Coal-Friendly Climate Changes in Kansas
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DARK DAYS?: At least 16 new coal-fired power plants throughout the U.S. have either been cancelled and many more have been delayed due to concerns about pollution, particularly the carbon dioxide that drives climate change. |
New coal power plants won't find a home in Kansas, according to the state's Department of Health and Environment (KDHE). The agency, tasked with protecting the state's environment and public health, denied air quality permits for two 700-megawatt, coal-fired power plants proposed by Sunflower Electric for Holcomb, a municipality in the southwestern corner of the state.
"After careful consideration of my responsibility to protect the public health and environment from actual, threatened or potential harm from air pollution, I have decided to deny the Sunflower Electric Power Corporation application for an air quality permit," Roderick Bremby, KDHE secretary, said in a written statement. "I believe it would be irresponsible to ignore emerging information about the contribution of carbon dioxide and other greenhouse gases to climate change and the potential harm to our environment and health if we do nothing."
The Kansas decision is just one of a string of setbacks for proposed new coal-fired generation and builds upon a Supreme Court decision in April that carbon dioxide meets the definition of an air pollutant under the federal Clean Air Act.
For example, four separate proposed coal-fired power plants in Florida have either been rejected by state authorities or withdrawn, including a nearly 2,000-megawatt coal plant near the Everglades and an additional unit at an existing plant outside Tampa—one of the U.S.'s few integrated gasification and combined cycle (IGCC) power plants, which use an advanced coal-burning technology with fewer emissions. All told, utilities have canceled 14,000 megawatts of planned coal-fired generation and delayed an additional 32,000 megawatts, according to the latest survey by the U.S. Department of Energy's (DOE) National Energy Technology Laboratory (NETL) in Pittsburgh.
Investors have rejected coal-fired generation as well; Texas-based utility TXU found itself under new ownership after announcing plans to build as many as 11 new coal-fired power plants. Instead, a private consortium of investors, including investment bank Goldman Sachs and private equity firm Kohlberg Kravis Roberts & Co., purchased the power generation company and last week changed its name to Energy Future Holdings Corporation after withdrawing eight of the planned applications.
"I look forward to working with management and employees to demonstrate our commitment to being a leading corporate citizen, to implementing stronger environmental policies, and to providing reliable and affordable power," Donald Evans, new chairman of Energy Future, said in a statement last week.
But there are technology options on the horizon that might allow for future coal-fired power plants to avoid the average emissions of more than four million metric tons of carbon dioxide every year per plant. Such carbon capture and storage can either be built into the smokestacks of existing plants or into the combustion cycle of advanced plants, like those using IGCC technology. Once the carbon dioxide is captured, it is compressed and pumped as a liquid deep underground. "The bad news is [that] it increases the cost of power roughly 60 to 70 percent for a new plant and probably by more than double for an existing plant," says L. Doug Carter, senior energy advisor at Washington, D.C.–based law firm Van Ness Feldman.
It also has yet to be demonstrated on a single power plant, though the DOE has several projects underway. "You can't get to stabilization without having to deal with carbon capture and storage from both the coal fleet [of power plants] and the natural gas fleet," says Scott Klara, NETL's director of the office of coal and power systems research and development. "It will take from 15 to 20 years for these to come online, assuming they are successful in research and development."
Until that happens, it may remain difficult to build coal-fired power plants. "I think that this decision represents a clear and powerful recognition of how serious the threat of global warming is and that our reliance on coal for power generation needs to be changed," says Eric Young, spokesman on global warming at New York City–based environmental group Natural Resources Defense Council. "Instead, we need to become more energy-efficient, build more efficient cars and trucks, and also produce a greater share of our electricity from renewable sources like wind, especially in a state like Kansas."
Strange but True: Black Holes Sing
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SUPERMASSIVE SOUND: This image of the Perseus cluster, derived from information captured by the Chandra X-Ray Observatory, shows the ripples—or sound waves—created by jets from the supermassive black hole at its center. |
In the dark heart of the Perseus galaxy cluster, 300 million light-years from Earth, a supermassive black hole has been singing the same note for 2.5 billion years. Its tone registers 57 octaves below middle C and, according to scientists at NASA's Chandra X-Ray Center, is a resounding B-flat. Yet, how is this possible in the vacuum of space?
