BPA NEWS Board on Physics and Astronomy • National Research Council • Washington, DC • 202-334-3520 • [email protected] • December, 1997

challenges they face. tions was available only to concertgoers. The Physics of Within our lifetimes, improvements in Just a few generations ago, a trip Materials our understanding of materials have across the United States was a great transformed the computer from an exotic adventure. Today, jets whisk us safely by Venkatesh Narayanamurti, tool, used only by scientists, to an essen- across the continent or the oceans in only Chair, Committee on Condensed- tial component of almost every aspect of a few hours. Matter and Materials Physics and our lives. Computers enable us to keep Making these extraordinary accom- Dean of Engineering, UC Santa track of extraordinarily complex data, plishments possible are a wide variety of Barbara from managing financial transactions to polymeric, ceramic, and metallic materi- forecasting weather. They control auto- als, as well as the transistor, the magnetic mobile production lines and guide air- disk, the laser, the light-emitting diode, HE Committee on Condensed- craft around the world. and a host of other solid-state devices. TMatter and Materials Physics, which During the same period, telecommu- The development of these materials and was commissioned by the BPA to prepare nication has evolved from rudimentary devices depended on our ability to predict a volume of the new survey, Physics in a telephone conversations to instantaneous and control the physical properties of New Era, has just completed a short simultaneous worldwide transmission of matter. That ability is the realm of con- preliminary report entitled The Physics of voice, video images, and data. The cellu- densed-matter and materials physics Materials. The report highlights a num- lar phone is even unleashing us from (CMMP). ber of areas of forefront research and also telephone wires. Fifty years ago, the major intellectual points out in a popular format the role Almost every American can now challenge facing researchers in CMMP that this field plays in our lives. The enjoy, while relaxing in the living room or was to understand the physical properties following article draws from the text of driving the car or even while jogging, of nearly perfect single crystals of ele- the report, which is available in printed music of a quality that in previous genera- See “Physics of Materials” on Page 4 and electronic form from the BPA (see www.nas.edu/bpa). Introduction BPA Gathers on the West Coast Condensed-matter and materials Report of the Committee on Optical Science and Engineering physics has played a key role in many of the scientific and technological revolu- Unveiled tions that have changed our lives so HE Board on Physics and Astronomy all of physics in a way that does not in- dramatically in the last fifty years. The held its semiannual meeting at the volve comparing one branch of physics years ahead will see equally dramatic T Academies’ Beckman Center on the UC directly with another. advances, making this an era of great Irvine campus on November 1-2. Just scientific excitement for research in this New Survey of Astronomy and before the BPA convened, there were field. It is also a time of stress on the Astrophysics several special meetings at the Center to institutions that support the field. The launch new activities. On the morning of November 1, goal of the report The Physics of Materials Board member Tony Readhead convened is to give the reader a sense of what con- Physics Survey Overview a distinguished group of astronomers to densed-matter and materials physics is On October 31, former BPA chair begin preparations for the next survey of about—of the excitement that scientists David Schramm convened a group to astronomy and astrophysics. Among the feel, the importance of their work, and the plan the Overview volume of the new participants was John Bahcall, chair of the survey, Physics in a New Era. Most of the last Astronomy and Astrophysics Survey components of the survey are completed Committee, which published a report In this issue: or in progress, and it is time to begin work entitled The Decade of Discovery and on its capstone, the Overview, which will which carried on the tradition of the • The Physics of Materials. summarize the conclusions and priorities astronomy community of setting clear Page 1 of the various branches of physics and priorities for the field. George Field, who address a number of broad unifying chaired the committee that prepared • BPA Gathers on the West themes and common issues that affect all Astronomy and Astrophysics for the 1980s, Coast. Page 1 of physics. The group wrestled with the attended. Also present were the cochairs question of how to identify priorities for See “BPA Meeting” on Page 2 2 BPA News • December 1997

