Download a free audiobook version of "A Brief History of Time" and support TED-Ed's nonprofit mission: https://adbl.co/2NWYjAh Check out our full book recommendation: https://shop.ed.ted.com/collections/ted-ed-book-recommendations/products/a-brief-history-of-time View full lesson: https://ed.ted.com/lessons/does-time-exist-andrew-zimmerman-jones The earliest time measurements were observations of cycles of the natural world, using patterns of changes from day to night and season to season to build calendars. More precise time-keeping eventually came along to put time in more convenient boxes. But what exactly are we measuring? Andrew Zimmerman Jones contemplates whether time is something that physically exists or is just in our heads. Lesson by Andrew Zimmerman Jones, directed by Nice Shoes. Thank you so much to our patrons for your support! Without you this video would not be possible! Chung Wah Gnapp, Andrew Sprott, Jane White, Ayan Doss, BRENDAN NEALE, Lawrence Teh Swee Kiang, Alex Pierce, Nick Cozby, Jeffrey Segrest, Anthony Arcis, Ugur Doga Sezgin, Kathryn Vacha, Allyson Martin, Srinivasa C Pasumarthi, 张晓雨, Ann Marie Reus, Nishant Suneja, Javier Lara Rosado, Jerry Yang, Shubham Arora, Sebastian Regez, Danielle Downs, Clovis Norroy, Liz Candee, Vinh-Thuy Nguyen, Amy Lopez, SANG HAN, Aries SW, Sebastiaan Hols, Grimes Gregory, João Henrique Rodrigues, Michael Lucke, Annastasshia Ames, Claudia Hernandez Chavarria, Livia-Alexandra Sarban, Lee, Karthik Balsubramanian, Mathew Samuel, Turine Tran, Ido brown, Jordan Tang, Christopher Jimenez, Juan, Tracey Tobkin, Sid, emily lam, Kathryn J Hammond, Elliot Poulin, Noel Situ and Latora Slydell.