EVEN TO A NONSCIENTIFIC OBSERVER LIKE ME, there are several obvious peculiarities about the life and work of Garrett Lisi. For instance, despite his being 40 years old and possessing a Ph.D. in theoretical physics, he has held few steady jobs—and those the likes of hiking guide and snowboarding instructor. An adventurer who's happiest when he's sliding down snow or waves, Lisi routinely follows a morning of surfing or boarding with an afternoon spent hunched at his laptop, puzzling over high-level mathematics. And he does it while leading a rootless, ascetic existence, sleeping on couches, house-sitting, or living in a van parked at Maui surf breaks.

Most peculiar of all, though, is that he's sitting in the dining room of his latest borrowed home, overlooking Lake Tahoe, explaining to me that he is not the next Albert Einstein. Only the most arrogant or deluded person would mention himself alongside the frizzy-haired former patent clerk. But Lisi appears to be neither. He seems "very sane," says John Baez, a mathematician at the University of California at Riverside. "Which is not exactly universal in people who are trying to crack the mysteries of physics."

A few weeks ago, Lisi posted an academic paper called "An Exceptionally Simple Theory of Everything" to arxiv.org, a site for scientists that's maintained by Cornell University. The paper outlined his attempt at a theory that would lay out the physics of the universe in one tidy package. For half a century, researchers have sought to reconcile gravity with the three forces that operate inside atoms, where gravity seems to hold no sway. No one—not even Einstein, who spent the later years of his life trying—has been able to explain how these four forces can coexist.

To understand fully Lisi's own stab at the problem requires a grasp of mathematics far beyond all but a handful of people, but the basic premise is that all physical forces and particles can be explained by mapping them onto an incredibly complex geometrical structure known as E₈. If Lisi is right, his theory would give an elegant shape to the physics of the cosmos, and E₈ would become as significant as E=MC². This would be a remarkable feat coming from any of the most accomplished physicists alive. Coming from a surf bum, it would be beyond extraordinary.

Lisi began presenting his theory at conferences last year, and many well-regarded physicists found it interesting, even plausible. So he posted the paper, hoping for feedback. And with that, he set off a rogue wave of hype and backlash that he's having a hard time riding. SURFER DUDE STUNS PHYSICISTS WITH THEORY OF EVERYTHING, thundered London's Telegraph. Discover magazine asked, COULD THE NEXT EINSTEIN BE A SURFER DUDE?

More than a few physicists, meanwhile, took to blogs to trash his idea. "A huge joke," one called it. "Nonsense," said another. Some reached for the ultimate scientific insult: "crackpot." More thorough critics argued that the E₈ model wouldn't be able to accommodate all the universe's particles.

Though Lisi has detractors, he also has his fans, those who like the idea that it's still possible for a maverick physics genius to exist. "I and other people think the academic world suffers from not being more inclusive of people of this kind," says Lee Smolin, a highly regarded researcher at the Waterloo, Canada–based Perimeter Institute for Theoretical Physics, who has corre­sponded with Lisi. "We're not talking about a crackpot. He has a Ph.D. from a good graduate program, and his work is well within the bounds of good research."

The furor is still raging in November 2007, when I meet Lisi in Tahoe. He greets me in a pair of fluffy bear-paw slippers and has a slightly top-heavy surfer's physique, with wide shoulders and a thick neck. Having recently started shaving his head of its receding blond hair, he has a tendency to rub his scalp idly when he's thinking. And he's had a lot to ponder lately.

Lisi knows that by even addressing the Einstein comparison he risks coming off as a lunatic, but too many people have reached for the E-word for him to ignore it totally. "Yeah, I am a guy working on physics outside of academia," he says, shuffling his bear paws on the Pergo floor. "But I'm nowhere near Einstein's caliber. Certainly in terms of what I've accomplished, and also because this theory might be wrong. It's not a justified comparison."

There's nothing unusual about Lisi suggesting that he might be off target. Only one grand theoretical picture of reality can be correct, after all—both mathematically consistent and experimentally validated against the real world. All the rest are just scribblings on paper. What is truly peculiar is that this scientist hobo, a man who abandoned the security of academia to take his chances as a physics nomad, has any shot at all at being right.