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Light Wave Outlasts Itself
Physical Review Focus, May 12, 2004
A flash of light in water can cast off smaller flashes with surprising properties--they can travel faster and farther than the original flash. New evidence of these so-called precursors appears in the 14 May PRL. The experiment is a rare confirmation of a 90-year-old theory and the first complete demonstration of the effect using visible light. A fuller understanding of precursors could lead to advances in medical imaging and underwater communication.
If you flash a quick burst of white light in empty space, it will travel unchanged. But in a material like water or glass, the pulse will spread out as it travels, because each color within the white light moves with a different speed. If you use an ultrashort pulse of laser light instead of white light, the pulse will also break up, shedding smaller bits called precursors as it goes. Water, like most materials, has a set of exceptional frequencies at which light can travel especially cleanly, and the precursors appear at those favored frequencies. But the frequencies aren't fixed--they change as the precursor moves through the material. An observer with superhuman vision watching a flash of light travel through water would first see a high frequency precursor galloping along at close to the speed of light. The color of that precursor would change as the observer watched. Additional precursors, with morphing colors, would follow. A bit later she would see the flash of the original light pulse.
"The precursor is like soap in the bathtub; it's kind of slippery," says Ulf Österberg of Dartmouth College in Hanover, New Hampshire. "It's like it's alive, it's breathing, it's moving along and changing the whole time," in terms of the frequencies it contains. That mercurial nature makes a precursor hard to detect--only two teams have reported seeing precursors with visible light, and those were under special conditions [1, 2].
The key to observing precursors is their surprising tenacity. At long distances, where the main pulse has faded into oblivion, the precursor will still be detectable because it propagates so efficiently at its "favored" frequencies. Mathematically, the main signal dies away exponentially as it is absorbed by the material, whereas the precursors only fade away with the square root of the distance from the source.
To detect a visible precursor, Österberg and his Dartmouth colleague Seung-Ho Choi sent a 100-femtosecond pulse of light into a tube of water. With such an ultrashort pulse, the laser's color is not sharply defined, and it automatically contains all the necessary frequencies. They detected a flash in the water a meter away--a distance at which the initial pulse should have all but disappeared. The signal that they observed faded away gradually, as the square root of the distance.
"That's the smoking gun right there, " says Kurt Oughstun of the University of Vermont, who has been describing precursors theoretically for the past 25 years. "I was very pleased to see it. It's a very nice result." He is more confident that Österberg and Choi have seen a true visible precursor than he is about the two earlier experiments [1, 2].
"The applications of this are far reaching, " says Oughstun. "You can use [precursors] for communication underwater, which has obvious military applications." They could also have medical uses. Precursors could probe deeper into the body for better imaging, such as in mammography, says Oughstun.
--Stephanie Chasteen
Stephanie Chasteen is a freelance writer and physics graduate student at the
University of California at Santa Cruz.
References:
[1] J. Aaviksoo, J. Kuhl, and K. Ploog, "Observation of optical precursors
at pulse propagation in GaAs," Phys. Rev. A, 44, 5353 (1991).
[2] M. Sakai, et al., "Polariton pulse propagation at exciton resonance
in CuCl: Polariton beat and optical precursor," Phys. Rev. B 66, 33302
(2002).
Dinosaur find HOST This week a team of Indian and American scientists unveiled a new species of dinosaur. It's skull is the most complete yet found in India. NPR's Stephanie Chasteen reports CHASTEEN Rajasaurus narmadensis, "the prince of the Narmada region"
was a stocky carnivore. Horse Clone Spot HOST This week italian scientists reported the birth of the first cloned horse. The foal, named Prometea (pro-ME-tee-ah), joins a growing list of cloned animals. NPR's Stephanie Chasteen reports. CHASTEEN The horse is the second equine species to be cloned. Stephanie Chasteen, NPR News, Washington Depression Gene Spot. Not for air HOST Scientists have found a gene that may play a role in how people respond
to traumatic life events. This may explain why some people get clinically
depressed after the death of a loved one or the breakup of a relationship,
whereas others bounce back more quickly. CHASTEEN Researchers in London and Wisconsin asked 800 young adults about the
most terrible things that had happened to them during the last 5 years.
Depression Gene Story Not for air HOST: People respond differently to life's traumas. But it's not known why ONE person may get clinically depressed when (for example) a parent dies, whereas someone else bounces back relatively quickly. Scientists have now found a gene that plays a role in people's sensitivity to life's stresses. NPR's Stephanie Chasteen reports.
Genes are like ingredients in a recipe. Many things about us can be traced back to our DNA: The color of our eyes. How many fingers and toes we have. Our genes even play some role in shaping our personality. But genetics tell only PART of the story. For example, many illnesses are caused partly by genes, and partly by life. Terrie Moffitt is a psychologist at King's College in London. (MOFFIT: with heart disease there's a poor diet, lack of exercise, and too much smoking... in case of depression the environmental risk factor is stressful life events.) [Duration:0'12"] For instance, the death of a parent, or the ending of a relationship. But while most people get sad when something like that happens, not everyone gets clinically depressed. Researchers wanted to know WHY. So Moffitt and her colleagues looked at whether it had anything to do with their GENES. In particular, they studied a gene called 5-HTT. 5-HTT varies from person to person. Some people have a short version. Others have a long version. (MOFFITT: There was already some research that animals that have the short variant were more sensitive to stress and more fearful in a frightening experiment than animals that have the long variant, and that's why we chose to look at this particular gene.) [Duration:0'18"] They ALSO suspected that 5-HTT had something to do with DEPRESSION. 5-HTT regulates the flow of serotonin. Serotonin is a chemical messenger in the brain known to be involved in depression. It's the target of many antidepressant drugs, like Prozac and Paxil. So Moffitt and her colleagues studied about 800 young adults in New Zealand. They asked them whether they had suffered from clinical depression, and if they had experienced any stressful events. The researchers also tested them to see which form of the 5-HTT gene they had. A remarkable pattern emerged. (MOFFITT: If you have the short version of the gene your risk of depression is doubled if you have stressful life events, if you have the long version, your risk of depression is halved.)[Duration:0'10"] 5-HTT isn't really a "depression gene" says Moffitt. (MOFFITT: The gene itself has no direct effect on depression, it only controls sensitivity to life stress.)[Duration:0'08"] …although of course it's not the only thing affecting how people handle their problems. The study was published in this week's issue of the journal Science. So, should we all run out and get tested to see which version of 5-HTT we have? Terrie Moffitt wondered what version she had, so she got tested, and came up short - that is, she had the short version of the gene. That suggests that she's more sensitive to life's hardships. (MOFFITT: So that tells me that if I ever see a stressful life event coming, I want to engage a psychotherapist right away)[Duration:0'08"] That may not be an option for many people. And besides, other geneticists say such use of the 5-HTT gene is premature. Douglas Levinson is at the University of Pennsylvania. (LEVINSON: I don't think we have enough evidence to indicate that any one genetic variation should dictate someone's behavior. I think that people who are very vulnerable to stress know who they are... Some people know they're thrown for a loop, and they've seen other people who are much more resistant to that sort of thing)[Duration:0'20"] For now, that's a much better way to predict who's likely to get depressed, he says, than any particular gene. He says, however, that Moffit has discovered the first of many genes that play some role in depression. Future studies will turn up more genes. (LEVINSON: … but it remains to be seen how many and how quickly and how fast. And eventually the whole picture will be known, but it will take some time) [Duration:0'6"] That could mean better treatment, and even prevention, for the millions of people suffering from clinical depression. For NPR News in Washington, I'm Stephanie Chasteen. Labor Onset Spot
Scientists have come a step closer to solving the puzzle of what prompts women to go into labor. This could eventually help researchers develop therapies to prevent premature births. NPR's Stephanie Chasteen has more. CHASTEEN The hormone progesterone maintains a pregnancy, by keeping the uterus
from contracting. NASA… Down to Earth? HOST Warp drive…wormholes… light speed travel… sounds like a bunch of craaaazy science fiction. But look at how LONG it's gonna take the MARS rovers to get to the red planet…7 MONTHS for the galactic equivalent…of crossing the street. With this technology, it would take THOUSANDS of years to get to the next solar system. As Intern Edition's Stephanie Chasteen reports, some folks at NASA have seriously explored some far out ideas on how we could reach the stars. CHASTEEN Like lots of kids, Marc Millis was fascinated by the idea of space travel. (MILLIS: If we could truly figure out how to travel easily to other star systems and reach other planets that would have a huge benefit on humanity...it would give us hopefully, if there's one out there, a backup earth to find someday if we mess up this one.) [Duration:0'16"] So when he grew up, he went to work for NASA. (MILLIS: We're trying to make the kinds of things you see on star trek REAL.) [Duration:0'03"] …or at least investigate some science inspired by those ideas. For example… there's a force driving the universe's continuing expansion.
