bluuebunny/crossref_metadata_2025 huggingface dataset:
Cabrera counts flux quanta to find a Dirac monopole
Authors: Lubkin Gloria B.
Published: September 2008

Take a superconducting loop, place it in an ultralow magnetic-field device, and monitor the current with a Superconducting Quantum Interference Device for many months. That was the experiment that Blas Cabrera of Stanford University did in his search for a moving magnetic monopole. On Valentine's Day he found a single event consistent with one Dirac unit of magnetic charge. When rumors of the observation spread, the organizers of the Third Workshop on Grand Unification phoned Cabrera in Blacksburg, Virginia (where he was giving a colloquium), and asked him to address the Workshop the next morning (16 April). After a long, wee-hours-of-the-morning drive to Chapel Hill, N. C., Cabrera electrified the workshop participants with his careful, low-key account of his possible monopole discovery.
Laser annealing of silicon
Authors: Poate John M. , Brown Walter L.
Published: September 2008

Silicon is one of the best understood of all materials because it lies at the heart of one of the central technologies of the twentieth century: integrated circuits. How much more can we learn about silicon and ways of handling it? Quite a lot, apparently, if the remarkable developments in laser annealing over the past five years are any indication.
My work with Millikan on the oil-drop experiment
Authors: Fletcher Harvey
Published: September 2008

Lorena (Chipman) and I were married on 9 September 1908. Soon after we left by train for Chicago. On arrival there, we found a small apartment near the University.
Two-photon laser excitation yields positronium 1S–2S line
Authors: Schwarzschild Bertram M.
Published: September 2008

Positronium—the bound state of an electron and a positron—entices the experimenter with a unique opportunity for testing the predictions of quantum electrodynamics. Not only does this purely leptonic “atom” avoid the complications of hadronic nuclear structure, but it also involves virtual-annihilation terms absent in the case of hydrogen or muonium. Furthermore, because the usual reduced-mass formalism for hydrogen-like atoms is relativistically inappropriate for this system of two equal masses, one must use the Bethe–Salpeter formalism rather than the Dirac equation as the starting point for calculating QED corrections in positronium.
Monte Carlo yields hadron masses
Authors: Lubkin Gloria B.
Published: September 2008

The odds look increasingly favorable that Monte Carlo methods will pay off as a computational tool in the theory of quarks. Over a year ago, theorists began to gain insight into the nature of strong interactions by applying statistical methods to a formulation of quantum chromodynamics on a discrete space–time lattice, but their calculations involved only a pure gluon field and no quarks. The inclusion of fermions, and hence the calculation of physical observables, appeared to require formidable amounts of computer time. In the interim, several theorists have devised approximations and algorithms that allow them to estimate some hadron masses with fairly good agreement and with reasonably small errors. Reaction to this new work has ranged from careful scrutiny of the specific premises to great enthusiasm for the general promises of the technique.
High-resolution scanning ion microscopy
Authors: Schwarzschild Bertram M.
Published: September 2008

Scanning electron microscopes operating in the reflecting mode can resolve surface detail at the level of a few tens of angstroms. A University of Chicago–Hughes Research Laboratories collaboration expects to do about as well with ions by the end of the year. A pair of scanning ion microscopes being built at Hughes (Malibu, California) is designed to achieve a resolving power as fine as 20 Å.
CP symmetry violation
Authors: Cronin James W. , Greenwood Margaret Stautberg
Published: September 2008

Sixteen years before the discovery of charge-conjugation–parity nonconservation in the decay of K mesons, a very fine high-school physics teacher got me interested in physics. I'm not sure that I wouldn't have been interested in it anyway, but nevertheless he was a remarkable gentleman in a high school in Dallas, Texas. I think high-school physics teachers continue to play a crucial role today, so I want to make one or two remarks about physics teaching before I describe the fascinating behavior of K mesons and discuss some of the historical and human aspects of the research that Val Fitch and I did on their decay.
Polarized plasmas may prove useful for fusion reactors
Authors: Schwarzschild Bertram M.
Published: September 2008

A casual cocktail-party inquiry by Maurice Goldhaber (Brookhaven) has set in motion the detailed examination of a quite novel approach to fusion in magnetic-confinement reactors. Last winter Goldhaber asked Harold Furth, director of the Princeton Plasma Physics Laboratory, whether he had ever considered polarizing the nuclear spins in a magnetically confined reactor plasma. The answer was no, basically because naive considerations lead one to expect that such a polarized hot plasma would much too quickly become thermally depolarized.
Electroweak interference confirmed
Authors: Schwarzschild Bertram M.
Published: September 2008

