Time: the most familiar, and most mysterious quality of the physical universe. Theoretical physicist Brian Greene, PhD, has been challenged to explain the nature of time to 5 different people; a child, a teen, a college student, a grad student, and an expert. Director: Maya Dangerfield Producer: Wendi Jonassen Field Producer: Katherine Wzorek Director of Photography: Charlie Jordan Editor: Shandor Garrison Host: Brian Greene Level 1: Kayla Martini Level 2: Maria Guseva Level 3: Zain Kamal Level 4: Alexander Novara Level 5: Massimo Porrati Line Producer: Joseph Buscemi Associate Producer: Paul Gulyas Production Manager: Eric Martinez Production Coordinator: Fernando Davila Casting Producer: Nick Sawyer Camera Operator: Britney Berger Gaffer: Gautam Kadian Audio: Brett Van Deusen Production Assistant: Nicole Gaitan Hair/Makeup Artist: Yev Write-Mason Post Production Supervisor: Alexa Deutsch Post Production Coordinator: Ian Bryant Supervising Editor: Doug Larsen Assistant Editor: Andy Morell Still haven’t subscribed to WIRED on YouTube? ►► http://wrd.cm/15fP7B7 Listen to the Get WIRED podcast ►► https://link.chtbl.com/wired-ytc-desc Want more WIRED? Get the magazine ►► https://subscribe.wired.com/subscribe/splits/wired/WIR_YouTube?source=EDT_WIR_YouTube_0_Video_Description_ZZ Follow WIRED: Instagram ►►https://instagram.com/wired Twitter ►►http://www.twitter.com/wired Facebook ►►https://www.facebook.com/wired Get more incredible stories on science and tech with our daily newsletter: https://wrd.cm/DailyYT Also, check out the free WIRED channel on Roku, Apple TV, Amazon Fire TV, and Android TV. ABOUT WIRED WIRED is where tomorrow is realized. Through thought-provoking stories and videos, WIRED explores the future of business, innovation, and culture.