(MILLIS: The easiest way to describe it is, that if you take all the energy out of a space there still appears to be some energy left)(.)[Duration:0'08"] A handful of SUPPORTERS hoped they could eventually harness that energy to power a space-ship. Or, what if gravity could be blocked…even a little bit? He said that if you spin a ceramic disk in a magnetic field, and hit
it with some radio waves, then things above the disk seem to get lighter
somehow. (KOCZOR: It's beyond our understanding why this would happen but here we have a fellow who's a reputable scientist working in a university in Finland, he did some research, he got it published in a peer reviewed scientific journal) [Duration:0'14"] So NASA decided to take a look at it and see if this was for real…
(KOCZOR: You can't say that we know everything there is today, and if you close your mind to new possibilities, you're on the way back to the caves, as far as I can tell. [Duration:0'10"] Those are pretty strong words. Scientists tend to be fairly cautious.
Laurence Krauss is a physicist at Case Western University. (KRAUSS: We understand classical gravity and E&M as well as anything in nature, infact they've been tested at the level of one part in a billion, so there's an area that's WELL understood, where there AREN"T mysteries and you're not going to expect sudden new discoveries) [Duration:0'16"] He's not against doing science on the edge… But the spinning disk
experiment went too far. (KRAUSS: I think the goals were laudable, I think the people involved in the program were well-intentioned... But the programs that they were looking at really weren't he programs I would fund as a scientist)[Duration:0'14"] So -- if there was so little chance of any of this stuff panning out, why did NASA bother? Well, defenders argue that the benefits would be huge, and the agency
wasn't exactly emptying its pockets. But according to Bob Park, professor of physics at the University of Maryland, these projects carry another… HIDDEN cost. (ACT 9 - BP: It tends to mislead people about what is possible and what is not. People need to understand that there's some things we CAN'T do, no matter how badly we WANT to.) [Duration:0'10"] Today a pile of completed hardware for the gravity shielding experiment
sits unused, in the back of a Lab at NASA. For Intern Edition, this is Stephanie Chasteen. August/September 2003 ISSUE of APS News APS Selects Three as 2003 Mass Media Fellows
(excerpted) Three young physicists are spending this summer gaining invaluable firsthand experience in communicating science through the media as the 2003 APS mass media fellows. Stephanie Chasteen, a graduate student at University of California, Santa Cruz, is interning at National Public Radio (NPR) in Washington DC. Allison Heinrichs, a recent graduate of Ohio State University, is interning at the Los Angeles Times. And Cathy Nangini, a graduate student at the University of Toronto in Ontario, Canada, is interning at the Milwaukee Journal Sentinel. Chasteen attended Bard College in New York's Hudson Valley as an undergraduate, and while she loved physics, she decided to pursue a major in psychology. Chasteen was the only woman in her department, and while her grades were excellent, "I felt intimidated by the physics classes, even though I did very well, because it seemed to come so much easier for the guys," she says. "No one told me I was good at it, so I felt I didn't have what it took." But physics continued to fascinate her. Her confidence received a boost when a former physics professor expressed his disappointment at her decision not to major in his subject, telling her she'd been one of the best students in the class. Encouraged, she decided to pursue graduate studies at the University of California, Santa Cruz. First, however, she chose to spend two years volunteering with the Peace Corps in Guinea, West Africa. At Santa Cruz, she elected to specialize in condensed matter physics, working on polymer photovoltaics (solar cells). During this time, she also became interested in science writing. "I have a very general interest in science, from biology to physics to ecology," she says. And I have a great interest in scientific literacy: helping the public to achieve a greater view of the role science plays in their lives, particularly on environmental issues like global warming." Chasteen decided to apply for the APS Mass Media Fellowship as a means of furthering her career goals in science writing by gaining some firsthand experience. She started freelancing over the last year, and plans to go into science communication when she completes her PhD in 2005. For more information on the APS Mass Media Fellowship program, see
http://www.aps.org/public_affairs/massmedia/ Santa Cruz Sentinel: STYLE (Article about my NPR experience, by another reporter) September 16, 2003 Townsend: Namedropping On NPR That’s right, Stephanie Chasteen. Stephanie, a UC Santa Cruz student, worked as an intern for National Public Radio, helping to produce a news show called "Intern Edition." Stephanie is a science reporter for "Intern Edition," a fourth-year doctoral candidate in condensed matter physics. She was chosen for the internship as part of an American Association for the Advancement of Science fellowship program designed to teach researchers to communicate science to the public. Stephanie graduated from Bard College in New York, and spent two years in the Peace Corps in Guinea, West Africa, as a public health volunteer. "Intern Edition" debuted July 30.
Science & Spirit, Critical Mass lead Jan/Feb 2004 Who Owns the Wind? Louis Woodward has ranched his land in a desolate area of western Texas near McCamey since the 1950s. Dirt roads snake over his property, following the path of the wind rushing up the sides of the flat-topped mesas. Pockmarked by the fat straws of oil wells feeding our nation's hunger for energy, the Texas landscape has added something new to its horizon: windmills. Hundreds of them now dot the southwest. The roads on Woodward's property lead up to 242 monolithic wind turbines that generate enough electricity to supply upwards of 40,000 U.S. homes. Woodward is pleased to lease his land to the third-largest wind farm in the state - he likes the idea of clean power, he gets paid an ample sum, and his sheep and goats huddle in the scant shade at the bottom of the towers. And for a dying oil-patch town like McCamey, it represents a breath of fresh air. "The main street where everybody used to trade doesn't have many merchants on it anymore," says Woodward. "At one time you could get most anything you wanted there… Now I'm not right sure you could buy lumber in McCamey." Maybe that, too, is changing. McCamey has embraced wind energy as a new source of revenue, welcoming the lease payments, tax money, and jobs. Texas, second only to California in wind-energy production, is once again playing host to a promising new source of power, but this time the product is a renewable resource - not a fossil fuel. Technological advancements and federal tax credits have recently granted the gift of profitability to wind energy, landing it on the radar screen of private developers and utilities. While this would seem to be great news for the future of wind power and renewable energy, not everyone is convinced. Some opponents worry that the massive wind turbines will dominate the natural landscape or pose a hazard to birds. Others protest the rapid development of a nascent industry that lacks well-defined regulations. Many skeptics simply distrust the looming specter of big business and wonder how a balance between public good and private gain will be achieved and maintained. One thing is clear: Once profit is involved, all motives become suspect. Take Cape Wind, for example. This proposed wind farm would include an estimated 130 wind turbines, each taller than the Statue of Liberty. It would produce up to three-quarters of the energy consumed by Cape Cod residents and would cover twenty-four square miles of terrain. And like many other wind farms in densely populated regions, it's been slated for development offshore - five miles off the coast of Cape Cod, in the waters of Nantucket Sound. Some welcome the idea; others are not so sure. "[Nantucket Sound] is a public resource that belongs to everybody," says Isaac Rosen, executive director of Save Our Sound, an organization dedicated to protesting the Cape Wind project. "The idea of a developer simply sticking a shovel into it and claiming it as his own … infuriates not only environmentalists but also the taxpayers who own the resources." Private use of a public resource is nothing new. Lumber companies log our national forests, oil rigs are anchored in coastal waters, and mining companies scrape coal from the soil. But, argues Rosen, those industries are mature and well-regulated. Offshore wind is not. In Texas, Woodward is familiar with the protests. "They don't want it in their backyard," he says, comparing
it to the introduction of oil refineries in his home state. "I suppose
