# Random Samples

Science  11 Mar 2005:
Vol. 307, Issue 5715, pp. 1558
1. # Non-Euclidean Potholders

Knot theory is no longer the only branch of mathematics that appeals to the handicrafts set. A big crowd showed up last month at the Kitchen, one of Manhattan's hippest performance spaces, to hear a pair of Cornell mathematicians talk about hyperbolic space. Their main props: crocheted models of objects in the hyperbolic plane, a central concept in non-Euclidean geometry.

In ordinary Euclidean space, a flat plane stretches out forever and parallel lines never meet, explained geo-meters Daina Taimina and David Henderson. However, as mathematicians discovered in the early 1800s, that's not true in other kinds of space. In the sphere, for example, parallel lines meet at the poles. In the hyperbolic plane, which can be thought of as the opposite of the sphere, parallel lines shy away from each other.

Hyperbolic space is very hard to picture. For more than a century, mathematicians struggled without notable success to make 3D models of it. Then Taimina had the idea of using her crochet hook. She and Henderson use crocheted models in their classes at Cornell and hope that when people create and play with the objects—which look like witches' hats, flamenco skirts, or curly kale—they'll develop an intuitive sense of what hyperbolic geometry is all about. “We all play with balls as children. With a sphere, you have that memory in your hands. But you don't have that with hyperbolic geometry,” says Taimina.

2. # Man the Eroder

For the past millennium, humans have been moving more earth than all natural processes combined. Just how far have we tipped the balance? Geologist Bruce Wilkinson of the University of Michigan, Ann Arbor, decided to find out.

He calculated prehistoric rates of erosion through the amount of sedimentary rock, the end result of erosion, that has accumulated over the past 500 million years and estimated that natural erosion lowers Earth's land surface about 24 meters every million years. He then calculated the human contribution, combining estimates of erosion from crop tillage, land conversion for grazing, and construction. Averaged out over the world's land surface, that came to about 360 meters per million years, or 15 times the natural rate.

This difference amply demonstrates that current agricultural practices are unsustainable, says Wilkinson, who points out in this month's issue of Geology that at the current rate, the soil eroded from Earth's surface would fill the Grand Canyon in 50 years.

Wilkinson's estimates for natural erosion are similar to those of geologist Paul Bierman of the University of Vermont, Burlington, who has used beryllium isotopes to estimate erosion rates in the Appalachian Mountains from the past 10,000 to 100,000 years. “The most intriguing part of this study is to be able to look back over 500 million years of earth history,” says Bierman.

3. # Talking Turkey on Greenhouse Gas

“It is essential that the G8 summit [next July in Scotland] focuses on securing from the United States an explicit recognition that the case has now been made for acting urgently to avoid the worst effects of climate change by making substantial cuts in greenhouse gas emissions. …

[Denial of global warming in the press] brings to mind the ill-fated and disreputable campaign by The Sunday Times during the early 1990s to deny that HIV causes AIDS.”

—Robert May, president of the U.K.'s Royal Society, in a speech scheduled for delivery in Berlin on 7 March.

4. # Life in the Air

Gene sequencer extraordinaire J. Craig Venter has launched yet another bold venture: inventorying the DNA from bacteria, viruses, fungi, and other microbes floating around in the air.

Venter is currently engaged in a round-the-world project cataloging the organisms—and in particular, their genes—in seawater following a pilot project in the Sargasso Sea (Science, 2 April 2004, p. 66). He has chosen Manhattan as the test bed for a new Air Genome Project.