BPA Meeting There are many new approaches and also Board on Physics and Astronomy new ways to identify and evaluate what (Continued from Page 1) works. The physics survey should also Robert C. Dynes, Chair address the role of faculty members in University of California, San Diego of the NRC’s Committee on Astronomy improving high-school science education. and Astrophysics, which was created in Could a high-school physics course serve Robert C. Richardson, Vice Chair Cornell University response to the recommendation of the as a foundation for learning other natural Bahcall Report that a continuing commit- sciences? Should high-school science be Ira Bernstein tee be established to carry out short-term taught in a way that blends the sciences Yale University studies in between the major decadal and is not bound by disciplinary bound- Steven Chu surveys. The chairs of the sponsoring aries? Can the university community be Stanford University Boards—the Board on Physics and As- mobilized to help high-school teachers Val Fitch tronomy and the Space Studies Board— and administrators to address these Princeton University participated along with former Commis- issues? The Board enthusiastically en- sion member Jerry Ostriker. With sup- dorsed pursuing these issues and encour- Ivar Giaever aged Dr. Lederman to continue develop- Rensselaer Polytechnic Institute port from the National Science Founda- tion and the National Aeronautics and ing a plan for a component of the physics John Huchra Space Administration, the new decadal survey treating education. Harvard-Smithsonian Center for Astrophysics survey is expected to get under way early Computational Physics Nathan Myrhvold (pending) next calendar year. Microsoft Corporation David Arnett reported on a program- BPA Meeting initiation meeting that he led to consider Anthony C. S. Readhead The Board itself was convened in the a study of computational physics. The California Institute of Technology afternoon of November 1 by newly- group concluded that computation is R. G. Hamish Robertson installed BPA Chair Robert Dynes, faculty playing such an important role in physics, University of Washington member of the Physics Department and both in simulation and modeling as well Kathleen C. Taylor Chancellor of the University of California as data integration and visualization, that GM R&D Center San Diego campus. New BPA members there should be a study of this area as part of the physics survey. The Board encour- J. Anthony Tyson Val Fitch (Princeton), Kathleen Taylor Lucent Technologies (GM R&D Center), and George age Dr. Arnett to work with the BPA staff Whitesides (Harvard University) were to develop a study plan. George M. Whitesides welcomed. The Board congratulated Harvard University Biological Physics fellow-member Steven Chu on his receiv- David Wilkinson ing the Nobel Prize for his work in trap- Steve Chu discussed biological phys- Princeton University ping and cooling of atoms. ics with the Board. He recounted the The Board is developing studies in a results of a program initiation meeting NRC Staff number of cross-cutting areas: education, that Steve Block chaired, which con- Dr. Donald C. Shapero, Director computational physics, and biological cluded that a study of the “New Biology” Dr. Robert L. Riemer, Associate Director physics. should be undertaken. The study that Dr. Daniel F. Morgan, Program Officer Block’s group developed is motivated by Natasha Casey, Program Associate Education the need for the field of biology to rein- Grace Wang, Project Assistant Leon Lederman reported on a pro- vent itself in the post-genomic era, mov- gram-initiation meeting on education to ing toward a more quantitative approach. š develop a focus on education for the The Board applauded this result and physics survey that he recently led. Be- encouraged the NRC’s Board on Biology The Board on Physics and Astronomy is a continuing cause an important audience for the to take the lead in developing this study. interdisciplinary body with expertise spanning the physics survey will be physics depart- Dr. Chu emphasized that physicists have various subfields of physics, astronomy, and ments, one of the major topics to be made and continue to make important astrophysics. It serves as a focal point in the National addressed by a study of physics education contributions to biology and that there- Research Council for issues connected with these fore, there should be a component of the fields. The activities of the Board are supported by in the context of the physics survey will be funds from the National Science Foundation, the the role of the departments in improving physics survey that addresses “biological Department of Energy, the Department of Defense, physics education for undergraduates, physics.” The Board encouraged Dr. the National Aeronautics and Space Administration, including not only those who are potential Chu, Ivar Giaever, and Hans Frauenfelder the National Institute of Standards and Technology, physics majors, but also students who will (attending the BPA meeting on behalf of and private and other sources. study in other areas of science and those the NAS Physics Section) to develop a who will study humanities and liberal arts. plan for a study of biological physics. BPA News • December 1997 3

Studies in Progress national long-haul network backbone. The Board heard reports on the Computer technology is headed toward Committees of the tera-operations per second, and optical progress of a number of studies (some of Board on Physics and which are near completion) including: technology will play various roles in these developments. For example, interchip Astronomy • Optical science and engineering - communication may use optical tech- Charles V. Shank niques. And optics will play a crucial role Committee on 1 • Elementary-particle physics - Bruce in terabyte data banks. These develop- Astronomy and Astrophysics Winstein ments will have a growing impact in the John Huchra, Harvard-Smithsonian Nuclear physics - Sam Austin commercial sector, but a roadblock in the Center for Astrophysics and Thomas • Prince, Caltech, Cochairs • Condensed matter and materials path to individual consumer access to the physics - Venky Narayanamurti full power of the global information Committee on Atomic, Molecular, network is providing an infrastructure for • Gravitational physics - James Hartle and Optical Sciences broadband data transmission to the