Friday, 16 October 2009

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Missed Kicks Make Brain See Smaller Goal Post

Posted: 16 Oct 2009 10:20 AM PDT


Flubbing a field goal kick doesn't just bruise your ego — new research shows it may actually change how your brain sees the goal posts.

In a study of 23 non-football athletes who each kicked 10 field goals, researchers found that players' performance directly affected their perception of the size of the goal: After a series of missed kicks, athletes perceived the post to be taller and more narrow than before, while successful kicks made the post appear larger-than-life.

Professional athletes have long claimed that their perception changes when they're playing well — they start hitting baseballs as large as grapefruits, or aiming at golf holes the size of a bucket — but many scientists have been slow to accept that performance can alter visual perception.

"The reason why this is so radical is that perception has always been conceived as being all about information received by the eye," said pychology researcher Jessica Witt of Purdue University, who co-authored the paper published last month in Perception. "In my studies we keep all the optical information constant, so the eye is seeing the exact same info — but it looks different depending on performance."

According to visual perception researcher Maggie Shiffrar of Rutgers University, who was not involved in the research, Witt's conclusions are troubling to many scientists because they suggest that computer studies of perception might not be a reflection of reality. "If Witt is right that what we see depends upon what we can do, then it logically follows that many of us
have spent our lives studying perception in the WRONG WAY," Shiffrar wrote in an email. "In the vast majority of studies conducted in my lab, for example, observers view displays on a flat computer screen and make simple, dichotomous judgments about their perceptions of those displays. Thus, subjects in my studies don't do anything other than push a button. The results of Witt's studies suggest that the results that I've collected and the corresponding theoretical conclusions that I've drawn won't generalize to perception in the real world. In the real world, people look at objects so that they can do something with those objects."

Although many scientists are surprised, Witt says subjective perception is a concept most of us are already familiar with. For example, she said, when running around a track, you may know logically that long, straight stretch is always a constant 100 meters — but by the end of a run, those same 100 meters appear to stretch on forever.

Witt and her colleague, graduate student and former football player Travis Dorsch, chose to experiment with field goal kicks because they wanted to study the disconnect between what people think they can do and what they can actually accomplish. "When you watch college and pro football, field goal kicks seem so easy," Witt said. "But when I went out with Travis to try it myself, it was actually really hard to do."

goal-fig-1The researchers used a small, adjustable replica of a goal post to test players' perception before and after attempting 10 kicks. While standing in front of the real-life goal, participants were asked to adjust the width and height of the model to scale.

The players' pre-performance estimations didn't correlate at all with their subsequent success rate. But after 10 field goal attempts, their perceived goal size was highly correlated with peformance.

Interestingly, the change in players' perception didn't just depend on how many goals they missed — it also mattered how they missed their goals. Folks who failed because they didn't kick high enough perceived the crossbar to be taller, while those who kicked to the side viewed it as more narrow.

Previous studies by Witt and her colleagues have shown that performance can also influence perception among golfers and softball players. But the researchers say this is the first time that particular performance errors have been correlated with specific effects on perception.

"One of the things that has been asked of us in our research is, if you're playing well, do you just see everything as bigger, does the whole world look like it's expanded?" Witt said. "But this research shows that changes in perception are specific to what you're acting on."

Next, Witt hopes to look at whether professional athletes can improve their performance by changing their pre-game perceptions. For instance, are golfers who see a larger hole more likely to make the shot? "Currently, we're testing this using visual illusions in golf that make the hole look bigger or smaller," Witt said.

Image 1: Flickr/sethhenry1. Image 2: Jessica Witt/Purdue University. From "Kicking to bigger uprights: Field goal kicking performance influences perceived size," Perception, 2009, Vol 38: 1328-1340.

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Why Eggs Could Be Getting Harder to Peel

Posted: 16 Oct 2009 07:39 AM PDT


Consider the farm-fresh egg, the pristine symbol of the simple days of pre-industrial farming.

People love them, but there's a problem: They seem to be getting harder to peel. And though I've messily discovered this on my own, there's some science to back this idea up.

Here in food-crazed San Francisco, fresh eggs are everywhere. After purchasing some of these just-collected treasures for hard boiling, I found it nearly impossible to peel off their shells without pockmarking them. My once-beautiful eggs ended up with more craters than the moon.

It couldn't be my fault, I told myself. I'd been hard-boiling eggs for decades, most intensively during a six-month egg salad kick in ninth grade. I got my technique down and everything.

What happened, then?

As an egg ages, it loses some carbon dioxide through tiny pores in the shell, making the egg white more basic. At the same time, it loses moisture, which increases the size of the "air cell" at the bottom of the shell, between the inner and outer membranes. The dynamics of this process are, in the words of a University of California, Davis agriculture publication, "not completely understood," but the combination of these changes makes an old egg a lot easier to peel than a one that is fresh out of the bird.

"The best guarantee of easy peeling is to use old eggs!" wrote Harold McGee, in his monster 800 page tome, On Food and Cooking: The Science and Lore of the Kitchen. "Difficult peeling is characteristic of fresh eggs with a relatively low albumen pH, which somehow causes the albumen to adhere to the inner shell membrane more strongly than it coheres to itself."egg-schematic

The USDA provides a complementary explanation more focused on the air cell, which you can see in the schematic, sitting between the outer and inner shell membranes.

