IN 2002, LISI SUCCUMBED to island fever and relocated to Breckenridge, Colorado, where he taught snowboarding. He rode an extra-long carving board and was known for bombing down slopes in a lab coat. Because he tends to think most clearly early in the day, which also happens to be when conditions are best for surfing and snowboarding, Lisi typically alternates mornings between recreation and work—the former a head-clearing jaunt that enables him to dive happily into the latter. It was in the shadow of the mountains that he began making progress on unifying gravity with the Standard Model, the collective name for the three subatomic forces and their interactions with matter.

Lisi's first significant insight came from an obscure formulation of gravity he found in a paper by Lee Smolin. Instead of viewing gravity, as Einstein had, in terms of how matter disrupts space-time (the frequent analogy is a bowling ball on a trampoline), Smolin and two colleagues had revived an unusual description involving the connection between moving shapes. That's the kind of gravity a snowboarder can get behind. And by looking at it in this way, Lisi was able to combine gravity and the Standard Model into a crude geometric structure. "But," he says, "I didn't know what the heck it was."

Restless again, Lisi decided to head back to Maui in 2004, in true drifter style. Before leaving, he bought a white utility van, tore out the seats, and outfitted it with a sleeping platform, 12-volt shower pump, sink, stove, and surfboard storage. Around the same time, he started dating Crystal Bara­nyk, an artist he'd met online. "We were just starting to get to know one another," recalls Baranyk, who's been with Lisi for four years now. "He said, ‘Do you want to go live in a van?' And I said, ‘I guess I'll know if our relationship will work out, so better now than later.' " They shipped the van to Maui and lived wherever the surf took them.

In Maui, Lisi continued to explore the questions his Breckenridge insight had raised. But physics theories don't buy food, so he and Baranyk scraped together a piecemeal income. Lisi worked as a script consultant for a Hollywood sci-fi movie—still in development—involving spaceships with fusion drives. Von Wolfsheild hired him to create probability tables that predict payout rates for Las Vegas poker machines. Baranyk sold paintings and worked as a hiking guide. Lisi also took a job teaching introductory physics at a branch of the University of Hawaii.

Through it all, he stayed busy piling up adventures, many of which he gleefully chronicled on his Web site, sifter.org/~aglisi: kitesurfing on a skateboard; scaring off car strippers trying to steal parts from his van; hiding from park rangers looking to evict him and Baranyk; snapping his surfboard while diving through triple-overhead swells and getting swept so far down the coast he had to hitchhike back, his face bloodied. One of his most enthusiastic posts is about getting his ass kicked in chess by a naked man on a life-size board, during one of his frequent visits to Burning Man.

"I've tried to make the rest of my life good enough that even if the physics theories don't work out," he says, "it wasn't a waste of time."