Wendell T. Hill, III, University of Optical Science and Engineering home. Here again, optical technology Maryland, Chair The Committee on Optical Science holds a possible answer. Optics is also affecting health care in Committee on Elementary- and Engineering has nearly completed its Particle Physics work. From March 1995 to March 1996, dramatic ways. Optical tools for biotech- nology show promise in gene sequencing. Bruce Winstein, University the Committee conducted a series of six of Chicago, Chair workshops with a use/application orienta- New understanding of light-tissue inter- tion: actions will lead to better laser surgical Committee on Gravitational Physics techniques. And optics will enable ad- James Hartle, University of California at • Health and life sciences vances in minimally invasive therapies. Santa Barbara, Chair • Manufacturing NIH has an opportunity to play a major Committee on Nuclear Physics • Information technology role in these developments. One of the greatest possible impacts of John C. Schiffer, University of Chicago, • Energy, space, environment, optical Chair sensing optics is in the area lighting, where revo- lutionary changes are in the offing. Light- Committee on Optical Research and education • ing accounts for about 20 percent of U.S. Science and Engineering2 • Defense electricity consumption. High-technol- Charles Shank, University of Over the last year, COSE has worked ogy lighting offers various options for California at Berkeley, Chair on synthesis of the results of the work- improved efficiency that, taken together, Plasma Science Committee shops , formulation of conclusions and could cut power consumption, perhaps Chuan Liu, University of Maryland, recommendations, and preparation of an by as much as half over the next decade. Chair overview chapter that summarizes the Optics plays a central role in modern results of the study. warfare. Military systems and functions Solid State Sciences Committee The chapters of the report are as featuring optical applications include Thomas P. Russell, University of follows: missile guidance, night vision, laser gyros, Massachusetts, Chair laser weapons, and satellite surveillance. 1 Overview Committee on Condensed- Manufacturing of conventional optics 2 Optics in Information Technology Matter and Materials Physics is making great strides. There has been a 3 Optics in Health Care and the Life Venkatesh Narayanamurti, University of revolution in optical-design software. Sciences California at Santa Barbara, Chair 4 Optical Sensing, Lighting, and Energy There is a growing demand for mass 5 Optics in National Defense manufacturing techniques that enable Committee on Radio Frequencies 6 Optics in Industrial Manufacturing cheaper, faster, and more flexible produc- Michael Davis, Arecibo 7 Manufacturing Optical Components tion processes for optical components Observatory, Chair and systems. and Systems U.S. National Committees3 8 Optics Research and Education Optics has many applications in industrial manufacturing, including Dr. Shank reviewed some of the optical lithography of semiconductors, 1 In cooperation with the Space Studies Board. findings in these areas. Among the most laser materials processing, rapid 2 impressive of these has to do with the role In cooperation with the National prototyping, sensors for real-time moni- Materials Advisory Board. of optics in “tera era” information tech- toring and control, optical metrology, and 3 See www.nas.edu/bpa for more nology of the future. In information lasers for alignment and guidance. information. transport, optical fiber will play a crucial See “BPA Meeting” on Page 7 role in establishing a terabit per second 4 BPA News • December 1997

plinary field linked strongly to other fascinating low-temperature states of Physics of Materials science and engineering disciplines, superfluid helium. Scientists in this field (Continued from Page 1) which benefit from and contribute to its have long-standing interests in essentially successes. Indeed, CMMP is distin- all aspects of magnetism and magnetic ments, simple compounds, and alloys. guished by its extraordinary interdepen- materials. They investigate the properties Today our challenge is to extend that dence with other science and engineering of glasses, polymeric materials, granular understanding to much more complex fields. Its practitioners include those who materials, and composites in which forms of matter—high-temperature make and refine new materials, those who diverse constituents are combined to superconductors, multicomponent mag- seek to understand such materials at a produce entirely new substances with netic materials, disordered crystals, fundamental level through experiments novel properties. They are reaching out polymers, glasses, and to more complex and theoretical analysis, and those who to researchers in the earth and atmo- phenomena like the fracture of solids and apply the materials and understanding to spheric sciences because they share the continuous interests in topics hardening of glass such as friction, as it cools. Ever in COMPOUND SEMICONDUCTOR ELECTRONICS fracture, and fluid view in today’s Silicon is the material underlying most elec- flow. The outreach CMMP is another tronics, but compound semiconductors com- to biology and the scientific revolu- posed of more than one element, such as gal- lium arsenide (GaAs) and silicon germanium study of biological tion, the dramatic (SiGe), have advantages that can lead to de- materials are now change under way vices with intrinsically higher speed and lower beginning in a in the biological noise. The worldwide market for compound serious