Caltech, SLAC, and LANL Set New Network Performance Marks

PHOENIX, Ariz.--Teams of physicists, computer scientists, and network engineers from Caltech, SLAC, LANL, CERN, Manchester, and Amsterdam joined forces at the Supercomputing 2003 (SC2003) Bandwidth Challenge and captured the Sustained Bandwidth Award for their demonstration of "Distributed particle physics analysis using ultra-high speed TCP on the Grid," with a record bandwidth mark of 23.2 gigabits per second (or 23.2 billion bits per second).

The demonstration served to preview future Grid systems on a global scale, where communities of hundreds to thousands of scientists around the world would be able to access, process, and analyze terabyte-sized data samples, drawn from data stores thousands of times larger. A new generation of Grid systems is being developed in the United States and Europe to meet these challenges, and to support the next generation of high-energy physics experiments that are now under construction at the CERN laboratory in Geneva.

The currently operating high-energy physics experiments at SLAC (Palo Alto, California), Fermilab (Batavia, Illinois), and BNL (Upton, New York) are facing qualitatively similar challenges.

During the Bandwidth Challenge, the teams used all three of the 10 gigabit/sec wide-area network links provided by Level 3 Communications and Nortel, connecting the SC2003 site to Los Angeles, and from there to the Abilene backbone of Internet2, the TeraGrid, and to Palo Alto using a link provided by CENIC and National LambdaRail. The bandwidth mark achieved was more than 500,000 times faster than an Internet user with a typical modem connection (43 kilobits per second). The amount of TCP data transferred during the 48-minute-long demonstration was over 6.6 terabytes (or 6.6 trillion bytes). Typical single-stream host-to-host TCP data rates achieved were 3.5 to 5 gigabits per second, approaching the single-stream bandwidth records set last month by Caltech and CERN.

The data, generated from servers at the Caltech Center for Advanced Computing Research (CACR), SLAC, and LANL booths on the SC2003 showroom floor at Phoenix, a cluster at the StarLight facility in Chicago as well as the TeraGrid node at Caltech, was sent to sites in four countries (USA, Switzerland, Netherlands, and Japan) on three continents. Participating sites in the winning effort were the Caltech/DataTAG and Amsterdam/SURFnet PoPs at Chicago (hosted by StarLight), the Caltech PoP at Los Angeles (hosted by CENIC), the SLAC PoP at Palo Alto, the CERN and the DataTAG backbone in Geneva, the University of Amsterdam and SURFnet in Amsterdam, the AMPATH PoP at Florida International University in Miami, and the KEK Laboratory in Tokyo. Support was provided by DOE, NSF, PPARC, Cisco Systems, Level 3, Nortel, Hewlett-Packard, Intel, and Foundry Networks.

The team showed the ability to use efficiently both dedicated and shared IP backbones. Peak traffic on the Los Angeles-Phoenix circuit, dedicated to this experiment, reached almost 10 gigabits per second utilizing more than 99 percent of the capacity. On the shared Abilene and TeraGrid circuits the experiment was able to share fairly over 85 percent of the available bandwidth. Snapshots of the maximum link utilizations during the demonstration showed 8.7 gigabits per second on the Abilene link and 9.6 gigabits per second on the TeraGrid link.

This performance would never have been achieved without the use of new TCP implementations because the widely deployed TCP RENO protocol performs poorly at gigabit-per-second speed. The primary TCP algorithm used was new FAST TCP stack developed at the Caltech Netlab. Additional streams were generated using HS-TCP, implemented at Manchester, and scalable TCP.

Harvey Newman, professor of physics at Caltech, said: "This was a milestone in our development of wide-area networks and of global data-intensive systems for science. Within the past year we have learned how to use shared networks up to the 10 gigabit-per-second range effectively. In the next round we will combine these developments with the dynamic building of optical paths across countries and oceans. This paves the way for more flexible, efficient sharing of data by scientists in many countries, and could be a key factor enabling the next round of physics discoveries at the high-energy frontier. There are also profound implications for integrating information sharing and on-demand audiovisual collaboration in our daily lives, with a scale and quality previously unimaginable."

Les Cottrell, assistant director of SLAC's computer services, said: "This demonstrates that commonly available standard commercial hardware and software, from vendors like Cisco, can effectively and fairly use and fill up today's high-speed Internet backbones, and sustain TCP flows of many gigabits per second on both dedicated and shared intracountry and transcontinental networks. As 10 gigabit-per-second Ethernet equipment follows the price reduction curve experienced by earlier lower-speed standards, this will enable the next generation of high-speed networking and will catalyze new data-intensive applications in fields such as high-energy physics, astronomy, global weather, bioinformatics, seismology, medicine, disaster recovery, and media distribution."

Wu-chun (Wu) Feng, team leader of research and development in Advanced Network Technology in the Advanced Computing Laboratory at LANL, noted: "The SC2003 Bandwidth Challenge provided an ideal venue to demonstrate how a multi-institutional and multi-vendor team can quickly come together to achieve a feat that would otherwise be unimaginable today. Through the collaborative efforts of Caltech, SLAC, LANL, CERN, Manchester, and Amsterdam, we have once again pushed the envelope of high-performance networking. Moore's law move over!"

"Cisco was very pleased to help support the SC2003 show infrastructure, SCINET," said Bob Aiken, director of engineering for academic research and technology initiatives at Cisco. "In addition, we also had the opportunity to work directly with the high-energy physics (HEP) research community at SLAC and Caltech in the United States, SURFnet in the Netherlands, CERN in Geneva, and KEK in Japan, to once again establish a new record for advanced network infrastructure performance.

"In addition to supporting network research on the scaling of TCP, Cisco also provided a wide variety of solutions, including Cisco Systems ONS 15540, Cisco ONS 15808, Cisco Catalyst 6500 Series, Cisco 7600 Series, and Cisco 12400 Series at the HEP sites in order for them to attain their goal. The Cisco next-generation 10 GE line cards deployed at SC2003 were part of the interconnect between the HEP sites of Caltech, SLAC, CERN, KEK/Japan, SURFnet, StarLight, and the CENIC network."

