Field of Science


Reasons for Short People to Gloat

So there I was, living my life, happily assuming that kooky physics notions (black holes, extra dimensions, everything made of strings) were not affecting my ordinary, three-dimensional existence. And then I read this headline: "Superaccurate Clocks Confirm Your Hair Is Aging Faster Than Your Toenails." Thanks for shattering my dreams, physics.

Really, I should be thanking Einstein and his theory of relativity. One of his ideas was that gravity affects time the same way it affects people: the closer you are to a gravitational force, the stronger it is. This is why you weigh a tiny bit less at the top of a mountain--Earth's gravity is pulling you down just a little less strongly. Time, like your body, is a little more weighed down closer to Earth. So the watch you're wearing will run a smidge slower once you come back down that mountain.

("But why?" I asked my physics-major sister. In response, she told me a bewildering story about Usain Bolt sprinting through a barn while carrying a giant pole. "I wouldn't worry about it in your day-to-day life," she reassured me.)

Einstein didn't have the equipment to test his outlandish ideas, but nowadays we do. Researchers at the National Institute of Standards and Technology (these are the people who keep the official time for the United States, among other things) used a new, hyper-accurate atomic clock to demonstrate time moving faster with an elevation increase of less than a meter.

You can also see relativity in action when one clock is in motion and the other one is at rest. (The key is any kind of difference in acceleration--gravity is a downward acceleration, but a non-downward motion works too.) With their extremely sensitive clocks, these researchers showed that even a pretty slow movement--"like the speed of you sitting on a swing, slowly swinging"--caused time to slow down.

This isn't the first time that relativity's creepy time warp has been demonstrated in real life. But in the past, most of the demonstrations have required huge differences in elevation or extreme speeds.

Your feet, then, are experiencing time at a slower pace than your head. But this difference is unbelievably small. And for practical purposes, your head is actually living--ready?--in the past.

So says neuroscientist David Eagleman. To see what he means, imagine stepping on a pebble. After the pebble touches your toe, the signal has to travel all the way up the nerves in your leg to your spinal cord, and from there to your brain. This is a fast trip, to be sure, but it's not instantaneous. It can take about a tenth of a second. Meanwhile, other information such as sights and sounds--or touches closer to your head--are arriving in the brain much more quickly.

If your brain were to process all this sensory information on a first-come, first-served basis, your world would be in total disarray. You'd see yourself stepping on the pebble before you felt it. To smooth everything out, Eagleman proposes, your brain puts a tiny delay on the moment you perceive as "now." He compares this to live TV: The show is actually on a small lag, in case, for example, someone swears and needs to be bleeped out. Since your brain has to wait for information from your farthest extremities to arrive before it assembles each moment in time, what you perceive as "now" actually happened a tiny bit in the past.

Experiments have confirmed that when people are touched on their toe and their nose simultaneously, they perceive the two events as simultaneous. That tenth of a second delay gets erased in the brain's editing. And it's not just a question of low resolution: Visually, we can perceive differences of just a few milliseconds. But when our brains assemble a moment in time, they have to wait for sounds and touches to catch up with what we've seen.

The oddest extension of this idea is that taller people have more of a delay than shorter people, since signals have to travel even farther along their gangly limbs. Short people, then, can say they live more in the present than tall folks do.

And don't forget, short people: you're also aging more slowly! Over a lifetime, that missing foot of height might add 90 billionths of a second to your life. Meanwhile, we taller people are whizzing through time and missing every moment of it.

How to Win Friends and Influence People

How much of a narcissist are you? Take this quiz if you'd like to find out (though that, in itself, might be a red flag).

Psychologists define narcissism as a specific kind of personality trait, and they use a test called the Narcissistic Personality Inventory (NPI) to measure it. In a study coming out this fall, researchers from Cornell looked for a relationship between narcissism and creativity. Are creative people, they asked, necessarily more self-absorbed?

In the first of three experiments, the researchers had subjects fill out the same kind of quiz you may have just taken. Then they measured subjects' creativity with such apparently standard tests as "Draw a really wacky alien" and "How many uses can you think of for a brick?" The result: there was no link between narcissism and creativity. (Whew.) Unsurprisingly, though, narcissists rated their own creativity very highly.

In the second experiment, subjects who had filled out the NPI had to write down an idea for a movie, and pitch their idea to an observer. The narcissists' movie pitches were (according to outside readers) not more creative than anyone else's. But the observers who listened to the movie pitches felt differently: they thought the narcissists' pitches were more creative.

What was so winning about these movie pitches? Observers described the most convincing pitchers as energetic, enthusiastic, and charismatic. Having a narcissistic personality, it seems, helps you to sell your ideas better. If you're excited about your idea--like a narcissist, who assumes all his ideas are awesome--then people around you will absorb that excitement.

