String theory is the most promising candidate for a “theory of everything”—a set of ideas that unifies all of physics and describes reality at the largest and smallest scales. String theory takes scientists to truly bizarre places—to six-dimensional shapes billions of times smaller than a proton, to the uncharted interiors of black holes, and to the rapidly expanding universe a fraction of a second after the Big Bang.

These 12 lectures are a deep dive into string theory for anyone eager to learn what it’s all about: how tiny vibrating strings account for all the particles in particle physics, what led researchers to postulate 10 dimensions instead of the three plus time in our daily lives, and why we can’t perceive these “compactified” regions of space.

The course is taught by Professor Shamit Kachru of the Stanford Institute for Theoretical Physics. A prominent string theorist, Dr. Kachru explains the unsolved questions that gave birth to string theory in the 1970s, its evolution into a quantum theory of gravity, the disparate versions of the theory, its major thinkers, and objections and alternatives to string theory.

The lectures are generously illustrated with animations and graphics to make the ideas clear, as viewers venture across time, space, and unseen dimensions.