"Level 3 was pleased to support the SC2003 conference again this year," said Paul Fernes, director of business development for Level 3. "We've provided network services for this event for the past three years because we view the conference as a leading indicator of the next generation of scientific applications that distinguished researchers from all over the world are working diligently to unleash. Level 3 will continue to serve the advanced networking needs of the research and academic community, as we believe that we have a technologically superior broadband infrastructure that can help enable new scientific applications that are poised to significantly contribute to societies around the globe."

Cees de Laat, associate professor at the University of Amsterdam and organizer of the Global Lambda Integrated Facility (GLIF) Forum, added: "This world-scale experiment combined leading researchers, advanced optical networks, and network research sites to achieve this outstanding result. We were able to glimpse a yet-to-be explored network paradigm, where both shared and dedicated paths are exploited to map the data flows of big science onto a hybrid network infrastructure in the most cost-effective way. We need to develop a new knowledge base to use wavelength-based networks and Grids effectively, and projects such as UltraLight, TransLight, NetherLight, and UKLight, in which the team members are involved, have a central role to play in reaching this goal."

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About Caltech: With an outstanding faculty, including four Nobel laureates, and such off-campus facilities as the Jet Propulsion Laboratory, Palomar Observatory, and the W. M. Keck Observatory, the California Institute of Technology is one of the world's major research centers. The Institute also conducts instruction in science and engineering for a student body of approximately 900 undergraduates and 1,000 graduate students who maintain a high level of scholarship and intellectual achievement. Caltech's 124-acre campus is situated in Pasadena, California, a city of 135,000 at the foot of the San Gabriel Mountains, approximately 30 miles inland from the Pacific Ocean and 10 miles northeast of the Los Angeles Civic Center. Caltech is an independent, privately supported university, and is not affiliated with either the University of California system or the California State Polytechnic universities. http://www.caltech.edu

About SLAC: The Stanford Linear Accelerator Center (SLAC) is one of the world 's leading research laboratories. Its mission is to design, construct, and operate state-of-the-art electron accelerators and related experimental facilities for use in high-energy physics and synchrotron radiation research. In the course of doing so, it has established the largest known database in the world, which grows at 1 terabyte per day. That, and its central role in the world of high-energy physics collaboration, places SLAC at the forefront of the international drive to optimize the worldwide, high-speed transfer of bulk data. http://www.slac.stanford.edu/

About LANL: Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore National Laboratories to support NNSA in its mission. Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear weapons stockpile, developing technical solutions to reduce the threat of weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and national security concerns. http://www.lanl.gov/

About Netlab: Netlab is the Networking Laboratory at Caltech led by Professor Steven Low, where FAST TCP has been developed. The group does research in the control and optimization of protocols and networks, and designs, analyzes, implements, and experiments with new algorithms and systems. http://netlab.caltech.edu/FAST/

About CERN: CERN, the European Organization for Nuclear Research, has its headquarters in Geneva. At present, its member states are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland, and the United Kingdom. Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission, and UNESCO have observer status. For more information, see http://www.cern.ch.

About DataTAG: The European DataTAG is a project co-funded by the European Union, the U.S. Department of Energy through Caltech, and the National Science Foundation. It is led by CERN together with four other partners. The project brings together the following European leading research agencies: Italy's Istituto Nazionale di Fisica Nucleare (INFN), France's Institut National de Recherche en Informatique et en Automatique (INRIA), the U.K.'s Particle Physics and Astronomy Research Council (PPARC), and the Netherlands' University of Amsterdam (UvA). The DataTAG project is very closely associated with the European Union DataGrid project, the largest Grid project in Europe also led by CERN. For more information, see http://www.datatag.org.

About StarLight: StarLight is an advanced optical infrastructure and proving ground for network services optimized for high-performance applications. Operational since summer 2001, StarLight is a 1 GE and 10 GE switch/router facility for high-performance access to participating networks and also offers true optical switching for wavelengths. StarLight is being developed by the Electronic Visualization Laboratory (EVL) at the University of Illinois at Chicago (UIC), the International Center for Advanced Internet Research (iCAIR) at Northwestern University, and the Mathematics and Computer Science Division at Argonne National Laboratory, in partnership with Canada's CANARIE and the Netherlands' SURFnet. STAR TAP and StarLight are made possible by major funding from the U.S. National Science Foundation to UIC. StarLight is a service mark of the Board of Trustees of the University of Illinois. See www.startap.net/starlight.

About the University of Manchester: The University of Manchester, located in the United Kingdom, was first granted a Royal Charter in April 1880 as the Victoria University and became the first of the U.K.'s great civic universities. As a full-range university it now has more than 70 departments involved in teaching and research, with more than 2,000 academic staff. There are more than 18,000 full-time students, including 2,500 international students, from over 120 countries studying for undergraduate and postgraduate level degrees. The University of Manchester has a proud tradition of innovation and excellence which continues today. Some of the key scientific developments of the century have taken place here. In Manchester, Rutherford conducted the research which led to the splitting of the atom and the world's first stored-program electronic digital computer, built by Freddie Williams and Tom Kilburn, successfully executed its first program in June 1948. The departments of Physics, Computational Science, Computer Science and the Network Group together with the E-Science North West Centre research facility are very active in developing a wide range of e-science projects and Grid technologies. See www.man.ac.uk.

About National LambdaRail: National LambdaRail (NLR) is a major initiative of U.S. research universities and private sector technology companies to provide a national scale infrastructure for research and experimentation in networking technologies and applications. NLR puts the control, the power, and the promise of experimental network infrastructure in the hands of the nation's scientists and researchers. Visit http://www.nationallambdarail.org for more information.

