More than 400 years ago, one of Leonardo da Vinci's greatest works disappeared from view. An Emory physicist may finally get a chance to answer this centuries-old art mystery.

Ray DuVarney is a man of many interests.

The chair of the Emory University physics department, he teaches courses in astronomy and electronics and designs special cameras for telescopes and microscopes. He plays bluegrass and show tunes on the bass in the Physics Department Washtub Band and hymns on the keyboard at St. Stephen the Martyr Church in Lilburn every Sunday. He likes to putter with model trains, planes and cars.

Art, you will note, is not on that list. In fact, the affable, 67-year-old Massachusetts native cheerfully allows that in that regard, his wife considers him a philistine. Yet DuVarney just might play a crucial role in recovering a Leonardo da Vinci mural no one has seen in 400 years. He thinks he can build a machine that would use nuclear energy to locate "The Battle of Anghiari," thought to be hidden behind a wall in Florence's Palazzo Vecchio.

Call his idea a da Vinci decoder.

There is an army of ifs at play here. If he can test his idea, if it works, and if the mural still exists, the scientist could enter the annals of art history as a participant in what one enthusiast calls "the greatest art discovery in modern times."

The idea alone has added new dimensions to DuVarney's life. It has pulled him into the orbit of art gumshoe Maurizio Seracini, who has been trying to find the da Vinci mural for 32 years, and British philanthropist Loel Guinness, whose foundation, the Kalpa Group, may fund the project. It has introduced him to the worlds of art history and painting conservation, and the mysteries of Italian bureaucracy.

How did this happen? Credit an utterly unscientific equation: Creativity + serendipity = being the right person in the right place at the right time.

A fondness for 'building stuff'

Ray DuVarney is not the kind of academic who remains aloft in his ivory tower. He spends Saturdays, for instance, down in the basement of his Lilburn home, where locomotives snake through a tiny town, train yard and pastoral countryside along 360 feet of track. As he modestly puts it, DuVarney likes "building stuff." He is the mechanic among the group of fellow hobbyists who have spent 10 years and counting working on this miniature railroad. A tiny camera on the engine, which sends an engineer's-eye-view of the ride to a nearby laptop monitor, is the latest of his bells and whistles, which also include a digital switching system he designed and installed well before such technology became available commercially.

The physicist also builds "stuff" in his professional life.

"Ray has always been a fantastic experimentalist," says Charlie Bleau, CEO of SciMeasure, the scientific-instrument company DuVarney founded. "He's always been able to solve problems. First, he designed instruments for his own research. In the last 20-25 years, he has designed instruments for biology and astronomy."

He is, to put a fine point on it, an electronics wiz. The Wavefront Sensor Camera he developed through a NASA grant, which eliminates the distortions caused by atmospheric turbulence, serves observatories around the world. Computer science majors attend his electronics course for scientists, their only academic opportunity to learn how to build a computer.

In fact, it was a seminar on solid state devices for physics and astronomy held in Italy in the summer of 2005 that brought Leonardo into DuVarney's life. He chanced to attend a lecture at his hotel by Maurizio Seracini, a Florentine whose company Editech does high-tech research for museums and conservators. The bioengineer spoke about his quest to locate the long-lost mural "The Battle of Anghiari," conceived for what can only be termed the Art Super Bowl of 1504.

To celebrate its new status as a republic, the government of Florence commissioned Leonardo and Michelangelo, the acknowledged titans of the day, to execute murals in its town hall. The duo's undertaking attracted artists and scholars from all over Europe, who came to see the works in progress.

Writers of the day marveled at the naturalism of da Vinci's central image, a scrum of equestrian soldiers in a pinwheel of energy, which captured the fury of battle, not to mention the anatomy of horses, as no other before it. But the famously commitment-phobic artist never completed his mural. (For that matter, Michelangelo left his undone, too.) In 1563, the artist Giorgio Vasari painted his own fresco in the same spot.

Here, the mystery starts. Did Vasari destroy "The Battle of Anghiari" when he created his mural? Or did he build another blank wall in front of it first? And if he did, has the hidden mural survived the centuries, given Leonardo's notoriously ruinous experiments with paint?

