As cheat sheets go, it is a long one. Every four years, a task force of the Committee on Data for Science and Technology (CODATA), headquartered in Paris, releases a short-hand description of the ...

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 ...

It doesn’t happen too often, but after a vote that took place earlier today near Paris, science textbooks really will have to be rewritten. At the Congress Chamber in the Palace of Versailles, ...

Tampa, Fla. – A fundamental number that affects the color of light emitted by atoms as well as all chemical interactions has not changed in more than 7 billion years, according to observations by a ...

Weighty matters: a platinum-iridium kilogram belonging to the US National Institute of standards and Technology. (Courtesy: J.L. Lee/NIST) Metrologists and policy-makers from 60 countries around the ...

While quantum physics and general relativity don’t always play well together, they agree on important points, including that of the spectra of atoms. To wit: the spectrum of hydrogen shouldn’t depend ...