Time Travel

Maybe time has its origins in grief and longing for people we've lost. That idea certainly resonates with theoretical physicist Ron Mallett. He's spent a lot of his career studying time — which he traces back to the tragedy that marked his childhood.

We all think about time but probably not as deeply as the groundbreaking theoretical physicist Lee Smolin. Smolin has created a radical new view of the nature of time and the cosmos. He lays it out in a book called "Time Reborn: From the Crisis in Physics to the Future of the Universe."