About CENIC: CENIC is a not-for-profit corporation serving California Institute of Technology, California State University, Stanford University, University of California, University of Southern California, California Community Colleges, and the statewide K-12 school system. CENIC's mission is to facilitate and coordinate the development, deployment, and operation of a set of robust multi-tiered advanced network services for this research and education community. http://www.cenic.org

About University of Amsterdam: The Advanced Internet Research group of the University of Amsterdam's Faculty of Science researches new architectures and protocols for the Internet. It actively participates in worldwide standardization organizations Internet Engineering Task Force and the Global Grid Forum. The group conducts experiments with extremely high-speed network infrastructures. The Institute carries out groundbreaking research in the fields of security, authorization, authentication and accounting for grid environments. The Institute is developing a virtual laboratory based on grid technology for e-science applications. For more information see http://www.science.uva.nl/research/air>www.science.uva.nl/research/air.

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Robert Tindol
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Gamma-Ray Bursts, X-Ray Flashes, and Supernovae Not As Different As They Appear

PASADENA, Calif.—For the past several decades, astrophysicists have been puzzling over the origin of powerful but seemingly different explosions that light up the cosmos several times a day. A new study this week demonstrates that all three flavors of these cosmic explosions--gamma-ray bursts, X-ray flashes, and certain supernovae of type Ic--are in fact connected by their common explosive energy, suggesting that a single type of phenomenon, the explosion of a massive star, is the culprit. The main difference between them is the "escape route" used by the energy as it flees from the dying star and its newly born black hole.

In the November 13 issue of the journal Nature, Caltech graduate student Edo Berger and an international group of colleagues report that cosmic explosions have pretty much the same total energy, but this energy is divided up differently between fast and slow jets in each explosion. This insight was made possible by radio observations, carried out at the National Radio Astronomy Observatory's Very Large Array (VLA), and Caltech's Owens Valley Radio Observatory, of a gamma-ray burst that was localized by NASA's High Energy Transient Explorer (HETE) satellite on March 29 of this year.

The burst, which at 2.6 billion light-years is the closest classical gamma-ray burst ever detected, allowed Berger and the other team members to obtain unprecedented detail about the jets shooting out from the dying star. The burst was in the constellation Leo.

"By monitoring all the escape routes, we realized that the gamma rays were just a small part of the story for this burst," Berger says, referring to the nested jet of the burst of March 29, which had a thin core of weak gamma rays surrounded by a slow and massive envelope that produced copious radio waves.

"This stumped me," Berger adds, "because gamma-ray bursts are supposed to produce mainly gamma rays, not radio waves!"

Gamma-ray bursts, first detected accidentally decades ago by military satellites watching for nuclear tests on Earth and in space, occur about once a day. Until now it was generally assumed that the explosions are so titanic that the accelerated particles rushing out in antipodal jets always give off prodigious amounts of gamma radiation, sometimes for hundreds of seconds. On the other hand, the more numerous supernovae of type Ic in our local part of the universe seem to be weaker explosions that produce only slow particles. X-ray flashes were thought to occupy the middle ground.

"The insight gained from the burst of March 29 prompted us to examine previously studied cosmic explosions," says Berger. "In all cases we found that the total energy of the explosion is the same. This means that cosmic explosions are beasts with different faces but the same body."

According to Shri Kulkarni, MacArthur Professor of Astronomy and Planetary Science at Caltech and Berger's thesis supervisor, these findings are significant because they suggest that many more explosions may go undetected. "By relying on gamma rays or X rays to tell us when an explosion is taking place, we may be exposing only the tip of the cosmic explosion iceberg."

The mystery we need to confront at this point, Kulkarni adds, is why the energy in some explosions chooses a different escape route than in others.

At any rate, adds Dale Frail, an astronomer at the VLA and coauthor of the Nature manuscript, astrophysicists will almost certainly make progress in the near future. In a few months NASA will launch a gamma-ray detecting satellite known as Swift, which is expected to localize about 100 gamma-ray bursts each year. Even more importantly, the new satellite will relay very accurate positions of the bursts within one or two minutes of initial detection.

The article appearing in Nature is titled "A Common Origin for Cosmic Explosions Inferred from Calorimetry of GRB 030329." In addition to Berger, the lead author, and Kulkarni and Frail, the other authors are Guy Pooley, of Cambridge University's Mullard Radio Astronomy Observatory; Vince McIntyre and Robin Wark, both of the Australia Telescope National Facility; Re'em Sari, associate professor of astrophysics and planetary science at Caltech; Derek Fox, a postdoctoral scholar in astronomy at Caltech; Alicia Soderberg, a graduate student in astrophysics at Caltech; Sarah Yost, a postdoctoral scholar in physics at Caltech; and Paul Price, a postdoctoral scholar at the University of Hawaii's Institute for Astronomy.

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Robert Tindol
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Aeronautical Lab Celebrates Its 75th

PASADENA, Calif. – It might seem a bit of a stretch to see what the flight control of a 747 and the way a boxfish maneuvers in very turbulent water have in common. But such thinking is all in a day's work within the walls of the California Institute of Technology's Graduate Aeronautical Laboratories (GALCIT), which this week celebrates its 75th anniversary.

It's fitting that GALCIT celebrates its 75th in the same year the world celebrates the 100th anniversary of flight. GALCIT's celebration will span two days, Friday and Saturday, November 14 and 15. On Friday there is an all-day symposium on solid mechanics and laboratory tours in the afternoon. On Saturday there will be presentations and a panel discussion on different aspects of aeronautical and astronautical research by various alumni and guests, followed by a banquet in the evening.