way. sciences. Great semiconductors is estimated to be $750 mil- Hardly any other opportunities lie lion in 1996, and it is growing at the rate of 40% per year. Discrete components are now widely field of science so ahead as con- used in the low-noise receivers of cellular tele- seamlessly spans the densed-matter and phone handsets, in addition to the specialized whole range materials physicists high-speed microwave applications for which between the most they have long been the materials of choice. increasingly work FIGURE 1 A high electron-mobility transistor basic research and together with Compound semiconductors such as GaAs, SiGe, and gallium nitride (GaN) are key to the (HEMT) such as those used in cellular telephones. the most applied. biological scientists. development of the next generation of wire- The round bonding pads are 100 microns in Advances in basic diameter, roughly the size of a human hair. The Technology in less telephones, which will use higher fre- research inspire new quency microwaves in order to transmit more gate of the transistor, just 0.05 microns across, Daily Life ideas for applica- information. GaN transistors, for example, are appears as the two narrow lines in the center of this tions, and applica- characterized by high breakdown voltage and scanning electron micrograph. (Courtesy of Sandia The second part tion-driven techno- of the report illus- great robustness. A potential high-volume ap- National Laboratories.) plication for such transistors is in transmitter logical advances trates the vital power amplifiers for wireless base stations. provide tools that impact of CMMP Pushing the limits of semiconductor materials technology is essential for increasing the enable new funda- on our daily lives. It speed of transistors and advancing our ability to modulate lasers for high-speed optical infor- mental investiga- mation transmission. Because compound semiconductors are composed of more than one consists of a brief tions. At the same story—a few simple element, they promise a vastly increased range of materials from which to select those with desired electronic properties. This promise can be realized with manufacturing techniques time, technological events that happen such as molecular beam epitaxy, which allows the repeated, controlled, precise growth of one problems raise every day—accom- material on another in single atomic layers, producing compound layered materials not seen in questions that panied by descrip- nature. In the future, the use of novel forms of microscopy for fabrication and testing will demand new tions that highlight determine our ability to design and build such structures on the atomic scale—a scale on which the motion of electrons is governed by quantum mechanics. fundamental a sampling of the insights. For scientific and tech- make new devices. This work is done in example, with new fundamental under- nological advances in CMMP that make universities, in industry, and in govern- standing of nonequilibrium phenomena, those everyday events possible. The ment laboratories. we may soon see a qualitative im- sidebar (Figure 1) illustrates the role of Part 3 speaks, as well, of a field in provement in our ability to predict compound semiconductors in making transition. New linkages with disciplines and control complex properties of the possible the cellular telephone and the such as polymer chemistry and the bio- structural materials used to manufac- pocket pager, both increasingly familiar logical sciences are growing in impor- ture everything from airplanes and fixtures of everyday life. tance. bridges to electronic devices. Techno- The Research Endeavor Fifty years ago, the transistor emerged logical advances provide tools such as Part 3 of the report explores the from this area of physics. High-tempera- synchrotrons, neutron sources, nature of the CMMP endeavor itself. ture superconductivity was discovered by electron microscopes, high magnetic CMMP is a diverse, evolving, interdisci- condensed-matter physicists, as were the field facilities, computers, and BPA News • December 1997 5 scanning probe microscopes. These us. Consider the fact that essentially none important, condensed-matter and tools, in turn, provide unprecedented of the most important discoveries in this materials physicists have learned that opportunities to investigate materials on area made in the last decade were antici- chemically complex materials, like the the atomic scale, leading to fundamental pated in the 1986 National Research new superconductors, can have extraordi- discoveries that drive both science and Council report Physics Through the 1990s. narily interesting properties. The study of technology. The new physics of the And the pace of scientific change, such complexity in solids is emerging as a fractional quantum hall effect, for especially when viewed on an interna- whole new style of inquiry. example, was made possible by new tional scale, is now accelerating. A different kind of unanticipated materials fabrication technology. (See the A particularly dramatic surprise was complexity is emerging in artificially sidebar, Figure 2.) The study of matter the discovery in 1986 of high-temperature structured materials, engineered with under extreme conditions has led both to superconductivity, which disproved a features so small that they behave like fundamental and artificial atoms. practical break- These structures throughs. THE FRACTIONAL QUANTUM HALL EFFECT are candidates for Several of the the next generation The fractional quantum Hall effect is an example of beautiful and fundamental new physics of computing most profound made possible