TL;DR

Veritasium unpacks how Paul Dirac’s quest to fix the Schrödinger equation led him to predict negative-energy solutions—and, unexpectedly, an entire “anti-universe.” By marrying relativity with quantum mechanics (via the Klein-Gordon and Dirac equations), he not only revealed the existence of the positron (the electron’s antiparticle) but also hinted that antiparticles behave as if they’re traveling backward in time.

Along the way, we get the lowdown on Dirac’s genius (and his quirks!), the tragic hurdles in early particle physics, and why the idea of an “anti-world” was as wild then as it sounds now. Special thanks to the experts, archives, and animators who helped bring this story to life.

Watch on YouTube