Science Update - the Sharpest and the Fastest.
Bob - This week on Science Update, we'll talk about some ants that have set the world record for fastest-moving body part. But first, Chelsea reports on another world record - for sharpest object.
Chelsea - The tip of the world's sharpest needle is a single atom of tungsten. I asked physicist Robert Wolkow of the University of Alberta what it would be like to hold it in my hand.
Robert - It would be just like a sewing needle or a pin and you would see that it was very sharp but you wouldn't be able to see the end of it-it's so small it's invisible. And if you put it under the most powerful microscope in the world, you would only then just barely see the tip of it.
Chelsea - Wolkow says they make these needles by exposing a normal needle made of tungsten to nitrogen gas and electricity. The gas and electricity interact with the end of the needle to pluck off atoms until there's only one left.
Robert - It's kind of like sculpting. In a sculpture the final shape is already in the block of stone and the sculpture knows what to take away. Well, we're not sculptors, but we take away the atoms form the edge, leaving a tiny, tiny needle.
Chelsea - Since it's so sharp, Wolkow says the needle could prove to be the best probe ever made for use in powerful electron microscopes.
Bob - Thanks, Chelsea. A type of insect called the Trap - jaw ant has jaws that now hold the record for the fastest - moving self-propelled body part in the animal kingdom. But it's what they do with those super-speed jaws that's really interesting, according to University of Illinois entomologist Andy Suarez.
Andy - These ants will use their mandibles not only to capture food, but to propel themselves off the ground, to escape threat or predators.
Bob - Using a high-speed imaging system, Suarez found that the ants cock their jaws open against the ground and then snap them shut at close to 100 miles per hour. That's enough force for some pretty impressive flips and serious hangtime.
Andy - In the field when they start jumping around, it's just a fraction of a second-they just pop up in the air and they're on the ground again. And when you can slow this down and dissect the movement, the kinematics, of what's going on, it's really quite beautiful-it's very acrobatic.
Bob - Suarez says the ants probably first evolved the fast jaws to capture prey, but then repurposed the skill to escape becoming prey.
Chelsea - Thanks, Bob. That's all for this week. Next week we'll discuss a new estimate of how many types of dinosaurs are still waiting to be dug up. Until then, I'm Chelsea Wald.
Bob - And I'm Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists