Ever since Einstein published his Special Theory of Relativity, one equation has been the bane of humans hoping to explore the stars: E=mc². In addition to informing our understanding of gravity, space, and time, this formula implies that traveling at or beyond light speed is impossible. Why is that? Lindsay DeMarchi and Fabio Pacucci explain the physics behind this unbreakable speed limit. Lesson by Lindsay DeMarchi and Fabio Pacucci, directed by Igor Ćorić, Artrake Studio.