The final experiment had to do with group work. The researchers found that a group of people with a higher average degree of narcissism will produce more creative ideas--up to a point. They speculate that the narcissists in the group compete with each other to come up with ideas, and even if those ideas aren't really great, the whole group benefits from more active brainstorming. But after a certain level of group narcissism is reached, there are diminishing returns.

This study may explain why people are still letting M. Night Shyamalan make movies. It also gives a slightly depressing insight into how groups work productively. ("Production blocking," the authors say, "is caused by group members listening to other group members' ideas and waiting until the other person has finished before expressing his/her idea.")

Here are some people, though, who want to tell you about their ideas but are definitely not vain about it.

Science magazine sponsors a contest each year called "Dance Your PhD," in which entrants create interpretive dances about their theses. At the link, you can watch videos of grad students dancing as bison, chromosomes, and phosphorous molecules. There's still time to vote for your favorite finalist!

I especially recommend "Selection of a DNA aptamer for homocysteine using systematic evolution of ligands by exponential enrichment," if only for the shock value of seeing them incorporate dance moves from Lady Gaga.


Toot Toot!

That's the sound of me tooting my own horn. Why? My writing is in the October issue of National Geographic, hot off the presses!

You can find me about a third of the way into the magazine, after a big pull-out map, in a column called "The Big Idea." (I'd direct you to the online version, but for some reason it's missing the first 20% or so.) Check me out at your local bookstore, newsstand, or grandparents' basement!

The End of Football?

I hate to be a party pooper about the start of the football season--and it's not only bitterness about my second-drafted fantasy player dropping the ball four times in this week's game. It's just that it's hard to watch all these guys steamrolling each other, in light of Monday's news.

Owen Thomas was a junior on the football team at U. Penn. Last spring, after a sudden emotional breakdown, he killed himself. His parents let researchers at Boston University autopsy Owen's brain, and what they found was shocking: Owen was the youngest person ever with chronic traumatic encephalopathy (CTE), a deterioration of the brain that comes from repeated pummels to the head.

CTE was first described in boxers, back in the 1920s. It can only be diagnosed with an autopsy. The disease involves protein buildup in the brain, and can lead over time to memory loss, impulsivity, aggression, depression, and dementia.

More recently, researchers started to find CTE in the brains of retired NFL players who had died of dementia or drug overdoses. Before Owen Thomas, the youngest person ever diagnosed was Chris Henry, the 26-year-old Bengals player who died last year after he jumped or fell from a moving truck during a domestic dispute.

After denying the science for as long as possible (that is, until they were compared to the tobacco industry in a congressional hearing), the NFL finally changed its tune last year. They started funding CTE research and tightened rules about allowing players to return after concussions.

Not that people are necessarily following those rules: In their opening game this Sunday, two players were allowed to stay on the field after suffering concussions. The resulting criticism, at least, shows that the sports world is becoming more aware of the issue.

Neuropsychologist and invented-word enthusiast Adam Shunk thinks football is getting more dangerous: "I think the game is unsafer," he says. "Just look at the physicalness of football now." Neologisms aside, is there a way to reconcile obvious safety concerns with our national desire to see guys knock each other down? If research continues to show that years of tackles can lead to brain deterioration even in young people, what happens next? Will the NFL change the rules? Build fancier helmets? Disallow tackles for kids and teens, whose brains are still forming?

In the longer term, maybe a genetic test can be developed to predict who's most at risk for CTE. After all, repeat concussions clearly don't have the same effect on every player. Or maybe football as it's currently played will go the way of Joe Camel.

If anybody who knows more about football than I do (which is to say, anybody) has thoughts about how the game will change--or whether it will change at all--feel free to share!

Slime and Other Silly Projects

You know when it's the middle of a workday and you realize you're doing something really silly? Like the day I was looking at technical plans of school buses because I wanted to express the weight of a blue whale with an analogy kids could appreciate. Or the day I was out in the alley with a mixing bowl full of green slime and a hammer, and someone stopped to ask directions to the Guatemalan embassy.

If you work in a science lab, all of your days might be silly in the exact same way, at which point it becomes less funny. I used to spend all day staring at a little pile of dirt and grass roots under a lamp, and picking out the roots with tweezers. When the roots started to squirm around on the table, you knew it was time to get up and take a walk.

This week brought us three especially silly moments in science. I just hope the people in the labs were able to appreciate it.

1. Boozy Bacteria
When researchers studied the bones of 1,700-year-old Nubians and found what appeared to be tetracycline--a modern-day antibiotic--their results were met with some skepticism. After all, archaeologists hadn't yet uncovered any fourth-century pharmaceutical factories. But after further research, the scientists think they've figured out where the drugs were coming from: beer.

