# Math Digest

## Summaries of Media Coverage of Math

Edited by Allyn Jackson, AMS
Contributors:
Mike Breen (AMS), Claudia Clark (freelance science writer), Lisa DeKeukelaere (2004 AMS Media Fellow), Annette Emerson (AMS), Brie Finegold (University of California, Santa Barbara), Adriana Salerno (Bates College)

### August 2009

"Baseball by the Numbers" and "Cable Boxes Identify Bargain and Lemon Commercial Slots," by Laura Sanders. Science News, 29 August 2009, page 16.

 These two articles cover the Joint Statistical Meetings, which were held August 1-6 in Washington, DC. In a session entitled "Evaluating and Predicting Player Performance," Benjamin Baumer, who is the Statistical Analyst for the New York Mets and a graduate student in mathematics, presented his paper on improving the system by which baseball players' abilities to field are quantified. The current rating is a function of the number of errors and the number of opportunities the player had to catch the ball. The proposed rating would assign a weight to each catch according to the part of the field on which the ball was caught. Thus players who make particularly difficult plays would be duly rewarded, where they currently are not. This method assumes that the player's position on the field can be easily and accurately measured. Although the new rating system would be fairer than the current one, the point is made that human observations are not to be discounted in favor of numbers only. The second article discusses the mistake in assuming that the most valuable commercial spots are during hit shows. According to data taken from cable boxes, blockbuster shows are not necessarily more likely to retain viewers during commercial breaks than other shows. Marketing professor David Schweidel has found that drama fans "don't touch that dial" while reality show viewers tend to flip channels. He hopes further data collection will reveal more patterns in our tv-watching habits. --- Brie Finegold

"Who Should Get Swine Flu Shots First?," by Bryan Walsh. Time, 21 August 2009, and "Vaccinate students, parents first: study," by Tom Spears. Ottawa Citizen, 20 August 2009.

 With not enough H1N1 flu virus to go around, health officials will need to prioritize who gets the vaccine first. A paper published in the August 20 issue of Science ("Optimizing Influenza Vaccine Distribution," by Jan Medlock and Alison P. Galvani) says that the vaccine should be given first to the groups of people most likely to spread the disease--school-aged children (ages 5 to 19) and adults (many of whom would be parents, ages 30-39). Co-author Jan Medlock, a mathematician at Clemson University, built a mathematical model to determine the optimum age groups to receive a vaccination in order to contain the spread of a potential pandemic. As Walsh concludes, "The Science study offers a chance to get a kind of herd immunity on the cheap by inoculating the super-spreaders first." The story was picked up by newswires and blogs. --- Annette Emerson

"It's Your Beautiful Eyes," by Dr. E. Kirsten Peters. GadsdenTimes, 20 August 2009.

The article profiles mathematician Kevin R. Vixie (Washington State University), whose work includes improving approximations that help in facial recognition done by computers--such as those that might be used in security areas of an airport. Vixie was home-schooled during his teen years, explored various options, then went to graduate school in mathematics. He worked at the Los Alamos National Lab, where he started to focus on the branch of mathematics that led him to this area of research. Kirsten writes, "Not many people can do highly technical work like Vixie. But he is adamant we can all do something well. He found a new start in mathematics at an older age than most, and he believes bright students who may struggle greatly for a time can come roaring back--even in what many of us consider difficult arenas. Vixie's outlook renews my hope for youngsters who have just plunged into the new school year."

--- Annette Emerson

"Who Will Win In Human, Zombie War?, an interview by Robert Siegel. National Public Radio All Things Considered, 20 August 2009.

 In a relatively light-hearted interview, Professor Robert J. Smith? (yes, that's his name, with a question mark because, he says, there are so many Smiths), University of Ottawa, translates work on mathematical models of infectious diseases into a paper "about a different kind of contagion--zombies." The paper, "When Zombies Attack!: Mathematical Modeling of an Outbreak of Zombie Infection" (Philip Munz, Ioan Hudea, Joe Imad and Robert J. Smith?) introduces a basic model for zombie infection, and shows that "only quick, aggressive attacks can stave off the doomsday scenario, the collapse of society as zombies overtake us all." Smith? says the work was a project in a class on disease modeling. "It was just a fun way of really illustrating some of the process that you might have in modeling an infectious disease." The example of a hypothetical zombie attack can of course be likened to a potential outbreak of disease and the possible means of fighting its spread and dealing with those infected. The zombie concept caught on: articles were published in Wired, Globe and Mail, Canada.com, and TimesOnline, among other media. --- Annette Emerson

"A tight squeeze," by Henry Cohn. Nature, 13 August 2009, page 801.

 Princeton researchers have beaten the present world record for packing the most tetrahedra into a volume. Research into these so-called packing problems have produced deep mathematical ideas and led to practical applications as well. Image: Princeton University/Torquato Lab. Two Princeton University researchers, Salvatore Torquato, a professor in the Department of Chemistry and the Princeton Institute for the Science and Technology of Materials, and Yang Jiao, a graduate student in the Department of Mechanical and Aerospace Engineering, have made a major advance in addressing the packing problem of jamming more tetrahedra--solid figures with four triangular faces--and other polyhedral solid objects into a space. The work could result in better ways to store data on compact discs as well as a better understanding of matter itself. Henry Cohn, a mathematician with Microsoft Research New England in Cambridge, MA, summarizes the research paper ("Dense packings of the Platonic and Archimedean solids") published in the same issue of Nature on page 876. "We all know from experience with luggage how difficult it is to pack objects efficiently into a limited space. These difficulties are even greater when huge numbers of objects, such as grains of wheat, are involved." He goes on to note that although the researchers study packings of the precise shapes of five Platonic solids (tetrahedron, cube, octahedron, dodecahedron and icosahedron), "they are a beautiful test case for understanding the effects of corners and edges and the role of symmetry... This latest insight into the part played by symmetry might take on the role of a twenty-first-century Kepler conjecture [and] inspire many future research papers." The paper and graphics by Torquato and Jiao are featured on the front cover of the 13 August Nature with the headline "A Platonic Affair." --- Annette Emerson

"Earth Science From the Sky: The Next Generation," by John Hamilton. National Public Radio Morning Edition, 12 August 2009.

