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 ↓↓↓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.____________________________________Be Smart explores science questions you didn’t even know you wondered about. It is hosted and produced by Joe Hanson, PhD. We post new videos all the time, so please subscribe! If you enjoyed this video, hit the ‘like’ button, leave a comment, or watch another of our videos!CONNECT WITH ME____________________________________Website: https://www.itsokaytobesmart.com/ Instagram: https://www.instagram.com/okaytobesmart/ https://www.instagram.com/drjoehanson/ Facebook:https://www.facebook.com/itsokaytobesmart Patreon: https://www.patreon.com/c/itsokaytobesmart 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 BrewerSPONSORSHIP INQUIRIES____________________________________Please email [email protected] video and images provided by Shutterstock, Artlist, and MotionArrayMusic provided by APMWritten by Joe HansonEdited by PW SheltonProduced by Least Square Media and Spotzen for PBS Digital Studios Learn more about your ad choices. Visit megaphone.fm/adchoices