if they were getting a little money out of it they So what benefit does Cape Wind promise to the locals, and how best can we assign a value to what can potentially be gained - and lost? There are practical rewards, like new jobs, but unlike destitute little McCamey, the tourist-rich Cape doesn't need a wind farm to jumpstart a renaissance. And there are broad-view advantages, such as using renewable energy to lessen dependence on fossil fuels, but these benefits aren't as tangible as a wind turbine in a public backyard, and some see them as short-shrift in exchange for their unfettered view of the natural world. "I just can't sit back and witness the ruination of our magnificent, irreplaceable rural heritage without doing something to avert such a disaster," says Angela Kelly, chairperson of an opposition group called Country Guardian, based in the rolling hills of Wales. "The wind industry…is composed of hardnosed businessmen hell-bent on fulfilling their ambitious money-making schemes at the expense of the countryside and their fellow men who have to endure the consequences. They're not environmentalists." Indeed, private businesses are often motivated by profit, not necessarily the public good. But that's how regulated capitalism works. Shell, for instance, has made significant investment to build a wind portfolio. "On the one hand, we see the environmental benefit and we believe in that 100 percent," says Jeremy Cohen, spokesperson for Shell Renewables. "But on the other hand, we're not going to see wind or solar or anything else being the solution to the energy needs of the future if it can't be commercially successful." And that commercial success is key to the rising interest of private companies in wind development. On a dollar-for-dollar basis, wind is cost-competitive with the soaring prices of natural gas. It's still more expensive than nuclear and coal power, but studies suggest that when all costs (such as health care for coal miners stricken by black lung disease, or federal subsidies of nuclear power) are taken into account, wind energy is actually cheaper. It's certainly the most cost-effective and mature renewable energy technology -- about five times cheaper than solar power. So maybe it should come as no surprise that wind energy generation has quadrupled globally over the last five years, and some scenarios predict renewables will meet up to one-third of the world's energy needs by 2050. Increased reliance on renewable fuels, as well as decreased energy consumption, is crucial to curbing the threat of global warming. And it seems to make sense for major energy companies to invest strategically in what may be the future of energy. FPL Energy, a subsidiary of the utility giant FPL Group, is the largest developer, owner, and operator of wind projects in America. Like Shell, the oil and gas company ABB has a growing wind energy unit, and General Electric bought out Enron Wind when that company went bankrupt. "I think the best outcomes occur when economic interests align with the ethical interests of society," says "We have to transform the energy system of the world and I think that's only going to happen through the marketplace."," says William Moomaw, a professor of Environmental Policy at Tufts University near Boston. The energy giants have the resources to do wind power in a big way - a way that would make a real dent in global consumption of fossil fuels. If consumers want clean power, the fastest way to get there may be by working with these big energy players. According to Russel Smith of the Texas Renewable Energy Industries Association, that's the key to Texas' wind energy success. "They have the resources, they know the energy business, they have the energy infrastructure," says Smith, who worked closely with the utilities to secure passage of a key state bill four years ago that fueled the wind energy boom in Texas. "They are the energy industry, and we are trying to be part of the energy industry. Anyone who thinks that we are going to be the energy industry anytime lives in a fantasy world." Yet history is instructive. Time and again, the common good has been overshadowed by the pursuit of profit. In the 1970s GE dropped about 1.3 million pounds of toxic PCBs into the Hudson River. Exxon was said to have scrimped on measures to clean up the 1989 Valdez oil spill. And the hulks of abandoned steel mills still litter the towns of the eastern seaboard. While windmills are a relatively benign development compared to such threats, they could have long-lasting impacts. Save Our Sound, for example, is concerned that the waters of Nantucket Sound will be filled with obsolete windmills in twenty-years time. "I don't think it's farfetched to worry about this kind of thing," says Moomaw. "But there are ways in which the public can protect itself against these adverse outcomes. I think we need a good, clear set of rules. I think the best outcomes occur when economic interests align with the ethical interests of society," Ideally, some balance between public and private ownership would give communities not only the ability, but the incentive to drive these regulations themselves. They would also get some direct economic benefit from the project, further vesting their interest in its success. This sort of joint ownership is part of the reason wind energy has been so successful elsewhere - particularly in Europe. But in the absence of cooperative development, the struggle for consensus continues. "We have to ask the larger question: Should wind be owned and financed differently from other energy projects?" says Seth Kaplan, a senior attorney with the Conservation Law Foundation. "It's asking an awful lot of wind power to overcome public concern about aesthetics and commercialize a new technology and ask it to be developed completely different from everything else. It's just really important that we do not sacrifice the good to the perfect." So why not just build wind farms where they are wanted and avoid these thorny issues? Theoretically, we could generate enough power from the America's heartland to supply the country, but wind energy isn't transportable, like oil or gas, and needs to be produced close to the population centers where it will be used. To promote the development of this renewable resource, compromises must be made. "In order to be fair to our children and future generations, we have to act like they're in the room with us when we're making these decisions," says the Sierra Club's Gary Skulnik. "If we're trying to save our little patch of water or our little patch of woods then that means that our children won't grow up in a world with a stable climate and they'll have all these disasters. Is that a trade-off we're willing to make?" We have to decide what we want. So forFor some, like Woodward in the desert plains of Texas where dollars are so desperately needed and the land is privately owned and drab, the decisions are clear. But on the coastline of Nanutucket and Cape Cod, things are more complicated. It's not simply a question of Cape Wind or no Cape Wind, or private interest versus public good. Wind is like a Rorschach test in that different people see shadows of their favorite issues within the burgeoning industry, such as the need for renewable energy, regulated development, or public ownership of energy. The problem is how everyone can win, when someone's got to lose a little. Ultimately, the question becomes: Who will own the wind?
Science & Spirit, Critical Mass section May/June 2003 Bait & Switch A scuba diver off the coast of Hawaii marvels at the rainbow of coral
reef fish surrounding her -- yellow tang, silvery smooth wrasse, and flame
angelfish the color of a sunrise. Yet there is even more diversity in
the water than the stunning array of flickering colors - about one quarter
of the fish that she sees have changed from male to female, or vice versa,
at some point in their lives. Citing such examples as sex-changing fish, homosexual behavior among
over 300 vertebrates, and promiscuous female birds, many evolutionary
biologists are clamoring for a change in theories of how sexual and behavioral
traits evolved. At February's annual meeting of the American Association
for the Advancement of Science (AAAS) - the largest interdisciplinary
scientific meeting in the world - Stanford biologist Joan Roughgarden
and four other scientists presented accumulating evidence that Darwin's
theories require sweeping revision. In particular, evidence is mounting that neither males nor females act
in distinct and prescribed ways, as claimed by Darwin's theory of sexual
selection. Darwin's theories of natural selection provided biologists with a good
explanation for the evolution of traits over time, favoring 'survival
of the fittest.' But natural selection doesn't explain the unwieldy characteristics
often shown by males, such as the beautiful but cumbersome peacock's tail.
To solve this problem, Darwin quietly made the revolutionary claim that
females essentially bred such characteristics into males. Because females
prefer certain types of males - the bullfrog with the loudest voice, the
bowerbird with the prettiest bower, or the peacock with the fanciest tail
- this acts as a selection pressure on males of the species. This is called
sexual selection. Research casts doubt on Darwin's claims that certain essential sexual
behaviors distinguish between the sexes. In particular, Darwin postulated
that promiscuous males compete amongst themselves for females who are
reluctant to mate. But in the ten years he has spent studying Japanese
macaques, a type of monkey that lives in the snowy mountains near Kyoto,
researcher Paul Vasey has compiled evidence to the contrary. "I see
females competing for males all the time.I see males ignoring females
that are desperate to copulate with them.", says Vasey, adding that
he has also observed female macaques actively seeking out other females
as sexual partners. If the sexes aren't simply distinguishable by behavior, can't we at least
classify an individual as male or female based upon whether it produces
eggs or sperm? Not necessarily. Some species are asexual, unisexual, hermaphroditic,
or have up to five distinct genders. Sex is surprisingly flexible in fish,
says marine biologist Robert Warner, who was among the first to study
sex-changing fish twenty years ago. Half of the known species of coral
fish may develop as male or female, change sex during the course of their
lives, or pursue mates in different ways, depending upon what works best
for them at the time. Roughgarden also suggests that some sexual behaviors fulfill social functions
that cannot be explained by Darwinian sexual selection theory. For instance,
homosexuality among bonobos, a type of ape, appears to have evolved to
help ease group tensions. Even the human brain could be explained as a socially selected trait,
says Roughgarden. She believes that our large brains give us the group
membership necessary for survival. This proposal is in stark contrast
to the work of evolutionary psychologist Geoffrey Miller [Science &
Spirit, September-October, 2002] who views the human brain as a product
of sexual selection. Miller argues that brains evolved because females
found smart men attractive, taking IQ as an indicator of good genes, thus
creating selection pressure for the evolution of large brains. While we can't be sure who is right, it would seem that traditional Darwinian
sexual selection is insufficient to explain the array of sexual behaviors
in nature - it must either be discarded or broadened. While it does a
good job with showy males like peacocks, it fails to explain the social
function of sex or the fuzzy lines between male and female. For Roughgarden, these new ideas about evolution represent a fundamental
shift in how we view biology and gender - she believes the weight of evidence
has tipped the scales against long-held views of gender and sexuality.
