In 1878—before Einstein was born, before quantum mechanics, before we knew that our galaxy was one among many—a well-known physicist named Phillip von Jolly told young Max Planck, a student aspiring ...

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 ...

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 remarkable thing about our universe is that it’s possible to explore at least some of its inner workings with very simple tools. Gravity is one example, to which [Galileo]’s inclined planes and ...

A high-tech version of a balance scale has just brought scientists a critical step closer toward a new and improved definition of the kilogram. The scale, called the NIST-4 watt balance, has conducted ...

Engineers have designed an experiment that uses Lego blocks and a few other electronic bits and pieces that would allow any keen tinkerer to build a device that not only determines Planck's Constant ...

Deep underneath the Parisian suburb of Saint-Cloud, in a vault that can only be opened by three people wielding three different keys, there lies a hunk of metal that is so crucial to the world of ...

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 ...

The kilogram has the dubious distinction of being the only SI unit still based on a physical object; specifically, a metal cylinder kept in a vault in France. Plans are well underway to redefine the ...