A mathematician with a knife and ball begins slicing and distributing the ball into an infinite number of boxes. She then recombines the parts into five precise sections. Moving and rotating these sections around, she recombines them to form two identical, flawless, and complete copies of the original ball. How is this possible? Jacqueline Doan and Alex Kazachek explore the Banach-Tarski paradox. Lesson by Jacqueline Doan and Alex Kazachek, directed by Mads Lundgård.