Time. We waste it, save it, kill it, make it. The world runs on it. Yet, ask physicists what time actually is, and the answer might shock you: They have no idea. Even more surprising, the deep sense we have of time passing from present to past may be nothing more than an illusion. How can our understanding of something so familiar be so wrong? In search of answers, Brian Greene takes us on the ultimate time traveling adventure, hurtling 50 years into the future before stepping into a wormhole to travel back to the past. Along the way, he will reveal a new way of thinking about time in which moments past, present, and future-from the reign of T. Rex to the birth of your great-great-grandchildren-exist all at once. This journey will bring us all the way back to the Big Bang, where physicists think the ultimate secrets of time may be hidden. You'll never look at your wristwatch the same way again.
Never miss a Nat Geo moment
Member Sign In
Set Reminder
Join our curious community and you'll have access to some great features!
Personalised content reflecting your interests on the site
Watch exclusive videos before anyone else
Favourite content that you like or want to check out later
Free SMS and Email reminders so you never miss a show
Get notified when content that interests you is published
Share your photos on Snap! that could appear on TV
Share your thoughts and opinions on various matters
Receive a monthly newsletter with loads of great content