Before 1973, all observed weak interactions had involved charge exchange between the participating particles, implying that the carriers of the weak force were themselves always electrically charged. But if one is to unify the weak and electromagnetic interactions in a single gauge-invariant framework, one requires a weak analog of the uncharged photon—an electrically neutral, weak, spin-one boson. The discovery of the neutral-current weak interactions at CERN in 1973 (for example, the elastic scattering of neutrinos off nucleons) was thus a crucial piece of evidence for the Weinberg–Salam–Glashow electroweak gauge theory—the scheme that has since come to be regarded as the “standard theory” for the unification of the electromagnetic and weak interactions. Sheldon Glashow and Steven Weinberg (both then at Harvard) and Abdus Salam (Imperial College, London and International Centre for Theoretical Physics, Trieste) shared the 1979 Nobel Prize in Physics for this work.
Search for the sparking of the vacuum
Authors: Greenberg Jack S. , Greiner Walter
Published: September 2008

Our concept of the nature of the vacuum has been evolving for the last 25 centuries. Indeed, some aspects of today's perception of the vacuum, established by modern experimental probes, date back to ancient Greek philosophers.
Philip Morrison—a profile
Authors: Eisenberg Anne
Published: September 2008

When Philip Morrison, Institute Professor at MIT, came to the Polytechnic Institute of New York recently to give the Sigma Xi lecture, a diverse group attended. The group included physicists, chemists, engineers; people who admired Morrison for his sustained fight against red-baiting in the 1950s (in 1953 a national newsletter called him “the man with one of the most incriminating pro-Communist records in the entire academic world”); and people in the humanities who had enjoyed his book reviews, films, articles and textbooks. The diversity of the audience reflected the diversity of Morrison's career.
Solar Optical Telescope will orbit on space shuttle
Authors: Schwarzschild Bertram M.
Published: September 2008

To the naive outsider it seems surprising that solar astronomers complain of being hampered by the inadequate spatial resolution of their telescopes. The Sun is, after all, only eight light minutes away, and most of us don't think of it as possessing small-scale surface features beyond our powers of resolution. Sunspots were studied by Galileo almost four hundred years ago. But in fact, magnetohydrodynamic mechanisms with characteristic scales of 70 km or less appear to be crucial to our understanding of the astrophysics of our nearest star.
High-energy electrons to probe nuclei
Authors: Schwarzschild Bertram M.
Published: September 2008

Quantum chromodynamics, the gauge field theory that describes strongly interacting particles in terms of their quark constituents and the “colored” gluons that bind them, promises us a definitive theory of the nuclear force. QCD has evolved in the past few years primarily through the rich theoretical and experimental progress of elementary-particle physics at very high energies. Now the nuclear-physics community, whose traditional experimental realm has largely been confined to much lower collision energies, has begun looking to QCD and multi-GeV electron accelerators to provide for the first time an adequate basis for understanding the short-range behavior of nuclear phenomena.
The feasibility of inertial-confinement fusion
Authors: Nuckolls John H.
Published: September 2008

So concluded the chairman of a Department of Energy ad hoc committee of experts in 1979, after a comprehensive review of the US inertial-confinement fusion program. In spite of this positive evaluation, the role of inertial-confinement fusion in the total US energy program continues to be a subject of disagreement. Before I mention the issues of contention, let me describe inertial-confinement fusion briefly. In a typical scheme, a pea-sized target pellet containing hydrogen isotopes is projected into a reactor chamber, where it is suddenly irradiated with an intense beam of light or ions from a “driver” (see figure 1). As the surface of the target blasts away, the rocket-like reaction forces implode the target's interior to densities and temperatures sufficient to cause the hydrogen nuclei to fuse, releasing an amount of energy equivalent to that of a barrel of oil (see PHYSICS TODAY, August 1973, page 46).
Harold Urey and the discovery of deuterium
Authors: Brickwedde Ferdinand G.
Published: September 2008

It was on Thanksgiving day in 1931 that Harold Clayton Urey found definitive evidence of a heavy isotope of hydrogen. Urey's discovery of deuterium is a story of the fruitful use of primitive nuclear and thermodynamic models. But it is also a story of missed opportunity and errors—errors that are particularly interesting because of the crucial positive role that some of them played in the discovery. A look at the nature of the theoretical and experimental work that led to the detection of hydrogen of mass 2 reveals much about the way physics and chemistry were done half a century ago.
Solving physics problems—how do we do it?
Authors: Fuller Robert G.
Published: September 2008

Scribblings on the back of an envelope are as much a part of the professional mystique of the physicist as they are of the story of the Gettysburg Address.
NCAM not peer-reviewed, critics say; review panel named
Authors: Lubkin Gloria B.
Published: September 2008

In response to widespread criticism of the proposed National Center for Advanced Materials at Lawrence Berkeley Laboratory, the Department of Energy has formed an ad hoc review panel. Headed by Al Narath of Sandia Laboratories, the panel has been asked to review the technical and programmatic aspects of NCAM.
Science and technology in France
Authors: Friedman Abraham S.
Published: September 2008

Jean-Pierre Chevènement had a bold plan: to bolster the French economy by envigorating science and technology. As the first head of the new French Super Ministry of Research and Industry, this brilliant young socialist sought to create new jobs—especially in high-technology production—by making French companies internationally competitive.
Entangled polymers
Authors: de Gennes Pierre-Gilles
Published: September 2008

