Physics Survey

Physics in a New Era

Background

Our society is re-examining its priorities as it enters a period characterized on the one hand by reduced expectations for growth and expansion and on the other by tremendous opportunities for greater productivity and functionality. The enhancement of communications and information processing by orders of magnitude is perhaps the most conspicuous example of the latter. The physics community must participate in this process of reexamination by considering its own goals and priorities. It must articulate those goals in relation to the broader aims of the country in a way that is fresh, meaningful and persuasive in the new environment in which we find ourselves. In this new environment, we cannot take for granted acceptance of a number of ideas that we have treated almost as self-evident--that scientific progress is essential for the welfare of the nation, that expanding the reservoir of scientific knowledge is intrinsically good, and that pursuing science for its own sake is the best way to secure the benefits of research for the country.

To provide a means for the physics community to explore these issues, the Board on Physics and Astronomy is now sponsoring a new decadal survey under the title Physics in a New Era. The objectives of the new survey have some elements in common with previous surveys, but also some new features. The new elements are a response to the BPA's conclusion that both society and the field of physics are at critical junctures.

Previous surveys have focused on documenting the accomplishments of physics and analyzing the requirements for continued progress. To some degree, it has been assumed that physics is a coherent enterprise whose value is already recognized by society. The justification for the nation's physics program has been taken for granted, and we have focused our arguments on the increments needed to expand our research capabilities. But the time has come to look at the physics enterprise from the bottom up and to approach the question of the value of physics to society without relying on the ways of the past.

The frontiers of knowledge in physics have become increasingly challenging to reach, and the costs of expeditions to the forefronts of some areas have mounted. We have tended to assume that society will bear the increasing costs without complaint, even as some of the realms of exploration grow more remote. In the present climate in Washington, it does not seem realistic to rely on the continued growth of the GDP to mask the increasing cost of doing some kinds of forefront physics. We have to confront the question "How can the intellectual vitality of physics best be continued into the next millennium?"

Another topic that bears reexamination is the place of physicists in the labor market. With the expansion of our system of higher education that has taken place over the last 30 years now coming to a close, doctoral recipients find opportunities waning in academe while they are growing in small, high-technology startup companies and other areas where the physicist's approach to problem solving is useful. Physics departments must think about whether the program that they offer undergraduates and graduate students prepares them with the versatility and flexibility that they will need in rapidly changing labor markets.

In addition to addressing the new problems that physics and society face, the new survey will follow tradition in describing the advances that have occurred since the last survey. It will include a volume on each of the major branches of physics that will identify the priorities for the respective area. But the new survey is carrying out this traditional role in a new way. Past surveys have looked at all the branches of physics at once. While that method has had a great virtue in giving a synchronous snapshot of physics, it has had the disadvantage that it has been difficult to focus attention on particular problems and to follow them up in such a way that action is taken and recommendations are implemented.

This survey therefore breaks with tradition by focusing on a few areas of physics at a time, following up the assessments with an intense implementation effort. A key part of this effort has been cooperation with the appropriate divisions of the American Physical Society forming the committees that prepare the assessments and in distributing copies of reports to the members of the corresponding division for use in bringing the message to their colleagues in university and industry research settings and even more importantly to the government, including their senators, representatives, and program managers in federal agencies that support research.

The new survey will also include an overview volume that will discuss the unity of physics, its relationships with other fields, and its contributions to national needs. In this volume we will try to take a fresh look at the ways in which society reaps benefits from its investment in physics (and in science in general). The overview will also explore such issues as demographics, career paths, education, and others as discussed in more detail later on in this article.

When a field of science speaks up for itself, there is always the worry that thoughtful recommendations will not be heard because of the suspicion that the research community is thinking more about its own well-being than that of the citizenry generally. We believe that continuing to carry out the survey under the auspices of the National Research Council will help to convince the audience for the report that its advice is broadly based and credible. The Board on Physics and Astronomy itself represents all the branches of physics (and astronomy and astrophysics as well); it therefore can serve, in some sense, as a voice for the community as a whole that does not favor any particular branch of physics over another. Further, the BPA operates under the auspices of the National Research Council and the National Academy of Sciences, with their Executive Branch and Congressional Charters to advise the federal government on science and technology issues. NRC reports are reviewed by panels that include scientists from many different fields. So the survey can give voice in Washington to the priorities of the physics community through a mechanism that is understood by both sides of the dialogue to be even handed, authoritative, and possessing a broad portfolio to advise the government.

