Sara Walker is an astrobiologist and theoretical physicist. She is the author of a new book titled "Life as No One Knows It: The Physics of Life's Emergence"

Paul Davies is an English physicist, writer and broadcaster, a professor at Arizona State University as well as the Director of the Center for Fundamental Concepts in Science. His research spans fields like cosmology, quantum field theory, and astrobiology.

When searching for E.T., scientists tend to look for signs of life with certain similarities to life on Earth. But abiding by that narrow definition of life could be the reason we still haven't found any aliens. Are we truly alone in the universe, or do we simply have no idea what we're looking for?

You don't want to miss this amazing article featuring Sara Walker!