Most of us have played with lumps of “silly putty,” the strange substance shown in the photographs on page 34. Given a bit of time, this material flows like a viscous liquid. Forced to respond quickly, it bounces like rubber. We can trace this “viscoelastic” behavior, which shows up in all polymer melts, to the knotting of the chains of “monomers” that make up the polymers. Shearing forces tend to undo certain knots, but this takes a finite time τ. In a time greater than τ the original knots fade out, and the melt flows. Over shorter times the original knots are all present, and the melt behaves like an elastic network.
Synchrotron radiation research—An overview
Authors: Bienenstock Arthur , Winick Herman
Published: September 2008

Synchrotron radiation, with its remarkable properties and eminent suitability for scientific and technical applications, is having a profound effect on the many disciplines that make use of radiation in the x-ray and vacuum ultraviolet regions of the spectrum. Indeed, the rapidly increasing availability of this radiation is revolutionizing some fields and is leading to a variety of new interdisciplinary collaborations. Seeking to take advantage of this incisive tool, scientists around the world are requesting time at synchrotron radiation facilities in such large numbers that the fast-paced construction of new sources—including several in less-developed countries—has yet to bring the level of availability up to that of demand.
Debate on a comprehensive nuclear weapons test ban: Pro
Authors: DeWitt Hugh E.
Published: September 2008

The 1963 Limited Test Ban Treaty prohibits nuclear explosions in the atmosphere, the oceans and space. Nevertheless, nuclear tests continue at an alarming rate—almost one explosion per week somewhere in the world—although now the testing is largely underground.
Large-N quantum mechanics and classical limits
Authors: Yaffe Laurence G.
Published: September 2008

For a physical theory to be useful, we should be able to extract from it quantitative predictions for physical observables. With most theories, this process of practical application requires some approximation method that is both tractable and adequately accurate. The lack of a useful approximation scheme can seriously impede progress in a field of research. Molecular quantum mechanics and critical phenomena, for example, have both suffered from this problem during periods of their development. The physics of strong interactions is in such a period today. Naturally, our inability to extract useful predictions from a promising theory is a strong incentive to develop novel approximation techniques.
Panel says: Go for a multi-TeV collider and stop Isabelle
Authors: Lubkin Gloria B.
Published: September 2008

A high-luminosity proton-proton collider (often called the Desertron) with 10 to 20 TeV in each beam should be the highest priority for the next US particle accelerator, according to all 17 members of the HEPAP subpanel, headed by Stanley Wojcicki of Stanford. By a slim majority, 10 to 7, the subpanel also recommended killing the Colliding Beam Accelerator (formerly known as Isabelle) at Brookhaven.
Overview of the problem
Authors: Layman John W.
Published: September 2008

Science and mathematics education in this country is in a precarious state. Most of our students do not learn nearly as much as they could and many of our teachers are ill prepared. That the state of affairs has deteriorated to the point of becoming a crisis is confirmed by the number of editorials in our journals, the amount of legislation being proposed at all levels, the attention given the subject in the popular press and the number of meetings held to discuss the crisis. Thus, for example, the National Academy of Sciences sponsored a national convocation (May 1982) to consider the state of precollege education in the United States. The topic also received special attention in October 1982 at The American Institute of Physics Corporate Associates meeting and at the Spring 1983 meeting of the AIP Assembly of Society Officers and the AIP Governing Board meeting.
Why Physicists leave teaching
Authors: Porter Beverly Fearn , Kelly William H.
Published: September 2008

Educators have long been concerned about the quality of science and mathematics education in US secondary schools. In recent years, this concern has spread: Congressional task forces, governors, mayors and the media have begun to recognize the serious educational crisis now facing the nation. While this time there is no dramatic event like the Sputnik of 1957 to spur increased attention to education, some fundamental challenges are becoming apparent. These include the decline in this country's competitive edge in many areas of industry and research, the structural change in the nation's industrial base from heavy manufacturing to high-technology and service industries, and the revolution in information technology and exchange. In many ways we are entering a new era, and there are serious questions about how well prepared today's youth and future generations will be to participate in it.
Leaving teaching: a difficult choice
Authors: Mowbray James E.
Published: September 2008

For eleven years physics was my hobby, and, fortunately for me, my source of employment. As a physics teacher in the public school system, Rabi's words served as the philosophical basis of my teaching long before I ever read them. I had a love affair with physics—its mysteries, its doers and shakers, its application to the benefit of human beings and society. I tried to develop a cohesive teaching strategy consistent with this philosophy that would instill in my students a similar love of physics and appreciation for the work of mankind in unlocking the secrets of nature.
Paths to a solution
Authors: Franz Judy R. , Aldridge Bill G. , Clark Robert Beck
Published: September 2008

