Could there be infinite versions of us, spinning off into their own universes from every choice we make? Is all of time happening all at once? Do we have free will? 

"When we try to answer such big questions about our existence, we basically have three options. That's religion, philosophy and physics," Dr. Sabine Hossenfelder told The Takeaway. "And of those three, I think physics has made the biggest progress in the past century."

Sabine Hossenfelder, a physicist at the Frankfurt Institute for Advanced Studies in Germany, has made it her mission to make physics engaging to the public. She's the creator of the YouTube show, "Science without the Gobbledygook," and her newest book is "Existential Physics: A Scientist's Guide to Life's Biggest Questions." She plumbs the depths — and limitations — of the best knowledge physicists currently have about our universe, where it overlaps with some of our biggest spiritual and existential questions, and the possibilities they present.