Physicists in the US say that they have used publicly available data from global positioning system (GPS) satellites to put a limit on how much Planck’s constant might vary from place to place. Their ...

For nearly 130 years, the kilogram has been defined by a small platinum and iridium cylinder sitting in a vault outside Paris. Every other unit of measurement is defined by reproducible physical ...

Planck’s constant is one of the most important numbers in science. It describes the relationship between the energy and frequency of an electromagnetic wave in an equation known as the Planck-Einstein ...

Lego is a popular Christmas gift, and young and old alike can derive hours of pleasure building with those little plastic blocks. But, like a lot of playthings, the novelty wears off soon enough and ...

Philosophical Transactions: Mathematical, Physical and Engineering Sciences, Vol. 369, No. 1953, The new SI based on fundamental constants (28 October 2011), pp. 3936-3953 (18 pages) Since 1889, the ...

A high-tech version of an old-fashioned balance scale at the National Institute of Standards and Technology (NIST) has just brought scientists a critical step closer toward a new and improved ...

What does a kilogram weigh? Middle school science classes often teach that the unit is based on the weight of water—specifically a cube of water, a tenth of a meter on each side, at just above ...

Scientists and policy makers from around 60 nations voted unanimously Friday to redefine the kilogram. The decision at the General Conference on Weights and Measures in Versailles, France was greeted ...

Researchers from the CNRS and Université de Sherbrooke, have discovered a universal law for the electronic properties of high-temperature superconductors. They exposed superconductors to an intense ...