"Darwin is incorrect in the particulars, but more importantly, [his
theory of sexual selection] is inadequate even as an approach,'' she says. Miller, and others, disagree with Roughgarden's dramatic approach: "What's
happening is a very exciting refinement of Darwinian theory concerning
sexual selection, by no means an overthrow of it," says Miller. "Every
good evolutionary biologist working on sexual selection theory is working
to extend [Darwin's key] insights in new directions - without throwing
the baby out with the bathwater." Page 1 - Santa Cruz Sentinel - November 15, 2002 Bonnie Raitt Powers Solar Benefit Stephanie Chasteen, Sentinel Correspondent
The Vote Solar initiative was responsible for the $100 million solar bond passed last year in San Francisco. Next week Raitt will join Robert Redford in the dedication ceremony for the first project on the bond - the solarization of the Moscone Center. At 675 kW the installation will be one of the largest solar rooftops in the country, second only to the 1100 kW system on the Santa Rita jail. "Our goal is to bring solar energy into the mainstream," said Vote Solar's program director, David Hochschild. "Every time demand for solar doubles the costs go down by about 20 percent, so what we're trying to do is to encourage a number of local governments to make large investments in solar energy." "I certainly hope Santa Cruz does. I think the opportunity is there,"
he said. Local nonprofit Santa Cruz Energy Action Coalition is pursuing, among
other projects, a solar bond modeled after that in San Francisco. "We really believe that local control (of power) and renewable energy
sources are the way to go, and hopefully our leaders will lead and if
not, we'll do whatever's required to bring initiative on the ballot to...
bring this to the public's awareness," said Luke Lehman of SCEAC. "The presence of these companies and their products means they endorse
our basic principle of ecological harmony, and our belief in the timeless
Quaker philosophy - that you can do good at the same time you are doing
well," said Raitt. One way local businesses can "do good" is to install a solar
electric system. Due to the high rate of energy usage by businesses, solar
electric can make a lot of sense for these customers as well as making
a large environmental impact. Solar electric systems over 10 kw currently
represent the most financially feasible and probably the fastest-growing
sector of the solar industry, according to Scott Ragsdale of Cooperative
Community Energy. "There is a lot of roof space on many buildings around town that
can be used for this purpose," said Roger DeNault of Solar Technologies.
Adelman's record will soon be surpassed: West Marine Products, on 17th
Avenue in Santa Cruz, recently contracted with Solar Technologies to build
a 57.6 kW system capable of providing about half of the store's energy
usage. Barry Swenson Builders plans to install a similar system at its
Live Oak office. "They deserve a lot of credit for being one of the first companies
in this area to recognize the cost effectiveness of solar energy and its
beneficial effect on an environment we all care about," said DeNault. Other local business/institutional installations include Artwork Conversion
Software, Inc. in Westside Santa Cruz, and the Unitarian Universalist
Fellowship in Freedom. The coffee shop at 120 Union St. (formerly Jahva
House) has also made inquiries into a modest solar installation. Raitt, along with Robert Redford, Graham Nash, and David Crosby (of Crosby,
Stills, and Nash) lobbied for passage of this bill. Santa Cruz Sentinel - Real Estate - November 10, 2002 Solar Power Still Too Expensive Stephanie Chasteen, Sentinel Correspondent BONNY DOON - If you look at the bright side, Debi Baker hasn't paid
a Pacific Gas and Electric bill for 3 years. Instead, the beleaguered
utility pays her for the excess energy that she feeds back into the grid
from the solar panels mounted on her roof. Despite Santa Cruz's environmentally friendly leanings - even Santa Cruz
City Hall is solar powered - less than 100 homes (about 0.1% of single
family residences) in the county are generating solar power. In the nation,
solar electric provides less than 0.005% of total U.S. electricity consumption,
according to an analysis by Greenpeace. Why? It's simply too expensive up front. Two local men have been involved with solar since the 1970's: Roger DeNault
works with Santa Cruz-based solar-installation company Solar Technologies,
and Mike Arenson constitutes the Santa Cruz branch Sunnyvale-based Ecoenergies.
Both estimate that they get 20-25 queries for every job installed. DeNault
notes that this is a substantially worse ratio than in real estate sales.
What turns customers away? "Mostly money," he says. "Even though the state pays for
half the deal, the other half is still expensive for a lot of people." "They love watching their meter run backwards," he said. And
for him, "it's just a lot of fun. This is the opportunity we've been
looking for to give power back to the people; (solar power) is free, it's
already there." Tapping into that power, however, is not free at all. After 25 years of research, the cost of silicon solar cells has been
slashed to just 1% of what it was in the 1970's. The best route to further
reductions is unclear. Tehnological advances could make better solar cells,
or increased demand and mass production could drive down the price. The construction of a large-scale photovoltaic production plant could
bring the cost of solar within range of fossil fuels, according to a study
conducted by independent consulting company KPMG for Greenpeace. The up-front
cost of such production would be $660 million. "The question of who
will make this scale of investment needs to be answered," says Greenpeace.
"(The Federal government's) present commitments are… entirely
inadequate for the task." Dr. Greg Smestad, a local researcher in solar energy, argues instead that we must focus on developing new materials for solar energy. "The market isn't growing fast enough," he says. Because silicon is fabricated at extreme temperatures and low pressures, it is intrinsically expensive to make. Smestad says that even large-scale production cannot offset these intrinsic costs to making silicon photovoltaics. "The challenge," he says, "is to figure out physics so that they're cheaper." Interest in solar electricity has surged in recent months for a variety
of reasons. Energy prices have exploded since last year's energy crisis.
In addition, a variety of new economic incentives are available for consumers,
including a cash rebate of up to 50 percent on new solar systems installed
on your home and a 15 percent state tax credit on residential solar installations.
Recent federal and state law also require that utilities allow "net
metering," so that people like Ms. Baker can receive credit for excess
energy they feed back to PG&E. Consumers can't count on these credits forever. The tax credit is slated
to drop by half in 2004. On Sept. 12 Gov. Gray Davis signed SB 1038 guaranteeing
the continuation of the cash rebate, or "Buydown Program" for
another 5 years. The $20 million per year allocated to Buydown, however,
just isn't going to be enough - the money set aside for 2002 has already
run out. The cash amount of the rebates is likely to be reduced next year.
It is cheaper than ever to install solar. But for most consumers, the
cost has still not decreased enough. According to Arenson and DeNault,
and the California Energy Commission, a 4 kW solar system to meet most
of the energy needs of the average family typically has a net cost from
$25,000 - $30,000 -- even after the generous rebates and tax incentives.
Spreading this price over the lifetime of the solar panels (about 20
years) this brings solar energy within the range of current market prices
from conventional sources. In essence, consumers have to pay 10-20 years of PG&E bills all at
once, or finance the purchase through a mortgage loan, according to the
California Renewable Energy Program. A more modest system, like Ms. Baker's, can cost as little as $13,000
and will cover the needs of households which have less than average electricity
usage. Unfortunately, it will take longer to realize the return on the
investment, because utility rates are cheaper for lower use. "It would probably take us about 30 years to recoup our initial
capital outlay - quite possibly longer than the life of the system,"
she said. People in developing nations, for whom solar energy would bring dramatic
improvements in lifestyle, are even less able to afford it. Carter, and many of her colleagues, is working on finding alternative
materials to silicon, which promise cheaper solar energy in the future.
She is frustrated by the continued reliance on non-renewable fossil fuels;
"The way we do energy in this country is very silly," she said. Fossil fuels are likely to last a few generations at least, before the
cost of extraction overcomes the payback. Researchers and the government
agencies which appropriate their funding - and the public whose tax dollars
are spent on such research - must make the best use of this "period
of grace" to continue the quest for cheap, stable, easily manufactured
solar cells, among other types of renewable energy. At the same time, stimulation of the existing solar market must continue
- through government rebates and increased mass production. "This is the largest renewable energy fund by far in the U.S.,"
says Ralph Cavanagh of the Natural Resource Defense Council. "It
accounts for about half of all the other states combined. It's a substantial
investment." Yet, this amount only works out to a half of a percent of what we spend
on energy production for the state. "This doesn't seem like very much to pay as an insurance policy," he said. If you're considering solar, it's worth looking at the numbers. Depending
on your location, energy usage, and priorities, solar may be for you.
