Break Step Bridge (Episode)

Episode Cast:[]

Myth statement	Status	Notes
Soldiers marching in unison can cause harmonic oscillation in a bridge and cause it to collapse. (see Broughton Suspension Bridge)	Busted	Adam built a 60ft (18m) by 6ft (1.8m) suspension bridge from metal tubing and nylon rope, while Jamie built 12 dummy soldiers out of air-powered actuators and combat boots. In the initial test, the soldiers moved far too slowly due to a disconnected hose. During the second and third tests, the soldiers stomped too hard on the bridge, causing the bridge to collapse from impact without any harmonic vibration. The myth was retested for Myths Revisited and found plausible. It was ultimately cut out of the episode, but later included in MythBusters Outtakes.^[2]

Myth statement	Status	Notes
A rowing eight can pull a water skier at sufficient speed for them to stay upright.	Confirmed	After several tries, Jamie was able to stay upright for over 40 seconds, with only a few hours experience in waterskiing.

Myth statement	Status	Notes
Fecal coliform bacteria can travel from a toilet to a toothbrush and grow in its bristles.	Confirmed	After confirming that a toilet flush does put out an aerosol spray, Adam builds a rack to hold 44 toothbrushes at various distances from the toilet in the shop, as well as two controls kept in the office. Each day, Adam and Jamie exposed the brushes to toothpaste and rinsed with distilled water, with brushing with a pair kept right above the toilet bowl. Fecal coliforms were indeed found on all the test brushes, including the control ones, but none at a level high enough to be dangerous. A microbiologist from UCSF confirmed that such coliforms were impossible to completely avoid, and that there was no significant difference in the number of bacteria based on where the toothbrushes were placed in respect to the toilet bowl.