The Nubians brewed their beer from grain that was contaminated with strep bacteria. (Streptomyces makes tetracycline to kill off competing bacteria.) They got lots of antibiotics in their diet, starting young--even babies drank the tetracycline in their mothers' milk. The population may have recognized that drinking the beer kept them feeling healthy.

The goofiest part of the story, though, is that Emory professor George Armelagos had his students brew their own Nubian-style beer, complete with strep. It does contain tetracycline, and is described as "drinkable," but with a "greenish hue."

2. Stressing Slime Molds
Quick, how would you stress out a slime mold? (Slime molds, for the uninitiated, are single-celled organisms that sometimes come together en masse to form alarming, bright-yellow blobs and ooze across the forest floor like mobile toxic waste slicks.)

In their multi-celled form, slime molds are able to do some low-level problem solving. Researchers tested how well slime molds made decisions--choosing between foods of different concentrations--when they were stressed. So how did they stress the blobs? Shining a strong light on them worked, as did starving them.

The result was that the slime molds made hastier, and worse, decisions when stressed. Like humans, they have a hard time thinking when they're hungry.

3. Awkward Avatars
Over in the UK, some mostly-male researchers were wondering (perhaps as a result of personal experience) what kinds of dance moves women find most attractive. But you can't just ask women to watch men dance and rate them, because there could be other factors at work. A mediocre dancer might get high scores just for being good-looking. Or perhaps the "best dancer in the world" has "an awful haircut or something like that," as the lead researcher speculates wistfully.

So the scientists took inspiration from James Cameron and asked 19 guys to dance to a beat while wearing motion-capture markers. Then they transformed each dancer into a purple avatar that strongly resembles one of those bendable wooden drawing dummies.

Women were asked to watch the videos and rate the bopping androids on their dancing skills. (This guy above did not fare well; you can watch a video of his "I'm-sowing-a-field" dance, as well as a more successful dancer, here.) Researchers concluded that a few factors make a dance really successful. Moving your head and trunk around a lot is good. Also, mysteriously, "speed of movements of the right knee." Take note, guys.

To follow up, the researchers are wondering whether good dancing is an "honest signal"--that's an evolutionary term for a feature that broadcasts how fit you are. It applies to lots of male birds whose flashy feathers (or, often, dance routines) tell females they're strong and healthy. I only hope there will be videos to go with that experiment, too.

Avatar image: Northumbria University

What's Up with Chronic Fatigue?

Here is some of the best drama you're going to see in science: two major studies are published six weeks apart and report exactly opposite results. Their subject? A squirrely syndrome that is anything from a devastating infectious disease to a made-up malaise, depending who you ask.

Chronic fatigue syndrome, or CFS, is (quick overview!) pretty much what it sounds like. Its trademark is a crippling exhaustion that lasts for months or years. There's no test or cure for CFS. Doctors first rule out every other possibility--such as hormonal problems, mental illnesses, sleep disorders, or lupus--before giving a diagnosis of CFS.

The syndrome jumped into headlines last year when Science published a paper announcing a correlation between CFS and a certain retrovirus called XMRV. A retrovirus is (quick overview!) a virus that cleverly inserts its own genes into your DNA, so your body keeps replicating it. HIV is one.

The authors of the paper found this retrovirus in 68 out of 101 patients with CFS, but in only 3.7% of healthy patients. This could mean that XMRV causes or contributes to chronic fatigue (but not in all patients). Or it could mean nothing: XMRV could be an unremarkable infection that easily takes hold in people who already have poor health.

Other researchers criticized the methods of the first study. Meanwhile, three other studies failed to find any link between chronic fatigue and XMRV. But all these studies were done in Europe; could XMRV only be responsible for chronic fatigue in the U.S.? Then, this July, an American study done by the CDC also failed to find any connection.

You might think that would be the final nail in the coffin for the virus theory. But wait! In August, another group of American researchers announced that they'd studied the blood of CFS patients and found--well, not XMRV. But they found gene sequences that come from a group of viruses related to XMRV.

So what's going on? The CDC suggests that chronic fatigue is "a common endpoint of disease resulting from multiple causes." Maybe a retrovirus is relevant to some percentage of CFS cases, or maybe it's not. A controversial researcher named Simon Wessely has proposed that whatever event triggers CFS is, ultimately, not as important as the behavioral and psychological patterns people fall into after the illness starts. That's not to say that chronic fatigue isn't real, but that it represents a kind of physical and mental rut the body gets into.

It would certainly be easier to treat CFS if it turned out that a virus or some other single factor was to blame. But given the way the research has swung back and forth, I wouldn't bet on anyone finding a magic bullet. Some CFS patients are eager to try antiretroviral drugs--the same ones used to treat HIV. But these drugs can have severe side effects. The editor of the journal that published the most recent study said that patients taking off-label antiretrovirals would be "a very bad consequence of this."

Stay tuned, because more research--and more drama--is sure to come.