"I love my solar system!" says Debbie Malkin of Santa Cruz,
grinning. "I love seeing the meter run backwards, I love the idea
of getting my energy from the sun." "We have limited financial resources, so we also have to consider
the economic wisdom of solar as an investment," she said.
Solar Energy Research Heats Up Santa Cruz Sentinel, Page 1 November 10, 2002. Stephanie Chasteen, Sentinel Correspondent In a UC Santa Cruz physics laboratory, researcher Sue Carter eyes a small
vial of grains of fluffy, red plastic. In nearby Monterey, her colleague
Greg Smestad smears berry juice on a glass slide. Together, the scientists - among a handful of solar technology researchers
in the Bay Area - are helping respond to the challenge thrown down Sept.
12 when Gov. Gray Davis signed Senate Bill 1078 requiring California to
generate 20 percent of its retail energy electricity from renewables by
2017. The bill, the strongest of its kind in the country, would double
the existing use of wind, solar, and other renewable power sources. Lauded
by environmentalists, this bill is coupled with SB 1038, which promises
$62.5 million to solar R&D in the next 5 years. "This is the largest renewable energy fund by far in the U.S.,"
says Ralph Cavanagh of the Natural Resources Defense Council. "It
accounts for about half of all the other states combined. It's a substantial
investment." After the oil crisis of 1973, research on solar technology exploded and
with 25 years of research and improvements on the manufacturing process,
the cost of silicon photovoltaics has been reduced dramatically from $15
per kilowatt-hour (kWh) in 1977 to about 24 cents per kWh today. It's
still not low enough to compete with coal, nuclear, or natural gas, however
- an average Pacific Gas and Electric customer pays between 10 and 24
cents per kWh This challenge may require a switch to completely new types of materials.
The vast majority of solar panels today are made of silicon, the workhorse
of the semiconductor industry. It makes for highly efficient, stable solar
cells, but conventional silicon must be fabricated and deposited at high
temperatures and low pressures, an inherently expensive process. In response, researchers are working on a variety of different materials
that are cheaper to make but can still compete with silicon. Some of these
materials offer other advantages. Some are transparent or semi-transparent,
offering the possibility of windows that can produce electric power. Others
are flexible, like plastic, and so may be used in clothing or rolled out
in sheets - a property of some silicon technologies that is already being
exploited. Carter works with polymers - plastics - that can conduct electricity.
It is surprising, when you think about it, that a plastic could conduct
electricity at all; your credit card doesn't conduct, neither do the tires
of your car. Wires are insulated with rubber and plastics, both polymers,
because these materials do not conduct. But specially designed polymers
- called "conjugated" for their staccato pattern of alternating
single and double bonds - behave in interesting ways. The consistency
of flour or fluffy hair, they dissolve in solvents to form liquidy solutions
that can be spread out into films thinner than a soap bubble and deposited
on flexible plastic sheets. These materials can be tweaked to emit or absorb almost every color that
can be seen, and may form the basis of the next generation of flat panel
televisions, cell phone displays, and such futuristic applications as
electronic paper. This summer, Philips launched the first such product
- the Philishave -- an electric razor with a polymer display that indicates
battery life. Polymers also hold great promise for solar cell applications, because
they're cheap. Polymers are liquid and may be screen-printed or ink-jet
printed at room temperature and pressure using the same basic technology
as we use to make t-shirts, says Carter. This brings the hypothetical
cost to 2-7 cents per kW-Hr, as compared to 10-24 cents for fossil fuels. So why aren't polymer photovoltaics coating our homes and businesses?
At this point, says Carter, they simply aren't tough enough. These materials degrade in strong sunlight and so last a year or two.
Commercial solar panels for residential applications need to be stable
for about 10 years, says Smestad. But Carter is cautiously optimistic. "Silicon didn't last any longer than the polymers when it first
came out," she said. "Where I see polymer photovoltaics coming out is in … temporary
displays, like billboards." While Carter struggles with improving the polymer cells, Smestad, formerly
of the Monterey Institute for International Studies and his colleague,
Jin Zhang of UC Santa Cruz, are working on a completely different type
of solar device. Smestad and Zhang were awarded one of only a few research
grants available through the California Energy Commission to improve the
performance of Grätzel cells. "This cell could do the job if we could make it last 10 years,"
he said. The challenge lies within the materials that make the Grätzel cell
so unique. Instead of polymers or silicon, a Grätzel cell uses a
semiconductor commonly found in toothpaste and sunscreen - titanium dioxide.
A glass sheet is coated with bump nanoparticles of titanium dioxide and
then dipped in die. A special liquid known as an electrolyte, which helps
replenish the supply of electrons, is poured over this bumpy surface and
soaks in like a sponge. The whole cell is then sealed. When light knocks
an electron free from the titanium dioxide, it travels to the positive
side of the cell, creating an electric current. The construction is so simple that Smestad has developed a kit for students
to make a cell out of berry juice, cheap titanium dioxide and commercial
iodine.The cell is strong enough to power a tiny fan. So, why use petroleum instead of Grätzel cells? The trouble is that
even with the best seal, eventually, liquid evaporates. "This is not a technical problem," says Smestad. Rather, it may indicate a fundamental physical stumbling block. "It's
like asking someone who makes a vacuum system to pump it down, (turn off
the pump) and then come back 10 years later and have it at the same pressure." Without constant pumping, this is impossible. Like Carter's plastics,
these cells last only one or two years, said Smestad. "We can't seem
to seal it and make it reliable enough to last 10 years." Polymer and Grätzel cells are not the only technologies that promise
to reduce energy costs in the future. At UC Berkeley, physicist Paul Alivisatos is investigating a hybrid approach
to get around the efficiency problem faced by Carter's group. He blends
nanoparticles - particles on the order of one-billionth of a meter --
of silicon-like semiconductors with polymers. Once incoming light knocks
an electron free from an atom, the electron's journey across the cell
is hastened by the presence of the nanoparticles. A variety of other research avenues are being explored by groups around
the world, many in partnership with the National Renewable Energy Labs
in Colorado. These approaches include cadmium telluride, which is close
to production, and amorphous and thin-film silicon, among others. Most
of these approaches are aimed at improving device performance, but manufacturing
costs remain high. Smestad is adamant that the future of solar technology depends upon a
concerted research effort, and government funding to support that research.
Current government spending on renewables is just pennies to every dollar
spent on coal or nuclear energy, not to mention the defense budget. "Every cell that is coming out is showing us one thing - that we haven't scratched the surface with what can be done with low-cost solar cells," he says. "I'm not getting any younger, and there are new discoveries that need to be made." For more information:
Santa Cruz Sentinel: LOCAL NEWS May 16, 2003
Have you noticed the air smelling a little cleaner around Santa Cruz these days? It’s not just the late season rain. The Waste Water Treatment Facility near Neary Lagoon is now pumping out clean power and sweeter-smelling emissions. Saturday at 10 a.m. the city will invite the public to attend a celebration to mark the installation of a larger photovoltaic array to generate electricity, generation of power from methane and natural gas, and improved odor control. The ceremony will include refreshments, remarks from Mayor Emily Reilly and a tour of the plant at 110 California St. With the addition of these new power sources, the city is using almost 50 percent renewable power for its municipal buildings. Most of the power comes from cogeneration systems at the facility and at the landfill, which burn gas to generate heat and electricity. The cogeneration systems may burn methane gas from decomposing garbage and sewage sludge, or natural gas piped in from PG&E; only methane is considered in the renewable power calculation above. "We’re looking at the potential of saving about $20,000 a month, and that’s a significant savings for us," said plant superintendent Dan Seidel of the recent cogeneration upgrade. "That’s a quarter of a million dollars a year." The city and county paid $1.3 million for the upgrade. The system is expected to pay for itself in less than five years. On the other hand, the new solar system, installed by Renewable Energy Concepts in Los Osos, is expected to save the city about $15,000 a year and will pay for itself in about 13 years. The system cost $385,115, but after subtracting a rebate from the state Public Utilities Commission, the city and county paid $194,212. The solar system is the second largest operating array in the county — at 50 kilowatts, it surpasses solar pioneer Ken Adelman’s 30 kilowatt system on his home in Corralitos. A 57.6 kilowatt array was installed by Solar Technologies of Santa Cruz this month at the West Marine boating supply store on 17th Avenue in Santa Cruz. Why spend the money — almost $200,000 — on a solar array when the energy it produces is so much less than that from cogeneration? "You get much more bang for the buck with the (cogeneration system)," said longtime Santa Cruz solar advocate Joe Jordan. "(But to bring down the cost of solar energy,) you need these early adopters who kind of go out on a limb and do something that’s not strictly economical in the bean counter sense because it’s the right thing to do environmentally." Residents near the Waste Water Treatment Facility have additional environmental concerns. "About six years ago odor complaints seemed to become an overriding issue around the treatment plant," said Steve Wolfman, a civil engineer at the facility. On the basis of a study, new carbon filters were added to the existing bleach treatment to scrub smells from much of the foul air leaving the plant. The project cost the city $1.5 million, with no grant funding, and has been operating since late fall. It seems to be working. There have been no odor complaints since the new system was installed, according to superintendent Seidel. The solar and cogeneration systems won the public works Project of the Year award for 2003 in Monterey Bay Area. Grant funding through the California Energy Commission and the California Public Utilities Commission made building the systems possible, said Mary Arman, an analyst with the city’s Public Works Department.
