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5 November 2009 |
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QUaD: High-precision measurements confirm cosmologists' standard view of universe, The University of Chicago News Office |
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4 November 2009 |
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University of Chicago announces new Director of Office of Special
Progams - Key Partner for KICP Space Explorers Program, The University of Chicago News Office |
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29 July 2009 |
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O'Hare Airport exhibit provides portal to cosmos, The University of Chicago News Office |
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21 July 2009 |
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Evalyn Gates on Cosmic Magnification, Discover |
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10 July 2009 |
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Aiming High: The Search for Ultra High-Energy Cosmic Rays, American Museum of Natural History Science Bulletin |
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30 June 2009 |
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Astronomer Michael Gladders named 2009 Cottrell Scholar, The University of Chicago News Office |
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15 May 2009 |
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QUIET team to deploy new gravity-wave probe in June, The University of Chicago News Office |
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15 May 2009 |
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Bruce Winstein discusses the QUIET experiment, which will explore physics at ultra-high energies generated at the birth of the universe (video), The University of Chicago News Office |
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26 April 2009 |
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Class probes nexus of science and policy: Rocky Kolb helped teach a 10-week class called Science, Technology, and Policy, The University of Chicago News Office |
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2 April 2009 |
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'Around the World in 80 Telescopes' webcast to include South Pole Telescope, The University of Chicago News Office |
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23 February 2009 |
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Evalyn Gates, Eyeing the universe through Einstein's telescope, The University of Chicago News Office |
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16 February 2009 |
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Cosmologists aim to observe first moments of universe, The University of Chicago News Office |
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5 November 2009
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QUaD: High-precision measurements confirm cosmologists' standard view of universe
The University of Chicago News Office
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4 November 2009
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by Sarah Galer, University of Chicago announces new Director of Office of Special
Progams - Key Partner for KICP Space Explorers Program
The University of Chicago News Office
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29 July 2009
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by Steve Koppes, O'Hare Airport exhibit provides portal to cosmos
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Visitors to Chicago's O'Hare International Airport this summer may find themselves taking an unplanned "journey" into the cosmos.
"From Earth to the Universe," an exhibit of 56 astronomical images, is on display through the end of the year at O'Hare. Scientists at the University of Chicago's Kavli Institute for Cosmological Physics contributed four of the images.
Two of the Chicago images come from Earth, and two are from space:
* A detector of the Pierre Auger Observatory sitting in the shadow of the Andes Mountains of South America. James Cronin, University Professor in Physics Emeritus, co-founded the Auger Observatory, which is dedicated to the study of rare, ultra-high-energy cosmic rays.
* The South Pole Telescope (SPT) in silhouette against the southern night sky and the aurora australis (southern lights). John Carlstrom, the S. Chandrasekhar Distinguished Service Professor in Astronomy & Astrophysics, leads the SPT collaboration.
* Supercomputer simulation of the evolving, large-scale structure in the distribution of galaxies. Andrey Kravtsov, Associate Professor in Astronomy & Astrophysics, performed the simulations.
* A mosaic of galaxy clusters producing the gravitational lensing effect. Michael Gladders, Assistant Professor in Astronomy & Astrophysics, took the images, which display how the gravity of massive clusters bends light, producing arc-like images of distant galaxies behind the clusters.
The exhibit spans 1,000 feet of wall space in a tunnel connecting Terminals 2 and 3 and the Chicago Transit Authority bus stop. Curated by the Adler Planetarium and Astronomy Museum, the exhibit is part of a yearlong celebration of the 400th anniversary of the telescope, the International Year of Astronomy.
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The University of Chicago News Office
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21 July 2009
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Evalyn Gates on Cosmic Magnification
Discover
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10 July 2009
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Aiming High: The Search for Ultra High-Energy Cosmic Rays
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The history of cosmic ray research is a story of scientific adventure. For nearly a century, cosmic ray researchers have climbed mountains, soared in hot air balloons, and traveled to the far corners of the Earth in the quest to understand these energetic particles from space. They have solved some scientific mysteries - and revealed many more. With each passing decade, scientists have discovered higher-energy and increasingly more rare cosmic rays. The Pierre Auger Project is the largest scientific enterprise ever conducted to search for the unknown sources of the highest-energy cosmic rays ever observed.
