And while we know a LOT thanks to science, there’s still so much that we don’t know.
These mysteries have stumped scientists throughout the ages—and will leave you scratching your head.
A few things we know about the universe: it’s infinite, it’s littered with black holes, and thinking about it can make your brain hurt.
And one of those things we don’t know: how it began. Even otherwise all-knowing Stephen William Hawking, PhD, theoretical physicist, cosmologist, and director of research at the Centre for Theoretical Cosmology in Cambridge, England, isn’t sure.
Some brilliant minds wonder if it even had a beginning at all, or if it was always there.