Santa Cruz Sentinel
February 1, 2003 Several times a week, you may have the opportunity to buy fresh organic produce from a small farm stand at the base of the UC Santa Cruz campus. These are, quite literally, the fruits of decades of research and training. The UCSC Farm and Garden, managed by experienced farmer Jim Leap, is the fertile research ground for The Center for Agroecology and Sustainable Food Systems — one of just a handful of programs dedicated to training the next generation of organic farmers and to research on improving organic systems. Although organic is the fastest growing sector of agriculture, there is precious little information on how to farm organic. "It’s one of the oases, nationwide, as far as hands-on organic farming experience is concerned," said Bob Scowcroft of the Organic Farming Research Foundation, based in Santa Cruz. "People do not know the jewel of a program that they have there." The farm is considered by many to be the birthplace of organic farming. Using then-revolutionary techniques such as raised beds, close spacing and double digging — the charismatic actor Alan Chadwick sparked the interest of a generation of students in the late 1960s. With the help of mesmerized apprentices, he transformed a rocky hillside into the 2-acre Chadwick Garden. To test his ideas on a larger scale, his students later created the 25-acre farm complete with row crops, orchards and research plots. "This is really unique because we’re doing organically based research, we’re doing practical training, we’re running a farm, selling product and teaching," said Leap, farm manager. Leap is the man in the middle of it all, juggling the practicalities of running a farm, training apprentices and managing research trials. He is a lucky man whose soil-worn hands are grappling with a variety of challenging jobs. "I have two passions: One is being actively engaged in the farming system and the other is teaching and instructing," said Leap. "I really have the best job, for someone of my inclinations." Leap is particularly well-suited to the job: He was an independent farmer near Fresno for 15 years prior to coming to Santa Cruz. "He’s definitely one of the more experienced organic farmers in the Central Coast," said Eric Brennan, the first USDA researcher to focus on organic farming. Leap is actively involved in training the next generation of farmers. He lectures at universities and conferences, and devotes much of his time to hands-on teaching of farm apprentices. Apprentices spend six months living and working at the farm, learning aspects of soil science, botany, compost production, irrigation, weed and pest management, and farm equipment as well as marketing and social issues. "You can take soil classes, but god, you gotta go out and get sweaty, you gotta dig the dirt," said Scowcroft in praise of the program. The apprenticeship is unique, he said, because of the freedom to be creative, the lack of pure academic boundaries, and opportunities to interact with local farmers and organizations such as his own. Tom Broz, owner of Live Earth Farm in Watsonville, said the apprenticeship, and Leap’s experience, were instrumental in launching him in his career in organic farming. Graduates of the program have spread their experience around the globe. You can find UCSC progeny at their farms from Sebastopol to North Carolina, from Mexico to Kenya. Several others teach agriculture through colleges, high school or the Peace Corps. Leap’s expertise is also invaluable to researchers who are working to understand organic farming systems. "Just because a system is organic doesn’t mean it’s necessarily sustainable," said Brennan. Instead of focusing on comparisons between organic and conventional agriculture, he said, we need to know more about how to improve organic farming methods. Organic farmers are floundering when it comes to finding tried-and-true methods to manage weeds and pests and to increase their crop yield. When a researcher proposes a field trial, Leap tells them if, how and when it can be done. He is the one who figures out how to work the trial in with the crop rotation sequence, how to irrigate it and how to apply the fertilizers, as well as managing much of the practical work such as ground preparation. USDA researcher Carollee Bull has collaborated with Leap to help find out what varieties of strawberries are best suited to organic farming. "Working with Jim as a farmer is so much different than working with some other farmers because his bottom line isn’t making money," said Bull. Leap’s main product is research, not food, so researchers know their plot won’t fall victim to neglect or replanting and that the data will be collected right. For Bull’s research, Leap harvested berries twice a week from 80 plots, counting the pounds of berries harvested from each plot. "It was a lot of work," he said. It’s work he probably wouldn’t have been able to do as an independent farmer. "Farmers often don’t have the time to set up trials," acknowledged Leap. "When I was running my own small farm I rarely had time to interact with farm advisors, researchers or even other farmers to discuss observations." The work at the farm is important for the public as well as for farmers. "We aren’t just thinking about how to grow something," said professor Steve Gliessman, the founder of The Center for Agroecology and Sustainable Food Systems. "Organic’s not just a way to produce, it’s a whole aspect of how a community relates to its land." Scowcroft agrees, and argues that the cost of organic produce reflects its value. Consumers take for granted cheap food without understanding the implications. "Look at our groundwater, look at our air, look at our youth," he said. "Hey consumer, you get what you pay for."
From Science's Next Wave. A publication of the AAAS. http://nextwave.sciencemag.org STEPHANIE CHASTEEN Every Tuesday and Thursday, at the base of the sunny, rolling hills of the University of California, Santa Cruz (UCSC), campus, locals gather at a farm stand to buy fresh tomatoes and salad greens. A small sign advertises, "UCSC Farm and Garden: Organic Produce for Sale." Affiliated with the UCSC Center for Agroecology and Sustainable Food Systems (CASFS), the UCSC Farm and Garden make up a 25-acre research farm, one of only a handful in the country devoted to 100% organic research. The Farm provides fertile soil--and fertile research opportunities--for a diverse group of scientists and educators. It serves as a nexus for a wide variety of activities: a field research station for scientists; a classroom for visiting students; a training ground for organic apprentices, and a fully functioning organic farm. Thanks to the collaboration between the Farm and CASFS, "We have
made pretty amazing contributions to our understanding [of sustainable
agriculture]," says Steve Gliessman, the Center's founder. But, scientific research into organic farming lags behind. Marc Los Huertos, a postdoctoral researcher with CASFS says, "There is a high percentage of organic ag in the region, and [yet] we don't know anything about organic agriculture." The authors of the U.S. Department of Agriculture (USDA) State of the States report agree that more research is needed: "Even now, efforts at doing long-term organic systems research can be counted on one hand." The UCSC Center is one such program, but it is unique in that it focuses both on the "how to" and the "how come," blending the social and the natural sciences with hands-on farming. "You won't find an interdisciplinary approach in all the other programs," says Gliessman.
