His finalist year: 1973

His finalist project: Building a way to launch objects from the moon

What led to the project: Growing up as the eldest of eight children of a University of Arizona materials science professor and a biochemist-turned-homemaker in the 1960s, Joseph Demer was always designing his own experiments. For instance, he built a low-frequency radar system on the roof of his parents' Tucson house to measure the height of the ionosphere—an electrically charged layer of the atmosphere that starts about 45 miles (70 kilometers) above Earth's surface.

In 8th grade—around the time of the Apollo 11 moon landing—he got the idea to try building an electromagnetic linear accelerator (something akin to a rail gun that would use electromagnetism to accelerate projectiles to high speeds) based on the "far-fetched idea" that since lunar gravity is lower than terrestrial gravity, it might conceivably be more efficient to extract minerals from the moon and launch them into space to build space stations there than to lob such materials from Earth. Ideally, the launching machine would use electrical energy (which he figured could be produced on the moon via nuclear or solar power).

So he built the accelerator, hand-winding the magnetic coils, and did a number of experiments in his backyard to check how far he could shoot a given chunk of steel or iron. ("I began by shooting short distances inside the house, but it became clear that wasn't going to work," he says.) He refined the machine over the next four years until it shot metal almost 100 feet (30 meters), entered it in the 1973 Westinghouse Science Talent Search, and landed a finalist spot.

The effect on his career: Going to Washington, D.C., for the finalist competition was quite an adventure—"I'd never been on a commercial airplane before," he says. Then, all of a sudden, he got to ride on many of them. Due to a scheduling conflict with the Arizona State University debate championships (Demer was also active in debating, a skill possibly honed by having seven brothers and sisters), he flew to Washington, back home to Arizona to compete, then returned to D.C. over the course of a few days. Although he came in 12th in the Westinghouse competition, he won Arizona's top debating prize.

For awhile, it looked like he might pursue a career in something like communications. As a kid, he'd been an amateur radio operator, eventually earning his broadcast engineering license. So, in college at the University of Arizona, he got a job at the local NBC affiliate running the transmitter installation on a remote mountain peak outside Tucson. One of his first projects was broadcasting the Watergate hearings. He majored in electrical engineering, however, and then wound up choosing a biomechanical engineering specialty within that.

After college, he decided to earn an MD/PhD at Johns Hopkins University, where he became fascinated by the study of eye movements—"a very direct application of engineering ideas to physiology," he says. Through an internship at Baylor College of Medicine in Houston, a residency in pediatric ophthalmology at Texas Children's Hospital, and later an appointment at the University of California, Los Angeles's school of medicine, he specialized in understanding and treating strabismus—a disorder in which the eyes don't properly align. (A common symptom is when people are "cross-eyed".) Whereas most people don't even think about the fact that their two eyes naturally move in the same direction, "it isn't simple at all," Demer says—and when it doesn't happen, patients can have a lot of trouble with daily activities like studying and sports.

What he's doing now: These days, Demer splits his time between doing strabismus corrective surgery on patients and building complex biomechanical models of how the eyes work with the goal of coming up with better treatments.

Although the eyeball, being a sphere, can in theory rotate in any direction, it usually only rotates in a certain subset of these directions, in accordance with something called Listing's law, notes Demer's colleague Joel Miller, a senior scientist at Smith-Kettlewell Eye Research Institute in San Francisco. "People had been searching in vain for decades for brain circuitry that coordinated the muscles to work this way," Miller says.

But by working with data gathered from Demer's patients, Miller and Demer determined that the connective tissues and muscles around the eye functioned more like a set of pulleys to move the eye according to Listing's law, "without the brain being bothered," he says. "This discovery showed that much of what underlies normal eye movement lies in the therapeutically accessible orbit, as opposed to being hidden deep in the brain." This finding caused quite a bit of excitement in the field of ophthalmology, because treating the area around the eye is quite a bit more feasible than trying to rewire something in the brain.

Also still causing excitement for Demer? Airplanes. He has a pilot's license and owns a small craft that he uses for family trips—easier because there are only five immediate members of his family, rather than the 10 he grew up with. He flies to Arizona to visit extended family, and occasionally to places like Catalina Island off the California coast. "My family enjoys it," he says, "and you beat some of the traffic."