OVEREXCITED IMAGINATIONS SOMETIMES SUPERSEDE THE SCIENTIFIC FACTS

by Keay Davidson

Now you see them, now you don't: subatomic "particles" and "forces" that mysteriously appear in scientific experiments, then disappear.

The frequent reason: they never existed in the first place. Like sightings of spooks, UFOs, and the Loch Ness monster, they're often the product of a bright but overexcited physicist's imagination.

Physicists have been embarrassed many times before, but this summer has brought a bumper crop of challenges to purported scientific "discoveries." [Recently], scientists have questioned earlier reports of:

• The "discovery" of the 118th element in the periodic table. In 1999, scientists at Lawrence Berkeley National Laboratory claimed they had generated the element and its decay product, Element 116, using the lab's 88-inch cyclotron.

Oops! [In July], Berkeley scientists admitted they had misinterpreted their observations: The "superheavy" element wasn't there after all. Lab officials have launched an investigation to figure out what went wrong.

• A possible detection of the "Higgs boson," the hypothetical particle that supposedly gives objects mass. Last October, researchers at the high-energy physics lab CERN in Geneva reported possible evidence for the particle.

Whoa! Subsequent analyses of data have largely undermined the report, CERN scientists acknowledged.

• The discovery of intense energy emissions from the isotope hafnium-178. The isotope contains so much energy that it's the equivalent of a 10-ton bomb shrunk to the size of a golf ball, claims a scientific team led by physicist Carl B. Collins of the University of Texas at Dallas.

But hold on! On August 13, Lawrence Livermore National Laboratory and other Energy Department labs announced they had been unable to replicate the Texas team's claim. Both teams are now fighting over their different interpretations of the data.

The moral of the story: in physics as in everyday life, reality may be in the eye of the beholder.
"It's a question of: when does a science community step over this line from nonbelief to belief? It's a very fuzzy line, and it differs from one scientific community to another," says Michael Riordan, a physics historian at Stanford University and author of several books on the history of modern physics.

The most famous modern case of a now-you-see-it, now-you-don't "discovery" is "cold fusion."

In 1989, Utah scientists reported detecting nuclear energy emitted by a simple laboratory gadget. If valid, their observations could have transformed modern technology.

However, other scientists' follow-up experiments undermined their claims. (A tiny band of diehard researchers continues to take cold fusion seriously.)

Many other scientific "discoveries" of yesteryear have vanished into history. Where, oh where are they now: the "heavy" neutrino, the "zeta" particle, the "split A2" effect, and "N rays"? They have joined unicorns, mermaids, and leprechauns in the dump site of discarded "breakthroughs."

So have reported sightings of the "magnetic monopole," "gravity waves," "fractional quarks," and "axions."

Mind you, that doesn't mean such phenomena don't exist, somewhere in the cosmos. For example, the existence of magnetic monopoles and axions is predicted by some respected physical theories. And physicists would be downright startled if they don't eventually discover gravity waves, whose existence is implied by Albert Einstein's equations. The only catch is, they haven't been spotted yet.

Or have they? A few decades ago, respected physicist Joseph Weber claimed he had detected gravity waves using his laboratory equipment. Nowadays, most physicists think Weber (who died in 1999) misinterpreted his observations.

Weber was a "brilliant guy," observes Nobel Prize-winning physicist Martin Perl of Stanford Linear Accelerator Center (SLAC). "One of the things that gets guys like Joe is obsession. . . . They just don't want to believe they've made a mistake. They tend to operate alone, with a very loyal group of graduate students, so they do get somewhat isolated."

Physicists are human, and it's only natural for humans to get excited when they think they might be on the brink of a great discovery. In such cases, their excitement may cloud their judgment.
"When the effect might be something you've wanted to see for years," says SLAC physicist Helen Quinn, "it is natural to get excited at even a shadow of a chance that it has been found, even when knowing full well that few such shadows materialize into real effects, and most vanish as the data samples grow."

