What is the universe expanding into?
2,004,865 views | Sajan Saini • TED-Ed
The universe began in a Big Bang nearly fourteen billion years ago, and has been expanding ever since. But how does the universe expand and what is it expanding into? Sajan Saini explains the existing theories around the Big Bang and what, if anything, lies beyond our universe. [TED-Ed Animation by Wooden Plane Productions]