It's every swimmer, surfer, and slow fish's greatest fear, but to understand just how deadly a shark's bite can be, researchers wanted to study the cutting power of various sharks' teeth. So they did what any mad scientist would: build a saw blade covered in shark's teeth, attach it to a Sawzall, and hack their way through a hunk of salmon.
Affectionately known as the Jawzall, the blade used the teeth from a sixgill shark, a sandbar shark, a silky shark, and a formidable tiger shark. The results were satisfying if not all that surprising: larger teeth with more serrations were far more effective at cutting through flesh and bone, but surprisingly, after just twelve cuts, all of the teeth showed significant signs of wear. So that probably explains why sharks shed and re-grow their teeth so quickly, although they're probably still just as deadly with a mouthful of dull chompers. [Popular Science via Technabob]