Meters, kilograms, degrees Celsius. To most Americans, these units of measurement are little more than funny inconveniences on trips abroad. To scientists, they’re the very standards that allow for ...

When the kilogram, the world's basic unit of mass, gets a new definition in 2018, it will be based not on a physical artifact but a constant of nature. However, researchers will still need to "realize ...

Hackers, advanced hobbyists, makers, and hands-on physics experimenters are always looking for their next great project, and I think this is a good one: an apparatus to establish the “standard” ...

How do you define one kilogram? Easy: it's the exact mass of a metal cylinder called the International Prototype Kilogram, IPK for short, kept in controlled conditions in France. But the standard ...

We measure stuff all the time—how long, how heavy, how hot, and so on—because we need to for things such as trade, health and knowledge. But making sure our measurements compare apples with apples has ...

One of the most iconic hunks of metal in the world is set to get a demotion. The official metallic cylinder that defines the mass of a kilogram may soon be set aside in favor of a measurement that is ...

There’s long been debate over the accuracy of the standardized kilogram. Now, though, scientists have shown once and for all that the lump of metal defining the ...

Most people know how much a pound weighs — 16 ounces. The worldly among us may know that a kilogram is 2.2 pounds — or 1,000 grams. But do we really know what these numbers mean? Agreeing on units of ...

One of the most illuminating high school courses no doubt for many readers as much as for your scribe, was the series of physics lessons during which the SI units were explained. That glorious sense ...

Kevin Pimbblet receives funding from STFC and the Royal Astronomical Society. How much is a kilogram? 1,000 grams. 2.20462 pounds. Or 0.0685 slugs based on the old Imperial gravitational system. But ...

Contaminants have made the standard kilogram weigh slightly more than it originally did, but a careful cleaning method may slim it down. Sophie Bushwick reports How do you define one kilogram? Easy: ...