by technological advances in the fabrication of artificially structured materials. It conceptual develop- takes place in a two-dimensional electron “gas” produced in a transistor-like device subjected to elements, but their ments in science extreme conditions of high magnetic fields and low temperatures. Under these conditions, potential uses in have occurred in electron correlations become dominant. The basic observation is a precise quantization of the both science and Hall conductance with the unusual property of being described by a quantum number that is CMMP in the last technology go far fractional rather than an integer. beyond computing two decades. The The application of a strong magnetic field at low temperature induces large numbers of vor- so-called tices (“whirlpools”) that attach themselves to the electrons to form composite objects, which as we know it. As “renormalization- condense into a special quantum “fluid.” This fluid of composite particles has the bizarre prop- we learn how to group” theory of erty that the low energy excitations consist of a single vortex that binds a fraction of an electron assemble increas- charge. These objects have recently been observed through direct measurement of their frac- critical fluctuations ingly complex tional charge and by tunneling experiments in which an electron added to the system is seen to structures from in condensed matter break up into three excitations, each with one-third of the charge. Theoretical work on this has helped us problem has led to profound and intellectually exciting new concepts and techniques with appli- more and more understand phe- cations both in other areas of condensed-matter physics and in quantum field theories studied complex building nomena as varied as in elementary particle physics. We are familiar with the idea in high-energy physics that certain blocks, perhaps elementary particles such as protons are actually composite objects made up of fractionally phase transforma- even from biologi- charged quarks. These quarks can be observed in collisions at very high energies (or equiva- cal molecules, we tions, the interac- lently, high temperatures) carried out using particle accelerators. In condensed matter physics, tions between one does the reverse: the analog of the accelerator is the refrigerator. At sufficiently low tem- can anticipate a elementary particles, peratures, in a strong magnetic field, electrons added to a quantum Hall system break up into whole new world and the fluctuations fractionally charged elementary vortex excitations. This, then, is a fundamentally new form of of scientific conduction in an artificially created, layered ma- phenomena and of the stock market. terial. Chaos, turbulence, practical applica- and pattern forma- tions. FIGURE 2 A pictorial representation of the many- tion are other core particle state that underlies the fractional quantum Hall An Era of Change concepts in this field effect. The height of the landscape represents the The evolution that have had wide- amplitude of the quantum wave of one electron as it of CMMP is taking ranging implications travels among its companions (balls). The arrows place within an across the world of indicate the vortices induced by the magnetic field. evolving national science. The These vortices attach themselves to the electrons to form and international historic role of composite particles. (Courtesy of Lucent Technologies context, as de- condensed-matter Bell Laboratories.) scribed in Part 4 of physicists, ever since the report. The the emergence of quantum electronics great industrial laboratories, so promi- and the transistor, has been to discover consensus then growing among scientists nent over the last half century, have new concepts and phenomena and to that superconductivity could exist only at shifted the scale, scope, and emphasis of develop their new knowledge in ways that temperatures very near absolute zero. their R&D investments in CMMP to are meaningful for fundamental advances Now, just over a decade later, we are adjust to changes in the global market- in many fields and for practical applica- beginning to see commercially marketed place. Industry is looking more and more tions. devices based on superconductivity at to universities and government laborato- What does the future hold for con- easily accessible liquid-nitrogen tempera- ries to perform basic research that will densed-matter and materials physics? tures, and we can look forward to decades There must be many surprises in store for of new developments. Even more See “Physics of Materials” on Page 6 6 BPA News • December 1997

Physics of Materials them cost effectively will require contin- the physical sciences leaves a significant ued scientific advances. National issues gap in the nation’s scientific infrastruc- (Continued from Page 5) related to security, the environment, and ture and its ability to transform the fruits energy resources will also need to be of research into applications. The lead to the next generation of technology. confronted. Condensed-matter and economic impact of this shift may not Yet these very academic and government materials physics will play a pivotal role in become apparent for decades, because of institutions are themselves facing consid- ensuring the nation’s prosperity in this the time required for fundamental erable stresses that limit their abilities to new world. scientific advances to be incorporated respond to new demands. This report demonstrates that con- into new products. If U.S. industry no Part 4 also discusses issues arising densed-matter and materials physics lies longer can support