Sound requires a medium, such as water or air, to travel. Here on Earth a sound wave moves from its origin by causing the surrounding air molecules to vibrate. The vibrations pass from one molecule to another; when they hit an ear, they are understood as noise. But because neither air nor water nor much of anything else exists in the majority of vast reaches of space, it is difficult for sound to travel there.
It takes a supermassive black hole—like a robust opera diva—to sing a resonant note in space. These monstrous celestial objects range from hundreds of thousands to tens of billions times our sun's mass and are commonly found in the center of active galaxies. For example, Sagittarius A*—a supermassive black hole—sits at the center of our own galaxy, the Milky Way.
Black holes are notorious for their gravitational might, which is so strong that nothing can escape, according to conventional wisdom. But this isn't quite correct—some matter does. A black hole's gravity pulls a mishmash of matter and energy into its surrounding accretion disk—a ringlike structure formed by gas and dust. But some of this matter is violently expelled from the black hole's poles as "relativistic jets." These jets surge into the scorching gas surrounding the hole and generate pockets in the otherwise uniform cloud.
"Sound waves are pressure waves. And black holes, or at least their relativistic jets, can generate enormous sound waves, which then propagate through surrounding galactic gas," explains astronomer Steven Allen, a professor of physics at Stanford University who studies the Perseus galaxy cluster. "When relativistic jets, which contain material moving at close to the speed of light, slam into the hot gas that pervades giant elliptical galaxies and clusters of galaxies, they beat a 'galactic drum,' as it were." The jet acts as the "stick," whereas the surface of the gas is the "drum."
Although people can't hear these waves (because sound can't travel through the vast vacuum separating this "drum" and us), we can "see" them using x-ray observations. As sound waves spread through the scorching gas in galaxies and galaxy clusters, regions of greater pressure (sound wave peaks) tend to appear brighter in x-rays; fainter regions (troughs) are dimmer.
Chandra x-ray telescope observations of the Perseus Cluster show roughly concentric ripples of brighter and fainter gas, which indicate sound waves. "We can't see the waves moving," Allen says. "The relevant timescales are too long, since the period of the waves is about 10 million years—but we have a clear 'snapshot' of them."
Perseus' black hole is not the universe's sole galactic vocalist. M87, a galaxy that holds one of the universe's most massive black holes, is also known to croon. Although its song isn't as steady as Perseus', it is more involved, with notes as deep as 59 octaves below middle C.
"There's no reason for black holes to sing the same note," says Peter Edmonds, an astrophysicist at the Chandra X-Ray Center. Galaxies that have more matter may provide a deeper sound, because this matter could lead to bigger, but less common eruptions from the black hole. There are bound to be other important factors contributing to a black hole's specific sound, such as the temperature of the gas and its location, but the details aren't well understood, says Edmonds.
Other interstellar objects and events produce sound waves as well, he adds. In fact, the echoes of the big bang have been humming and hissing since shortly after the universe's birth.
According to astronomer Mark Whittle of the University of Virginia, the big bang's sound waves were created during the universe's first 380,000 years when space was still foggy with gas containing free electrons. Once the fog cleared, however, the universe fell silent.
The big bang's ballad is still detectable though, and is described by Whittle as "a descending scream, changing into a deepening roar, with subsequent growing hiss." He adds: "Perhaps most remarkably, within the big bang's sound there is a fundamental tone and a set of harmonics."
Of course, the big bang itself was mute, because it takes time for pressure to act across distances and generate a sound wave. Only later, as the pressure forces crossed regions of outer space and set up sound waves did the latter establish their presence.
Closer to home, the sun has been chanting for billions of years. Convection currents on the solar surface produce pressure waves that travel to the inner corona and back to the surface, causing the surface to broil and vibrate. These deep, three-dimensional sound waves allow scientists to better understand the sun's internal structure.
