Astrophysicist Janna Levin, PhD, is asked to explain the concept of gravity to 5 different people; a child, a teen, a college student, a grad student, and an expert.

Levin is the Claire Tow Professor of Physics & Astronomy at Barnard College of Columbia University and author of "Black Hole Blues and Other Songs from Outer Space."

She is also the Chair and Director of Sciences at Pioneer Works, where this video was filmed. To learn more, visit https://pioneerworks.org/​