Discovery

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Posts Tagged ‘Science’

Patterns In The Sand

Mother Nature may be the world’s greatest mathematician.

Bonni Kealy saw that firsthand in how tiger bush will grow in patterns found throughout other parts of nature, like the spots on a cat.

Tiger Bush in Sierra de la Gessa, Spain. Creative Commons Flickr photo courtesy of Jorge Franganillo, http://www.flickr.com/people/franganillo/

“Math isn’t just about equations,” Kealy said. “It’s beautiful and natural. You see it around you every day.”

Indeed, mathematicians often tease out the numerical underpinnings of seemingly random phenomena, discerning patterns in everything from the coats of felines to algae-filled water, Kealy said. In effect, two dissimilar things are interacting in predictable ways, and a mathematician can describe how.

Kealy, 29, and her advisor David Wollkind started to create a new modeling equation for the spread of tiger bush, a plant unique to arid and semi-arid areas, by mining the past, Kealy said.

They used existing pattern formulas as a foundation for their work, but the earlier models worked only on sloped land. Kealy and Wollkind’s model works on flat land, a more common habitat for tiger bush. It focuses on how water spreads over the soil surface and interacts with plants as vegetation expires.

Kealy and Wollkind refined their formula and presented it at the Joint Mathematics Meetings earlier this year in Boston. They received so many invitations to speak at the conference that they had to turn down a few opportunities.

“The work has kind of taken on a life of its own and grown,” Kealy said. “The Joint Mathematics Meetings is kind of the Big Kahuna of math research, so we are getting some recognition.”

The work also has practical implications beyond the simple beauty of math. The equation has joined an ongoing discussion on stopping desertification, the expansion of desert landscapes.

“The big picture is to help understand this vegetation in arid climates and prevent any further desertification,” she said. “That and to show that when math works, it’s really cool.”

According to the International Fund for Agricultural Development, one-fourth of the earth is already desertified. An additional 12 million hectares are lost each year to soil degradation. This equates to losses of $42 billion in income from agriculture and other lost infrastructure.

Kealy thinks her and Wollkind’s equation can help, but she still sees room for improvement. She hopes to adjust the equation for new variables, like how water moves below the soil surface.

“This whole thing seems a little surreal,” Kealy said. “You can’t beat the chance to see your own math in action.”

 

The Myth—and Psychology—of the Better Bat

Lloyd Smith spends a lot of time pondering the performance of bats and balls—aluminum, wood, baseballs, softballs. It’s his job, and he does it well enough that his Sports Science Laboratory is the official bat testing facility for the NCAA.

But while the WSU associate professor of engineering might use his ball cannons and high speed cameras to facilitate an arms race of ever bouncier balls and more powerful bats, the lab focuses more on uniformity, or to mix a metaphor, a level playing field among the tools of the trade.

Flickr photo courtesty of MelvinSchlubman, http://www.flickr.com/photos/pauldineen/

In fact, if you ask him what bat is best, he can’t tell you. That would be a conflict of interest, an implicit endorsement of the people he is supposed to help regulate. Moreover, he says, it just doesn’t matter that much.

It’s a common misconception that there is an enormous difference between bats, he says. By design, the highest-performing softball bat is 10 percent more powerful than a wood bat. The best college bat is 5 percent better.

“The big difference is in player ability,” he says, referring to an on-the-field study showing as much as a 20 percent variation between players.

“When parents come to me and say, ‘Hey, which bat should I buy for my kid,’ I tell them, ‘Go to the weight room and work out. Go play the game. Go work on your skills.’ That’s going to make a lot more difference than spending $300 on the latest and greatest bat.”

Then there are the intangibles that lie outside the realm of measurable physics, like bat comfort. Smith can measure 100 bats and determine the best performer, “but if a player is convinced that this other bat is better, what does that psychology do? What factor does that have?”

That may even have been a factor in the use of illegally corked bats. A study co-authored by Smith in the recent American Journal of Physics found a ball bounced better off a solid wood bat than one hollowed out and filled with a material like cork.

It could be that the lighter corked bat improves a player’s ability to turn on the ball, and a player like Sammy Sosa—caught with a corked bat in 2003—was aiming to improve his batting average, not power. Or it could go back to that intangible psychological factor: He thought the bat worked better, and thinking made it so.

“Suddenly superstition does have a reality,” says Smith, “but we can’t really measure that here, so we stick with the science part.”

To learn more, see “The Physics of Cheating in Baseball” at Smithsonianmag.com.

 

 

Next Stop, Neptune, If the Brakes Work

Next time you’re in a pub with a dart board, pick up a dart, stand at the regulation distance, and toss a bull’s eye. Piece of cake, right? Now, stand in that same pub but throw the dart so that it goes into a nice, near orbit around Neptune. Not so easy this time, eh?

But we’re not done. To make things a little trickier, figure on using Neptune’s atmosphere to brake your dart’s velocity. While you’re at it, calculate the path your dart took to get from the pub to Neptune. Write that path out in a series of differential equations. Write a 500-word abstract. Do all this is 48 hours under the auspices of your faculty mentor. You’re almost done! Last step: enter the paper you’ve just written in the University Physics Competition.