GALCIT was formally established in 1928 as the Guggenheim Aeronautical Laboratory by a donation from the Daniel Guggenheim Fund for the Promotion of Aeronautics. It was one of seven such donations made in the 1920s to advance the then-dismal state of aeronautical science in the United States. Its first director was Theodore von Kármán, one of the early scientific pioneers in aeronautics. Under his leadership, GALCIT became the birthplace of aeronautical research in Southern California. This led to the rapid development of the area's aeronautics industry in the 1930s, and ultimately to the modern aerospace industry. The original investment of the Guggenheim Foundation was the beginning of U.S. supremacy in aeronautics research, particularly for commercial and military aviation.

The most famous project of GALCIT was the establishment of the Jet Propulsion Laboratory (JPL), which today is the lead NASA institute for planetary exploration. It grew out of a combination of scholarly and popular interest in rocket propulsion. Beginning in 1935, GALCIT students and staff, including Frank Malina, A. M. O. Smith, H. S. Tsien, and W. Arnold, joined with two young explosives entrepreneurs, Jack Parsons and Ed Forman, to build and test rockets. The first long-duration solid propellant rocket motors and spontaneously ignitable liquid propellants were developed by the group. The solid propellants enabled the development of jet-assisted take-off rockets used in World War II and the founding of Aerojet Engineering Corporation, the first U.S. manufacturer of rocket engines. Ultimately, the liquid propellants were used in the Apollo program and the Titan missile. JPL was established as a separate organization in 1943 and now plays a key role in robotic activities in deep space and planetary exploration. The original concept of von Kármán was that GALCIT should be an institute in the European style that developed " . . . a tradition of research and teaching which stresses an appreciation for real applications in a very broad and deep base of fundamentals." Originally the application was strictly aeronautics, the development and operation of aircraft, and many contributions were made to aircraft structures, aerodynamics, and propulsion. But over the years the subject of aeronautics has been broadly interpreted to be "a wide discipline encompassing a broad spectrum of basic as well as applied problems in fluid dynamics and mechanics of materials." These days that's led to research into the study of fluid and solid mechanics, and the use of specialized large facilities like the Lucas Adaptive Wall Wind Tunnel, the supersonic shear layer facility, the free surface shear flow tunnel, the T5 hypervelocity shock tunnel, and the Ludwieg tube.

In addition, there are smaller laboratories to study cardiovascular fluid dynamics, combustion, and detonation. They also conduct numerical studies of vortex dynamics, turbulent mixing, fracture, the mechanics of materials, and shock waves.

All of which leads to the boxfish and the 747. It is just one specific example of the kind of work that goes on at GALCIT, and is part of the work of Morteza Gharib, the Hans W. Liepmann Professor of Aeronautics and Bioengineering at Caltech. Gharib believes the next wave of smart propulsion devices will be based on the biomechanics of flying and swimming. The goal, then, is to learn how nature engineers these things, with the hope of gleaning insight into the design of such aircraft as the 747. So one of the animals he studies is the humble boxfish, which is capable of staying within one millimeter of a sharp coral reef in highly turbulent water. It does this, Gharib notes, using "seven fins that are flapping and creating vortices here and there, keeping the fish right there, dead accurate."

Seventy-five years, and GALCIT is still learning.

For more information on the celebration and to register for events, please see http://www.galcit.caltech.edu/galcit75/.

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Caltech, JPL researchers unveil details on new type of light detector based on superconductivity

PASADENA, Calif.—A new and improved way to measure light has been unveiled by physicists at the California Institute of Technology and the Jet Propulsion Laboratory. The technology exploits the strange but predictable characteristics of superconductivity, and has a number of properties that should lead to uses in a variety of fields, from medicine to astrophysics.

Reporting in the October 23 issue of Nature, Caltech physicist Jonas Zmuidzinas and his JPL colleagues outline the specifications of their superconducting detector. The device is cleverly designed to sidestep certain limitations imposed by nature to allow for very subtle and precise measurements of electromagnetic radiation, which includes visible light, radio signals, X-rays, and gamma rays, as well as infrared and ultraviolet frequencies.

At the heart of the detector is a strip of material that is cooled to such a low temperature that electrical current flows unimpeded—in other words, a superconductor. Scientists have known for some time that superconductors function as they do because of electrons in the material being linked together as "Cooper pairs" with a binding energy just right to allow current to flow with no resistance. If the material is heated above a certain temperature, the Cooper pairs are torn apart by thermal fluctuations, and the result is electrical resistance.

Zmuidzinas and his colleagues have designed their device to register the slight changes that occur when an incoming photon—the basic unit of electromagnetic radiation—interacts with the material and affects the Cooper pairs. The device can be made sensitive enough to detect individual photons, as well as their wavelengths (or color).

However, a steady current run through the superconducting material is not useful for measuring light, so the researchers have also figured out a way to measure the slight changes in the superconductor's properties caused by the breaking of Cooper pairs. By applying a high-frequency microwave field of about 10 gigahertz, a slight lag in the response due to the Cooper pairs can be measured. In fact, the individual frequencies of the photons can be measured very accurately with this method, which should provide a significant benefit to astrophysicists, as well as researchers in a number of other fields, Zmuidzinas says.

"In astrophysics, this will give you lots more information from every photon you detect," he explains. "There are single-pixel detectors in existence that have similar sensitivity, but our new detector allows for much bigger arrays, potentially with thousands of pixels."

Such detectors could provide a very accurate means of measuring the fine details of the cosmic microwave background radiation (CMB). The CMB is the relic of the intense light that filled the early universe, detectable today as an almost uniform glow of microwave radiation coming from all directions.

Measurements of the CMB are of tremendous interest in cosmology today because of extremely faint variations in the intensity of the radiation that form an intricate pattern over the entire sky. These patterns provide a unique image of the universe as it existed just 300 thousand years after the Big Bang, long before the first galaxies or stars formed. The intensity variations are so faint, however, that it has required decades of effort to develop detectors capable of mapping them.

