Last winter, inventor John Kanzius was already attempting one seemingly impossible feat -- building a machine to cure cancer with radio waves -- when his device inadvertently succeeded in another: He made saltwater catch fire.

TV footage of his bizarre discovery has been burning up the blogosphere ever since, drawing crackpots and Ph.D.s alike into a raging debate. Can water burn? And if so, what good can come of it?

Some people gush over the invention's potential for desalinization or cheap energy. Briny seawater, after all, sloshes over most of the planet's surface, and harnessing its heat energy could power all sorts of things. Skeptics say Kanzius's radio generator is sucking up far more energy than it's creating, making it a carnival trick at best.

For now, Kanzius is tuning out the hubbub. The retired radio- and television- station owner says the saltwater stuff is interesting, but a cancer breakthrough is what he's really after. Diagnosed with leukemia in 2002, he began building his radio-wave blaster the next year, soon after a relapse. His lifelong fascination with radio provided further inspiration.

Radio station antennas, he knew, can turn a bystander's metal eyeglasses toasty warm. If he could seed a person's cancerous cells with nanoscopic metal particles and blast them with radio waves, perhaps he could kill off the cancer while sparing healthy tissue.

The saltwater phenomenon happened by accident when an assistant was bombarding a saline-filled test tube with radio waves and bumped the tube, causing a small flash. Curious, Kanzius struck a match. "The water lit like a propane flame," he recalls.

"People said, 'It's a crock. Look for hidden electrodes in the water,' " says Penn State University materials scientist Rustum Roy, who visited the Erie, Pennsylvania, inventor in his lab in August after seeing the feat on Google Video. A demo made Roy a believer.