Traffic Lights Are So Much Weirder Than You Realize

Thank you to Squarespace for supporting PBS. Go to https://www.squarespace.com/besmart for a free trial and use code BESMART to save 10% off your first purchase of a website or domain. ↓↓↓ More info and sources below ↓↓↓ Support us on Patreon / itsokaytobesmart Why are stop lights red? The common explanation about red light traveling farther through fog is actually wrong. The real story involves early railroads, deadly accidents, an exploding gas traffic light, forgotten inventors, and even the evolution of primate color vision. Here’s how history and biology accidentally created the nearly perfect traffic signal. ----------- High fives to all our Brain Trust Patrons: Baerbel Winkler Brent Lopez dani bowman David Johnston Ed Eyden Eric Meer Holly, Brett, and Ashe Bullion Jaap Westera Karen Haskell Marcus Pingel Mike and Patty Loftis Olivia Ruiz Paul Weir Reuben Brewer SUBSCRIBE so you don’t miss a video! ►► http://bit.ly/iotbs_sub Join us on Patreon! https://patreon.com/itsokaytobesmart Instagram http://www.instagram.com/DrJoeHanson http://www.instagram.com/okaytobesmart Facebook https://www.facebook.com/itsokaytobesmartpbs/ Merch https://store.dftba.com/collections/its-okay-to-be-smart