Murphy's lab - combatting obstacles in researching for new data

Science News, April 25, 1992 by Ivars Peterson

Not every experiment requires such extreme care. "Lots of experiments are fairly easy to do, which means Murphy doesn't get in as often," Rubin says. "But sooner or later, you're going to run into a problem. Worse, you may not even know it happened, and as you continue taking data, it never occurs to you that all the digits in the computer don't mean a thing."

Fiendishly erudite, Murphy can also call upon unfamiliar or previously unknown physical effects to do his bidding.

Normally, researchers can assume that immersing a sample in a boiling liquid means that both sample and liquid will stay at the same temperature. So long as it remains in the liquid, there's no way the sample can be at a higher temperature.

But that's exactly what MIT researchers were astonished to find several years ago when they placed a sample in a liquid-helium bath. Surrounded by a hefty magnetic field, the sample's temperature rose as high as 6 kelvins above helium's boiling point of 4.2 kelvins.

"It took a lot of effort to figure out what was going on," Rubin says.

Bubbles form naturally within liquid helium and generally rise to the surface. However, the applied magnetic field exerted a greater force on gaseous helium than on the liquid. As a result, bubbles tended to collect at the magnetic field's center, where the sample was placed. Because a gas conducts heat less readily than a liquid, the gas layer trapped around the sample acted as an insulator and the sample's temperature rose.

"Conditions had to be special to create this particular problem. It took a very high magnetic field," Rubin says.

"Murphy found the loophole," he notes with grudging admiration. "Now there's a genius."

Researchers are constantly battling Murphy. Whether measured in megamurphies for colossal blunders or mere nanomurphies for everyday annoyances, such glitches remain a fact of life in experimental science.

"It amazes me that science copes with it as well as it does," Kristian says. "I'm surprised people don't get stung more often, particularly in difficult experiments. That speaks very well for the way people really do science."

Indeed, Murphy serves as a persistent prod, constantly pushing scientific research and technological development to new levels in efforts to overcome the obstacles he tosses in their way.