The crisis in physics education—and in math and science education in general—has two primary features: the severe shortage of qualified teachers and the small fraction of high-school students choosing to take physics and other elective science and math courses. Both of these problems have contributed to the science illiteracy that is now the focus of national attention. As the American public, scientists, politicians and other citizens have become aware of the significance of the crisis, they have put forward many new ideas. State and local governments, teachers' unions, university professors and leaders of business and industry have gone beyond the stereotypical and Pavlovian responses that have often blocked change in the past.
Places where things are right
Authors: Wilson Jack M. , Ingoldsby Tim C.
Published: September 2008

While the general state of high-school physics teaching in the United States is cause for concern, there are many areas with outstanding programs. These exemplary programs stand out as hopeful symbols of what might and should be done. Excellence in physics teaching is not confined by region or type of community and can be found in large cities, small towns, or rural farming communities.
Has the Higgs boson been seen in the Crystal Ball?
Authors: Schwarzschild Bertram M.
Published: September 2008

From the Crystal Ball detector at the DORIS electron–positron collider in Hamburg comes strong evidence of an 8.3-GeV particle for which there appears to be no prosaic explanation. “If it's real, it has to be very important,” says Gordon Kane (University of Michigan), expressing the widespread excitement that this new state has generated among high-energy theorists.
R & D funding for the Super Collider
Authors: Lubkin Gloria B.
Published: September 2008

A group of 150 scientists led by Maury Tigner of Cornell submitted a report to DOE in May containing three reference designs for the Superconducting Super Collider. In June the Universities Research Association, which is to administer the R & D phase of the SSC project, designated Tigner as director of the SSC design and R&D program. The Department of Energy, in its FY 1985 budget request, had asked for $20 million for R&D on the collider. However, it was not until mid-August that it decided to release the $20 million at the start of FY 1985, on 1 October.
Noncrystalline semiconductors
Authors: Fritzsche Hellmut
Published: September 2008

After rapid growth over the past 15 years, research on noncrystalline semiconductors is now one of the most active and exciting areas in condensed-matter physics. Technological interest has always been an important stimulant for fundamental materials research, and work on noncrystalline semiconductors is no exception. The field is active because the unique properties of these new semiconductors, together with techniques for spreading thin films over large areas, open many new possibilities for applications. Among the noncrystalline semiconductor devices at one or another stage of research or development are optical memory disks with extremely high information density, large-area electronic circuits on thin flexible substrates, faster and more durable photoreceptor drums for xerographic copying machines, x-ray lenses, holograms and inexpensive photovoltaic cells, just to mention a few
Superpolymers, ultraweak solids and aggregates
Authors: Lubensky Tom C. , Pincus Philip A.
Published: September 2008

In elementary science courses, we learn that matter can exist in the gaseous, liquid or solid states. In more advanced courses, we divide the solid state into regular periodic solids, possibly with defects, and amorphous solids such as glasses. Although these classifications are useful, they are incomplete and do not reflect the full variety of states of natural and synthetic materials.
Perkin–Elmer ships 2.3-m optical space-telescope assembly
Authors: Lubkin Gloria B.
Published: September 2008

This month the Optical Telescope Assembly of Space Telescope is being shipped from Perkin–Elmer Corp to Lockheed Missiles and Space Co, where the remaining hardware and observing instruments will be installed and tested. Once planned for launch in 1984, Space Telescope is now scheduled to be launched by the Space Shuttle in August 1986 into an orbit 360 miles above the Earth.
Orsay free-electron laser demonstrates uv harmonic generation
Authors: Schwarzschild Bertram M.
Published: September 2008

Coherent sources of vacuum-ultraviolet and extreme-ultraviolet radiation are hard to come by. The selection of lasers emitting in the vuv (wavelengths below 2000 Å) is very limited, and the first clear observation of laser emission in the xuv (below 1040 Å) is only a year old (PHYSICS TODAY, November 1983, page 19).
Infrared free-electron laser uses electrostatic accelerator
Authors: Schwarzschild Bertram M.
Published: September 2008

From the near ultraviolet to the near infrared—2000 Å to 25 microns—we have access to an abundance of coherent sources, some of them tunable over limited ranges. For the outer reaches of the optical spectrum—the far ultraviolet and the far infrared, where conventional laser sources offer very little—free-electron lasers present a unique opportunity. The preceding story describes the promise of FEL harmonic frequency multiplication for the vacuum ultraviolet and extreme ultraviolet. At the other end of the spectrum, a novel, electrostatic-accelerator-based, broadly tunable, far-infrared FEL at the University of California, Santa Barbara, began lasing at 400 microns two months ago.
Ion implantation metallurgy
Authors: Picraux S. Thomas
Published: September 2008

Metallurgists are now able to take any element in the periodic table and implant it in the surface region of virtually any metal. Although the resulting novel metastable alloys are usually only a fraction of a micron thick, they have potentially important commercial applications and are contributing greatly to fundamental research on metals.
High-polymer physics
Authors: Passaglia Elio , Broadhurst Martin , DiMarzio Edmund , Sanchez Isaac
Published: September 2008

