Field of Science


I Think I Can! (Do Physics)

Mmmm. It's been a refreshingly long time since I've had to read any arguments published by the New York Times about the innate inferiority of women in hard sciences. I'm looking at you, John Tierney.

(I did, however, read an entertaining rant by Natalie Angier about STEM, the annoying new acronym we're supposed to use instead of saying "hard sciences." "Aficionados pronounce STEM exactly as you'd imagine," she says, "like the plant part, like the cell type, like what you do to a tide and I wish I could do to this trend, but it's probably too late.")

While Tierney was polishing his bro card, researchers at the University of Colorado were conducting a pretty spiffy study about women in physics. For their subjects, they used an entire entry-level college physics class of 399 students (283 male and 116 female). As in any good psych study, the students were unaware of what was going on.

The study examined "stereotype threat," the phenomenon in which certain groups underperform when they're reminded of negative stereotypes about themselves. Specifically, the researchers wanted to know whether stereotype threat was bringing down the grades of the women in the class. Twice during the semester--once at the beginning, and again before the first midterm--all students completed a 15-minute writing assignment. Whether male or female, they were randomly assigned to write about either values that were important to them ("values affirmation") or values that were important to other people (control group). The values-affirmation exercise had been previously shown to help close the achievement gap for minority middle-school students. Neither the instructor nor the TAs knew which writing assignment the students had done.

At the end of the semester, the researchers looked at students' test scores, both on the usual class exams and a standardized physics test. They found that the values affirmation exercise didn't increase men's test scores--if anything, it lowered them a tiny bit. For the women, though, there was a clear jump from the control group to the values-affirmation group. In the control group, men outperformed women. After the values-affirmation exercise, the gap was gone.

Researchers also looked at the grade distribution in the class. While the values affirmation, again, hadn't affected men's grades, it clearly shifted a group of women out of the C range and into the B range. Interestingly, the percentage of women with A's didn't increase--it seems that the exercise was most helpful to the women who were struggling a bit to begin with. And there was one more piece of data: As part of an online course survey, the students had responded to the question, "According to my own personal beliefs, I expect men to generally do better in physics than women" on a five-point scale. It turned out that the women who agreed with this stereotype got the biggest boost from the values-affirmation exercise.

These students weren't insecure, math-averse middle-schoolers; they were college kids who were voluntarily taking physics because they wanted to major in science. It's surprising to see that stereotype threat could still have such a strong effect in this group. But it's encouraging that researchers are finding simple ways to counteract it. Or, unlike some columnists, acknowledging that there's a problem in the first place.

Elevate Your Performance!

In my tradition of examining science-y shoes, I'd like to talk about these sneakers, the Gravity Defyers. I found this advertisement in a magazine called Invention & Technology, which seems (if all the ad space dedicated to commemorative coins is any indication) to be targeted at an older demographic.

The logo on the shoe is sort of like a Nike swoosh, but a little more...swimming.

Is this an accident? A joke? A tadpole? It's hard to say.

The ad's copy tells the tale of a man with a problem:
Low energy and laziness has got me down. My energy has fizzled and I'm embarrassed to admit that I've grown a spare tire (I'm sure it's hurting my love life.)...Gravity has done a job on me.
To counteract his saggy problem, the man's doctor recommends Gravity Defyer shoes, which "ease the force of gravity" with Veroshock Trampoline technology. (Springs, to the layperson.)

On receiving his shoes in the mail, our hero says, "Excitement swept through my body like a drug!"
Sturdy construction. Cool colors. Nice lines...I was holding a miracle of technology. This was the real thing.
He was understandably eager to experience all the benefits of Gravity Defyer shoes, which "Relieve pain," "Elevate your performance," and "Be more active."
I put them on and all I could say was, "WOW!" In minutes I was out the door...I was back in the game. Gravity had no power over me!
A pair of these amazing shoes can be yours for only $129.95 (energy drink pouring itself all over your foot not included).

Ladies, don't feel left out--there's something for you, too!
"Customer Satisfaction Speaks for Itself."

Are Dogs Smarter than Cats?

You may see a headline or ten today screaming, DOGS SMARTER THAN CATS! (Subhead: Scientists Say So!) It may not surprise you to learn that those headlines are a little overblown. But what the scientists actually say is pretty interesting, too.

