For millennia, scientists have puzzled over the reason why rubbing two insulators together can produce static cling — and you may be shocked to hear that the standard explanation is wrong.

Static electricity, also known as contact electrification, is "one of the oldest areas of scientific study," researchers from Northwestern University observe in their paper on the subject, published online today by the journal Science. Questions about the phenomenon's cause date back to around 600 B.C., when Thales of Miletus conducted experiments with amber charging against wool.

The traditional view was that electrons were transferred from the surface of one material to another — for example, from a plastic balloon to the strands of hair on a child's head. That would cause one material to carry a slight positive charge while the other material carried a slight negative charge. Because opposites attract, the hair would be drawn toward the balloon, resulting in that cute "bad hair day" look.

To test that explanation, the Northwestern team took an ultra-close look at the static-charged surfaces of plastic material as well as silicon and aluminum, using Kelvin force microscopy. What they found was different from what they expected. The surfaces were actually "mosaics" of electrically charged nanoscale regions, alternating between positive and negative charges. When the surfaces were rubbed together, tiny patches were transferred from one surface to the other.

"It's not just transfer of electrons when two pieces of material come together," principal study author Bartosz Grzybowski, a chemistry professor at Northwestern, told Science in a video clip. "It's about transfer of material that then mediates the buildup of charge."

When those nano-bits of material are torn away from the surfaces as a result of the rubbing, that breaks chemical bonds and leads to changes in the net electric charge of each material. So when you rub a plastic balloon on a child's head, tiny flecks of that balloon are actually being rubbed onto the little one's locks of hair.

"A picture that emerges is that contact electrification is a complex process involving a combination of, at least, bond cleavage, chemical changes and material transfer occurring within distinct patches of nanoscopic dimensions," the researchers write. "The exact relationship between these effects — and possibly also those due to the presence of surface water and local electric fields — remains unclear but prompts several intriguing questions for future research."

Grzybowski and his colleagues point out that contact electrification isn't just a parlor trick: Through the ages, the phenomenon has sparked technologies ranging from photocopying and laser printing to do-it-yourself biodiesel and spray painting. Grzybowski said his research group was already trying to apply what they've learned to come up with better ways to apply coatings to surfaces. So it's nice to know that even after 2,600 years of study, our view of contact electrification isn't ... heh, heh ... static.

More about electricity:

• Power beamed through the air
• Static buildup may explain Martian mystery
• Avoid getting burned at the pump — literally!

In addition to Grzybowski, the authors of "The Mosaic of Surface Charge in Contact Electrification" include H.T. Baytekin, A.Z. Patashinski, M. Branicki, B. Baytekin and S. Soh. For more about the research, check out this report from the Nobel Intent blog.

You can connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. Also, give a look to "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Brian Snyder / Reuters

Tiger Woods hits his tee shot on the third hole during final round play in the 2010 Masters golf tournament at the Augusta National Golf Club in Augusta, Ga., on April 11, 2010.

Back in the noughties, Tiger Woods, dressed in a red shirt, hoisted a trophy on the 18^th green on almost every Sunday that he started out with at least a share of the lead. Science is helping explain how the red shirt helped him — and why it won't do much for the golfer now.

"It made him feel more confident and powerful and made others shrink in fear of this alpha male among us," Andrew Elliot, a professor of psychology at the University of Rochester, told me Tuesday.

We were talking about a new study in the journal Emotion where Elliot and colleagues find that our reactions immediately become faster and more forceful when we see red.

The conclusion stems from data showing that students more quickly and strongly pinched a metal clasp or squeezed a handgrip after reading red, gray and blue numbers and words that were controlled for lightness and saturation.

In a sense, the research documents our intuitive reaction to red. "It's a danger cue. So your body reacts as if it has just seen a threat. What happens when your body sees a threat is it immediately, automatically, mobilizes energy to flee or fight," Elliot said.

This reaction, the researchers speculate, is an evolved response. In great apes, for example, the alpha males are red in color. Other apes see the alpha males as a threat and thus keep their distance. Humans haven't lost this tendency, he explained.

So, what's this have to do with golf and other sports? The current research, Elliot noted, indicates that "seeing red immediately and very quickly in a short time period does make you stronger. But I don't think it lasts. It is a very quick response."

