What is life? What is alive?
These can seem like pretty basic questions, but scientists have been researching — and struggling with — them for generations.
Science writer Carl Zimmer delves into these, and other questions, in his new book, "Life’s Edge: The Search for What it Means to Be Alive." Zimmer also writes the Matter column for the New York Times, among other things.
The Show spoke with him about what led him to want to try to answer some of these big, deep questions.