If scientists had sacred objects, this would be one of them: a single, closely guarded 137-year-old cylinder of metal, housed in a vault outside of Paris. It is a prototype that precisely defines a ...

SI Unit: Every measurement we make, be it for length, time, temperature, or electric current, needs a standard unit so that results are understood universally. To maintain uniformity worldwide, ...

Nick van Remortel demystifies natural unit systems — and advises what to do when you see a mass expressed in GeV. Several unit systems for describing the natural world exist. The International System ...

In a landmark decision, representatives from 60 countries voted to redefine the International System of Units (SI), changing the world's definition of the kilogram, the ampere, the kelvin and the mole ...

What unit of measurement should be used for specific reports? Whether printing out a check register or calculating square footage, using the correct team is essential. A size mistake can lead to ...

In addition to other scientific units, the kilogram also is now defined by a natural constant. This is made possible by single crystals grown from highly enriched silicon-28. In addition to Ampere, ...