The 11-Year Quest to Create Disappearing Colored Bubbles

Calling in the Expert

Ram Sabnis is a leader among a very small group of people who can point to a dye-chemistry Ph.D. on their wall. Only a handful of universities in the world offer one, and none are in the U.S. (Sabnis got his in Bombay). He holds dozens of patents from his work in semiconductors (dying silicon) and biotechnology (dying nucleic acids).

Sabnis wasn't the first chemist to reply to Kehoe's deliberately vague Monster.com ad. He was just the first one who didn't think that what Kehoe and his partners wanted-a water-soluble disappearing dye that could color the very thin wall of a bubble-was impossible. Sabnis told them he'd have it ready to market in a year. Like Kehoe, Sabnis doesn't seem to consider the possibility that a problem can't be solved. But even he had no idea how hard this one would turn out to be.

"This is the most difficult project I have ever worked on," Sabnis says now. "You think it's easy. Why could someone not make it? But when you actually do it, it's just impossible." For months, he ran 60 to 100 experiments a week, filling notebooks with sketches of molecules, spending weekends in the library studying surfactant chemistry, trying one class of dyes after another.

The breakthrough finally happened in an empty lab in Minneapolis on a Sunday this past February. As with Kehoe's first bubble, it arose from the slow, subtle refinement of a process over thousands of experiments. But Sabnis could re-create it. He synthesized a dye that would bond to the surfactants in a bubble to give it bright, vivid color but would also lose its color with friction, water or exposure to air-not fade, not transfer to something else, but go away completely, as though it had never been there. When one of these bubbles breaks on your hand, rub your hands together a few times and look: Poof. Magic. No more color. If the bubble breaks on your shirt or the carpet or the dog, you have two choices: Dab it with a touch of plain water to remove it immediately, or forget about it for half an hour. Either way, the color will soon be gone.