News & Comment

The use of quantum effects and digital technologies is changing the measurement of electrical power and energy, as explained by Héctor Laiz.

Units of length have come a long way: from countless local variants to standardized measures. Peter Sidaway looks back at some milestones.

The vast majority of devices for processing quantum information — from communication to computation and sensing — operate with quantum bits. Federico Levi tells us what makes a good qubit.

Although the ohm is ‘only’ a derived SI unit, the assumption that it plays an unobtrusive role could not be further from the truth, as Karin Cedergren reveals.

The digital transformation doesn’t stop at metrology as Shanay Rab, Meher Wan and Sanjay Yadav explain.

The impact of legal metrology often remains unnoticed in our everyday lives. Pavel Klenovsky, Marc Wouters and Wilfried de Waal instruct us in trade and legal regulations.

The shift of the definition of the kilogram in 2019 away from an artefact to one relying on the Planck constant inspires technological innovation, as Naoki Kuramoto elucidates.

Juris Meija takes a look at the tumultuous past of the atomic unit of mass from its beginnings as an idea to its most recent revisions in a hotel bar.

A task group recommends values for many constants in fundamental theories of physics and chemistry. Eite Tiesinga and Peter Mohr tell some of the constants’ stories.

The coexistence of qualitative and quantitative scales characterizes advances in earthquake measurements. Although often confused, intensity and magnitude refer to very different things, as Leonardo Benini explains.

The establishment of a global metric system of units as agreed upon in the Metre Convention relies on international as well as national institutes and organizations, of which Stefanie Reichert gives an overview.

To celebrate the International Year of Basic Sciences for Sustainable Development, James Gallagher tells the story of the British thermal unit, a unit for heat.