"As the contents of the egg contracts and the air cell enlarges, the shell becomes easier to peel," the USDA Shell Eggs from Farm to Table factsheet states. "For this reason, older eggs make better candidates for hard cooking,"

McGee also suggests an easy cooking chemistry solution.

"If you end up with a carton of very fresh eggs and need to cook them right away, you can add a half teaspoon of baking soda to a quart of water to make the cooking water alkaline (though this intensifies the sulfury flavor)," he wrote.

While I've noticed the Peeling Problem most distinctly with superfresh farm eggs, the eggs you buy at the supermarket could be getting fresher too. Most American eggs are produced and distributed by agribusiness concerns like Cal-Maine and Rose Acre, which each have more than 20 millionhens cranking out eggs just for you.

Statistics on the time it takes for an egg to go from hen to supermarket have not been calculated, a USDA representative told, but there's some reason to believe that new production techniques could be delivering eggs to markets faster.

A 1998 report by the agency found that big consolidated chicken egg facilities, which wash and package the eggs on-site instead of sending them to a separate processing location, could reduce the time from farm-to-store from 100 hours to 53 hours. And, according to Cal-Maine's SEC filings, the industry continues to centralize, squeezing out the old facilities in favor of the new ones.

Eggs tend to sit on the retail shelf longer than they spend in processing and distribution, so the few extra days of freshness might not make the eggs as dramatically hard to peel as farm eggs.

But if you have any trouble, consider another technofix: automatic Eggstractor egg peeler, anyone?

Image: 1. flickr/YoAmes 2. University of California, Davis.

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Huge Holes in the Earth: Open-Pit Mines Seen From Space

Posted: 15 Oct 2009 04:40 PM PDT

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People have become significant earth movers, outpacing all sources of natural erosion. More and more of our footprint can be seen from space in many forms, including cities, reservoirs, agriculture and deforestation. Among the most impressive human scars on the planet are open-pit mines.

We've gathered some of the biggest, most spectacular and interesting mines, as captured by astronauts and satellites on the following pages.

Above: Berkeley Pit, Butte, Montana

This former copper mine operated between 1955 and 1982. Gold and silver were also mined. An elaborate system of pumps and drains kept the local water level low enough for mining. Today, the 1,780 foot-deep pit is filled with around 900 feet of very contaminated water filled with metals and chemicals such as arsenic, cadmium, pyrite, zinc, copper and sulfuric acid. The water can be as acidic as battery acid, and copper can actually be "mined" directly from the water.

Currently, the 1-mile-by-0.5-mile pit is listed as a federal Superfund site with the potential to contaminate surrounding ground water, and, surprisingly, is also a tourist attraction, complete with gift shop and $2 admission fee.

This photograph was taken Aug. 2, 2006, by astronauts aboard the International Space Station.

Image: NASA

The Edge of the Solar System Is Not What We Expected

Posted: 15 Oct 2009 02:18 PM PDT


The edge of the solar system is tied up with a ribbon, astronomers have discovered. The first global map of the solar system reveals that its edge is nothing like what had been predicted. Neutral atoms, which are the only way to image the fringes of the solar system, are densely packed into a narrow ribbon rather than evenly distributed.

sciencenews"Our maps show structure and energy spectra that are completely different from what any model has predicted," says study coauthor Herbert Funsten of the Los Alamos National Laboratory in New Mexico.

NASA's Interstellar Boundary Explorer satellite, or IBEX, discovered the narrow ribbon, which completes nearly a full circle across the sky. The density of neutral atoms in the band is two to three times that in adjacent regions.

These and related findings, reported in six papers posted online October 15 in Science, will not only send theorists back to the drawing board, researchers say, but may ultimately provide new insight on the interaction between the heliosphere — the vast bubble in which the solar system resides — and surrounding space.

The bubble is inflated by solar wind, the high-speed stream of charged particles blowing out from the sun to the solar system's very edge. For 48 years, researchers have assumed that the solar wind sculpted the structure at the heliosphere's boundary with interstellar space, says Tom Krimigis of Johns Hopkins University's Applied Physics Laboratory in Laurel, Md.. But the newly found ribbon's orientation suggests that the galaxy's magnetic field, just outside the heliosphere, seems to be the chief organizer of structure in this region, says theorist Nathan Schwadron of Boston University, a lead author of one of the studies.

It's not known whether the ribbon lasts for just a few years or is a permanent feature.

Equally puzzling are observations of the same boundary region with an instrument on the Cassini spacecraft, which recorded the density of atoms at higher energies, above 6,000 electron volts. From its vantage point at Saturn, Cassini sees a belt rather than a ribbonlike structure, a team led by Krimigis also reports in Science. The belt is substantially broader than the ribbon seen by IBEX but is in the same general area.