Susanne Shultz and Robin Dunbar at Oxford University studied "encephalization," which is how much a species increases its brain size over evolutionary time. If your ancient ancestors had pea brains, but nowadays you have a giant brain (compared to your body size), congratulations! Your species encephalized. Since it costs a lot of energy to power a big brain, scientists assume that highly encephalized species are getting a big benefit out of those brains in the long term (say, by inventing tools).

Shultz and Dunbar conducted a statistical analysis that included 511 mammal species. Within groups of related species, they included fossil data from extinct species as well as data from living species. In all cases, they looked at how the size of an animal's brain, relative to its body size, has increased (or not increased) over time.

They found some groups of mammals that had clearly become more encephalized over time, and other groups whose brain size had stayed the same. The orders of primates (such as monkeys and apes), cetaceans (whales and dolphins), Perissodactyla (horses and rhinos), and carnivores (carnivores) all had increased their brain sizes, with primates increasing the most.

When the groups were divided into suborders, a few things changed. Among the carnivores, for example, the Caniformes (dog-like animals, which include wolves, bears, seals, and skunks) seemed to account for all the encephalization. The brains of Feliformes (cat-like animals) had stayed pretty much the same size over time.

So what separated the brain growers from the brain slackers? The mammals that had encephalized were social animals--they live in groups, packs, or herds. Those with solitary lifestyles had not encephalized.

Though relative brain size is connected to intelligence--big-brained animals do tend to be smart--it's not the only thing that matters. The study authors don't conclude that these animals are smarter than less-encephalized ones (horses, after all, are still dumb as rocks). But they do conclude that the brains of social animals have grown the most as they evolved. Something about living in groups, it seems, requires some extra equipment upstairs.

How does this apply to your dog and your cat? Housecats weren't actually included in the study. But they actually have slightly larger brains, relative to their bodies, than dogs do--even though their brains haven't grown over evolutionary time. As for dogs, they were just one of many dog-like species included here. And since domestication tends to shrink brains, cats and dogs are probably both dumber than their wild cousins. But we love them anyway!

Big Balls (a quiz)

Do you have what it takes to conquer this special-edition, oversized quiz?

1. Data from a NASA telescope recently revealed two giant balls of:
a. ice and rock, hurtling toward Mars
b. garbage, lodged in an air-circulation chute on the International Space Station
c. energy, sandwiching the Milky Way galaxy
d. gas and dust, blocking our view of the Orion nebula

2. Using an iPhone app called Track your Happiness, researchers at Harvard found that:
a. people who daydream the most are the happiest
b. 10% of people claim to never daydream
c. focusing on the task at hand makes people unhappy
d. daydreaming makes people unhappy

3. Last week, researchers reported that ozone depletion is causing:
a. sunburned whales
b. skin cancer in penguins
c. deeper tans among Brazilians
d. a reversal of global warming

4. Researchers in Vietnam discovered a previously undocumented, all-female lizard species...
a. on a menu
b. in a pet store
c. living in their luggage
d. after running one over

5. A British team has proposed a new design for a Mars rover. Instead of rolling across the sandy terrain like Spirit and Opportunity, their rover would:
a. crawl
b. walk
c. fly
d. hop

6. Meanwhile, a new study on pterosaurs says that the 500-pound flying dinosaurs may have launched themselves into flight in a manner similar to:
a. high jumping
b. pole vaulting
c. skipping
d. trapeze-ing

7. New research has revealed which of the following about parrotfish mucus?
a. Parrotfish trap their prey in spit-bubble nets
b. Parrotfish create elaborate spit castles as part of their courtship routine
c. Parrotfish spit contains a potent antiviral agent
d. Parrotfish sleep in spit cocoons to deter bloodsucking predators

8. Scientists at MIT built a robotic tongue in order to study the physics of:
a. dogs lapping water
b. cats lapping water
c. camels spitting
d. goldfish eating

9. Haven't you ever wondered how a fruit fly larva (also called a maggot) keeps its squishy little body from shriveling in the sun while it's munching on rotten fruit? The answer, scientists recently announced, is that the maggot:
a. has tiny eyes all over its body to detect the sun
b. creates a protective spit tunnel as it chews
c. excretes urine from every part of its body
d. ...I'm sorry, I grossed myself out too much to write a fourth option.

10. With testes weighing in at almost 14% of its body mass, the title of World's Largest Testicles has been claimed by a species of:
a. lemur
b. parakeet
c. cricket
d. primitive hominid

Answers are in the comments.

Are You an Efficient Walker?