At the most, the effect might help with something such as weightlifting where a brief burst of strength and speed is needed. Otherwise, the effect of red, which the research shows is real, is likely more in the head when it comes to sports.

In previous research, Elliot and colleagues have shown that seeing red on an opponent makes you think the opponent is more dominant and stronger and so you think the opponent is going to do better than you. They have also shown that wearing red makes you feel more dominant.

"In both ways, viewing it on others and thinking that you are wearing it yourself, red is a dominance and power cue that makes you feel that you are stronger and are going to do better in these physical contests," he said.

On Sundays in the noughties, a dominant Tiger Woods put on his red shirt, walked onto the golf course and a handful of hours later walked off with a trophy. He knew he was powerful, and so did the other golfers. 

But a red shirt isn't magic, Elliot noted, not even for Woods, whose is experiencing the biggest slump of his career.

"If he wears red now, where he is no longer that dominant, it is probably not going to have the same effect because it is not really true, it is not an accurate signal," Elliot said.

"I think there's got to be something behind the signal that is accurate if it is going to work. Tiger is out of luck right now."

More stories on the science of colors:

• Seeking Olympic Gold? Wear red 
• Condi Rice knows – winners wear red
• Different colors describe happiness, depression
• Domestication led to horse color explosion

If you're reading this, the Rapture hasn't happened yet.

If it had happened, you might have been taken up to heaven with 200 million other members of the elect. (Or is that 144,000?) The alternative is even spookier: being left behind to face five months of tribulation leading up to the end of the world and Jesus' judgment. (Or is that seven years?)

The prediction that the end times would begin in earnest on May 21, 2011, was made years ago by Harold Camping — the preacher who heads Family Radio, a worldwide religious broadcasting concern. His prophecy is based on calculations so kooky that other end-time prophets say he's giving them a bad name. 

The real question is: Why has there been so much buzz over Saturday's scheduled Rapture?

"Obviously, what could be a bigger news story than the end of the world?" University of York historian Nicholas Guyatt, author of the book "Have a Nice Doomsday," told me. "It's absurd to think the world is going to end on Saturday, but even if there's an infinitesimally small chance that it's true, we should be interested."

One thing that sets Camping apart from most end-timers is that he sets actual dates. That runs counter to the usual Christian interpretation of the end times, which focuses on a passage in Matthew in which Jesus says "you do not know the day or the hour." It also runs counter to the lessons learned from centuries of failed doomsday predictions.

"Even among evangelists who believe in the Rapture,  most of them know we're not supposed to be trying to set dates," said Jerry Jenkins, co-author of the popular "Left Behind" apocalyptic book series.  "For one thing, it's going to make us look foolish on Sunday."

Jenkins jokingly acknowledges he's "one of those kooks who really believes it's going to happen one of these days." The 16-novel series he wrote with minister Tim LaHaye provides a fictional account of the end times, going all the way to the Second Coming. The tale is based on an interpretation of the end times known as pre-tribulation dispensationalism — which starts with some believers instantly disappearing in the Rapture while leaving others to fight it out with the Antichrist and his minions.

"It'd be a horrifying and chaotic event," Jenkins said. "I'm still a little confused whether Camping thinks that's going to happen, or whether there'll be an earthquake."

Nonsense from numbers
Jenkins and many others are also confused over how Camping came up with his prediction. This year-old posting from Church of God News runs the numbers: Saturday supposedly marks 7,000 years since the Noah's Ark flood, and 722,500 days since Jesus' crucifixion. By Camping's numerology, 722,500 represents (5 x 10 x 17) x (5 x 10 x 17), or the square of atonement times completeness times heaven. 

"Now the above is utter nonsense," the Church of God News' Bob Thiel wrote. That sounds about right.

Jenkins says such number-based predictions "happen fairly frequently" in the end-time game. "It's sort of seasonal," he said.

In fact, Camping himself predicted years ago that the world would end in 1994. When the prediction failed, Camping said he got his initial calculations wrong and corrected the figures to come up with Saturday's doomsday date.