The Division of High Polymer Physics of the American Physical Society was founded in 1944, spurred in large measure by the development of synthetic rubber during the Second World War. With the enormous postwar growth of the synthetic polymer industry, the field of polymer physics burgeoned—and along with it, the Division of High Polymer Physics. At the time of the March 1984 APS meeting, the division was an active, thriving community of 1001 members with a variety of scientific interests and activities. In this article, we will attempt to give the flavor of their work. We hope our account is sufficiently specific to be useful and interesting to polymer scientists, yet general enough to be intelligible and interesting to the general reader.
Thermodynamics and economics
Authors: Ayres Robert U. , Nair Indira
Published: September 2008

While physical sciences deal with the interactions of matter and energy, economics can be said to deal with the production and exchange of goods and services. Because goods and services incorporate matter and energy, the physical sciences are clearly relevant to economics. In particular, one can expect the laws of thermodynamics to impose constraints on economic processes as they do on physical processes (figure 1). It is clear that the laws of conservation—of matter and energy, for example—have implications for the use of resources and for the generation and treatment of wastes. The law of the increase of entropy—the second law of thermodynamics—constrains economic processes to those that reduce available work, increasing the entropy of the Universe.
Companion galaxies match quasar redshifts: the debate goes on
Authors: Schwarzschild Bertram M.
Published: September 2008

“Apostles of the noncosmological origin of quasar redshifts must now… recant, or else maintain that the unknown laws of physics which fix [these] redshifts…extend [over] appreciable distances to apparently normal galaxies…” The style may evoke the 17th century Holy Office, but the arguments, and the interesting new data that support them, are to be found in a recent issue of the Astronomical Journal. Timothy Heckman (University of Maryland) and his collaborators in this new investigation of the perennial quasar-redshift problem trust that their mock-theological tone will be taken in a spirit of good humor.
Magnetic information technology
Authors: Kryder Mark H. , Bortz Alfred B.
Published: September 2008

Important advances in robotics, communications and information processing are awaiting the development of faster and more compact devices that store and handle information. Magnetic information technology could provide such devices in the near future, but to do so will require basic research on topics ranging from magnetic phenomena to unusual mechanical systems.
How the Jefferson Physical Laboratory came to be
Authors: Holton Gerald
Published: September 2008

A hundred years ago, the first building in the western hemisphere designed for research and teaching in physics opened its doors. The consequences of such an event are of very different interest to different groups. The physicist will ask about the advances made in Jefferson Lab, and in nearby structures added later, by its faculty, students and collaborators: Lyman lines and broken symmetries; dimensional analysis and nuclear magnetic resonance; the muon and the 21-cm line; tests of the equivalence principle and of quantum electrodynamics; the acoustics of buildings and of violins; precise mass spectra, and the phase diagrams of hundreds of substances; the theory of magnetism and quadrupole moments; medical uses of particle beams and determinations of the structure of the ionosphere; the Duane–Hunt law of x-ray emission, and Russell–Saunders coupling; the research and teaching of Edwin C. Kemble, America's first quantum theorist; and the latest in mathematical physics, condensed-matter theory or elementary-particle interactions
Muon spin relaxation
Authors: Heffner Robert H. , Fleming Donald G.
Published: September 2008

Since its discovery in 1957, parity violation in the weak interaction has occupied both experimental and theoretical physicists in a broad effort directed toward its understanding. One manifestation of parity violation is found in the decay of spin-polarized muons. In the earliest searches for suitable stopping materials for studying the weak interaction through the decay of positive muons, physicists noticed that the muon polarization remaining after thermalization depends markedly on the nature of the stopping environment, varying from about 10% in some liquids such as benzene to 100% in most metals. Data of this nature contained the beginnings of the technique of muon spin relaxation, also known as muon spin resonance or muon spin rotation. In this technique, which is akin to magnetic resonance, one monitors the spin polarization of muons to learn about the materials into which they have been injected. Muon spin relaxation now constitutes a significant research effort at the world's meson-producing accelerators: at Brookhaven and LAMPF in the United States, Dubna and Leningrad in the Soviet Union, CERN and SIN in Switzerland, TRIUMF in Canada, KEK in Japan and NIKHEF in the Netherlands.
Science at General Electric
Authors: Wise George
Published: September 2008

The decade after 1945 saw substantial changes at the General Electric Research Laboratory in Schenectady both in the way in which research was done and in the people doing the research. The passing of the generations at a research laboratory in a small city in Upstate New York reflected a broader change undergone after World War II by all of American science. Science and technology had helped win the war. Scientists and engineers now appeared to be the bulwarks of national defense and the preservers of national prosperity. In the heady postwar climate, no one worried much about where science ended and where technology began. There was enough for both. Inventions and innovations launched before or during the war—televisions, plastics, atomic energy, electronics, computers—now loomed as huge and expanding opportunities. A person who had embarked on a career in science now had a wide choice of well-paying jobs in government or industry.
Nobel prize to Chandrasekhar and Fowler for astrophysics
Authors: Lubkin Gloria B.
Published: September 2008