The heliosphere shields the solar system from 90 percent of energetic cosmic rays — high-speed charged particles that would otherwise bombard the planets and harm life. Understanding more about the heliosphere and its ability to filter out galactic cosmic rays could be critical for assessing the safety of human space travel, Schwadron notes. The new findings may also help predict how the heliosphere varies in shape and size as it moves through the galaxy and encounters regions of space having different densities and magnetic field strengths.

ibexmapThe ribbon found by IBEX, recorded at energies between 200 and 6,000 electron volts, is brightest at about 1,000 electron volts and lies between about 100 and 125 astronomical units from the sun, notes David McComas of the Southwest Research Institute in San Antonio. One astronomical unit is the distance between the Earth and the sun. The atoms recorded by IBEX, which orbits Earth, took a year or two, depending on their energies, to reach the craft from the outer edge of the heliosphere.

The IBEX ribbon runs perpendicular to the direction of the galaxy's magnetic field at the interstellar boundary, an indication that the field has a much stronger than expected influence on the sun's environs, report Schwadron and his colleagues. One possibility is that pressure from this external magnetic field has forced particles just inside the heliosphere to bunch together into a ribbon.

"First and foremost, this is a big surprise because we thought we know a lot about this region, the edge of the heliosphere," McComas says. The Voyager 1 craft in 2004 (SN: 1/3/04, p. 7) and the Voyager 2 craft in 2007 (SN: 8/2/08, p. 7) journeyed to opposite sides of this fringe region of the solar system and crossed the termination shock — where the solar wind encounters a shock that precedes the influx of particles drifting into the solar system from interstellar space. Both craft recorded the density of particles and the strength of the magnetic fields.

Both Voyager 1 and 2 missed seeing the newly found ribbon because it spans a region between their flight paths, says McComas. No existing model can explain the ribbon, he adds, which was found independently by two instruments on IBEX.

Researchers had assumed that the pressure from the solar wind would compress in the heliosphere in the direction that the solar system was moving through space and create a cometlike tail in the opposite direction, notes Krimigis. "Now we know that's wrong," he says.

IBEX has also generated the first maps of neutral hydrogen and oxygen atoms entering the solar system from interstellar space. Previous observations had traced only incoming helium atoms. The sensitivity of the IBEX instruments allowed researchers to record the relatively small number of oxygen atoms that travel from beyond the termination shock, about 16 billion kilometers from Earth, to the spacecraft, notes study coauthor Stephen Fuselier of the Lockheed Martin Advanced Technology Center in Palo Alto, Calif..

Hydrogen atoms are more abundant than either helium or oxygen but their low mass means they are easily swept aside by the high-speed solar wind and can't readily be detected. The sun's unusually low activity during the current minimum in the solar cycle allowed more of the hydrogen atoms from the outer heliosphere to travel unimpeded to the inner solar system, enabling IBEX to record those atoms, Fuselier says.

Images: 1) NASA. 2) Southwest Research Institute.

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Sour: It’s What Carbonation Tastes Like

Posted: 15 Oct 2009 11:51 AM PDT


The carbon dioxide in your favorite soda pop tastes sour to your tongue, thanks to an enzyme that converts CO2 into protons that sour-sensing cells can detect.

That means your Coca Cola isn't just packed with high-fructose sweetness, but, perhaps counterintuitively, its carbonation delivers a delicious squirt of sour too, according to a new study in mice, published Thursday in the journal Science.

"The same taste cell has all the machinery to turn carbon dioxide into protons and then detect the protons as sour taste stimuli," said Alexander Bachmanov, who was not involved in the study.

The discovery is of particular interest in the food and beverage world, Bachmanov said, because carbonation has long been recognized as a complex phenomenon for the mouth. Even if the sour-sensing cells signal that the carbonation is sour, there are more elements to the process of actually tasting, say, soda water.

detailed-tongue"If you think about carbonation, it has more than one attribute," he said. "One is sourness, which we perceive, but there is probably also some tactile sensation how the bubbles form and burst, tickling the tongue."

The researchers, led by longtime taste researcher Charles Zuker, now at Columbia University Medical Center, conducted the study using mice that had been genetically altered to lack sour-sensing cells. They found that such mice could not detect carbon dioxide, as seen in the chart. While the study was carried out with mice, the mechanism is expected to have been preserved in other mammals.

Zuker and his colleagues posed a natural evolutionary question: Why would mammals have developed such an excellent carbon dioxide detector?

"CO2 detection could have evolved as a mechanism to recognize CO2-producing sources — for instance, to avoid fermenting foods," they wrote.

One happy irony of such a hypothesis is that the very same mechanism that allowed our deep ancestors to recognize and avoid fermentation allows modern humans to intentionally create the fermented beverages beer and champagne.

Or, our carbonation-detecting skills could be an accident. The sour-cell enzymes might be maintaining the pH balance of the taste buds, and the tang of soda water is just fallout.

Accident or adaptation, from sparkling wine to Coca Cola to energy drinks to the carbonated yogurt popular in Iran called doogh, humans love carbonation in its many forms. Though their share of the beverage market might be slipping a bit, the world's population still spends half its drink money on carbonated quenchers.

Zuker's company Senomyx develops artificial flavors, and have disclosed that they have a partnership with Coca Cola, among other companies.

Image: adamcomerford/Flickr

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