In its many consultations with federal officials, the BPA has learned that reports from the Academy do indeed play a special role in communicating the consensus of the scientific community to decision makers in Washington. Of course, broad participation of the scientific community in the process of carrying out assessments and preparing reports is essential for the development and articulation of consensus positions on the important issues in each field. The divisions of the American Physical Society play an important role in this regard, participating in launching studies, providing progress reports to the community through town meetings, and helping to disseminate the results.

That is the general philosophy behind the Board on Physics and Astronomy's program to reexamine physics through a new survey. Let's turn now to some specifics. The survey is being carried out in phases. The first phase (now complete) has produced several volumes described below, including studies of AMO physics and plasma science and several short reports on various topics. The second phase has produced three reports on elementary-particle physics, nuclear physics, and condensed-matter physics, also described below.

Phase I

Major Reports:

Atomic, Molecular, and Optical Science: An Investment in the Future

Chairs: Neal Lane and Gordon Dunn

This report begins with a recognition that "society is asking for greater accountability from scientists and evidence of a return on its investment in scientific research." The charge to the authoring committee was "to review advances of the last decade; determine requirements of the field in the context of national needs such as those related to industrial and technological competitiveness, human health and welfare, environment, defense, energy, and education; establish research and educational priorities from various perspectives; and identify scientific forefronts, technological opportunities, and windows of future opportunity."

The committee found that AMO science is an enabling factor in about 9 percent of the nation's GDP. It recommended a focus on research "that promises new technologies through the invention and development of techniques and instrumentation to better control and manipulate atoms, molecules, charged particles, and light for a broad range of applications and for furthering studies of interactions at the atomic and molecular level." It also recommended research leading to new and improved lasers and other advanced sources of light for a broad range of applications.

One response to the study is an increased emphasis at the National Science Foundation on (1) research on control and manipulation of atoms and light at the atomic scale as well as (2) optical science as a multidisciplinary research area. Another response was the undertaking of a major study of optical science and engineering (OSE) that treats the role of OSE in meeting societal needs in the areas of health and medicine; information technology manufacturing; research and education; and environmental, space, and energy technology. That study is being carried out independently of the physics survey by a committee with membership drawn from both the physical sciences and engineering communities that is jointly sponsored by the BPA and the National Materials Advisory Board in the physical sciences and engineering divisions (respectively) of the National Research Council. Recently, the Department of Energy has begun using the study as the basis for strategic planning for this field.

The Committee on Atomic, Molecular, and Optical Sciences, a continuing group operating under the auspices of the BPA, initiated this study and played an important role in overseeing the followup effort. The American Physical Society's Division of Atomic, Molecular, and Optical Physics distributed 2700 copies of the report to its membership to engage them in the implementation of the recommendations of the report.

Plasma Science: From Fundamental Research to Technological Applications

Chairs: Clifford Surko and John Ahearne

The authoring committee was charged with assessment of the state of plasma science in the United States and evaluation of its potential to contribute to the technology base of U.S. society. The report concludes that (1) plasmas are pervasive in nature, (2) many of the applications of plasma science are being pursued and exploited effectively. Despite that, basic plasma science is not being pursued adequately, and there is no structure in place to assure that the basic plasma science that underlies many applications will be developed. Eventually, this lack will undermine the development of the applications that depend on basic plasma science. The report recommended that basic plasma science be reinvigorated through emphasis on university-scale experimental research programs.

This greater emphasis on basic plasma science was incorporated into the restructuring plan for the fusion program that DOE's Fusion Energy Advisory Committee (FEAC) recommended in January 1996. The study chairs were also invited by the House Science Committee to testify at a March 1996 hearing on the FEAC plan. We are pleased that DOE now plans to allocate a definite fraction of each year's fusion budget to basic experimental plasma science.

The BPA's Plasma Science Committee, a continuing group that initiated this study, has played an important part in overseeing the follow-up effort. The American Physical Society's Division of Plasma Physics distributed 700 copies of the report to its membership to engage them in implementing the report's recommendations.

We are extremely pleased with the impact that these two reports have had in addressing the particular problems of plasma physics and atomic, molecular, and optical physics. They serve as models for the volumes of the physics survey that remain to be completed and demonstrate the effectiveness of the new strategy that we are pursuing.

Research Briefings and Short Reports

These relatively short reports focus on scientific forefronts.

Research Briefing on Contemporary Problems in Plasma Science and Research Briefing on Selected Opportunities in Atomic, Molecular, and Optical Sciences (1991)

These briefings set the stage for the studies Plasma Science and Atomic, Molecular, and Optical Sciences discussed above.

Neutrino Astrophysics: A Research Briefing (1995)

Chair: John Bahcall. This report describes the forefronts of the efforts to measure neutrino fluxes from the sun as well as from supernovas. It concludes that these new observational capabilities have opened up a new area of science that can be called neutrino astrophysics.