It was not until 1992 that the first hints of the patterns imprinted in the CMB by structure in the early universe were detected by the COBE satellite. In 2000, using new detectors developed at Caltech and JPL, the BOOMERANG experiment led by Caltech physicist Andrew Lange produced the first resolved images of the these patterns. Other experiments, most notably the Cosmic Background Imager of Caltech astronomer Tony Readhead, have confirmed and extended these results to even higher resolution. The images obtained by these experiments have largely convinced the cosmology research community that the universe is geometrically flat and that the theory of rapid inflation proposed by MIT physicist Alan Guth is a reality.

Further progress will help provide even more detailed images of the CMB—ideally, so detailed that individual fluctuations could be matched to primordial galaxies—as well as other information, including empirical evidence to determine whether the CMB is polarized. The new detector invented by Zmuidzinas and Henry G. LeDuc, a co-author of the paper, could be the breakthrough needed for the new generation of technology to study the CMB.

In addition, the new superconducting detector could be used to scan the universe for dark matter, and in X-ray astronomy for better analysis of black holes and other highly energetic phenomena, in medical scanning, in environmental science, and even in archaeology.

Other Caltech faculty are beginning to investigate these additional applications for the new detector. Assistant professor of physics Sunil Golwala is targeting dark-matter detection, while associate professor of physics and astronomy Fiona Harrison is pursuing X-ray astronomy applications.

The lead author of the paper is Peter Day, who earned his doctorate at Caltech under the direction of condensed-matter physicist David Goodstein and is now a researcher at JPL. In addition to LeDuc, also a researcher at JPL and leader of the JPL superconducting device group, the other authors are Ben Mazin and Anastasios Vayonakis, both Caltech graduate students working in Zmuidzinas's lab.

The work has been supported in part by NASA's Aerospace Technology Enterprise, the JPL Director's Research and Development Fund, the Caltech President's Fund, and Caltech trustee Alex Lidow.

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Robert Tindol
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Caltech Boasts Silver Medal Winners at the 34th International Physics Olympiad

PASADENA, Calif.—The California Institute of Technology adds two silver medals to its list of distinguished honors, won by freshmen Emily Russell and Yernur Rysmagambetov, at the 34th International Physics Olympiad in Taiwan.

In addition to her silver medal, Russell was named "Best Female Participant" in the physics competition.

Russell, who is from Yorktown Heights, New York, is majoring in physics at Caltech. She is the recent recipient of both a Lingle and an Axline scholarship.

Caltech freshman Rysmagambetov, who also earned a silver medal in the competition, is originally from Kazakhstan and plans to major in computer science while at Caltech.

Day one of the rigorous two-day competition was devoted to solving complex theoretical physics problems including "A Swing of a Falling Weight," "A Piezoelectric Crystal Resonator under an Alternating Voltage," and "Neutrino Mass and Neutron Decay." After a day of rest, the next competition day consisted of solving five-hour experimental problems utilizing laser beams or diodes, photodetectors, multimeters, and nematic liquid crystal.

At this year's International Physics Olympiad, 238 students from 54 countries participated. Originating in 1967 in Warsaw, this is the major international physics competition for secondary school students. Every year the competition is held in a different country around the world. Next year's 2004 competition will be held in July in Pohang, South Korea.

Contact: Deborah Williams-Hedges (626) 395-3227 debwms@caltech.edu

Visit the Caltech Media Relations Web site at: http://pr.caltech.edu/media

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A Detailed Map of Dark Matter in a Galactic Cluster Reveals How Giant Cosmic Structures Formed

Astrophysicists have had an exceedingly difficult time charting the mysterious stuff called dark matter that permeates the universe because it's--well--dark. Now, a unique "mass map" of a cluster of galaxies shows in unprecedented detail how dark matter is distributed with respect to the shining galaxies. The new comparison gives a convincing indication of how dark matter figures into the grand scheme of the cosmos.

Using a technique based on Einstein's theory of general relativity, an international group of astronomers led by Jean-Paul Kneib, Richard Ellis, and Tommaso Treu of the California Institute of Technology mapped the mass distribution of a gigantic cluster of galaxies about 4.5 billion light-years from Earth. They did this by studying the way the cluster bends the light from other galaxies behind it. This technique, known as gravitational lensing, allowed the researchers to infer the mass contribution of the dark matter, even though it is otherwise invisible.

Clusters of galaxies are the largest stable systems in the universe and ideal "laboratories" for studying the relationship between the distributions of dark and visible matter. Caltech's Fritz Zwicky realized in 1937 from studies of the motions of galaxies in the nearby Coma cluster that the visible component of a cluster--the stars in galaxies--represents only a tiny fraction of the total mass. About 80 to 85 percent of the matter is invisible.

In a campaign of over 120 hours of observations using the Hubble Space Telescope, the researchers surveyed a patch of sky almost as large as the full moon, which contained the cluster and thousands of more distant galaxies behind it. The distorted shapes of these distant systems were used to map the dark matter in the foreground cluster. The study achieved a new level of precision, not only for the center of the cluster, as has been done before for many systems, but also for the previously uncharted outlying regions.

The result is the most comprehensive study to date of the distribution of dark matter and its relationship to the shining galaxies. Signals were traced as far out as 15 million light-years from the cluster center, a much larger range than in previous investigations.

Many researchers have tried to perform these types of measurements with ground-based telescopes, but the technique relies heavily on measuring the exact shapes of distant galaxies behind the cluster, and for this the "surgeon's eye" of the Hubble Space Telescope is far superior.

The study, to be published soon in the Astrophysical Journal, reveals that the density of dark matter falls fairly sharply with distance from the cluster center, defining a limit to its distribution and hence the total mass of the cluster. The falloff in density with radius confirms a picture that has emerged from detailed computer simulations over the past years.

Team member Richard Ellis said, "Although theorists have predicted the distribution of dark matter in clusters from numerical simulations based on the effects of gravity, this is the first time we have convincing observations on large scales to back them up.

"Some astronomers had speculated clusters might contain large reservoirs of dark matter in their outermost regions," Ellis added. "Assuming our cluster is representative, this is not the case."