basic research at the from the growing dependence of CMMP at the heart of modern technology. levels it once did, then the realities of on shared large and medium-size experi- Advances in communications, comput- global economic competition place the mental facilities. Increasingly sophisti- ing, medicine, transportation, energy, and burden for support of such research cated equipment has become necessary defense have all been enabled by new squarely on government. Our nation for scientific innovation, from electron- materials and materials-related phenom- must move quickly to determine the scale beam instruments to giant x-ray synchro- ena. Research in condensed-matter and and form of this governmental responsi- trons. These facilities are essential for materials physics, pushing forward the bility. continued advances in the invention, frontiers of both science and technology, Innovation is the key to developing understanding, and control of increas- provides much of the fundamental breakthrough technologies. It must ingly complex materials. They are re- underpinning for these advances. Its continue to flourish despite the resource quired for a broad range of scientific and success has been one of the great sagas of constraints that are sending shock waves technological endeavors, not only in the 20th century. through the R&D system. Constrained CMMP but also in many other fields of As we enter the new millennium, the resources mean that hard choices must be science and in industry. But funding large field of condensed-matter and materials made, but the system must adapt in a way facilities strains the resources of the physics is evolving in several important that preserves the nation’s ability to agencies that have traditionally provided directions. It is becoming increasingly innovate and enables us to meet the research support to universities and interdisciplinary, with progress often challenges of the future. government laboratories, even as those being made at the interfaces with other Progress in condensed-matter and institutions are being asked to play a disciplines, such as biology, chemistry, materials physics, as in many other broader role. engineering, materials science, and scientific fields, will require continued The great industrial laboratories—the atomic and molecular physics. Partner- investment in major facilities for experi- engines that have driven technology for ships across disciplines and among ments in such areas as neutron scattering the past half century—have adjusted to universities, government laboratories, and synchrotron radiation. These the realities of the new global marketplace and industry have become essential to facilities provide capabilities far beyond and changed both the scale and scope of assemble the resources and diverse skills those available in individual laboratories. their long-term R&D investments in the necessary to continue advancing our Though they have been developed and physical sciences. Under pressure to knowledge. The emergence of national supported primarily by the condensed- balance the federal budget, the U.S. facilities, from atomic-resolution micro- matter and materials physics community, government is reducing its discretionary scopes to powerful synchrotron and they also serve thousands of scientists and expenditures, the category that includes neutron sources, has transformed both engineers in other endeavors, such as federal support for science. At the same the practice and the substance of the field. structural biology and environmental time, many other countries are increasing These developments foreshadow a science. The construction and opera- their investments in long-term R&D. The condensed-matter and materials physics tional costs of large facilities, however, debate about the appropriate roles in community more closely connected with force us to consider carefully their R&D of industry, government laborato- industry and with the rest of science, and budgets relative to those for other R&D ries, and the universities is set against this armed with experimental and computa- initiatives and to look more closely at the backdrop of constrained resources and tional capabilities that were not even role and impact of the internationaliza- increased global economic competition. imagined just a few decades ago. tion of science. In the next century, the United States The 21st century will bring significant Finally, increased cooperation will be will need to respond to world tensions challenges to condensed-matter and required among universities, government arising from economic competition, materials physics. Foremost among these laboratories, and industry to leverage regional military conflict, competition for challenges is ensuring the future vitality of existing resources and to ensure the energy and other strategic resources, and the field and its continued ability to effective integration of science and global environmental issues. These new enhance our quality of life. The shift of technology. These interactions will be international challenges differ from those the major industrial laboratories away facilitated by modern communication of the Cold War past, and addressing from long-term, fundamental research in and information technologies. BPA News • December 1997 7

