Frequently Asked Questions About the Universe

You've got questions: about space, time, gravity, and the odds of meeting your older self inside a wormhole. All the answers you need are right here.

As a species, we may not agree on much, but one thing brings us all together: a need to know. We all wonder, and deep down we all have the same big questions. Why can't I travel back in time? Where did the universe come from? What's inside a black hole? Can I rearrange the particles in my cat and turn it into a dog?

Physics profe ...