Using $2.5 million from the New York City-based Alfred P. Sloan Foundation, the J. Craig Venter Institute in Rockville, Maryland, has begun analyzing the material collected from a rooftop filter in midtown Manhattan. There's been “a lot of basic groundwork in terms of designing and trying out different air-sampling devices,” says Venter. The U.S. Department of Homeland Security does some air biomonitoring, he notes, but only for a few hazardous things like anthrax: “Nobody has any idea what the background in the atmosphere is.” Venter hopes the project will go beyond antibioterrorism to finding out “who is there,” including organisms that affect health. He's still tinkering with the technology, which builds on his pioneering use of the whole-genome shotgun approach to explore undefined populations. The institute also plans to collect samples inside buildings. All the data will be put in the public domain. 5. # Awards First choice. India's new science adviser is the inaugural winner of the country's biggest scientific prize. But officials say his high rank in government has nothing to do with his being chosen for the honor. Chemist C. N. R. Rao, who was appointed chair of the Scientific Advisory Council to the Prime Minister in January, wins the$62,500 Indian Science Award for his contributions to solid state chemistry and materials science. A government-appointed panel of 12 scientists from India and overseas picked Rao, 71, in a process that began in early 2004, several months before the current government came to power. “We cannot disqualify a person for being in a certain position,” says India's science minister Kapil Sibal. “The award goes to him for his excellent past work.”

The work has earned recognition outside India, too: Last month, Rao shared the $1 million Dan David Prize (see below) in the Future Time Dimension with Harvard chemist George Whitesides and MIT chemical engineer Robert Langer. Archaeologists Graeme Barker and Israel Finkelstein are the joint winners of the$1 million Dan David Prize in the Past Time Dimension. Barker, a professor at Cambridge University in the U.K., is honored for his contributions to landscape and environmental archaeology, while Finkelstein, a professor at Tel Aviv University in Israel, is recognized for applying archaeological knowledge to reconstruct biblical history. British theater director and filmmaker Peter Brook was honored for the Present Time Dimension. The prize is awarded by the Dan David Foundation and Tel Aviv University.

Open-ended inquiry. Physicist Charles Townes, who received the Nobel Prize in 1964 for inventing the maser and co-inventing the laser, has won the $1.5 million Templeton Prize for his efforts to bridge science and spirituality. The annual award, from the John Templeton Foundation, recognizes individuals who have “advanced knowledge in spiritual matters.” Two years after winning the Nobel, Townes generated controversy with an article on the convergence of science and religion. He has continued to write and talk about the subject. “It is important for us to be open-minded in science and religion. The two are more similar than one may think,” he says. Townes, 89, plans to donate half of the prize money to his alma mater, Furman University in Greenville, South Carolina. Much of the rest will go to faith-based institutions. 6. # Nonprofit World Building bridges. After 30 years in England, U.S.-born anthropologist Leslie Aiello is coming home. Next month, Aiello, a human evolution expert at University College London (UCL), becomes president of the Wenner-Gren Foundation for Anthropological Research in New York City. Last year, the foundation gave out 190 grants totaling over$3 million.

Aiello has spent nearly all of her career at UCL, gradually moving from research into administration. “I found that I liked to make things happen,” she says.

At Wenner-Gren, Aiello, 58, hopes to bridge the gap between biological and social anthropologists. “If we don't keep anthropology as a unified discipline,” she says, “we are in danger of losing some of the spark that could lead to major advances.”

7. # The Extra Mile

Deferred honor. A winner of Germany's top scientific award won't accept a \$2 million prize until her university completes an investigation she requested of a paper from her lab.

Stefanie Dimmeler, a cardiologist at Wolfgang Goethe University in Frankfurt am Main, is one of 10 winners of the Leibniz prize, awarded this month by the German research agency, DFG. Her celebrity revived charges raised a year ago that a figure Dimmeler and her colleagues published in Nature Medicine in November 2003 was identical to one published a few months earlier in Blood. The mistake was the result of a confusing computer system for storing images, Dimmeler says. She and her colleagues repeated the experiments, reached similar conclusions, and published corrections in both journals.

Dimmeler notified the DFG when the mistake was discovered, but the agency decided then that there was no need to investigate. When the Leibniz winners were announced in December, however, an anonymous letter to the DFG raised the issue again and suggested that Dimmeler didn't deserve the prize. To clear up any remaining questions, Dimmeler and the DFG asked her university to conduct an investigation. “We agreed that we should do everything in the most correct way,” she says. The panel is expected to finish its work by May.