Unless you're the handy practical type, you probably don't handle a screw very often. You can think of a screw as a cylindrical rod with a continuous spiral thread on the outside, and which is used ...

Researchers have discovered the first species pollinated by sap beetles in the genus Pandanus, a group of palm-like plants native to the tropics and subtropics of Africa and Eurasia. The discovery ...

Like one of the fastest airplanes that ever flew,† the two-man Japanese submarines which attacked Pearl Harbor had contrarotating propellers —two tandem screws placed close together, turning in ...