'Mythbusters' premieres with new hosts chopping off heads

Mythbusters returned for a new season on a new channel with new hosts. After winning Mythbusters: The Search, Jon Lung and Brian Louden replaced Adam Savage and Jamie Hyneman as the new busters of myths. They kicked off the premiere by testing the myth of whether a weapon can slice through a villain's neck with such force and precision... Welcome to the danger zone. ...That his head stays on his shoulders and doesn't move. But before they could get started, they had to some calculating. Lung said, "What makes a sword cut efficiently is a push and a draw. The draw's actually the action of when you pull that sword back, and it has to be a 1:1 ratio for an effective cut." Lung built a pneumatic sword that looked impressive while slicing watermelons, but would not supply the speed they needed to leave a decapitated head on a neck. Louden designed a rocket blade sled using 20 rockets mounted to a blade on sliding rails. They were able to get the speed of the blade up to 150 mph. While they easily decapitated the test dummies, it was clear that delayed decapitation was just a busted myth.