For millennia, humans have used units of measurement based on aspects of the human body. Familiar examples include the fathom (arm span) and the qubit (forearm length). Our guest in this episode of the Physics World Weekly podcast is the Finnish social scientist Roope Kaaronen, who has studied the development and use of body-based units in 186 cultures around the world.

While many traditional units have been superseded by international standards, Kaaronen tells Physics World’s Margaret Harris that some body-based units are alive and well today, and they can sometimes be more useful than their modern counterparts. Useful units include those that emerged from the need to fit technologies such as skis and kayaks to individual users. Indeed, Kaaronen says that the existence of such units suggests that rather than being a modern concept, the idea of ergonomics has been around for a very long time.

Also in the podcast, Physics World editors chat about the blockbuster film Oppenheimer.