Knives that never dull: I could stab you forever. I would too is the thing. They say stabbing is typically a crime of passion, and if I'm anything, it's
an alcoholic passionate. My lovemakin's off the charts, just sayin'.
After literally decades of research, scientists have figured out how sea urchins can eat their way through rocks while keeping their teeth razor sharp. The secret is how the teeth are constructed: layers of calcite biocrystals held together with calcite nanocement are interspersed with softer layers of organic material, and when the teeth start to get dull on the surface, the top organic layer flakes off, exposing a brand new and freshly sharp layer of calcite. Chew, flake, repeat, and you've got infinitely sharp teeth.
Now that scientists know how the urchins do it, they say that it's at least theoretically possible to create a material with the same properties that could be made into knives and other tools that would sharpen themselves with use.
Don't get me wrong, sea urchin teeth are interesting and all, but you know what's even more interesting? Street urchin teeth. No lie, I walked out of the bar yesterday and there was a bum by the door begging for cigarettes AND I SAW A WORM COME OUT OF HIS TOOTH. It was trying to say something.