A celebrated case occurred a century ago. French researchers reported a new form of radiation, which they dubbed "N-rays" after Nancy, France, home of N- ray champion RenŽ Blondlot, a respected physicist. The next year, the American physicist Robert W. Wood visited Blondlot's lab and mischievously removed a crucial prism from the Frenchman's instrument. Yet Blondlot, unaware of what Wood had done, continued to describe seeing the N-rays with the device.

Conclusion: Blondlot had been imagining things, just like those astronomers who reported seeing "canals" on Mars.

Of course, one shouldn't give the skeptics too much credit: Occasionally they're the ones who are wrong.

For example, in the early 20th century, a few noted physicists, including American Physical Society President Dayton C. Miller, published papers reporting serious flaws in Albert Einstein's theory of relativity. Yet Einstein triumphed in the long run.

Likewise, Collins is convinced that history will vindicate his team's report of excess energy from hafnium-178. If he's right, then the discovery may have at least one possible practical application. Because the energy is emitted purely in the form of electromagnetic radiation, it may give anti-terrorist teams a way to flash-sterilize sites contaminated by biological warfare agents. Intrigued, the U.S. Air Force is funding his research.

In cases like Collins', where different teams of qualified scientists reach wildly different conclusions, scientific decorum can give way to personal sniping. Collins accuses the Energy Department scientists of misdesigning their experimental test.

"Glib guys like (Livermore team leader John H.) Becker will tell you (our findings are) contrary to the laws of physics," Collins said. "But they're completely wrong. I'm an experimentalist, and it works."

Becker calls the dispute with Collins' team "a neighbor-to-neighbor squabble . . . a very dicey area."

In physics labs, a major bugaboo is "systematic errors"-numerous ways in which Mother Nature can fool scientists into thinking they've hit the scientific jackpot. They include glitchy instruments, software bugs, faulty statistical techniques, and electronic contamination from other gadgets.

But the worst form of "systematic error" is the human imagination. Scientists have to fight the semiconscious urge to tinker with their instruments in order to better "see" particles that they're convinced, in their hearts, really do exist.

A physicist eager to make a sensational discovery may "start looking at the data and will say, 'Gee, I think I do see a few (mysterious) particles . . . and I can get that (percentage of mysterious particles) to be a higher percentage if I throw out certain measurements,'" Perl explains.

"And so you start throwing out certain measurements," Perl says. "It's a partly unconscious (process, but) it's not completely unconscious."

Michael Witherell, head of Fermi National Accelerator Laboratory near Chicago, says: "One of the first things I did with every graduate student who worked with me is to convince them how difficult it was to keep oneself from unconscious bias."

Some scientists blame the media for overreacting to reported discoveries. It's hard for science to function efficiently when the whole world is breathing down physicists' necks, they complain.

Contrary to public impression, scientists at CERN never claimed to have discovered Higgs particles-only to have uncovered possible signs of their existence, says a top CERN scientist, Tiziano Camporesi, formerly of SLAC.

"The illusion of discovery has been created by the media frenzy around our preliminary evidence," Camporesi complained in an e-mail to the [San Francisco] Chronicle. "I was caught in the middle of it . . . and rather unwillingly . . . but I could not refuse answers to the tens of journalists who were calling, as I am the head of one of the four experiments at the (CERN) accelerator."

Why all the excitement over a hypothetical subatomic particle that no one expects to cure cancer or diminish the national debt?

"The reason for the media frenzy, in my opinion, was that the Higgs boson has been nicknamed 'God's particle' by (Nobel Prize-winning physicist) Leon Lederman," Camporesi said. "Headlines like 'God's particle discovered?' have been a bonanza for news agencies!"

Camporesi offers a moral to this long, sad story of soured "discoveries": "If you want a recipe for minimizing 'illusions,' here it is: Do not trust scientific evidence portrayed in daily newspapers. Wait for the final publications in scientific reviews."

#

Keay Davidson is a science writer for the San Francisco Chronicle.

"Red Faces: Sometimes, Scientists' Overexcited Imaginations Supersede the Facts," August 27, 2001, San Francisco Chronicle. copyright 2001 San Francisco Chronicle.