We face an era of vast opportunity for nism involves the so-called Higgs boson. is under construction at Brookhaven condensed-matter and materials physics Researchers in this field believe that there National Laboratory to explore the phys- and the technology it enables. Just as the is powerful evidence that the next genera- ics of the quark-gluon plasma. transistor, the optical fiber, and the solid- tion of experiments will begin to reveal Condensed-Matter Physics state laser have strengthened our more about how the mass-generating economy and changed our lives, new mechanism works and whether new Venkatesh Narayanamurti, chair of developments in quantum engineering, ultrastrong forces are involved. Theorists the Committee on Condensed-Matter and nonequilibrium phenomena, and have developed a new approach to de- Materials Physics, described the progress biomaterials (to name just a few high- scribing elementary particles and their of his committee and presented the Board lights) hold out the promise of revolu- interactions called “string theory.” Much with copies of a research briefing on this tionary breakthroughs in the next effort has gone into understanding this topic that his committee has prepared to century. To fulfill this promise, the new theoretical domain and connecting it acquaint a broad audience with the role of condensed-matter and materials physics with experimental results. String theory, materials physics in everyday life. The community will need to build on the unlike all previous theories, can incorpo- lead article in this issue of BPA News unique strengths of universities, govern- rate the fourth force, gravity, in a consis- presents some of the material from this ment laboratories, and industry, finding tent manner. It also predicts the existence briefing, which is available in its entirety new ways to meet the challenges of our of supersymmetric partners to the pres- from the BPA in printed form or in elec- changing world.n ently know spectrum of elementary tronic form on the web. (The BPA’s particles. Such a theory will be necessary website can be found at www.nas.edu/ BPA Meeting if an understanding of the details of the bpa.) (Continued from Page 3) Big Bang (the event that created the Gravitational Physics Universe) is to be reached. To explore The Committee on Gravitational In the area of basic research, there these ideas, experiments are needed that Physics is just getting started under the have been a number of breakthroughs, probe the energy domain connected with leadership of James Hartle. This area has including control and detection of single mass generation. The international Large been given a separate study in the physics atoms and molecules, new femtosecond Hadron Collider, to be built at the Euro- survey because of the growing links to techniques, nonlinear optical materials, pean high-energy laboratory CERN, will cosmology and elementary-particle and high-frequency sources and compo- host a number of these experiments, and physics and because of the major facilities nents. the U.S. community is heavily involved. that are under construction or consider- The COSE report is expected to be There is a joint agreement between the ation for the future. published early in 1998. United States Department of Energy and CERN that formalizes U.S. participation. Helium Study Elementary-Particle Physics The elementary-particle physics commu- Bob Richardson briefly commented The report of the Committee on nity foresees the need for an accelerator on the study of the impact on S&T of the Elementary-Particle Physics, chaired by that goes well beyond the energies attain- legislated privatization of the helium Bruce Winstein of the University of able at the LHC; there are many possibili- reserve. The Department of Interior has Chicago, has cleared the National Re- ties, and the report outlines a strategy for commissioned the BPA to study this issue search Council’s review process and is developing several of them. in response to a Congressional mandate. about to go to the National Academy Press for publication. The report explains Nuclear Physics Materials Facilities the motivations that drive the field, de- Sam Austin, a member of the Com- Tom Russell commented on the scribes its connections to other branches mittee on Nuclear Physics, another com- planned study of agency roles and re- of physics and science, outlines a strategy ponent of the physics survey, reported on sponsibilities in managing materials for addressing the principal questions, the progress of that study, chaired by facilities, noting that the recently-com- and shows how accelerator and detector John Schiffer of the University of Chi- pleted DOE study concluded that it is development have created technologies cago. Nuclear physics is a rich and com- important to maintain operation of all the that have brought benefits to society. One plex area of research and the committee is synchrotron facilities, including first of the principal questions in this area of assessing its many components. Of generation ones, because of the great research is “What is the origin of mass?” particular interest is the study of the demand from the user community. The standard model of particle physics, quark-gluon plasma, which is expected to which has successfully solved a number of be generated when nuclei are collided at Next BPA Meeting vexing theoretical difficulties and at the high enough energies so that the quarks The next meeting of the Board on same time explained a vast array of ex- that are bound into the individual neu- Physics and Astronomy is scheduled for perimental results, employs a new mecha- trons and protons within the nucleus Spring of next year, on April 24-25, just nism to explain how the particles in the become deconfined. An accelerator before the annual meeting of the National theory acquire their masses. The mecha- called the Relativistic Heavy-Ion Collider Academy of Sciences. n

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