Research: Why a Shower Is Bracing

  • Share
  • Read Later

To alert researchers, the ordinary bathroom has long been a fount of fascinating scientific knowledge. Archimedes divined the principle of buoyancy while dunking in his tub. Modern researchers have written learned treatises on the vortex formed by water draining from a sink. Now two physicists have found that a bathroom is the perfect place to study another phenomenon: how splashing water generates atmospheric electricity.

In 1892, German Physicist Philipp Lenard wrote a paper describing how the splashing of falling water charges the surrounding air with electricity. Recently, Welsh-born Physicist Edward Pierce decided to check out Lenard's theory that each waterdrop's skin of negative ions is stripped off and discharged into the atmosphere as the drop breaks up when it hits a surface. At first, Pierce haunted waterfalls in the Yosemite Valley. Suddenly he realized that "many of Lenard's experiments could be performed in a bathroom, and have indeed been constantly operating in American bathrooms."

To test his theory, Pierce and Arthur Whitson, a co-worker at California's Stanford Research Institute, spent''four weekends in four different bathrooms. After setting up a field mill—a device that measures the electric field in the atmosphere—they turned showers on and off, flushed toilets, and opened and closed doors. Then, with complex formulas, formal scientific language and elaborate graphs, Pierce straightforwardly presented their observations at a meeting of the American Geophysical Union in Washington.

Cool Reception. According to Pierce and Whitson, the atmosphere of a bathroom is electrified whenever water is running. The charge varies from a high negative field during a shower to a barely noticeable charge when a toilet is flushed. Water that falls into an empty tub produces a higher charge than when it bubbles into a filled one. Splashing water was not the only electrical-field generator noted by the scientists. The highest charge, measured by a field mill installed in a bathroom being used by guests at a cocktail party, occurred when a cocktail waitress combed out her hip-length hair. Though the bathroom observations have no apparent practical applications, they did suggest a conclusion. "It may be," speculated Pierce, "that the bracing effect of a shower is not because you feel clean, but because you've put a negative charge in the bathroom."

"Amusing, but not entirely appropriate," huffed one scientist in the A.G.U. audience, which greeted the bathroom research with polite but restrained applause. Pierce was unruffled by the cool reception. "If I had said that these were experiments on the breakup of water and had set it up as a laboratory experiment," he said, "then it would be taken very seriously. But as a matter of fact, it works perfectly in a bathroom and that's very much cheaper."