Who decides how long a second is? - John Kitching

Discover how scientists developed atomic clocks, which use the vibrations of atoms to measure and maintain a globally consistent time. --In 1967, researchers gathered to answer a long-running scientific question: just how long is a second? It might seem obvious at first. A second is the tick of a clock, the swing of a pendulum, the time it takes to count to one. But how precise are those measurements? And what is that length based on? John Kitching digs into how we scientifically define this fundamental unit of time.Lesson by John Kitching, directed by Tjoff Koong.Support Our Non-Profit Mission----------------------------------------------Support us on Patreon: http://bit.ly/TEDEdPatreonCheck out our merch: http://bit.ly/TEDEDShop----------------------------------------------Connect With Us----------------------------------------------Sign up for our newsletter: http://bit.ly/TEDEdNewsletterFollow us on Facebook: http://bit.ly/TEDEdFacebookFind us on Twitter: http://bit.ly/TEDEdTwitterPeep us on Instagram: http://bit.ly/TEDEdInstagram----------------------------------------------Keep Learning----------------------------------------------View full lesson: https://ed.ted.com/lessons/who-decides-how-long-a-second-is-john-kitchingDig deeper with additional resources: https://ed.ted.com/lessons/who-decides-how-long-a-second-is-john-kitching#digdeeperAnimator's website: http://greenhouseanimation.com/directors/tjoff-koong/----------------------------------------------Thank you so much to our patrons for your support! Without you this video would not be possible! Po Foon Kwong, NinjaBoffin, Jesse Jurman, Josue Perez Miranda, Scott Markley, Elija Peterson, Ovidiu Mrd, Lawrence Wu, Xavier Dupont, Aravind Battaje, Nathan Giusti, Helen Lee, Anthony Benedict, Karthik Balsubramanian, John Hong, Annastasshia Ames, Sebastiaan Hols, Aries SW, Amy Lopez, Liz Candee, Kathryn Vacha, Anthony Arcis, Jeffrey Segrest, Karmi Nguyen, Yelena Baykova, Harshita Jagdish Sahijwani, Nick Johnson, Carlos H. Costa, Mohamed Elsayed, Les Howard, Jennifer Kurkoski, Ryan B Harvey, Abhishek Bansal, Jose Arcadio Valdes Franco, Karl Laius, JY Kang, Charles A Hershberger, Robert Seik, Heidi Stolt, Alexis Hevia, Brady Jones, Christina Salvatore, Karlee Finch, Michael Goldberg, Mario Mejia, Nicolas Silva, Kurt Almendras, Denise A Pitts, Doug Henry and Kristiyan Bonev. Learn more about your ad choices. Visit megaphone.fm/adchoices