Planck's constant reveals the quantum world's fundamental energy levels. It shows how light and matter exist in discrete units (quanta). This constant defines limits to our knowledge of particle ...

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 ...

ADVANCES in fundamental theory have often been guided by the principle that reliance is to be placed on the most directly observed quantities, that is, those involving least theoretical assumptions.

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 ...

The purpose of this investigation was development of a simple method, using light-emitting diodes, to verify Planck's Constant. Early in the course of the work, the discovery of an invalid assumption ...

Researchers at the National Institute of Standards and Technology (NIST) have made their most precise determination yet of Planck’s constant. This will let NIST redefine the kilogram, the official ...

Redefinition of the kilogram will not make the kilogram more precise, but it will make it more stable. A physical object can lose or gain atoms over time, or be destroyed, but constants remain the ...

Planck's constant is a pretty important part of modern physics, but it's also pretty confusing. Maybe you were wondering what it was while reading about the new kilogram definition. Well never fear, ...

THE relation between the magneton and Planck's constant is even more intimate than Dr. Allen's remarks (NATURE February 5), and his numerical illustration would suggest.

Once upon a time, I was involved in an abortive attempt to measure the variation of the fundamental constants. Thanks to that experience, I’ve always had an interest in these measurements, so a new ...