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American Museum of Natural History Science Bulletin
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30 June 2009
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by Steve Koppes, Astronomer Michael Gladders named 2009 Cottrell Scholar
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The Research Corporation for Science Advancement has named the University of Chicago's Michael Gladders a 2009 Cottrell Scholar. Each of the 10 new Cottrell Scholars will receive a $100,000 grant.
Cottrell award recipients are chosen both for the quality of their scientific research and their dedication to teaching. The awards are named for Frederick Gardner Cottrell, whose generosity made the Research Corporation possible, and whose invention of the electrostatic precipitator was an early environmental innovation that reduced pollution from smokestacks.
Gladders, an Assistant Professor in Astronomy & Astrophysics, is constructing the largest-ever catalog of distance groups and clusters of galaxies. The formation of these objects over cosmic time is driven by dark matter and dark energy, and these catalogs will be used to test the properties of these engimatic but dominant components of the universe. He plans to use emerging technologies to bring this new astronomical research into the University's classrooms.
He will incorporate data from an extensive imaging survey of the faint sky into advanced computer programs for teaching and visualization, enhancing the capabilities of these desktop planetaria. Based on these and other new tools, Gladders will create new computerized astronomy labs for use in undergraduate courses.
Founded in 1912, the Research Corporation of Tucson, Ariz., is an advocate for the sciences and a major funder of scientific innovation and research in U.S. colleges and universities.
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The University of Chicago News Office
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15 May 2009
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by Steve Koppes, QUIET team to deploy new gravity-wave probe in June
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A tiny fraction of a second following the big bang, the universe allegedly experienced the most inflationary period it has ever known.
During this inflationary era, space expanded faster than the speed of light. It sounds crazy, but it fits a variety of cosmological observations made in recent years, said University of Chicago physicist Bruce Winstein.
"Theorists take it to be true, but we have to prove it," said Winstein, the Samuel K. Allison Distinguished Service Professor in Physics at the University of Chicago. "It needs a real test, and that test is whether or not gravity waves were created."
Winstein and his Chicago associates are part of the international QUIET (Q/U Imaging ExperimenT; the Q and U stand for radiation parameters called Stokes parameters) collaboration that has devised such a test.
QUIET's goal: detect remnants of the radiation emitted at the earliest moments of the universe, when gravity waves rippled through the very fabric of space-time itself.
The intensive gravitational fields that existed at these earliest moments, according to Einstein, produced gravity waves that alternatively compressed and expanded space, first in one direction, then another. The cosmic microwave background (CMB) radiation—the afterglow of the big bang—may still carry a faint signature of those gravitational waves, nearly 14 billion years after their creation.
Seeking ethereal quarry
Other collaborations, including the South Pole Telescope (SPT), seek the same ethereal quarry with different techniques. The University of Chicago's Kavli Institute of Cosmological Physics supports both projects.
"No one can say what the best approach is right now," Winstein said, "but we need a variety of attacks on this important problem, and ours is different from most of the others. It's very exciting to be in this game."
At stake is the potential elucidation of new physics, that which falls outside the scope of the standard model. This model, a set of theories that describes the behavior of matter and energy in the universe, cannot explain how points in the sky too far away to have ever been in contact have almost exactly the same temperature. A validation of inflation would solve that problem.
"If we see these gravity waves, they have been called the smoking gun of inflation," Winstein said.
The QUIET experiment began operating last October with an antenna array that contains 19 detectors. Since then, QUIET collaborators at the Jet Propulsion Laboratory in California have produced 91 detectors sensitive to the radiation at a higher frequency.
Over the past several months, the Chicago collaboration has assembled and calibrated these 91 detectors in the basement of the Laboratory for Astrophysics and Space Research.
Winstein's team has tested each detector, adjusting 10 critical voltages for each to yield the best performance. Correctly optimized voltages can improve detector performance by a large factor, Winstein said, making it possible to observe in one day what would have otherwise required a week. This newer, more sensitive array will begin operating in June.
High and dry operation
The QUIET experiment operates in Chile's Atacama Desert, at an altitude of 17,000 feet. "It's very dry, and that's important because this microwave radiation gets absorbed by water vapor," Winstein explained. "And we observe day and night, 10 to 11 months a year."
Observations will continue at least until the end of this year. The team must keep its detectors at a chilling minus 253 degrees Celsius (minus 423 degrees Fahrenheit, close to absolute zero) to boost the odds of detecting the extremely weak gravity-wave signals. These signals would be so weak that electronic noise could easily drown them out.
