Freeman Dyson, legendary mathematician and theoretical physicist, died at the end of February, aged 96.
The New York Times remembered him as a 24-year-old genius who, while riding a Greyhound bus in Nebraska, saw that two very different, and stupefyingly recondite, ways of describing the behavior of electrons and photons (and electrons’ antimatter equivalent, positrons) were mathematically equivalent. The diagrams of Richard Feynman and the equations of Julian Schwinger and Sin-Itiro Tomonaga were in fact alternative ways of saying the same thing. The result was quantum electrodynamics, which Feynman called “the jewel of physics — our proudest possession.”
It takes an extreme capacity of mind, of both analysis and synthesis, to see that this is actually also that. An Aquinas, a da Vinci, an Einstein can do it; not many can. Dyson also could, and many believe he should have shared in the Nobel Prize that went to the three colleagues he conceptually connected.
As a graduate student in America, having been born and educated in England, Dyson landed a research fellowship at Birmingham and then a teaching position at Cornell before completing his Ph.D., so he never bothered to finish it. He spent the rest of his career at the Institute for Advanced Study at Princeton, where he went for long walks with the likes of Robert Oppenheimer and Wolfgang Pauli.
Out of those long walks emerged a string of papers and books on a wide range of subjects. But Dyson’s most prominent interest was space travel, the search for extraterrestrial intelligence, and the colonization of the solar system and beyond.
If you have come across his name in the popular press, it’s likely for the idea of the “Dyson Sphere,” a hypothetical structure a future civilization could build entirely around its sun as a generous, lasting energy source. But he did enough serious science to win the prestigious Dannie Heineman Prize for Mathematical Physics in 1965 for his work in quantum field theory, just a few years after taking a leave to work on the possibility of an interplanetary spacecraft powered by controlled nuclear explosions.
Named a fellow of the British Royal Society and a member of the American National Academy of Sciences, Dyson received the Wolf Prize in physics in 1981. His writings also ranged over philosophy, ethics, and religion, however, such that he received the Lewis Thomas Prize, awarded to scientists for artistic achievements, in 1996, and the Templeton Prize for Progress in Religion in 2000.
Indeed, the list of concepts that bear his name indicates something of the vast reach of his imagination. There is Dyson’s transform, a fundamental technique in the mathematics of additive number theory (don’t ask me); the Dyson series, a perturbative series in which each term is represented by Feynman diagrams (ditto); the Dyson tree, a hypothetical genetically-engineered plant capable of growing in a comet (!); and his last great project, Dyson’s eternal intelligence, the project by which a civilization could escape the prospect of the heat death of the universe by extending subjective time to infinity while expending only a finite amount of energy.
How would it do that? By encoding its collective mind into a machine that would slow its own functions as energy sources diminished in a gradually expanding, and thus cooling, universe. Of course.
[For the rest, please click HERE.]