 Graduate student Daniel Tkacik (right) with engineer David Van Glist. The University of North Dakota organized this student activity with NASA funding and using NASA aircraft. The photo was taken by a multimedia person from the university. Image courtesy NASA Photo/University of North Dakota. NASA's new Student Airborne Research Program (SARP), a six-week session that includes research aboard a DC-8 flying laboratory, aims to get young people excited about solving problems like warming oceans, rising carbon dioxide levels and new pollutants in the air. One of the students interviewed for this NPR segment is Daniel Tkacik, who plans to start a Ph.D. program in civil and environmental engineering at Carnegie Mellon University. Narrator Hamilton notes that these students are highly motivated and interested in earth science, and have been taking all the right courses since high school. When asked what courses prepared him for the NASA program Tkacik rattles off "calculus, calculus II, linear algebra, differential equations, multivariable calculus..." --- Annette Emerson

"The economy needs agent-based modelling,” by J. Doyne Farmer and Duncan Foley. Nature, 6 August 2009, page 685.

In this article, Farmer and Foley propose a different, seemingly better way to model the economy to help guide financial policies, known as an agent-based model. Traditionally, two types of models have been used. The first one is based on empirical statistical models based on past data, and it fails whenever there are great changes. The second is “dynamic stochastic general equilibrium,” which basically assumes a perfect world. The authors propose using agent-based modeling, or computerized simulations of interactions between a number of agents and institutions with some prescribed rules. These models simulate complex and nonlinear behavior that is so far intractable in equilibrium models. They have been used successfully in areas such as epidemiology and traffic control. The authors give a detailed account of how the systems and models have evolved throughout history and how the ones currently used will continue to fail in predicting the economy. They also mention a few promising efforts in applying agent-based models in small portions of the economy, such as Farmer’s work exploring how leverage affects fluctuations in stock prices. In general, these models seem to give statistics that look very much like reality. Of course, the researchers admit, “creating a carefully crafted agent-based model of the whole economy is a huge undertaking.” Such research would require serious computing power and interdisciplinary collaboration, and “a few million dollars – much less than 0.001% of the US financial stimulus package against the recession.”

"Six Degrees of Nolan Ryan: Network Science Ranks Baseball Greats," by Brandon Keim. Wired, 4 August 2009.

 Mathematicians have recently announced more scientific approach to the time-honored, often subjective debate over how baseball greats stack up against each other--Mickey Mantle vs. Barry Bonds? Using network science, the scientists start by deriving a score for each time Pitcher A faced Batter B in a given season, based on the expected number of runs Batter B's team would earn before the end of the inning. Summing these scores for each at-bat results in a total score for each pitcher-batter pair in the league that season. From there, the model calculates a final score for A vs. B that involves how A performed against other batters and B against other pitchers. Extending the model to cover all at-bats between 1956 and 2008 allowed the scientists to compute a final score for any pair of players in that time period, similar to the "Six Degrees of Kevin Bacon" game. The scientists are still modifying the model to account for stolen bases and differences between ballparks, but so far the results have offered new fodder for the debate over who was robbed of Hall of Fame honors and which players may not have deserved that Cy Young Award. --- Lisa DeKeukelaere

"Dark energy may disguise shape of universe," by Pedro Ferreira. New Scientist, 3 August 2009.

 Image: European Space Agency. Cosmologist Ferreira dissects and questions the key idea that the universe is flat—a widely held belief that multiple research efforts appeared to confirm in the late 1990s and early 2000s. Cosmologists had believed the universe must be flat because it had not collapsed, as it would if it had positive curvature, or blown apart, as it would if the curvature were negative. Research in the past few decades examined the apparent change over hundreds of thousands of years in the size of spots in the earth’s cosmic microwave background and concluded that the results fit the change expected if the universe were flat. The problem, according to Ferreira, is gaps in cosmologists’ understanding of dark energy, which makes up 70% of the universe and whose properties contribute to how scientists computed the expected change in the size of the spots. Understanding dark energy is interdependent with understanding the universe’s curvature, but upcoming NASA missions and telescope construction are intended to address these questions. --- Lisa DeKeukelaere

"Too Much Happiness," by Alice Munro. Harper's, August 2009.

In this short story, well-known writer Alice Munro attempts to capture some moments in the life of a fictionalized Sonya Kovalevsky (a 19th century Russian mathematician). Munro paints a picture of a passionate woman who marries early in order to escape from home and study mathematics in Germany, who becomes a mother, a widow, a novelist, and a mathematician only to die early, even before her ailing mentor Karl Weierstrauss. Munro's Sonya alternately tip-toes around the egos of dismissive countrymen and carves her own way via her mathematical achievements to academic recognition in Sweden.

Whether personal details of the last few days of her life and of her romance with Maxim Kovalevsky are true to life or not, the references to Kovalevsky's mathematical life are accurate. Her winning the Bordin prize in France is mentioned as an emotional point in the story. And terms like "celestial mechanics", "partial differential equations", and "theta functions", which have probably never seen the pages of Harper's, naturally arise and make the story believable. The story "Too Much Happiness" is also contained in Alice Munro's newest book of the same name.

--- Brie Finegold