In fact, the music of the spheres, and even of supermassive black holes, provides insights into the fundamental nature of our universe. Though no living thing on Earth can hear the music of outer space, the cosmos continues its orchestral display. For understanding, scientists watch (and listen) closely—making astronomers the best audience on Earth.
Can Ancient Herbs Treat Cancer?
For Bionovo, the drug discovery and development company in Emeryville, Calif., that's behind BZL101, there's hope too. The trial is the first FDA-validated clinical study of a potential cancer drug derived from a Chinese medicinal herb, says Dr. Mary Tagliaferri, a co-founder of the company, former practicing acupuncturist and a breast-cancer survivor. "Sixty-two percent of chemotherapy drugs come from natural products, and plants have been the basis of almost every new class of medication," she says. "It makes sense that these plants can act as anticancer agents."
Tagliaferri's interest in Ban Zhi Lian, which has traditionally been used to treat swellings, sores and fever, was sparked in 1996 by a fellow acupuncturist, Isaac Cohen, who would later become a co-founder of Bionovo. At that time, Cohen had been treating, for a decade, women who were battling breast cancer with conventional medicines and had run out of treatment options. "In their exhaustion and desperation, they were trying to find an alternative treatment that was not so harsh," says Cohen, who often prescribed herbs to be prepared as teas to ease the side effects of chemo and hormone therapy. But the patients' oncologists, says Cohen, discouraged them from trying anything new. "They'd say Chinese medicine was quackery and that there was no evidence it worked," he says. Still, Cohen observed that many of the women to whom he gave Chinese herbs, including Ban Zhi Lian, responded well to the herbs and even experienced a relatively good quality of life. "At first I chucked it to luck," he says. "But then you see it's not just luck. And then you ponder why."
Cohen's early observations about Ban Zhi Lian may have started out as a hunch, but they may hold up. In 1996, Cohen and Tagliaferri, along with Dr. Debu Tripathy, then a breast cancer specialist at the University of California, San Francisco, co-founded the Complementary and Alternative Medicine program at the university's Carol Franc Buck Breast Care Center. Over the next several years, the trio amassed enough evidence about the herb's anticancer properties — in lab tests of animals and breast-cancer cells, BZL101 caused apoptosis or cell death, according to Tagliaferri — to get a green light from the FDA to begin clinical trials.
The researchers conducted Phase I trials at Buck and at the Cancer Research Network in Plantation, Fla. Their 21 participants had stage IV metastatic breast cancer, which had continued to progress despite an average of four rounds of standard treatment, including chemo and hormone therapy. The patients took 12 g a day of Ban Zhi Lian, a dose that's three times more concentrated than the amount found in a cup of brewed tea. After about a year, 25% of the patients saw stabilization in their disease for 90 days, and 19% for 180 days. The experimenters say BZL101 works by preventing cancer cells from undergoing glycolysis, a process of glycogen breakdown that accounts for as much as 85% of cancer cells' energy supply.
In 2002, Tagliaferri and Cohen left Buck to establish Bionovo, where they began Phase II trials of BZL101 in April 2006, expanding their studies to 10 hospitals and breast cancer centers, including the University of Chicago Medical Center, Duke University Medical Center and the M.D. Anderson Cancer Center in Houston. Bionovo expects the second phase of trials to conclude by early 2008.
Women with breast cancer have typically sought Chinese medical herbalists for relief from the side effects of chemotherapy and radiation or to strengthen and balance their immune systems; some have even hoped for a cure. Some women may have been helped; others not. But with so many variables — the broad range of patients, quality and potency of the herbs available, types of formulations prescribed and the expertise of the herbalist — outcomes in informal settings were never a sure thing. And it's the same kind of variability that has made clinical research so problematic. "Even though people are very interested in herbal therapy and a lot of people take herbs, research in herbal therapy is difficult because you're dealing with a mixture of compounds," says Tripathy, who is now a clinical professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas. During the research phase, Tripathy says, scientists often attempt to isolate one particular molecule or compound from the herbal extract — and the anticancer activity is lost. "There are herbal extracts in which the anticancer activity is actually due to the synergy between many of the compounds contained in that extract," he says.