"One way to eliminate electronic noise is to get your detector very, very cold," said QUIET's Allison Brizius, a graduate student in physics. "The colder it gets, the quieter it gets, the better it can pick up a signal."
The QUIET experiment must both detect and amplify the signal, which puts out only about a billionth of a volt.
"We have to be very careful with such small signals not to introduce any other noise," Winstein said. "We've demonstrated that this technology works, and we're proposing to mass-produce these modules, nearly 2,000 of them."
Winstein comes from a particle physics background, a veteran of 30 years of experimental research at Fermi National Accelerator Laboratory, which also plays a role in QUIET. As a particle physicist, he was exploring physics at the highest energies that an accelerator could then achieve.
Now, as a cosmological physicist probing the CMB, he stands on the brink of reaching nearly to the Planck scale, the highest energies that the universe can create. The CMB, he said, is "probably our best handle on the overall structure of the universe and how it was born."
Related links:
* Bruce Winstein
* QUIET's home page
* The South Pole Telescope and gravity waves
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The University of Chicago News Office
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15 May 2009
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Bruce Winstein discusses the QUIET experiment, which will explore physics at ultra-high energies generated at the birth of the universe (video)
The University of Chicago News Office
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26 April 2009
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by Sarah Galer, Class probes nexus of science and policy: Rocky Kolb helped teach a 10-week class called Science, Technology, and Policy
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Christine Kolb focuses on urban policy and public resource allocation at the Harris School of Public Policy Studies. And although her career interests lie in urban issues, the second-year graduate student's childhood made her a firm believer in the importance of introducing policy students to science issues.
"I grew up with dinner conversations about inadequate federal funding of science or how policymakers were not aware of what science is, what it accomplishes, and why it’s important," she says, referring to her father, Edward "Rocky" Kolb, the Chair of Astronomy & Astrophysics and the Arthur Holly Compton Distinguished Service Professor. "There is a chasm between the policy that regulates and funds science, and the process of science - what science must do."
Christine's passion for science and policy piqued the curiosity of Robert Michael, the Eliakim Hastings Moore Distinguished Service Professor Emeritus in the Harris School, for whom she is a teaching assistant. An idea started to germinate between them for a class that would combine the two disciplines, which had never been explored at the Harris School.
The result was a 10-week offering called Science, Technology, and Policy - an innovative, non-credit, elective created to expose public policy students to science policy.
"Rocky decided that he wanted students in policy to know more science, and I have 125 students of policy," explains Michael. "It did not take a rocket scientist to figure out that all we had to do is get the two of them together."
Genesis of the Class
When Kolb first spoke with Michael, he lamented how woefully little policy staffers on Capitol Hill knew about science and how he wished that would change.
"We, as political scientists, haven't taken advantage of the complementarity with physical science," says Michael, founding Dean of the Harris School. "Now that we are maturing, it is appropriate for our school to make ties with the physical sciences."
Kolb was one of the distinguished science experts to present weekly briefings at the Winter Quarter class. Other speakers included Kennette Benedict, Executive Director and Publisher of The Bulletin of the Atomic Scientists, who discussed nuclear proliferation; Robert Rosner, Director of Argonne National Laboratory, who discussed energy policy; and Leon Lederman, Nobel laureate and Fermilab Director Emeritus, who briefed the students on science education.
"What a great idea to have a class that would address this, especially because the leadership of the University has a science background, with a mathematician (President Robert Zimmer) and a physicist (Provost Thomas Rosenbaum)," Christine Kolb says.
And even though it was a noncredit obligation, the class was very popular with students.
"Students don't come to the University of Chicago for the weather or for the grades," says Michael. "They come for the knowledge."
'How the other half lives'
Kolb, as the scientist on the teaching team, hopes the success of the class will lead to the creation of a similar one for physical science students to learn about public policy.
"It is important to know a little about how the other half lives," he says.
He became interested in teaching the class for just this reason: to make students aware, as he succinctly put it, of "the policy of science and the science of policy."
The class signals the Harris School's expanding reach beyond the social sciences, all while remaining grounded in the policy tools that the Harris School teaches all of its students.
"From an institutional perspective, Science, Technology, and Policy reinforces the approach to policy taught at Harris," says Christine Kolb. However, "in order to fully understand policy you need to know about the economy, and if innovation from science and technology drives 50 percent of our economy, we need to know about those fields."