Guyatt noted that prophets have been predicting the end times, and getting the dates wrong, for hundreds of years. One of the best-known examples in America is the "Great Disappointment" of 1844. Baptist preacher William Miller predicted that the "Second Advent" would come on Oct. 22 of that year (after a couple of abortive predictions for earlier dates). He attracted as many as 50,000 adherents by the time the big day came. Nothing happened, of course. The result? Derision, church burnings, vandalism, even tar-and-feathering. Miller continued to await the Second Advent until his death five years later.

Miller's theology contributed to the later rise of denominations such as the Seventh-Day Adventists and Jehovah's Witnesses, but those churches did away with the date-setting.

Bart Ehrman, a professor of religious studies at the University of North Carolina at Chapel Hill and author of the newly published book "Forged," notes that the scriptural foundations for modern-day end-time scenarios are shaky. "In the Apocalypse, there's no reference to the Rapture at all," he told me. "The idea of the Rapture comes from the writings of Paul." And many of the details have been "completely made up by theologians, they're not found in the Bible," he said.

Ehrman said he could come up with his own scenario for the end times that would make more sense than Camping's. "What I'm looking for is some very wealthy believer," he joked.

Ah, the money angle. "The thing that's confusing about [Camping's prediction] is that he doesn't seem to be making money off this," Jenkins said.

Funding the Apocalypse
Lots of money is being spent on promoting the Rapture, however. Family Radio's financial records indicate that the nonprofit organization had $122 million in net assets in 2007. The figures for the following year, 2008, show $41 million in expenses, resulting in net assets of $86 million. The 2009 report shows expenses of $37 million and net assets of $72 million. And judging by the billboard ads, bus ads and direct-mail campaigns promoting the Rapture, the spending rate must have risen substantially since those reports were filed. After all, if you're going to heaven on Saturday, why wouldn't you spend it all?

Ehrman noted that this sort of pre-doomsday spending spree has happened before, when he was teaching Bible classes in the 1980s. One of the books that came out back then was "88 Reasons Why the Rapture Will Be in 1988."

"I had students in my classes whose parents literally sold the farm because they didn't need it, and then it didn't happen," he recalled.

Some Family Radio listeners, such as Staten Island retiree Robert Fitzpatrick, have spent tens of thousands of dollars of their own money to promote the Rapture. That worries Jenkins. "There are very well-meaning people who are telling me they're getting rid of their life savings," he said. "I wonder who's going to take care of them when it's all over?"

Gerry Broome / AP file

Allison Warden shows off her car, emblazoned with messages about Saturday's scheduled Rapture. Warden, of Raleigh, N.C., has been helping organize a pre-Rapture campaign using billboards, postcards and other media in cities across the U.S.

The big spending spree is one big reason why this particular date has gotten so much traction. But end-time tales do not live by billboard ads alone. Guyatt says this time in history is particularly well-suited for doomsayers.

"Whenever anything really bad happens, it kind of gives their case a little support," Guyatt said. "So if you think of the turbulent times we've had over the past decade — 9/11, Iraq and Afghanistan — it kind of feeds on that. Maybe it's not formal, but we have an affinity with the view that the world is becoming a more dangerous place, or maybe our days are numbered."

And every Twitter tweet, Facebook update, Rapture party invitation — for that matter, every blog post — turns up the wattage ever so slightly on the doomsday spotlight. "What's given this traction is the billboards and the media," Guyatt said. "At some point the ball is rolling, and we help tip it a bit further, because of you, because of us."

How imminent is 'imminent'?
Leave it to the veteran end-timers, who have been through all this before, to provide perspective. "I applaud the discussion," Jenkins said. "I think people should be thinking about this."

Jenkins' writing partner, Tim LaHaye, has said on many occasions that events such as the Japan earthquake and tsunami are signaling that the end is near. The way Jenkins sees it, the end of the world could well be imminent, but "our definition of 'imminent' is clearly not the same as God's."

"If he waits one more day in his mercy, it could be a thousand years in our time," he said.

So what will Jenkins be doing on Saturday?

"We're just going to carry on with the usual activities," he told me. "One of our granddaughters is going to have a ballgame."