The 1983 Nobel prize in physics has been awarded to Subrahmanyan Chandrasekhar (University of Chicago) “for his theoretical studies of the physical processes of importance to the structure and evolution of the stars” and to William A. Fowler (Caltech) “for his theoretical and experimental studies of the nuclear reactions of importance in the formation of the chemical elements in the Universe.” The two men shared the prize (worth about $190 000 this year) equally.
Non-Newtonian phenomena in simple fluids
Authors: Evans Denis J. , Hanley Howard J. M. , Hess Siegfried
Published: September 2008

Almost a hundred years ago, Osborne Reynolds carried out a simple experiment. He filled a leather bag with marbles, topped it with water and then twisted it, thereby inducing a shear. The water level drops because the close packing of the marbles is disrupted as layers of marbles slide over each other during the twisting motion; as a result the marbles are further apart on average, creating space that the water has to fill.
Computer simulation of many-body dynamics
Authors: Hoover William G.
Published: September 2008

The 300-year-old discipline of Newtonian mechanics is still the basis for today's computer calculations at our national laboratories. However, computers are prompting important changes within mechanics itself. Versions of atomistic mechanics now under development save time by matching numerical techniques to computer capabilities, which—even with the fastest, newest machines—are quite limited when compared to the complexities inherent in modeling the real world.
The kinetic theory of fluids—an introduction
Authors: Cohen E. G. D.
Published: September 2008

The main concern of kinetic theory over the last 35 years has been to understand the properties of dense gases and liquids in terms of the interactions and motions of the molecules. For dilute gases, the Boltzmann equation has provided a basis for a kinetic description of nonequilibrium properties, and although there are still many unresolved questions, there is little doubt that this equation is the correct starting point for an understanding of dilute gases. In spite of numerous efforts, no one has yet succeeded in deriving a comparable equation for dense gases or liquids. Several generalizations to higher densities of the Boltzmann equation have been found, and many interesting and unexpected results have been discovered, but something we could call a systematic and complete theory has so far eluded us. I want to emphasize that this article does not pretend in any way to be a survey of kinetic theory. I shall only try to sketch a few of the most striking developments in the kinetic theory of dense fluids to give an idea of what has been achieved so far. It will become clear then that a dense fluid behaves in many respects quite differently from what one would expect on the basis of the properties of dilute gases as known from the Boltzmann equation.
No more Valentines: New induction detectors see no monopoles
Authors: Schwarzschild Bertram M.
Published: September 2008

On St. Valentine's Day two years ago, Blas Cabrera's magnetic-monopole detector at Stanford, unattended on that Sunday afternoon, recorded a current jump in its superconducting detection loop that corresponded precisely to the induction one would expect if a Dirac monopole had passed through it. “Having now expanded our monopole search almost a hundredfold with a larger, more sophisticated detector,” Cabrera told us two years later to the day, “we've seen nothing comparable.”
Time-resolution experiments using x-ray synchrotron radiation
Authors: Mills Dennis M.
Published: September 2008

Many important biological, chemical and physical phenomena take place on time scales of nanoseconds or picoseconds. Those working to unravel the time development of such fast processes have long recognized that pulsed electromagnetic radiation and particle beams often make more incisive probes than do continuous emissions. During the last decade, a powerful new device joined the arsenal of modulated radiation sources available to scientists attacking problems that require good temporal resolution—the high-energy storage ring.
The art and physics of soaring
Authors: Hunter Lloyd
Published: September 2008

Modern materials technology, combined with three-quarters of a century of experience in glider design, has given us sailplanes capable of superb performance. In the hands of a pilot who understands the basic physics of soaring and has mastered the art of maneuvering his craft, the sailplane of today offers a truly exhilarating sport, whether one's interest is in recreation or competition.
The renaissance of x-ray optics
Authors: Underwood James H. , Attwood David T.
Published: September 2008

There has been a spectacular resurgence of interest in the soft x-ray and extreme ultraviolet regions of the electromagnetic spectrum in the past few years. In part, this is due to the development of new x-ray optical devices that have given us an x-ray view of the universe on scales ranging from the microscopic to the astronomical (see figure 1).
Shape-memory phenomena
Authors: Golestaneh Ahmad A.
Published: September 2008

If you deform an ordinary material below its elastic limit and keep it below its annealing temperature, it will return to its original shape once the load is removed. If the stress is too large, however, or if the temperature is allowed to become too high, the deformation becomes permanent, and the material retains no memory of its original shape.
SSC design goes to DOE: ICFA discusses CERN hadron collider
Authors: Lubkin Gloria B.
Published: September 2008

Early in May a report containing reference designs for the Superconducting Super Collider was submitted to the Department of Energy. A group of about 150 scientists, led by Maury Tigner of Cornell, submitted a 400-page draft report that considered three SSC designs—one using 3-tesla superferric magnets (proposed by a Texas consortium), one using 5-tesla superconducting magnets (proposed by Fermilab) and one using 6.5-tesla superconducting magnets (proposed by Brookhaven and Lawrence Berkeley Lab). Cost estimates for each of the three designs were roughly the same: $2.7–$–$3.0 billion in 1984 dollars. These estimates do not include the cost of site acquisition or the cost of the detectors.
Nuclear spin waves seen in dilute polarized gases
Authors: Schwarzschild Bertram M.
Published: September 2008