I apologize. If you are one of those people who's most comfortable walking down the exact center of the sidewalk with your earbuds in, or a random left-and-right weaver, or a reckless swinger of pointy umbrellas, or someone who likes to walk your terrier tripwire-style, you may have heard me scuffing my feet behind you and making frustrated little noises. If you're simply slow, I may have alarmed you by zooming around your left shoulder like a maniac. I can't help it. I'm a speed walker.

Even if you're a more relaxed stroller than I am, though, maybe you've wondered why people walk the way they do. Is a super-slow walker conserving energy? Do little kids really tire out that quickly from walking, or are they just lazy? If I walk the 4.2-mile round trip to Bobtail for a cone of Cubby Crunch ice cream, is my expedition calorie-neutral?

Researchers in Texas addressed these questions by putting 48 people of assorted sizes onto treadmills. They observed people's strides, measured their oxygen use and carbon dioxide output, and calculated their metabolic rates. (None of the subjects were wearing Shape-Ups.) The subjects ranged from age 5 to 23. They had to walk at various speeds, from a very slow 0.4 meters per second (0.9 mph) to a brisk 1.9 meters per second (4.3 mph). A few of the young kids never figured out how to walk on the treadmill, footage of which I assume would be YouTube gold.

The researchers found that shorter people are less efficient walkers than taller people. That is, they use more energy to walk the same distance. And the reason is simple: since taller people have longer legs, they need to take fewer steps.

The findings were remarkably consistent. Thin people, obese people, and even little kids walk with essentially the same mechanics across a wide range of paces. The researchers infer that "humans establish mature walking patterns sometime before they reach six years of age."

You might view this as another advantage to being short (more exercise over the same distance!) or a point for tall people (we're so efficient!). Either way, if you care to know how many calories you're burning, the authors' rule of thumb is as follows:

At a comfortable pace, it takes about 1 calorie per kilogram of body weight to move forward a distance equal to your height. So if you know your weight in kilograms and the distance of your trip in, um, inches, you can calculate whether you burned off that ice cream cone. Or not.


ADDENDUM: Those would have to be calories with a little c, which are one 1,000th of what we usually call a "calorie." So you should divide by a thousand.

Michael Jackson Mind Control

Whenever you recognize someone or something--your mother, the Space Needle, an iguana--it's because certain neurons in your brain light up with activity almost exclusively in response to that one thing. You may pretend you don't know who Heidi Montag is, but somewhere in your gray matter, your brain cells are proving you wrong. Researchers at CalTech used this principle to create a spooky game in which subjects manipulated a computer screen with their minds.

The research, like previous work in this field, was done on epileptic patients who'd had electrodes temporarily buried in their brains to study their seizures. (Pragmatic researchers figure that as long as patients are sitting around the hospital with wires coming out of their heads, they might as well make themselves useful.)

For each of 12 electrode-implanted subjects, the researchers repeatedly flashed over 100 familiar images on a screen while monitoring the activity of their neurons. Then they chose four images that elicited a particularly big crackle of activity in one area of the subject's brain. For one subject, this meant they identified an area of Marilyn Monroe neurons, one of Josh Brolin neurons, one of Michael Jackson neurons, and a fourth area of Venus Williams neurons.

The actual experiment required each subject to sit in front of a screen, which would flash one of their four images: say, Michael Jackson. This was the "target." Then the screen would show Michael Jackson superimposed with one of the other four images. The subject had to look at the hybrid image and concentrate on their target. A nifty feedback contraption, hooked up to those electrodes in the subject's head, listened to the activity of their neuron groups and responded accordingly: the more the subject activated the neurons for Michael Jackson, the stronger his image would become on the screen. If the subject got distracted by Marilyn Monroe, her image would take over.

Amazingly, all the subjects figured out how to "win" the game, getting their target image to 100%--often on the first try. While seeing both images, they were able to increase the activity of one set of neurons and simultaneously quiet down the other set. This technology doesn't have a lot of (OK, any) immediate practical applications. But it's intriguing to imagine the computers of the future responding to commands in your head.

As long as it requires brain surgery, I'm guessing the image game won't catch on. But you can play a much less invasive biofeedback game at the Museum of Science and Industry.

In an exhibit called Mindball, two contestants don electrode-containing headbands, face each other across a table, and try to relax. As their brainwaves slow, a metal ball travels back and forth along a track between them. Whoever is the best relaxer (producing more alpha and theta brainwaves, as opposed to the more alert beta waves) eventually pushes the ball all the way to their opponent's side of the table, winning the game.