Graduate students affiliated with CASFS--they're usually enrolled through the university's Environmental Studies department--interact with faculty from the social and natural sciences. They also benefit from the rich field-research opportunities offered by the Farm and the central coast. "What's unique here is [that] there's money in the region, and there just aren't enough people to do the research," says Los Huertos. "There are so many questions in ag … that almost any field, except perhaps astrophysics, could come in and ask [something] interesting. ... The questions here are really provocative." The interdisciplinary and applied nature of the work seems to attract a certain kind of scientist. Many have a passion for getting out in the field and doing work that addresses real-world problems. "I never would have come back into academics without the nontraditional approach available here," says Gliessman, who spent 10 years farming and doing research in Latin America before founding CASFS and continues to farm part time. "For me, it [the appeal of the program] was a real focus on getting out of the lab and into the field, and then from the field onto farms, working with people who are dealing with these problems every day." Sajeemas Pasakdee, a graduate student with CASFS, is typical of the problem-centered approach of the researchers who work on the Farm. Pasakdee, who studies fertilization and irrigation of organic broccoli, hopes to bring her knowledge home to Thailand, where she grew up as the daughter of a rice farmer. Pasakdee believes that agriculture is very important, but her work also reflects her personal interests. "I like gardening and plants," she says. Another researcher who likes to get his hands dirty is Jim Leap, the Farm's manager. Leap was an independent farmer for 15 years before completing his bachelor's degree and accepting the job at UCSC. He is a "research farmer"--but not in the conventional sense of a researcher for a large firm studying pesticides. "I've really got the best of both worlds," says Leap. "I am extremely lucky to be engaged in a production system and at the same time be involved in research and information sharing." Researchers--CASFS faculty or scientists from elsewhere--come up with a research question and plan of study. Leap is the one who tells them how and when it can be done, drawing on his considerable farming expertise. "He's definitely one of the more experienced organic farmers in the central coast," says USDA researcher Eric Brennan. Leap does the practical part of the research, such as laying out plots and data collection. He is also involved in education and public outreach, teaching classes and giving lectures at farm conferences and colleges. Leap's original goal was to become a farm advisor--another possible career path for those interested in agriculture. Farm advisors are generally employed by university cooperative extension programs and work closely with growers to develop research programs geared toward the farmer's needs. Depending upon the nature of the position, they may have any degree, from a bachelor's to a Ph.D. Farm advisors provide the crucial communication link between farmers and academic researchers, helping to inform scientists of farmers' needs. Carollee Bull, a USDA plant pathologist, is one of many government researchers who have collaborated with CASFS and the Farm. She and Leap worked together on variety trials for organic strawberries. Bull reports that "My parents kept saying, 'But, what will you do with a degree in botany?' " Despite her parents' skepticism, she followed her interests and is very pleased with the results; Bull enjoys her job because it has so many facets, including a large fieldwork element. As a viable profession, organic agriculture research has gained a lot of ground, but it still has a long way to go. When Eric Brennan, a future collaborator with the Farm, got his first (BS) degree in 1983, his advisor told him there was no future in organics. Now, he has just become the first USDA researcher in the country to focus on 100% organic research. Gliessman expects more research positions in organic agriculture to open up now that the National Organic Standards--which took effect on 21 October--have provided consistent labeling for organic produce across the country. Many of the program's graduates go on to do what Gliessman calls "action research"--trying to solve scientific problems with social aspects. Many find jobs--teaching, doing research, or concentrating on policy and funding issues--in universities and nonprofit groups. This typical career path for graduates is not surprising, considering the nature of the training they receive at CASFS: While completing a Ph.D., Gliessman says, students get to grapple with a difficult problem for a time. "And, when you're done with that, you can sort of ask yourself a question: Did I do this just so I could get a job at a university, or did I do it because I got to work on something that I really believed in?" Gliessman then adds, "In my opinion, if you choose the second, then you begin to accomplish things you never dreamed possible." Public release
date: 16-Feb-2003 Sex and gender scientists explore a revolution
in evolution At the annual meeting of the American Association for the Advancement of Science, leading researchers and theorists in the evolution of sexual behavior will gather to present the growing evidence that Darwin's idea of sexual selection requires sweeping revisions. ''I don't have a theory to address it all by any means,'' says Stanford biologist Joan Roughgarden, who organized the Feb. 17 symposium. ''I'm just trying to get the extent of diversity on the table.'' Roughgarden will present the evidence that gender is not limited to the static male/female binary and that sex can have social as well as reproductive roles. Robert Warner of the University of California-Santa Barbara will speak about fish that change sex. David Crews of the University of Texas-Austin will address the tenuous path linking genetic sex to behavior. Patricia Gowaty of the University of Georgia will present a new hypothesis on how animals select their mates. And Paul Vasey of the University of Lethbridge will discuss his research on homosexual behavior among female Japanese macaques. Sex and Darwin Darwin's theories of natural selection are well established and generally accepted: ''Survival of the fittest'' leads to the evolution of a particular species over time, and species evolve from other species. But a third theory has piggybacked upon the success of these other two: Darwin's theory of sexual selection. Sexual selection explains the evolution of physical and behavioral traits that increase the odds that an animal will reproduce. These same traits do not necessarily help the animal survive, as do naturally selected traits. The male praying mantis, for example, will sacrifice himself for love - the female begins to eat him even as they copulate. He doesn't survive long after finding his mate, but he does pass on his genes. Darwin postulated that females are ''coy,'' mating rarely and choosing their mates carefully, presumably betting their odds on the males with the best genes to contribute to their offspring. For their part, males are ''ardent'' and promiscuous, and fight amongst themselves for female partners. Later theories added that males are promiscuous because they have less to lose by making babies - unlike eggs, sperm are plentiful and small. Plus, females usually do most of the work to raise the offspring. Sexual selection theory helped Darwin explain many traits, especially in males, that otherwise seemed maladaptive. The unwieldy tail on the male peacock, for instance, makes him more vulnerable to predators but more attractive to females. Many behaviors do not fit sexual selection theory, however. Says Vasey of his work with Japanese macaques: ''I see females competing for males all the time. I see males ignoring females that are desperate to copulate with them.'' A great deal of empirical evidence exists that refutes Darwinian sexual selection. It's difficult to tell just how many exceptions there are to the rule because observations may have been skewed by Darwinian biases, says Roughgarden. ''The exceptions are so numerous they cry out for explanation,'' says Roughgarden, who has outlined a stunning array of behaviors that don't fit the mold in her upcoming book, Evolution's Rainbow: Diversity, Gender and Sexuality in Nature and People (University of California Press, 2003). Sex and society Roughgarden thinks that a more comprehensive theory of sexuality should take into account social as well as sexual selection. Mating can function to build and manage relationships as well as to procreate. ''Female choice, I'm pretty sure, has much more to do with managing male power than it does with trying to obtain good genes,'' says Roughgarden. For instance, anthropologist Sarah Hrdy studied langur monkeys in the 1980s and found that females promiscuously mate with many males. These females are attempting to protect their offspring, hypothesized Hrdy. Dominant male langurs regularly kill babies that aren't their own, so females protect their infants by spreading the possibility of paternity among several males. Other sexual traits, says Roughgarden, may represent a ''market economy'' dedicated to trading sexual opportunity for other resources. In many species, some individuals act as helpers to dominant males and reap some rewards in the process. Dominant male waterbucks, for example, establish a territory along a lakeshore and wait for a female to enter. Subordinate, ''satellite'' waterbucks help to defend the territory, and in turn may mate with a few females and get a shot at inheriting the territory when the dominant male retires. The payoffs for the dominant and satellite waterbucks may balance out in the long run. Homosexual behavior is common but unexplained by Darwin. Over 300 vertebrates, including monkeys, flamingoes and male sheep, practice homosexual behavior. Homosexuality in some species appears to play a social role. For instance, bonobos (pygmy chimpanzees) will have sex with same-sex partners to calm tensions after a squabble, or to make sure that a large amount of food is shared. But for some species, humans included, homosexual behavior may have no adaptive value at all. ''Looking for any single conceptual framework to explain homosexual behavior is an unattainable goal,'' says Vasey, one of the leading researchers on homosexual behavior. In female Japanese macaques, homosexual behavior appears to have evolved from female strategies to coerce reticent males to mate with them. Eager females will mount unwilling males and prompt them to mate with them - a strategy that was easily expanded to mounting other females. Despite these evolutionary origins, however, homosexual behavior among Japanese macaques may have no adaptive value - just as our tailbone evolved but is no longer useful. This finding is important because it suggests that sex may have functions other than procreation - a healthy ecosystem sports diversity for diversity's sake. Beyond male and female While two types of sex cells exist - sperm and eggs - it is more difficult to sort individuals into these binary classes. Several species have more than just male and female genders, where gender is defined as the body and sexual behavior of an individual. In some species, an individual's body may be difficult to classify as male or female. Most plants and some fish are hermaphrodites - capable of producing eggs and sperm. Some lizards are unisexual. There are no male whiptail lizards, and females will mount each other, prompting hormonal changes that result in cell division - a true ''virgin birth.'' A single individual also may switch from male to female or vice versa and back again - that is, may switch from producing sperm to producing eggs - due to a change in hormones triggered by external circumstances. In any coral reef, for example, about 25 percent of the fish have changed sex in their lifetime. Over 50 species of angelfish, wrasses, parrot fishes and groupers have changed from male to female or vice versa. Other invertebrates, such as shrimp and oysters, also may change sex. ''Gender can be surprisingly labile,'' says Bob Warner, who was among the first to study sex-changing fish in the 1970s. ''The young themselves may develop as one sex or the other, depending on the environment in which they find themselves. And individuals may function first as one sex, then another, over the course of their lives, and the change can be socially controlled.'' For instance, if the sole male is removed from a group of cleaning wrasse, the largest female will start to behave like a male within hours. Within 10 days she - now he - will produce sperm. Behavior is not tied to one's chromosomes, either - many species have three or more genders. For instance, bluegill sunfish have two different male genders - ''parental'' males who control territory and mate with females, and ''end-runner'' males, who are smaller with different coloring. End-runners will dart in and release sperm where a female and parental male are mating. So you say you want a revolution? ''The whole context for Darwin's theory of sexual selection is dissolving,'' says Roughgarden. ''So, Darwin is incorrect in the particulars, but more importantly, [his theory of sexual selection] is inadequate even as an approach.'' Both Roughgarden and Gowaty think it's time for a revolution, but not everyone agrees. ''This may be better viewed as a refinement of Darwinian theory, rather than a revolution,'' says Warner. Vasey agrees, however, that something has to give: ''What I'm seeing, in my one species [macaques], is an unbelievable amount of sexual diversity that is very common. I see it every day, and traditional evolutionary theories for sexual behavior are inadequate and impoverished to account for what is going on.'' What conclusions can we draw about gender and sexual diversity in humans from such findings? Both Vasey and Roughgarden caution strongly against extrapolating animal behavior to humans, as evolutionary psychologists have done for decades. ''People often look to animals to decide for themselves what's natural and what's not natural,'' says Vasey. ''I don't think that's necessarily a good thing to do. I mean, animals engage in cannibalism and infanticide. They also don't take care of elderly individuals. Just because animals do something doesn't make it right or wrong.'' Still, a revolution in the biology of sex relates to our perceptions of ourselves - and our sexual politics. People, like fish, can change sex midlife - the method is surgical, but the expression is one of gender identity. We also have a variety of sexual orientations - straight, lesbian, gay and bisexual. There are men who dress like women, women who dress like men, hermaphrodites born with both sex organs, and others with sex chromosomes that seem to have played musical chairs, resulting in such variations as XXX, XXY and XYY. Biology is destiny, but biology is diverse. ''This type of research [makes] us reflect on the categories that we use to describe nature and that we use to describe each other,'' says Roughgarden.
