Science

by Sarah Begley

by Sarah Begley and TIME Photo

by TIME Photo

by Helen Regan

by Jeffrey Kluger

by Kevin McSpadden

by Kate Pickert/Los Angeles

by Noah Rayman

by Eliza Berman

by Jeffrey Kluger

by TIME Staff

by TIME Staff

by Lily Rothman

by Jeffrey Kluger

by Kevin McSpadden