These questions have tantalized Seracini ever since he first participated in a search for the mural in 1975. He has pursued his quest sporadically, dependent on patronage and stymied by the Florentine Ministry of Culture's practice of giving and rescinding permission to work in the hall. The project was on hiatus when Loel Guinness came to his rescue in 2000.

The brewing company heir, who spends most of the year in Phuket, Thailand, takes a very personal approach to his philanthropy. He has supported such disparate projects as mountain-climbing expeditions and multipronged efforts to study and preserve an obscure pre-Buddhist Tibetan religion called Bon. Guinness was impressed with Seracini's creativity in adapting medical devices for use in art research. He decided to fund a number of the engineer's research efforts under the banner of "The Leonardo Project."

Seracini made progress. He studied the architecture of the hall to pinpoint the mural's location. Using radar and thermography, he located what he believes to be a crevice behind the Vasari painting, which might indicate the existence of another wall. But in 2002, Florentine officials halted the project without explanation. Seracini, it turned out, was stuck anyway, as DuVarney would learn during the lecture a few years later.

"Seracini mentioned that he had run into a wall, literally," DuVarney recalls. "He couldn't drill a hole or take out a brick. He asked if anyone knew of a non-destructive way to see through a wall. Nobody did. In fact, I didn't either at that moment. That evening I was sitting around thinking about it, and I came up with an idea."

Nature of neutrons

DuVarney's idea starts with the behavior of neutrons. When these particles hit heavy metals, they are absorbed and quickly give off high-energy X-rays called gamma rays, a particular amount for each metal. Pigments used in paint of that era contained heavy metals. DuVarney thought it might be possible to design a camera that would project a neutron beam through the wall of the Palazzo Vecchio. By counting and measuring the wavelengths of the returning gamma rays, he could plot an image of what was behind the wall.

The physicist ran into Seracini the next day and broached his idea, which he expanded on in a flurry of e-mails upon his return to Emory. Seracini loved it.

"I thought it was simply the best idea I had heard," says Seracini, in a phone interview from the University of California, San Diego, where he is director of the newly formed Center for Interdisciplinary Science for Art, Architecture and Archaeology. "It had a scientific grounding. It seemed the solution."

DuVarney quickly assembled an interdisciplinary team — fellow Emory physicists John Malko and P.V. Rao, business colleague Charlie Bleau, Carlos Art Museum conservator Renée Stein — and presented his idea.

"They all thought it might work," he says. "Of course, scientists are never 100 percent sure of anything. We don't know it's going to work until it works."

A few months later, DuVarney sent Seracini a proposal that suggested building a small test machine in the Emory physics department's machine shop and testing it on a mock-up of the wall in the Palazzo Vecchio. The cost: $50,000. Seracini took the proposal to Guinness' Kalpa Group, which contacted him in December. The foundation was interested, but didn't want to proceed until the Florence government approved the mission.

Then nothing — from anyone — for a year.

In late December, Florentine officials suddenly announced the search could resume. An elated Seracini reiterated his interest in the da Vinci decoder in January.

"I would be most pleased and honoured to work with Prof. DuVarney," he wrote in an e-mail. "I believe the project could bring international exposure to Emory University and to the city of Atlanta. I would like to mention that the Leonardo mural painting was considered by Leonardo's contemporaries the greatest masterpiece of the Renaissance. Even if we were to find just traces of it, it would be the greatest art discovery in modern times."

Seracini says the ministry is in the process of forming a panel of experts to oversee the project, who will then ask him for a proposal. He can't say exactly how soon that might happen.

"It's Italian time," he said, with the telephone equivalent of a resigned shrug.

Whatever the outcome, DuVarney has enjoyed the journey so far.

"I've learned a lot about art," he says, ensconced in his cluttered, book-lined office — which includes an unread copy of "The Da Vinci Code."

More importantly, he says, it is already benefiting the students. This semester, the departments of art history and physics inaugurated a course called "Investigating Art With Physics." The class is full.

By CATHERINE FOX, The Atlanta Journal-Constitution