CONTACT: Dawn Levy, News Service: 650-725-1944, dawnlevy@stanford.edu COMMENT: Joan Roughgarden, Biological Sciences: 650-723-3648, rough@pangea.stanford.edu EDITORS: Important embargo clarification: Joan Roughgarden is speaking at a special AAAS news briefing (''Gender, Sexuality and Evolution'') on Sunday, Feb. 16, at 4 p.m. MST, and at a symposium (''Evolutionary Aspects of Gender and Sexuality'') on Monday, Feb. 17, at 8:30 a.m. MST. The embargo lifts when the Feb. 16 talk begins. In addition, Paul Vasey is confirmed for both events. Patricia Gowaty is confirmed for Monday only. Robert Warner and David Crews are not speaking Feb. 16. This release was written by freelancer Stephanie Chasteen. A photo of Roughgarden is available on the web at http://newsphotos.stanford.edu
Stanford Report, January 22, 2003 Cosmos 'Big Bubble' theorist Alan Guth to deliver
Hofstadter Lecture BY STEPHANIE CHASTEEN The universe may have started with a bubble, not a bang. In 1980, an unknown physicist named Alan Guth proposed a modification to the Big Bang theory. Guth suggested that in the first moments of the life of our universe it inflated like an enormous bubble. Inflationary theory has been very successful at solving many of the problems that had puzzled scientists for years, including the fact that the Big Bang would not produce a universe large enough to hold even a sheet of paper. "The bang was there, but it was not big," says Stanford physics Professor Andrei Linde, a cosmological theorist. Guth, who is now the Victor Weisskopf Professor of Physics at MIT, will deliver a free, public talk at 8 p.m. Monday, Jan. 27, in the SEQ (Science and Engineering Quad) Teaching Center, Room 201. His invited talk, titled "Cosmic Inflation and the Accelerating Universe," is the 2003 Robert Hofstadter Memorial Lecture. Hosted by Stanford's Physics Department, the lecture is the 11th to honor Nobel Prize-winning physicist Robert Hofstadter, who served on the physics faculty from 1950 until his death in 1990. Guth also will deliver a more technical colloquium, "Time Travel and Cosmic Strings: A Playground for Theoretical Physicists," at 4:15 p.m. Tuesday, Jan. 28, in the same location. With Linde and Paul Steinhardt of Princeton, Guth is co-recipient of the 2002 Dirac Medal for groundbreaking work in cosmic inflation theory. He is also author of a popular book, The Inflationary Universe: The Quest for a New Theory of Cosmic Origins (1998). Inflationary theory does not replace Big Bang theory, but adds an extra stage: Before the Big Bang, the universe went through a period of extremely rapid expansion, growing by 30 orders of magnitude in a fraction of a second. It is difficult to imagine something becoming this large this quickly -- picture a pea expanding to the size of the Milky Way more quickly than the blink of an eye. After this exponential inflation, expansion slowed to the sedate pace observed today. When he came up with the theory of cosmic inflation, Guth was a 34-year old physicist at the Stanford Linear Accelerator Center (SLAC) in the ninth year of a seemingly interminable career as a postdoctoral fellow. He was working on the problem of magnetic monopoles: particles that behave like the North end of a magnet without the South end. The Big Bang model predicted an abundance of magnetic monopoles but none have ever been found -- a source of great concern to theoreticians. A few years earlier, Linde had suggested that, in its early stages, the universe had undergone a series of phase transitions, accompanied by supercooling. Supercooling is seen quite often in phase transitions from one form of matter to another, such as water cooling to ice. In supercooling, water will remain liquid as it cools below 32 degrees Fahrenheit -- the temperature at which it normally freezes -- but at the slightest disturbance it will immediately freeze. Guth and Cornell postdoctoral scholar Henry Tye were working on the problem of how supercooling in the early universe would affect the production of magnetic monopoles. "So I went home one night and did that calculation and discovered that it would have a dramatic effect on the evolution of the universe," Guth says of his revelation. The supercooled matter would cause gravity to reverse direction, so that objects would repel each other, resulting in exponential inflation. It would also make magnetic monopoles exceedingly rare. The impact of the theory was immediate. "People realized that this was a good idea," says Linde. "You can solve a lot of cosmological problems just by one simple trick." One major puzzle solved by inflation is the fact that the universe has been observed to be remarkably uniform. NASA's Cosmic Background Explorer (COBE) has measured cosmic background radiation -- a sort of cosmic white noise left over from the early years of the universe. The data show a picture of a universe that looks surprisingly similar in all directions, a highly improbable state viewed from Big Bang theory. In the inflationary scenario, however, stretching out a tiny, uniform universe exponentially would result in a similarly uniform larger universe. And what about galaxies and stars? Tiny departures from homogeneity of the energy field of the early universe -- quantum fluctuations -- may have grown like spots on an expanding balloon, eventually forming large-scale structures like galaxies. Data from COBE seem to support this assumption. Inflation also explains why parallel lines don't cross -- something everyone learns in school as a basic principle of Euclidean geometry. But other types of geometry are possible. According to general relativity, spacetime curves around massive objects, like a sheet of rubber bends or bulges when you put a rock in it. The universe as a whole can warp around the matter within it, and so the density of the universe determines whether it is "open" -- parallel lines eventually diverge -- or "closed" -- parallel lines ultimately meet. Theoretical calculations show that our universe should be very curved, whereas scientific observations show the universe as flat and Euclidean. This so-called "flatness" problem is solved by inflation. "If you take any curved space and expand it by a tremendous factor, and look at any small part of it, it looks flat," says Guth. "The surface of the Earth looks perfectly flat to us when we look at it, even though we know that the Earth is actually round if you look at it from much further away." And what's next for inflation? Guth is excited about current theories of eternal inflation, which picture the universe as a huge, growing fractal. "Once started, inflation never stops, but an eternal inflationary tree spawns a never-ending succession of bubble universes, each of which evolves according to the inflationary Big Bang description," says Guth. And so, says Linde, "the universe becomes immortal." Stephanie Chasteen is a freelancer and doctoral student in physics at the University of California-Santa Cruz. |