If you don't want to travel all the way to the Museum of Science and Industry, you can buy your own Mindball table from the Polish company that produces them. Why buy a pool table when you could outfit your den with a relaxing brain-reading game instead? The best part is that no one will be able to tell what celebrities you're thinking about.

Watch Out for Comets! (a quiz)

Facebook quizzes may tell you which Hogwarts house you belong in, which U.S. city is right for you, or what your Disney princess spirit color is--but only Inkfish tests your knowledge of polar research volunteers and space similes.

1. Researchers announced this week that which technology seen in the Star Wars movies is close to becoming a reality?
a. 3D holographs
b. Light sabers
c. Death stars
d. Doors that slide open when you wave your hand at them, Jedi-style

2. Last week, the U.S. Department of Justice issued a surprising statement regarding the breast cancer genes BRCA1 and BRCA2, going against what has been the usual policy in this country. It said that:
a. Genes should be patent-eligible.
b. Genes should not be patent-eligible.

3. A NASA spacecraft flew by a comet called Hartley 2 yesterday and returned a bunch of photos. All of the following are true about the mission EXCEPT:
a. The spacecraft is named Deep Impact--not to be confused with the movie about a comet heading toward Earth.
b. This comet is, eventually, heading toward Earth.
c. Those jets of light come from frozen materials on the comet's surface that are heated by the sun and shoot off as gases.
d. Hartley 2 was described by a NASA astronomer as "a cross between a bowling pin and a pickle."

4. Two recent studies found that this much-touted brain food did not slow cognitive decline in Alzheimer's patients; did not prevent postpartum depression when taken by pregnant women; and did not make their babies smarter.
a. Ginkgo biloba
b. Pomegranate juice
c. Fish oil
d. Snake oil

5. The Arctic waters of Baffin Bay are warming (no surprise there). To gather data on changing ocean temperatures, scientists recruited an unusual team of volunteers. They attaching their instruments to:
a. Illegal whaling ships
b. Polar bears
c. Penguins
d. Narwhals

Answers are in the comments. Image: NASA.

These Robots Are Ready for Liftoff

Liftoff of the space shuttle Discovery--the next-to-last NASA shuttle launch ever--has been delayed until at least Thursday (November 4). But one of the shuttle's postponed passengers to the International Space Station claims to feel no anxiety about the upcoming trip:
I'm not nervous--with my stomach full of brains, there's no room for butterflies.
That's from the Twitter feed of Robonaut 2, also called R2. No relation to R2D2, except that both are cute and helpful space-bots.

Once R2 makes it to the space station, it will take up permanent residence there. But it's not like robots will suddenly be running the place. R2 doesn't have much of a mind of its own, for one thing. It only carries out orders from human-nauts. And for now, it's a prototype. On the space station, humans will learn how R2 functions without gravity, and how well its extra-dextrous hands perform various functions.

For example, weightlifting.

Eventually, robonauts will use those hands, which NASA describes as "approaching human dexterity," to take over dangerous or boring tasks from human astronauts. R2 is already able to change an air filter, a trick which might get old fast. ("Mikhail! Stop playing with that robot; I told you the air filter is clean already!")

R2 is legless for now. It will stand on a fixed pedestal on the space station. But future generation might have legs--or even wheels. The "Centaur," currently being tested on land, is a robonaut torso attached to a four-wheeled rover.

Robonaut 2's dextrous and human-like hands are the pride of NASA, but other scientists have been working on a whole new model. Led by Eric Brown at the University of Chicago, a team created a "universal robotic gripper" that forgoes fingers altogether. Instead of bothering with all those complicated joints, the robotic gripper is just a round rubber sack filled with a granular material. When the sack comes in contact with an object, the grains flow around the shape (think of setting a small bag of rice on top of a pen). Then a vacuum quickly sucks a tiny bit of extra air out of the gripper. This changes the sack's volume by less than 1%, but it's enough to mold it around the object and grip it tight.

Here, you can (and should) watch a video of the robotic gripper pouring a glass of water and drawing with a pen. The gripper can pick up most sturdy objects, but still has trouble with porous or squishy things, such as cotton balls.

Brown says that amputees could one day benefit from prosthetic hands based on this technology. I have a hard time imagining that people would want their missing hands replaced by grippy blobs, but maybe I'm wrong. Either way, there are certainly plenty of robots that could use good hand technology. I wonder if the universal gripper works in microgravity...

Images:; John Amend