Tripathy also says that companies like Bionovo have a tough time getting funding either from the private sector or from pharmaceutical companies: "In the absence of controlled clinical trials, people are skeptical and say 'There's no evidence this works,'" he says. Bionovo, which expects to begin Phase III trials in 2009, hopes to upset this way of thinking. And, says Tagliaferri, the company is studying about two dozen other Chinese herbs with anticancer potential.
The FDA at least is eager to see more studies of botanical treatments of cancer. "We're not opposed to Chinese medicine," says Dr. Shaw Chen, botanical review team leader at the FDA. "We just like to see clinical studies that meet our standards." Chen agrees it can be tough to study the pharmacological activity of botanical compounds or to ensure consistency in quality, but Bionovo's efforts, if fruitful, may help pave the way for other research. "A successful application to market for a cancer drug based on Chinese medicine will be encouragement to the industry," he says. "I think the industry is watching for the first success story."
Distortion-Free Lens Technology Puts Things in a Negative Light
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GOING NEGATIVE: Researchers used alternating layers of semiconductors to create a new "metamaterial" that breaks the laws of nature and bends light backward. |
For years, researchers have struggled to find an efficient way to develop lenses that do not lose portions of light as it passes through—an effect that hinders the performance of lasers, medical diagnostic imaging equipment and sensor systems. Now researchers led by a group at Princeton University have developed a new technique using nanosize materials that sets the stage for new lenses that eliminate the errors and image distortion inherent in today's optical technology—and may one day be used to check for toxic chemicals in the air and the body.
The key component of the research was the creation of a solid-state crystal made of "metamaterials" that had the property of negative refraction, which causes light to curve in the opposite direction from where it naturally would while passing through naturally occurring materials, such as air and water. A lens for negative refractive properties would have a flat surface and would not share the same resolution limitations and image distortions of a normal curved lens with positive refractive properties, says lead study author Anthony Hoffman, a Princeton engineering graduate student.
Hoffman and his colleagues crafted their metamaterial semiconductor by placing alternating 80-nanometer-thick (one nanometer equals 3.94 x 10-8 inch) layers of indium gallium arsenide and indium aluminum arsenide atop an indium phosphide substrate 5.1 centimeters (two inches) in diameter. In all, the stack of ultrathin layers rose eight microns (one micron equals 3.94 x 10-5 inch), which is one-tenth the thickness of a strand of human hair. The researchers claim to have created the first three-dimensional metamaterial constructed entirely from semiconductors, the principal ingredient of microchips and optoelectronics.
In 2005 researchers at Purdue University in West Lafayette, Ind., created a metamaterial with a negative refractive index in the near-infrared portion of the spectrum using ultrathin gold nanorods 100 nanometers by 700 nanometers to conduct clouds of electrons. In another two-dimensional experiment to achieve negative refraction, earlier this year researchers Henri Lezec, Jennifer Dionne and Harry Atwater at California Institute of Technology in Pasadena, Calif., sandwiched a 100-nanometer-thick layer of silver between silicon nitride and gold, with openings on either end to allow laser light to enter and exit the silver.
Although these types of "two-dimensional metamaterials" have been around for a few years, the Princeton-led study offers researchers the ability to work with "something optically thick that could achieve a macroscopic effect," says Claire Gmachl, a Princeton electrical engineering professor and director of the Mid-Infrared Technologies for Health and the Environment (MIRTHE), a research center formed last year by the National Science Foundation.
The initial reason for conducting the research was scientific curiosity—a fascination with optical materials that could bend light in a new way, says Gmachl, who worked with Hoffman on the project. "This had been a theory since the 1960s, but ours is a step toward a simpler system that can be reproduced for manufacturing."