Cosmology: A Research Briefing (1995)

Chair: Marc Davis. This briefing describes the origin, evolution, and possible fates of the universe in a simple, easy-to-understand narrative. It has been used as background material for a number of courses in astronomy and astrophysics at several universities.

Cosmic Rays: Physics and Astrophysics (1995)

Chair: Thomas Gaisser. This report describes how energetic particles from distant regions in the universe bring us information about the processes whereby the particles are accelerated, about dynamical processes in our galaxy and beyond, and about matter and fields in interstellar space. It recommends a number of actions by NASA, NSF, and DOE that are now under consideration.

Phase II

The second phase of the survey treats the following areas:

Elementary-particle physics

A committee chaired by Bruce Winstein of the University of Chicago was established in consultation with the APS Division of Particles and Fields . The committee held a meeting at the DPF's Snowmass96 conference, which provided an opportunity for a broad cross section of the community to interact with the committee. It also gave the committee a sense of the prevailing views regarding the next steps for the field, including U.S. participation in the Large Hadron Collider at CERN and beyond. The committee has completed its report, Elementary-Particle Physics: Revealing the Secrets of Energy and Matter.

Nuclear physics

A committee chaired by John Schiffer of the Enrico Fermi Institute at the University of Chicago was formed to prepare a study of this area. The APS Division of Nuclear Physics was involved in the initiation of the study. The committee has completed its report, entitled Nuclear Physics: The Core of Matter, the Fuel of Stars.

Condensed-matter and materials physics

A committee chaired by Venkatesh Narayamurti of Harvard University organized a workshop in cooperation with the APS Divisions of Condensed-Matter and Materials Physics that provided broad community input for the study. The committee prepared an interim report entitled The Physics of Materials: How Science Improves our Lives, a brochure aimed at explaining the relationship between basic research and consumer technology in everyday language. The BPA's Solid State Sciences Committee, a continuing group that sponsors periodic forums and topical studies, is an active participant in this study. The SSSC organized one of its periodic forums, Materials in a New Era, to showcase the recently-published report--Condensed Matter and Materials Physics: Basic Research for Tomorrow's Technology.

Gravitational physics

A committee chaired by James Hartle of the University of California at Santa Barbara was formed to prepare a study of this area. The committee has completed its report, Gravitational Physics: Exploring the Structure of Space and Time. The report was published in 1999

Phase III

The main focus of Phase III will be the preparation of an overview of physics. Some of the issues to be addressed in the Overview are discussed below. A Physics Survey Overview Committee chaired by Thomas Appelquist of Yale University has been formed to prepare this report.

Overview

Unity of physics

Working in the various branches of physics, we sometimes lose sight of the fact that there is a strong commonality that links the different specialties together. The ties that bind physics into a whole derive partly from the education that all physicists have in common and partly from the style of thinking about problems that physicists learn. How do we nurture an appreciation of the unity of physics as the branches become more specialized? How do we preserve a balance between the reductionism of elementary-particle physics and the search for understanding of complex systems that goes on in condensed-matter physics?

Physics and society

Physics has made many contributions to the economy, but they aren't clearly recognized because, in part, there is no industry that is labeled as the "physics industry". But we might well give that label to (for example) the semiconductor industry, which depends on solid-state physics, chemical physics, plasma physics, materials physics, and so on. And the explosive growth of information technology and telecommunications that is now taking place has its roots in condensed-matter and materials physics of semiconductors as well as fiber optics.

Education

Looking outside the field, physicists need to pay more attention to educating people who will not become physicists-e.g., lawyers, doctors, humanists, and the business and financial community-so they will have a better understanding of the scientific and technological underpinnings of our society. Physics education needs to begin at the K-12 level. By the time most students reach college, they already know that "physics is too hard." Within the field, undergraduate and graduate education should be broader both in terms of subject matter and experience to increase the flexibility of physicists in responding to changing employment patterns.

Connections with other fields of science and engineering

Physics and physicists continue to connect with other areas of science and technology to produce advances. Some examples in biology and medicine include exploring the properties of DNA with optical tweezers, understanding the way proteins are configured, and making improvements in medical imaging (e.g., imaging lungs using laser-polarized noble gases). There are more examples in every field of science.

Biological physics

To understand how living systems function, one is faced with understanding complex systems and intricate mechanisms. It is rather remarkable that some of the most outstanding books on biology prepared by prominent biologists contain no equations! This fact illustrates the tremendous opportunity for applying physical thoughts and rigor to the field of biology. There are numerous examples of physicists that have made seminal contributions to biology. A few outstanding examples who received the Nobel Prize for their efforts are Francis Crick, Max Delbrück and Walter Gilbert.

