In the spring of 1966, Stewart Brand did 100 micrograms of LSD and sat on top of a roof in San Francisco. Perched there, he looked toward a curved horizon and imagined the spherical Earth and just how limited resources on our planet are. Out of that psychedelic drug-induced vision, he developed the Whole Earth theory. He campaigned for NASA to release satellite images of the Earth, and created the influential and generation-defining Whole Earth Catalogue. In this companion piece to Michael Pollan’s new book, How To Change Your Mind, go inside Brand’s legendary trip from a roof top in San Fran up into outer space.