Spin waves in crystalline ferromagnets have been known since the 1950s. It is less obvious that such collective propagating modes of oscillating magnetization can be excited in liquids. But spin waves in degenerate Fermi liquids were predicted as early as 1958 and eventually seen in such Fermi-liquid systems as liquid helium-3 and the conduction electrons of paramagnetic metals.
Native American astronomy
Authors: Aveni Anthony F.
Published: September 2008

Looking into the past, we find cultures very different from our own, yet we find people doing many of the things we do—discovering celestial order through observation, developing calendars, creating cosmologies. As scientists, we often endeavor to explain the unknown by seeking likenesses with known phenomena. However, we must be particularly careful when we use this strategy to study the astronomy of other cultures, for we often become enticed into thinking that their motivations and goals were the same as ours. Warning of this “presentist” trap in the thick of the Stonehenge controversy two decades ago, a historian commented that every age fabricates the Stonehenge it desires. Perhaps we gain a measure of security if we convince ourselves that prehistoric Newtons and Einsteins were preaching and practicing our outlook millenia ago. But were they?
APS and the international physics community in 1983
Authors: Marshak Robert E.
Published: September 2008

World War II was a turning point in the fortunes of American science. The many scientific contributions to the winning of the war—radar, the proximity fuse, the atomic bomb—led a grateful nation to expand greatly its support of basic research at universities, from which the bulk of wartime researchers had come and to which they returned. Since physicists had played such a prominent role in the war effort, it was not surprising that physics was one of the chief beneficiaries of the new public policy. It is worth recalling that the first Federal agency to provide substantial funds for academic physics was the Office of Naval Research, which, among other things, provided the funds for the first high-energy machines. By the early 1950s, the Atomic Energy Commission and the National Science Foundation were fully established and began to assume increasing responsibility for support of basic research in the physical sciences. After Sputnik in 1957, NASA joined NSF and AEC (now DOE) as one of three key civilian agencies funding physics research. The actual figures for FY 1984 may be of interest. The DOE budget, the largest, is $1.38 billion (under the categories of “high-energy physics,” “nuclear physics,” “basic energy sciences” and “magnetic fusion energy”), the NSF budget is $208 million (under the categories of “physics program” and “materials research program”) and the NASA budget is $324 million (under the categories of “physics and astronomy” and “planetary exploration”), for a grand total of $1.85 billion; incidentally, this represents a healthy 12.5% increase over the corresponding figure for the previous year.
Elephants and mahouts—early days in semiconductor physics
Authors: Herman Frank
Published: September 2008

I didn't really decide to become a physicist until I was about 23 years old, working as a research engineer at the RCA Laboratories in Princeton, New Jersey. To understand my decision, you will need some background. Ever since I was a boy I was fascinated by the operation of machines. I liked to take them apart, and often I was even able to put them back together again. I used to make model airplanes and construct mechanical toys. Originally, I wanted to become a civil engineer and design complex mechanisms.
High-spin molecular rotation spectra are surprisingly simple
Authors: Schwarzschild Bertram M.
Published: September 2008

In the past few years enormous experimental and theoretical progress has been made toward the understanding of the vibration–rotation spectra of polyatomic molecules. With a laser spectrometer of unprecedented size and complexity, Christian Bordé and his colleagues at the Université Paris-Nord are now able to resolve hyperfine and “superfine” splittings of less than one part in 1010 over a considerable infrared wavelength range in the spectra of such molecules as sulfur hexafluoride. SF6 is particularly interesting not only because its highly symmetrical configuration produces astonishing spectral patterns that have given impetus to a new level of theoretical understanding; it also serves as a stand-in for UF6. Much of the support for SF6 spectroscopy has been impelled by the practical interest in laser separation of uranium isotopes.
Research on conceptual understanding in mechanics
Authors: McDermott Lillian C.
Published: September 2008

Over the past decade, physicists, psychologists and science educators have been conducting research that has yielded detailed information about how students learn physics. Some investigators have used physics as a context for examining cognitive processes and approaches to problem-solving. For others, the primary emphasis has been on conceptual understanding in a particular area of physics such as mechanics, electricity, heat or optics. Regardless of the motivation behind the research, the results indicate that similar difficulties occur among students of different ages and ability, often in spite of formal study in physics. The persistence of these difficulties suggests that they are not easily overcome, and need to be addressed explicitly during instruction.
Computational synergetics
Authors: Zabusky Norman J.
Published: September 2008

Computers, used in what I shall call the “heuristic mode,” can greatly enhance our understanding of the mathematics of nonlinear dynamical processes—a field that is taking on increasing importance as we explore the complex behavior that even simple systems often exhibit. As I shall try to show, computers allow us to penetrate into unexplored regions of mathematics and to discover unforeseen linkages among ideas.
The Harvard summer school in astronomy
Authors: DeVorkin David H.
Published: September 2008