In finer detail, the team noticed that some structure emerged from their map of the dark matter. For example they found localized concentrations of dark matter associated with galaxies known to be slowly falling into the system. Overall there is a striking correspondence between features in the dark matter map and that delineated by the cluster galaxies, which is an important result in the new study.

"The close association of dark matter with structure in the galaxy distribution is convincing evidence that clusters like the one studied built up from the merging of smaller groups of galaxies, which were prevented from flying away by the gravitational pull of their dark matter," says Jean-Paul Kneib, who is the lead author in the publication.

Future investigations will extend this work using Hubble's new camera, the Advanced Camera for Surveys (ACS), which will be trained on a second cluster later this year. ACS is 10 times more efficient than the Wide Field and Planetary Camera 2, which was used for this investigation. With the new instrument, it will be possible to study clumps of finer mass in galaxy clusters in order to investigate how the clusters originally were assembled.

By tracing the distribution of dark matter in the most massive structure in the universe using the powerful trick of gravitational lensing, astronomers are making great progress towards a better understanding of how such systems were assembled, as well as toward defining the key role of dark matter.

In addition to Kneib, Ellis, and Treu, the other team members are Patrick Hudelot of the Observatoire Midi-Pyrénées in France, Graham P. Smith of Caltech, Phil Marshall of the Mullard Radio Observatory in England, Oliver Czoske of the Institut für Astrophysik und Extraterrestrische Forschung in Germany, Ian Smail of the University of Durham in England, and Priya Natarajan of Yale University.

For more information, please contact:

Jean-Paul Kneib Caltech/Observatoire Midi-Pyrénées (currently in Hawaii) Phone: (808) 881-3865 E-mail: jean-paul.kneib@ast.obs-mip.fr

Richard Ellis Caltech Phone: (626) 395-4970 (secretary) (Australia: Cellular: 011-44-7768-923277) E-mail: rse@astro.caltech.edu

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International Teams Set New Long-range Speed Record with Next-generation Internet Protocol

Scientists at the California Institute of Technology (Caltech) and the European Organization for Nuclear Research (CERN) have set a new Internet2 land speed record using the next-generation Internet protocol IPv6. The team sustained a single stream TCP rate of 983 megabits per second for more than one hour between the CERN facility in Geneva and Chicago, a distance of more than 7,000 kilometers. This is equivalent to transferring a full CD in 5.6 seconds.

The performance is remarkable because it overcomes two important challenges:

· IPv6 forwarding at Gigabit-per-second speeds · High-speed TCP performance across high bandwidth/latency networks.

This major step towards demonstrating how effectively IPv6 can be used should encourage scientists and engineers in many sectors of society to deploy the next-generation Internet protocol, the Caltech researchers say.

This latest record by Caltech and CERN is a further step in an ongoing research-and-development program to develop high-speed global networks as the foundation of next generation data-intensive grids. Caltech and CERN also hold the current Internet2 land speed record in the IPv4 class, where IPv4 is the traditional Internet protocol that carries 90 percent of the world's network traffic today. In collaboration with the Stanford Linear Accelerator Center (SLAC), Los Alamos National Laboratory, and the companies Cisco Systems, Level 3, and Intel, the team transferred one terabyte of data across 10,037 kilometers in less than one hour, from Sunnyvale, California, to Geneva, Switzerland. This corresponds to a sustained TCP rate of 2.38 gigabits per second for more than one hour.

Multi-gigabit-per-second IPv4 and IPv6 end-to-end network performance will lead to new research and business models. People will be able to form "virtual organizations" of planetary scale, sharing in a flexible way their collective computing and data resources. In particular, this is vital for projects on the frontiers of science and engineering, projects such as particle physics, astronomy, bioinformatics, global climate modeling, and seismology.

Harvey Newman, professor of physics at Caltech, said, "This is a major milestone towards our dynamic vision of globally distributed analysis in data-intensive, next-generation high-energy physics (HEP) experiments. Terabyte-scale data transfers on demand, by hundreds of small groups and thousands of scientists and students spread around the world, is a basic element of this vision; one that our recent records show is realistic. IPv6, with its increased address space and security features is vital for the future of global networks, and especially for organizations such as ours, where scientists from all world regions are building computing clusters on an increasing scale, and where we use computers including wireless laptop and mobile devices in all aspects of our daily work.

"In the future, the use of IPv6 will allow us to avoid network address translations (NAT) that tend to impede the use of video-advanced technologies for real-time collaboration," Newman added. "These developments also will empower the broader research community to use peer-to-peer and other advanced grid architectures in support of their computationally intensive scientific goals."

Olivier Martin, head of external networking at CERN and manager of the DataTAG project said, "These new records clearly demonstrate the maturity of IPv6 protocols and the availability of suitable off-the-shelf commercial products. They also establish the feasibility of transferring very large amounts of data using a single TCP/IP stream rather than multiple streams as has been customarily done until now by most researchers as a quick fix to TCP/IP's congestion avoidance algorithms. I am optimistic that the various research groups working on this issue will now quickly release new TCP/IP stacks having much better resilience to packet losses on long-distance multi-gigabit-per-second paths, thus allowing similar or even better records to be established across shared Internet backbones."

The team used the optical networking capabilities of the LHCnet, DataTAG, and StarLight and gratefully acknowledges support from the DataTAG project sponsored by the European Commission (EU Grant IST-2001-32459), the DOE Office of Science, High Energy and Nuclear Physics Division (DOE Grants DE-FG03-92-ER40701 and DE-FC02-01ER25459), and the National Science Foundation (Grants ANI 9730202, ANI-0230967, and PHY-0122557).