With slight variations on the process above (like, they didn’t actually throw a dart), that’s what three WSU physics majors did. Julian Smith, Kyle Welch and Ken Dorrance spent a recent weekend bravely battling the complexities of Lagrangian mechanics to calculate just what it would take to get a rocket from Earth to Neptune. Their efforts won them a bronze award in the competition.

Left to right: WSU Physics and Astronomy majors Kenneth Dorrance, Kyle Welch and Julian Smith/photo and montage by Brian Charles Clark

A couple centuries ago, mathematician Joseph-Louis Lagrange made significant contributions to celestial mechanics, the area of math that deals with the movements of planets, moons and various other objects in space – including rockets. “Newton’s second law–force equals mass times acceleration–beautifully describes many simple physical systems when forces are known,” says Dorrance, a junior majoring in physics with the nanotechnology option. “Lagrangian mechanics lets you solve some less-than-simple systems without knowing the forces.”

All three of the young physicists agreed that the mechanics involved in aerobraking a probe in the atmosphere of Neptune is a complex business. “Julian and I spent a lot of time staring at the white board, looking for analytical solutions, while Ken worked on coding methods for finding numerical solutions,” says Welch, a senior from Olympia majoring in physics and neuroscience.

“Being someone who focuses on theory, I often like to believe that there will be a clean analytical solution for everything,” says Welch. “However, the complexity introduced by the drag of aerobraking showed me that sometimes you have to give up on finding an exact solution.”

Not only was the problem complex, but the three-person team had only 48 hours in which to formulate their solution. This involved investigating the composition of the upper reaches of Neptune’s atmosphere where the probe would experience frictional resistance and be slowed enough from its interplanetary velocity to go into orbit around the gas giant. Between the three of them, they hammered out a solution that satisfied them.

The University Physics Competition annually offers teams a choice between two problems.

“We chose the problem we thought would be the most interesting, and opted out of the one we thought would be easier to solve,” says Smith a senior in physics from Vashon Island. “The aerobraking problem was exciting for all of us but we really had to think outside the box. This contest taught us to be creative and to think quick.”

Michael Allen, the students’ mentor and competition advisor, says the competition problems are unlike what they would find in a textbook.

“The problems do not have a single approach, and do not have a single correct answer,” he says. “Also, the students are allowed Internet access whilst solving the problem, hence they have a lot of information available to them and must pick that tiny, relevant bit of it to use. In other words, there is scope for being creative, but there is also a need for discipline.”

The Slime that Saves the Planet

Washington State University researchers have received half a million dollars to study a microscopic slime that they believe plays an outsized role in life on the planet.

The slime, also known as biofilm, forms a super-thin layer gluing the roots of plants to mineral surfaces and serves as a reactor in which a plant can break down the rock for vital nutrients. The process, says Kent Keller, was central to the start of land-based plant life as plants invaded the continents 350 million years ago. It continues to take place on modern volcanic ground and receding glaciers—anywhere a plant can’t get enough to eat.

A special root slime helps plants like this pine tree pull nutrients from bare rock. Flickr photo courtesy of eviltomthai.

“The magic of all of this is plants come in that are adapted to make the slime,” says Keller, co-director of the Center for Environmental Research, Education, and Outreach (CEREO) and professor in the School of Earth and Environmental Sciences. “Within 100 years, you’ve got soil. That’s an amazing thing. And it’s these slimes that are a key part of the mechanism.”

Wait, there’s more: The biofilm reactor also facilitates the most fundamental process on the planet for packing away carbon, as seen in the greenhouse gas carbon dioxide. As the plant dissolves minerals, the plant’s natural carbonic acids, made from CO2 through photosynthesis, are transformed into bicarbonate that is carried in runoff to the oceans. There it precipitates as calcium carbonate.

In other words, the biofilm acts as an intermediary between carbon from the atmosphere and its storage in the earth’s crust. Absent that process, carbon dioxide would continue building up in the atmosphere until oxygen-dependent life forms suffocated in a “runaway greenhouse.”

“Without that we wouldn’t be here,” says Keller. “We’d be Venus, because Venus has no mechanism to sequester volcanic CO2.”

But there’s a mystery to the process, which Keller and a group of colleagues will explore with $492,000 from the National Science Foundation. Somehow plants employ biofilms to build up nutrients for plants to use while also releasing them for long-term storage, and they’ve done this in a way in which plants thrive and the chemistry of oceans and the atmosphere is kept in balance.

The researchers—a team of earth, life, and soil scientists—plan to grow trees in different nutrient conditions, including pure sand, to see which are best at inducing the formation of biofilm. One indicator of that will be microbial communities, which essentially generate the biofilms for shelter. The researchers hypothesize that plants in the worst conditions will be predisposed to hosting the most diverse microbial communities, the better to generate slime and nutrients.

One experiment will rely entirely on fertilized irrigation as a proxy for conventional agriculture, which is less reliant on large microbial communities for nutrients. Comparing this system with those generating their own nutrients could help open the door to agricultural systems that can use fewer artificial fertilizers.