Professional astronomy in the 1920s and 1930s was a science in transition. Modern relativistic cosmologies were born, and three major areas of modern physics became central to progress in astronomy: quantum mechanics, nuclear physics and relativity. The old empirical and quantitative methods of spectroscopic astronomy, methods that generated vast amounts of systematic knowledge of the spectra of the Sun and stars and the dynamics of stellar systems, were being supplemented by rational and quantitative methods. These new techniques promised to reveal not only the compositions of the Sun and stars, their sources of energy and their ages, but also the origin and ultimate fate of the universe.
Stanford linear collider scheduled to operate in 1986
Authors: Schwarzschild Bertram M.
Published: September 2008

Construction of the Stanford Linear Collider is well under way. The SLC is the crucial testing ground of a new accelerator technology, widely thought to be indispensible if we are to push electron–positron collision energies much beyond what LEP will make available. LEP, the Large Electron–Positron storage ring under construction at CERN, near Geneva, is scheduled to provide e+e− collision energies of 100 GeV by the beginning of 1989. But this gargantuan $400-million ring, 27 km in circumference, is regarded by many as the largest practicable e+e− collider one can base on the well-tried storage-ring technology. Significantly higher e+e− energies, it is believed, will require linear colliders.
Stimulated desorption from surfaces
Authors: Knotek Michael L.
Published: September 2008

After spending years wondering how the surface bond is formed, we are now wondering just as hard how it can be broken. Investigation of the latter problem—possibly the more challenging of the two—is leading to new insight into chemical bonding and the dynamical processes important in chemical kinetics. In this article I discuss a very powerful technique that surface scientists are using in this research: stimulated desorption, the removal of atoms and molecules from surfaces by low-energy ionizing radiation. Concepts from the field of stimulated desorption are already finding their way into other areas. For example, we find that we can offer new insight into the problem of beam damage in electron microscopy and that we can contribute to the very important technological area of plasma processing of surfaces. Insights into chemistry and into the general problem of radiation-induced damage could affect our thinking in areas ranging from radiation treatment in medicine to the interaction of radiation with matter in space.
Experiment and mathematics in Newton's theory of color
Authors: Shapiro Alan E.
Published: September 2008

On 18 January 1672 Isaac Newton wrote Henry Oldenburg, Secretary of the Royal Society, that he would send him a paper that he modestly described as “being in my Judgment the oddest if not the most considerable detection wch hath hitherto beene made in the operations of Nature.” Newton was not referring to his theory of gravitation—that was still more than a dozen years away—but rather to his new theory of the nature of white light and color. He had discovered that rays of different color have different degrees of refrangibility—or, as we would put it, that the index of refraction varies with wavelength—and that white light and, in particular, sunlight consist of a mixture of innumerable colors. Less than three weeks later, as Newton promised, he sent to the Royal Society his famous paper, “A New theory about light and colors,” which was published at once in the Philosophical Transactions. In the “New theory” he boldly proclaims: “A naturalist would scearce expect to see ye science of [colours] become mathematicall, & yet I dare affirm that there is as much certainty in it as in any other part of Opticks. For what I shall tell concerning them is not an Hypothesis but most rigid consequence, not conjectured by barely inferring ‘tis thus because not otherwise or because it satisfies all phaenomena (the Philosophers universall Topick), but evinced by ye mediation of experiments concluding directly & wthout any suspicion of doubt.”
High-pressure research with synchrotron radiation
Authors: Skelton Earl F.
Published: September 2008

High-pressure research has undergone a quiet revolution over the past 15 years. This is a result of the creation and evolution of the diamond-anvil cell, an inexpensive, compact and transparent tool that allows one to perform a wide variety of experiments on materials subjected to extreme static pressures. By working with samples that measure only 0.1 mm on a side, the diamond-anvil cell can reach and hold pressures in excess of a million atmospheres
Thermodynamics in finite time
Authors: Andresen Bjarne , Salamon Peter , Berry R. Stephen
Published: September 2008

Until the 19th century, technology was essentially the domain of skilled artisans and constructors who relied on practical experience to design and build their machines. One of the first efforts to use physical theory to study the functioning of machines was undertaken by the French engineer Sadi Carnot. Motivated by the concern of the French about the superiority of British steam engines, he undertook a systematic study of the physical processes governing steam engines, resulting in his remarkable paper Reflexions sur la puissance motrice du feu (On the Motive Power of Heat) published in 1826. Among the earliest successes of this new science, thermodynamics, was the formulation of criteria describing how well real processes perform in comparison with an ideal model. Carnot showed that any engine, using heat from a hot reservoir at temperature Th to do work, has to transfer some heat to a reservoir at lower temperature T1, and that no engine could convert into work more of the heat taken in at Th than the fraction ηC = 1−(T1/Th) known as the Carnot efficiency.