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The University of Chicago News Office
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2 April 2009
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by Steve Koppes, 'Around the World in 80 Telescopes' webcast to include South Pole Telescope
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The South Pole Telescope (SPT), which the University of Chicago operates with eight partner organizations, will be among the observatories taking part in a 24-hour live Webcast titled "Around the World in 80 Telescopes."
The event is part of 100 Hours of Astronomy, the cornerstone project of the International Year of Astronomy 2009 (IYA2009). The United Nations proclaimed IYA2009 on Dec. 20, 2007, to help citizens of the world rediscover their place in the universe.
The 100-hour astronomy marathon will consist of more than 1,500 public outreach events in more than 130 countries from April 2 to 5. The SPT live video webcast is scheduled to begin at 2:25 a.m. CDT Saturday, April 4.
Serving as webcast spokesmen will be Ross Williamson, a research scientist at the University of Chicago, and Erik Shirokoff, a graduate student at the University of California, Berkeley. To view the webcast, visit http://www.100hoursofastronomy.org/, or http://www.ustream.tv/channel/100-hours-of-astronomy.
Taking advantage of the exceptionally clear, dry and stable atmosphere at the South Pole, the 10-meter SPT is mapping large areas of sky for clues about the mysterious phenomenon know as dark energy. A repulsive force, dark energy pushes the universe apart and overwhelms gravity, the attractive force that all matter exerts.
Other participants in Around the World in 80 Telescopes include Gemini North and Keck in Hawaii, the Anglo-Australian Telescope, telescopes in the Canary Islands, the South African Large Telescope, Chilean observatories such as the Magellan Telescope at Las Campanas Observatory, and the Hubble Space Telescope.
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The University of Chicago News Office
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23 February 2009
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by Steve Koppes, Evalyn Gates, Eyeing the universe through Einstein's telescope
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Scientists are harnessing the cosmos as a scientific "instrument" in their quest to determine the makeup of the universe.
The University of Chicago's Evalyn Gates calls the instrument "Einstein's telescope." The instrument is actually the phenomenon of gravitational lensing, which acts as a sort of natural telescope. Gates's recently published book, Einstein's Telescope: The Hunt for Dark Matter and Dark Energy in the Universe, explains how it works.
Although based on Albert Einstein's general theory of relativity, the effect is easily demonstrated. Look at a light through the bottom of a wine glass, Gates recommends, and see the resulting light distortion.
"Einstein's telescope is using the universe itself as a lens through which we can seek out galaxies that would otherwise be too faint to be seen," says Gates, Assistant Director of the University's Kavli Institute for Cosmological Physics.
Einstein's First Inklings
Long ago Einstein recognized the potential existence of gravitational lensing, a consequence of his theory of general relativity. According to general relativity, celestial objects create dimples in space-time that bend the light traveling from behind.
Einstein realized that the gravitational influence of a foreground star could theoretically bend the light of another star sitting almost directly far beyond it, producing two images of the background star.
"Gravitational lensing magnifies things as well as making multiple images and distorting the shape of images, so you can actually use it as a magnifying glass," Gates explains.
But, assuming that the effect would be too weak to detect, Einstein immediately dismissed its significance. "What he didn't anticipate, among other things, were the incredible leaps forward in telescope technology," Gates says.
Seeing the Invisible
Astronomers now use gravitational lensing to look for dark matter and the imprint of dark energy, two of the greatest modern scientific mysteries.
Dark energy, which acts in opposition to gravity, is the dominant force in the universe.
"We can't see dark energy directly by any means, but we're looking for how it has sculpted the matter distribution of the universe over the past few billion years, since it's been the dominant factor, and also how it has affected the rate at which the Universe is expanding" Gates says.
And gravitational lensing is essentially the only method astronomers have for tracing out the web of dark matter that pervades the Universe, and determining how dark energy has impacted the evolution of this web. "It's really hot scientifically," she says.
Like dark energy, dark matter is also invisible. It accounts for most of the matter in the universe, but exactly what it is remains unknown. Scientists only know that dark matter differs significantly from normal matter (which is essentially composed of protons and neutrons) that dominates everyday life.
"What we're made of is just about five percent of everything that's in the universe," Gates says.
A Look into Galaxies Past
Scientists also use galaxy clusters as gravitational lenses to probe 13 billion years back into the history of the universe. "They're seeing some of the very first galaxies," she says.
