15 December 1923 to 28 February 2020

Today, 28 February 2020, Freeman Dyson passed away. Many obituaries have appeared, rightly lauding his many contributions in many fields. Dyson was as close to a renaissance man as was possible in the twentieth and twenty-first century. For me, Dyson’s great contribution were his ideas on space exploration, SETI, and futurism, which was a futurism projected so far into the future that he dealt with the stability of physical laws, proton decay, and the possibility of surviving the heat death of the universe.

Dyson’s books — Disturbing the Universe, Infinite in All Directions, Origins of Life, Dreams of Earth and Sky, A Many-Colored Glass — and papers — “Search for Artificial Stellar Sources of Infrared Radiation,” “Time without End: Physics and Biology in an Open Universe,” “Human Consequences of the Exploration of Space,” “Looking for life in unlikely places: reasons why planets may not be the best places to look for life,” “Pilgrim Fathers, Mormon Pioneers, and Space Colonists: An Economic Comparison,” “Interstellar Transport,” and many others (many of which do not appear in his 600 page volume of selected papers published by the American Mathematical Society, or in the other essay collection, Birds and Frogs) — presented ideas of the kind that dreams are made on. Visionary to the point of megalomania — Dyson discussed disassembling planets in order to use their materials for megastructure engineering — Dyson’s ideas have dominated discussions of the far future, largely because he was among the very few who could project their imagination on such scales.

Even Dyson’s work on a practical spacecraft, Project Orion, which would have propelled a spacecraft by pulsed nuclear fission explosions, was visionary and unexpected. If you read Phillip F. Schewe’s biography of Dyson, Maverick Genius: The Pioneering Odyssey of Freeman Dyson, he conveys the seriousness with which this project was approached. It might have happened, and, with Dyson working on the project, had it gone forward, it might have been successful. Some designs of the Orion spacecraft would have achieved 1G acceleration and so might have been a spacecraft that could have opened up our solar system and beyond, and this with current technology. It didn’t happen, mostly for nuclear proliferation concerns, but this project demonstrates the possible achievements that could follow from unconventional approaches to problems.

Dyson’s books and papers will continue to be read, and his interviews and lectures will be listened to, and his influence will continue for the foreseeable future. Few will be able to match his imagination or his vision. So as the future unfolds, Dyson will be there in spirit to tell us that he had already visited these possibilities before the world caught up with him.