About the California Institute of Technology (Caltech):

With an outstanding faculty, including four Nobel laureates, and such off-campus facilities as Palomar Observatory, and the W. M. Keck Observatory, the California Institute of Technology is one of the world's major research centers. The Institute also conducts instruction in science and engineering for a student body of approximately 900 undergraduates and 1,000 graduate students who maintain a high level of scholarship and intellectual achievement. Caltech's 124-acre campus is situated in Pasadena, California, a city of 135,000 at the foot of the San Gabriel Mountains, approximately 30 miles inland from the Pacific Ocean and 10 miles northeast of the Los Angeles Civic Center. Caltech is an independent, privately supported university, and is not affiliated with either the University of California system or the California State Polytechnic universities. More information is available at http://www.caltech.edu.

About CERN:

CERN, the European Organization for Nuclear Research, has its headquarters in Geneva, Switzerland. At present, its member states are Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland, and the United Kingdom. Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission, and UNESCO have observer status. For more information, see http://www.cern.ch.

About the European Union DataTAG project:

The DataTAG is a project co-funded by the European Union, the U.S. Department of Energy, and the National Science Foundation. It is led by CERN together with four other partners. The project brings together the following European leading research agencies: Italy's Istituto Nazionale di Fisica Nucleare (INFN), France's Institut National de Recherche en Informatique et en Automatique (INRIA), the UK's Particle Physics and Astronomy Research Council (PPARC), and Holland's University of Amsterdam (UvA). The DataTAG project is very closely associated with the European Union DataGrid project, the largest grid project in Europe also led by CERN. For more information, see http://www.datatag.org.

 

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Astronomers "weigh" pulsar's planets

For the first time, the planets orbiting a pulsar have been "weighed" by measuring precisely variations in the time it takes them to complete an orbit, according to a team of astronomers from the California Institute of Technology and Pennsylvania State University.

Reporting at the summer meeting of the American Astronomical Society, Caltech postdoctoral researcher Maciej Konacki and Penn State astronomy professor Alex Wolszczan announced today that masses of two of the three known planets orbiting a rapidly spinning pulsar 1,500 light-years away in the constellation Virgo have been successfully measured. The planets are 4.3 and 3.0 times the mass of Earth, with an error of 5 percent.

The two measured planets are nearly in the same orbital plane. If the third planet is co-planar with the other two, it is about twice the mass of the moon. These results provide compelling evidence that the planets must have evolved from a disk of matter surrounding the pulsar, in a manner similar to that envisioned for planets around sun-like stars, the researchers say.

The three pulsar planets, with their orbits spaced in an almost exact proportion to the spacings between Mercury, Venus, and Earth, comprise a planetary system that is astonishingly similar in appearance to the inner solar system. They are clearly the precursors to any Earth-like planets that might be discovered around nearby sun-like stars by the future space interferometers such as the Space Interferometry Mission or the Terrestrial Planet Finder.

"Surprisingly, the planetary system around the pulsar 1257+12 resembles our own solar system more than any extrasolar planetary system discovered around a sun-like star," Konacki said. "This suggests that planet formation is more universal than anticipated."

The first planets orbiting a star other than the sun were discovered by Wolszczan and Frail around an old, rapidly spinning neutron star, PSR B1257+12, during a large search for pulsars conducted in 1990 with the giant, 305-meter Arecibo radio telescope. Neutron stars are often observable as radio pulsars, because they reveal themselves as sources of highly periodic, pulse-like bursts of radio emission. They are extremely compact and dense leftovers from supernova explosions that mark the deaths of massive, normal stars.

The exquisite precision of millisecond pulsars offers a unique opportunity to search for planets and even large asteroids orbiting the pulsar. This "pulsar timing" approach is analogous to the well-known Doppler effect so successfully used by optical astronomers to identify planets around nearby stars. Essentially, the orbiting object induces reflex motion to the pulsar which result in perturbing the arrival times of the pulses. However, just like the Doppler method, the pulsar timing method is sensitive to stellar motions along the line-of-sight, the pulsar timing can only detect pulse arrival time variations caused by a pulsar wobble along the same line. The consequence of this limitation is that one can only measure a projection of the planetary motion onto the line-of-sight and cannot determine the true size of the orbit.

Soon after the discovery of the planets around PSR 1257+12, astronomers realized that the heavier two must interact gravitationally in a measurable way, because of a near 3:2 commensurability of their 66.5- and 98.2-day orbital periods. As the magnitude and the exact pattern of perturbations resulting from this near-resonance condition depend on a mutual orientation of planetary orbits and on planet masses, one can, in principle, extract this information from precise timing observations.

Wolszczan showed the feasibility of this approach in 1994 by demonstrating the presence of the predicted perturbation effect in the timing of the planet pulsar. In fact, it was the first observation of such an effect beyond the solar system, in which resonances between planets and planetary satellites are commonly observed. In recent years, astronomers have also detected examples of gravitational interactions between giant planets around normal stars.

Konacki and Wolszczan applied the resonance-interaction technique to the microsecond-precision timing observations of PSR B1257+12 made between 1990 and 2003 with the giant Arecibo radio telescope. In a paper to appear in the Astrophysical Journal Letters, they demonstrate that the planetary perturbation signature detectable in the timing data is large enough to obtain surprisingly accurate estimates of the masses of the two planets orbiting the pulsar.

The measurements accomplished by Konacki and Wolszczan remove a possibility that the pulsar planets are much more massive, which would be the case if their orbits were oriented more "face-on" with respect to the sky. In fact, these results represent the first unambiguous identification of Earth-sized planets created from a protoplanetary disk beyond the solar system.

Wolszczan said, "This finding and the striking similarity of the appearance of the pulsar system to the inner solar system provide an important guideline for planning the future searches for Earth-like planets around nearby stars."

Contact: Robert Tindol (626) 395-3631

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Caltech Faculty Member Named Scientist of the Year

PASADENA, Calif. — The California Science Center has announced the joint selection of Andrew Lange and Saul Perlmutter as 2003 California Scientist of the Year.

