Deluged by responses to his request for your favourite units, Robert P Crease discovers that non-SI units persist, and are sometimes even popular, among the physics community Setting the standard ...

An upcoming change to SI units – due to be officially approved this month – will mark the end of a long journey from defining quantities in terms of objects to using precise, unchanging and universal ...

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 ...

It always fascinates us that every single thing that is made had to be designed by someone. Even something as simple as a bag and box that holds cereal. Someone had to work out the dimensions, the ...

The official object that defines the mass of a kilogram is a tiny, 139-year-old cylinder of platinum and iridium that resides in a triple-locked vault near Paris. Because it is so important, ...