The mathematician Stanislaw Ulam once turned the problem on its head, by telling a biological physicist that he finally understood the challenge of the field: "Ask not what physics can do for biology; ask what biology can do for physics." Biology provides excellent proving grounds for physics-based ideas about complex systems. If physics is going to attract young, ambitious people in the future, it is necessary that physics concern itself with rapidly developing areas such as medicine and biology.

Computational physics

This is another area where the insight into physical systems interacts with algorithm and machine development to accomplish feats of simulation and computation that could not otherwise be achieved. These accomplishments are playing an increasing role in the progress of physics. It may even be that simulation and computation are joining theory and experiment as a major mode for understanding physical systems.

Demographics and career paths

Doctoral production in physics appears to be at an all-time high. There is mounting concern about employment. Meanwhile, physics departments are noticing decreased enrollments. The community is considering ways to broaden the graduate education experience of physicists to give them the flexibility that they will need in today's job market.

There have been peaks in doctorate production in the past (around 1970, for example), followed by sharp drop-offs. Are we headed for a repeat of that phenomenon? Are there trends in the distribution of subfields? The two most rapidly growing areas appear to be solid-state/low temperature physics and "general physics". It is important to try to interpret and understand these trends.

International cooperation and competition and the position of U.S. physics relative to that abroad

The next major facility focus for high-energy physics is the Large Hadron Collider at CERN in Geneva. The premier neutron scattering facilities are in Europe. The future of the U.S. fusion program and its role in joint development of facilities with Europe is uncertain. What will the impact of these trends be on U.S. physics?

Emerging cross-cutting areas

Interdisciplinary and cross-cutting areas are becoming increasingly prominent. For example, optical science and techniques are everywhere. How should physics connect with such fields that draw on many science and engineering disciplines?

The changing environment for physics research

The role of the national laboratories has been reexamined recently by a number of groups. Much of the nation's effort in physics goes on in national laboratories and the potential impact of changes on the physics community is substantial. How do the profound changes in the nature and scale of industrial research affect the distribution of research effort among the traditional major performers (government laboratories, universities, and industry)? As discussed earlier, the role of science and technology in society is changing from a peripheral to a central one. Along with gratifying attention and visibility, the changing role brings demands for a better accounting of what is being done and its value to society.

Funding history and trends

Individual members of the physics community experience increasing difficulty in finding support for research. How much of this trend is due to demographic changes, how much to changes in funding levels, and how much to redistribution of funds in various program categories? Increasingly, there are calls to justify the nation's expenditures on basic research in a quantitative fashion. Perhaps one answer to these calls lies in "endogenous growth theory" propounded by (among others) Paul Romer of the University of California at Berkeley, a physicist turned economist. This theory is an attempt to account for the enormous growth in the economies and output of industrialized countries that has taken place over the last century. Romer says that "Output per hour worked in the United States today is ten times as valuable as output per hour worked 100 years ago." He attributes this change to accumulation of knowledge and expertise in science and technology and improvements in the labor force (due in turn, in part, to better education). He describes this accumulation as a form of capital and prescribes investment in research as an essential policy for promoting growth. Perhaps we should explore the place of physics in "endogenous growth."

Your Role

The target date for completion of the overview is 2000. It will summarize and update all the reports on the individual branches of physics and address topics such as those above that concern physics overall. This part of the physics survey will be the most difficult to write, but also potentially the most valuable.

We welcome suggestions from the community on how to approach this important task. The ideas above are preliminary and meant to stimulate discussion rather than indicate any final conclusions-we hope they will inspire you to write to us at bpa@nas.edu. Continuing input, participation, and help from the physics community is essential.

Physics in a New Era was launched by the previous chair of the Board on Physics and Astronomy, David N. Schramm, who died in December, 1997 in a tragic plane accident. The BPA dedicates the new physics survey to his memory.

Robert Dynes, BPA Chair (1997-2000)

Donald C. Shapero, BPA Director

Epilogue

With the publication of Physics in a New Era: An Overview, the physics survey is complete.

1 Physics Through the 1990s, National Academy Press, 1986.

2 National Academy Press, 1994. ISBN 0-309-05032-4.

3 National Academy Press, 1995. ISBN 0-309-05231-9.

4 Available from the Board on Physics and Astronomy.

5 Available from the Board on Physics and Astronomy.

6 Available from the Board on Physics and Astronomy.

7 National Academy Press, 1998. ISBN 0-309-06037-0

8 National Academy Press, 1999. ISBN 0-309-06276-4

9 National Academy Press, 1999. ISBN 0-309-06349-3

10 National Academy Press, 2001. ISBN 0-309-07342-1