Lange is Marvin L. Goldberger Professor of Physics at the California Institute of Technology in Pasadena, and Perlmutter is senior scientist and group leader at the Lawrence Berkeley National Laboratory in Berkeley. Using two very different techniques, Lange and Perlmutter's experimental efforts have confirmed a remarkable theory of how the universe expanded and evolved after the "big bang."

Lange and Perlmutter will be recognized during the annual presentation of the California Scientist of the Year and the Amgen Award for Science Teaching Excellence, a special event to honor excellence in scientific achievement and education, on May 8 at the California Science Center in Exposition Park, Los Angeles.

Lange is the 14th Caltech faculty member to be named Scientist of the Year.

The California Science Center established the California Scientist of the Year Award in recognition of the prominent role California plays in the areas of scientific and technological development. A blue-ribbon panel selects a nominee whose work is current and advances the boundaries of any field of science. Of those selected for California Scientist of the Year honors, 11 later became Nobel laureates. The panel concluded that Lange and Perlmutter's discoveries complement each other so well in revealing the nature of the universe that both scientists should be recognized this year.

According to the most widely held theory of cosmic evolution, the universe went though an inflationary phase during which its size rapidly increased and the universe's geometrical structure took on a very specific form: parallel lines never meet, and the sum of the angles inside an astronomically sized triangle add up to 180 degrees. Scientists refer to this particular form of geometry as being mathematically "flat." According to the general theory of relativity, a mathematically flat universe places constraints on the amount of mass and energy in the universe. Unfortunately, astronomers could not account for the requisite mass and energy. Therefore, either the standard cosmological or—"big bang"—theory was incorrect and the universe's geometrical structure was not that of Euclid, or the astronomers were missing something important.

Lange studies fluctuations in the cosmic microwave background (CMB) radiation, a relic of the primeval "fireball" that filled the early universe. These signals, which are visible today at microwave frequencies, provide a clear "snapshot" of the embryonic universe at an epoch long before the first stars or galaxies had formed. In general, this radiation reaches the earth uniformly from all directions in the sky. However, at the level of 0.003 percent there is an intricate pattern of fluctuations in the CMB. Using novel detectors developed at the Jet Propulsion Laboratory and flown on a balloon-borne telescope high above Antarctica, Lange's group was able to make the first resolved images of these very faint patterns. The images demonstrate that the radiation fluctuates on an angular scale of one degree, which is exactly what scientists expected from a mathematically flat universe. Since the 1930s, scientists have known that galaxies are moving away from one another, and there has been a concerted effort to study the rate of this expansion. Prior to Perlmutter's efforts, almost all astronomers expected that the expansion of the universe was slowing, due to the gravitational attraction of galaxies and other matter. However, Perlmutter's group found that the universe is actually expanding at an accelerating rate, as if a "negative pressure" were pushing everything apart. This negative pressure may be what scientists call the cosmological constant, first hypothesized by Albert Einstein in an attempt to prescribe a stable universe but later rejected by him. Perlmutter's estimates of the cosmological constant's magnitude are consistent with Lange's observations of a flat universe.

Lange's work demonstrates that the universe is mathematically flat, and that the standard cosmological theory is correct, while Perlmutter's work indicates that the source of astronomical energy giving rise to a flat universe comes from a type of negative gravitational pressure or dark energy permeating the universe. The nature of this dark energy remains a mystery.

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MEDIA CONTACT: Jill Perry, Media Relations Director (626) 395-3226 jperry@caltech.edu

Visit the Caltech media relations web site: http://pr.caltech.edu/media

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Caltech astrophysicist Shrinivas Kulkarni electedto National Academy of Sciences

Shrinivas Kulkarni, who is the MacArthur Professor of Astronomy and Planetary Science at the California Institute of Technology, has been elected to the National Academy of Sciences.

Kulkarni is a leading authority on exotic astrophysical phenomena such as gamma-ray bursts, brown dwarfs, and millisecond pulsars, and has been associated with many of the major advances in understanding the universe that have been made over the last decade.

In 1982, along with Don Backer of UC Berkeley, Kulkarni discovered the first millisecond pulsar. These pulsars have turned out to be very precise natural clocks with many applications. In 1995, Kulkarni led a group that discovered the first "brown dwarf." Hypothesized since the sixties, a brown dwarf is a "failed star," with a mass too low to shine brightly like our own sun but too high for it to be classified as a planet. Brown dwarfs are now considered to be quite abundant. In 1997, he and his colleagues demonstrated that gamma-ray bursts were extragalactic in origin, and Kulkarni has led many investigations since then that have further uncovered the nature of the phenomenon.

Kulkarni has been a prime mover in the quest to improve the resolution of optical instruments with a technique known as "interferometry," which exploits the wave nature of light in such a way that light from two or more mirrors can be combined for a superior image. Working in collaboration with Jet Propulsion Laboratory engineers, his research team used the testbed interferometer at Caltech's Palomar Observatory in 2000 to obtain the most precise distance to date for a Cepheid variable, a type of regularly pulsating star that has long been a standard of reference in the "cosmic yardstick" used to gauge astronomical distances.

Kulkarni is heavily involved in the Keck Interferometer and is the interdisciplinary scientist for NASA's ambitious Space Interferometry Mission (SIM), which is expected to be launched in 2009. With SIM, astronomers hope to measure and catalog planets around nearby stars.

A Pasadena resident, Kulkarni earned his master's degree in 1978 from the Indian Institute of Technology and his doctorate from UC Berkeley in 1983. He came to Caltech in 1985 as a research fellow, and received a faculty appointment in 1987. He is also a former Presidential Young Investigator and Sloan Research Fellow, and winner of the Waterman Prize.

Kulkarni joins 71 other prominent scientists this year as new members, bringing the total active membership to 1,922. Caltech currently has 67 other faculty members and three trustees who are members of the academy.

Contact: Robert Tindol (626) 395-3631

 

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