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 ...

As ever more digital data is created and stored, the world needs more unit measurements to keep up with the ever-expanding numbers. To do so, the 27th General Conference on Weights and Measures on ...

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 ...

The NIST-4 Kibble balance, an electromagnetic weighing machine that is used to measure Planck's constant, and in turn, redefine the kilogram. Jennifer Lauren Lee / NIST Locked in a vault that requires ...

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 ...