause harmonic oscillation in a bridge and cause it to collapse.


There were some difficulties in testing this myth conclusively.

*The original result was "busted," but when revisited in episode 14 it was changed to "plausible."

A rowing eight can pull a water skier at sufficient speed for him/her to stay upright.


Adam and Jamie recruited Stanford University’s rowing team to help test this myth. After several tries Jamie was able to stay upright for over 40 seconds, with only a few hours experience in waterskiing.

Fecal coliforms bacteria can grow in toothbrush bristles.


Fecal coliforms were indeed found on all the test brushes, including the control ones. However, none were of a level high enough to be dangerous, and experts confirm that such coliforms were impossible to completely avoid.