More about the Rapture rumblings:

• Rapture prophet says he'll be watching the action on TV
• Digital Life: Post-rapture video reveals stunning lack of zombies
• The Last Word: Only hours to go until the (fake) Rapture
• End of Days? Believers enter the final stretch
• End of the world? How about a party instead?
• Slate: 144 scenarios for America's apocalypse
• Pet sitting offered during Rapture
• Doomsday facts (or fictions)

In some parts of the world, it's already Saturday. I'll be blogging about the Rapture hype over the weekend, and you can follow the updates by checking CosmicLog.com/Rapture. You can also connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. And for something completely different, check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Rothamsted Research

Disrupting a mosquito's sense of smell can ward off a bug bite.

Researchers say that they’ve found a new class of chemicals that can drive away mosquitoes by disrupting their odor-sensing system — and the first chemical in that class seems to be thousands of times more effective than DEET.

The compound, called VUAA1, was identified thanks to the kind of high-throughput screening process that is more typically used for drug discovery, said Vanderbilt University professor Laurence Zwiebel, a member of the research team. Zwiebel and his colleagues published their findings online this week in the Proceedings of the National Academy of Sciences.

"This compound is really a first-in-class molecule to do this action," Zwiebel told me today.

A mosquito's olfactory system relies on a variety of receptors spread out on the bug's antennae — known odorant receptors, or ORs. The receptors are tuned to respond to different types of odors, including the smell of sweat and blood, and they activate switches called OR co-receptors (Orcos) to tell the mosquito's brain which scent is being picked up.

Researchers screened almost 120,000 small-molecule compounds to check their effects on human embryonic kidney cells that were genetically engineered to include the OR-Orco complexes.  "It was totally a shotgun approach," Zwiebel said. "Throw the kitchen sink at it and see what happens."

The scientists were surprised to find that VUAA1 consistently activated the odor-sensing complexes, even though it's not actually considered an odorant. "It wasn't something we set out to find. It was an anomaly in our tests," another member of the Vanderbilt team, graduate student David Rinker, said in a news release.

"If a compound like VUAA1 can activate every mosquito odorant receptor at once, then it could overwhelm the insect's sense of smell, creating a repellent effect akin to stepping onto an elevator with someone wearing too much perfume, except this would be far worse for the mosquito," said Patrick Jones, a postdoctoral fellow at Vanderbilt who is the study's first author. 

Zwiebel said that he and his colleagues compared the effectiveness of VUAA1 with that of the widely used DEET insect repellant by measuring how much of each compound it took to repel larval mosquitoes in a petri dish. "The more you use, the more the mosquito moves, as if it's trying to get out of Dodge," he explained. A tiny amount of VUAA1 had the same repellent effect as a concentration of DEET that was tens of thousands of times stronger, Zwiebel said.

However, Zwiebel stressed that VUAA1 isn't yet ready for prime time. "The commercialization of this compound has hardly begun," he said. The chemical still has to be fine-tuned and checked for toxicity, and it's possible that other chemicals in the same class will turn out to be more effective or safer. Vanderbilt University says it has filed for a patent on this class of chemicals and is talking with potential corporate licensees about commercialization, with special focus on the development of products to reduce the spread of malaria in the developing world.

Zwiebel noted that VUAA1 has been found to activate the odor-sensing complexes of flies, moths and ants as well. "Basically, every insect that has an olfactory system has this Orco ion channel," he told me. "We have an expectation that every insect will be affected by this molecule. Now, that's both good and bad."

It's good, because the new class of chemicals may yield new ways to drive away other types of nuisance insects and agricultural pests. But it'd be bad if they also drove away beneficial bugs such as bees and butterflies.

"We've all read 'Silent Spring,'" Zwiebel said. "We don't want to have the same DDT story."

More about mosquitoes:

• Scientists tweak mosquito genes to fight malaria
• A malaria mosquito is quickly becoming two species
• Scientists find natural mosquito repellent
• Researchers studying better insect repellents
• U.N.: Efforts on track to halt malaria deaths

In addition to Jones, Rinker and Zwiebel, authors of "Functional Agonism of Insect Odorant Receptor Ion Channels" include Gregory M. Pask. VUAA1 stands for Vanderbilt University Allosteric Agonist 1. The research was supported by the Grand Challenges in Global Health Initiative, funded by the Foundation for the NIH through a grant from the Bill & Melinda Gates Foundation.

Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," Alan's book about the controversial dwarf planet and the search for new worlds.