Thermal- and night-imaging equipment used by law enforcement and the military make use of the mid-infrared region of the light spectrum, which is where Hoffman, Gmachl and their fellow researchers have focused their work. MIRTHE, headquartered at Princeton University, also includes the City College of New York, Johns Hopkins University, Rice University, Texas A&M University in College Station and the University of Maryland, Baltimore County.
The Princeton team, which also included researchers from Oregon State University in Corvallis and the Murray Hill, N.J.–based telecommunications firm Alcatel-Lucent, is hoping that improved lenses could lead to sensor systems that can measure low concentrations of chemicals in the air. "Chemical trace gases that are vapors under normal conditions have characteristic absorption features," Gmachl says. Sensors that are able to identify the chemical fingerprints could be used to warn people when harmful chemicals have been released into the air, either on purpose or inadvertently. Medical professionals might also be able to use such a sensor to check a patient's breath for traces of chemicals that indicate liver disease or internal inflammation.
Beyond the development of new sensors, semiconductor metamaterials such as the one Hoffman and his team created will also improve light amplification used in lasers. "Having a new material with improved optical properties just enhances the toolbox of the things we can work with," Gmachl says, adding, however, that most of this technology today is only in the prototype phase "There is still much work to be done. You won't find these in commercial deployments yet."
| Why the Universe is All History |
It took 300 years of experiment and calculation to pin down the speed at which light travels in a vacuum: an impressive 186,282 miles per second.
Light will travel slightly slower than this through air, and some wild experiments have actually slowed light to a crawl and seemingly made it go backward, but at the scales encountered in our everyday lives, light is so fast that we perceive our surroundings in real time.
Look up into the night sky and this illusion begins to falter.
"Because light takes time to get here from there, the farther away 'there' is the further in the past light left there and so we see all objects at some time in the past," explains Floyd Stecker of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Light-years
We see the relatively close moon as it was 1.2 seconds ago and the more distant sun as it was about 8 minutes ago. These measurements—1.2 light-seconds and 8 light-minutes—can be thought to describe both time and distance.
The distance to more remote objects such as other stars is so great it is measured in light-years—the distance light will travel in a year, or about 6 trillion miles (10 trillion kilometers).. Even the nearest star system, Proxima Centauri, lies more than four light-years away, so it appears to us on Earth as it was just over four years ago when the light began its journey.
In this way, light's finite speed gives us a valuable view into the past, and as we strain our gaze deeper into the universe we look further back in time.
"In the case of distant galaxies, we see them as they were billions of years ago when the universe was relatively young," Stecker said.
Out of sight
Some galaxies are so remote that their light hasn't had sufficient time to reach us yet, despite about 13.7 billion years of travel. There could also be more distant objects that will forever remain unknown to us.
"Because the universe is expanding and the expansion appears to be accelerating, there may be distant galaxies which if we can't see them now because their light has not had time to reach us, we will never see," Stecker said.
So we can never see the universe as it is, only as it was at various stages of its development.
To interact with remote parts of the universe—to see them as they are now—would require some exotic means of travel, such as to travel faster than light which, according to Einstein's special theory of relativity, is impossible as it would require an infinite amount of energy.
"The equations of special relativity imply that nothing can go faster then the speed of light in empty space. Therefore, if super-luminal speeds are possible in empty space, they violate the principle of special relativity," Stecker told SPACE.com.
Offbeat theories
There are ways to travel faster than light that do not violate special relativity, but these either outpace light in a transparent medium such as water or do not involve the transmission of information.
To break light speed in space and gain the same easy interaction with the universe that we experience everyday on Earth is a task considered practically impossible even when offbeat theories are considered.
"There are some postulated but unproven theoretical models, inspired by the motivation to unite the quantum theory with the general theory of relativity, which violate special relativity," Stecker said.
These theories involve accelerating particles with mass to super-luminal speeds using ultra high energies. It may also be possible to take a shortcut to distant parts of the universe through a tunnel in space-time known as a wormhole.
"If stable wormholes can exist in space-time and if we can survive traveling through them, then they could provide shortcuts as in the sci-fi movies," Stecker said.
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