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

SI Units: In our daily lives, we use measurements constantly, whether it is checking the temperature, weighing vegetables, or measuring the distance between two places. But imagine how confusing it ...

October 18, 2010 marked the 50th anniversary of the International System of Units, also known as the SI System. Resolution 12 of the 11th meeting of the CGPM (1960) established the system as the world ...

We review the proposal of the International Committee for Weights and Measures (Comité International des Poids et Mesures, CIPM), currently being considered by the General Conference on Weights and ...

Relics in the form of rods, rulers, and weights go back thousands of years, suggesting that people have long cared about standardized measurements. Today, the International System of Units(SI) defines ...

In addition to Ampere, Kelvin, Mol and others, the kilogram is now defined by a natural constant. In concrete terms, this means that the original kilogram, which has been the measure of all things for ...

A flaw in the system leaves physicists grappling with dimensionless units. Water is a precious resource. So protest erupted when, last September, India’s Supreme Court ordered Karnataka state 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, ...