The International System of Units (SI Units), adopted in 1960, is the global standard for consistent measurement, replacing disparate systems. It has 7 base si units and all other units are derived ...

Taking the first steps of what would be a major historical advance in the science of measurement, the National Institute of Standards and Technology (NIST) is participating in a worldwide effort to ...

The 130-year-old physical artifact is retiring. Here's how a constant of nature will provide a more stable definition of mass. There's an old folktale involving a conversation. A nobleman who shouted, ...

A new definition of the kilogram is required, an international team of scientists contends. The current one is imprecise, they say, because it is not linked to an unvarying property of nature. The ...

SCIENTISTS HAVE SPENT the better part of the past four centuries, since the early days of the Enlightenment, discovering the truth about how the natural world works. A critical part of this endeavor ...