Gravitational lensing offers astrophysicists a tool comparable to magnetic resonance imaging and computing tomography, which have provided health professionals with unprecedented new views of the human body.
"Gravitational lensing is going to allow us to image the universe in ways that wouldn't have been possible even 50 years ago," she says.
During the 20th century, quantum mechanics and general relativity radically altered scientists' view of the universe, Gates says. Investigations of dark matter and dark energy may do likewise.
"It may lead us to another revolution in our understanding of the most fundamental aspects of the universe, time, matter, and energy."
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The University of Chicago News Office
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16 February 2009
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by Steve Koppes, Cosmologists aim to observe first moments of universe
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During the next decade, a delicate measurement of primordial light could reveal convincing evidence for the popular cosmic inflation theory, which proposes that a random, microscopic density fluctuation in the fabric of space and time gave birth to the universe in a hot big bang approximately 13.7 billion years ago.
Among the cosmologists searching for these weak signals will be John Carlstrom, the S. Chandrasekhar Distinguished Service Professor in Astronomy & Astrophysics at the University of Chicago. Carlstrom operates the South Pole Telescope (SPT) with a team of scientists from nine institutions in their search for evidence about the origins and evolution of the universe.
Now on their agenda is putting cosmic inflation theory to its most stringent observational test so far. The test: detecting extremely weak gravity waves, which Einstein's theory of general relativity predicts that cosmic inflation should produce.
"If you detect gravity waves, it tells you a whole lot about inflation for our universe," Carlstrom said. It also would rule out various competing ideas for the origin of the universe. "There are fewer than there used to be, but they don't predict that you have such an extreme, hot big bang, this quantum fluctuation, to start with," he said. Nor would they produce gravity waves at detectable levels.
Carlstrom and his colleague Scott Dodelson will be on panel of cosmologists discussing these and related issues on Monday, Feb. 16 at the American Association for the Advancement of Science annual meeting in Chicago. Their session, "Origins and Endings: From the Beginning to the End of the Universe," will meet from 9:30 a.m. to 12:30 p.m. at the Hyatt Regency Hotel.
Fellow panelists will include Alan Guth of the Massachusetts Institute of Technology. In 1979, Guth proposed the cosmic inflation theory, which predicts the existence of an infinite number of universes. Unfortunately, cosmologists have no way of testing this prediction.
"Since these are separate universes, by definition that means we can never have any contact with them. Nothing that happens there has any impact on us," said Dodelson, a scientist at Fermi National Accelerator Laboratory and a Professor in Astronomy & Astrophysics at the University of Chicago.
But there is a way to probe the validity of cosmic inflation. The phenomenon would have produced two classes of perturbations. The first, fluctuations in the density of subatomic particles happen continuously throughout the universe, and scientists have already observed them.
"Usually they're just taking place on the atomic scale. We never even notice them," Dodelson said. But inflation would instantaneously stretch these perturbations into cosmic proportions. "That picture actually works. We can calculate what those perturbations should look like, and it turns out they are exactly right to produce the galaxies we see in the universe."
The second class of perturbations would be gravity waves—Einsteinian distortions in space and time. Gravity waves also would get promoted to cosmic proportions, perhaps even strong enough for cosmologists to detect them with sensitive telescopes tuned to the proper frequency of electromagnetic radiation.
"We should be able to see them if John's instruments are sensitive enough," Dodelson said.
Carlstrom and his associates are building a special instrument, a polarimeter, as an attachment to the SPT, to search for gravity waves. The SPT operates at submillimeter wavelengths, between microwaves and the infrared on the electromagnetic spectrum.
Cosmologists also use the SPT in their quest to solve the mystery of dark energy. A repulsive force, dark energy pushes the universe apart and overwhelms gravity, the attractive force exerted by all matter. Dark energy is invisible, but astronomers are able to see its influence on clusters of galaxies that formed within the last few billion years.
The SPT detects the cosmic microwave background (CMB) radiation, the afterglow of the big bang. Cosmologists have mined a fortune of data from the CMB, which represent the forceful drums and horns of the cosmic symphony. But now the scientific community has its ears cocked for the tones of a subtler instrument—gravitational waves—that underlay the CMB.
"We have these key components to our picture of the universe, but we really don't know what physics produces any of them," said Dodelson of inflation, dark energy and the equally mysterious dark matter. "The goal of the next decade is to identify the physics."
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The University of Chicago News Office
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