Can you make your own universe? We usually think of the universe as 'everything that exists,' so how could you make another one?
Well, physicists have been speculating about the existence of multiple universes for some time now. And for Robert, the obvious next question was: 'Can we make one?' So he invited physicist Brian Greene to his kitchen to speculate about just that. And it turns out, it's not such a far-fetched idea. There are scientists right now trying to figure out whether it's possible and what it would take. According to Brian, it would require a tiny black hole, a dash of reverse-gravity, and a lot of luck. But the laws of physics don't rule it out.