All Episodes

July 21, 2025 10 mins
For over a century, the kilogram was defined by a single, shiny lump of metal locked in a vault near Paris. But what happens when your definition of mass starts...losing mass? In this episode, Tom Whipple, Science Editor at The Times, unpacks the surprisingly dramatic story of the kilo - from the French Revolution’s quest for order, to a quantum reimagining of what “weight” really means. Enter the kibble balance: a machine so precise it can weigh light itself. Sort of.

Hosted on Acast. See acast.com/privacy for more information.

Mark as Played

Advertise With Us

Popular Podcasts

Dateline NBC

Dateline NBC

Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com

Stuff You Should Know

Stuff You Should Know

If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.

Law & Order: Criminal Justice System - Season 1 & Season 2

Law & Order: Criminal Justice System - Season 1 & Season 2

Season Two Out Now! Law & Order: Criminal Justice System tells the real stories behind the landmark cases that have shaped how the most dangerous and influential criminals in America are prosecuted. In its second season, the series tackles the threat of terrorism in the United States. From the rise of extremist political groups in the 60s to domestic lone wolves in the modern day, we explore how organizations like the FBI and Joint Terrorism Take Force have evolved to fight back against a multitude of terrorist threats.

Music, radio and podcasts, all free. Listen online or download the iHeart App.

Connect

© 2025 iHeartMedia, Inc.