Humans have a need to quantify things. And sometimes the usual measurements — feet, meters, grams — are not good enough. Or funny enough. Sometimes you need to express things in bananas, Helens, or ...

The metric system is on track for a mass makeover. In an effort to provide accurate measurements at all scales, scientists are preparing to redefine four basic units by the end of 2018. The shift will ...

When someone tells you they'll be "back in two shakes!" they are guaranteed to take much, much longer than that — at least if we're talking shakes in the sense used by physicists. The shake is a unit ...