bluuebunny/crossref_metadata_2025 huggingface dataset:
James E. Keeler pioneer astrophysicist
Authors: Osterbrock Donald E.
Published: April 2009

In late December 1877 James E. Keeler appeared at Johns Hopkins University to begin his studies in physics and astronomy. He was a “raw country boy” from Florida, without benefit of a high-school education. Twenty years later, an outstanding astronomer, he was appointed Director of Lick Observatory, the best-known research institution of that era. Two years later he died unexpectedly of a stroke. Keeler had a brilliant career in astronomy and was, with his younger friend George Ellery Hale, one of the great American pioneers of the new science of astrophysics. His observational discoveries are described in every astronomical textbook today, although often his name is not mentioned, and the research techniques that he developed and the problems that he studied still form the basis of much of modern-day astrophysics. The portrait on the opposite page shows him at the height of his career.
CERN builds proton–antiproton ring; Fermilab plans one
Authors: Lubkin Gloria B.
Published: April 2009

Although some high-energy experimenters have been talking about proton–antiproton colliding-beam devices for over a decade, the financial commitment to build such a high-energy storage ring had not been made. Now CERN is indeed building such a device, in which 270-GeV protons will collide with 270-GeV antiprotons. Built out of the CERN operating budget, the project is expected to cost about 91 million Swiss francs ($50 million) and to be completed by the end of 1980. Two interaction regions have been approved, each requiring a complex detector whose cost is in addition to the 91 million Swiss francs. Besides the two large detectors, three other experiments have been approved.
Einstein's life in pictures
Authors: von Foerster Thomas
Published: April 2009

The year 1879 was a remarkable one for the sciences. James Clerk Maxwell's death in November had been more than compensated by four notable births during the previous year: Max von Laue on 9 October, Albert Einstein and Otto Hahn on 14 and 12 March, and Lise Meitner on 7 November, 1878. All four worked as friends and colleagues for many years at the Kaiser Wilhelm Institute in Berlin. Together with Max Planck, Walther Nernst and others they formed one of the most prestigious groups of scientists in the world. Laue discovered the interference of x rays. Hahn and Meitner worked side by side on nuclear chemistry; their work led to the discovery of nuclear fission.
Unitary field theories
Authors: Bergmann Peter G.
Published: April 2009

The spirit that motivated Galileo, Newton, Einstein and Bohr to strive to understand nature by tracing unifying principles that underlie the diversity of physical phenomena is the motivating force behind unitary field theories. In its earlier stages, in the absence of physical facts that could have given it direction, the quest for unitary field theories was stimulated primarily by geometric notions. In recent years quantum physics and elementary-particle theory have suggested new directions, some of which may be successful. Before we discuss these recent developments, let us review some of the background.
Squeezing xenon to a metal, sulfur to a superconductor
Authors: Lubkin Gloria B.
Published: April 2009

If you squeeze any substance hard enough to reduce the volume, it is destined to become metallic as the density of electrons is increased. It is also widely believed that the substance will probably become superconducting at sufficiently high pressure and low temperature.
Spin-dependent proton elastic scattering
Authors: von Foerster Thomas
Published: April 2009

Recent experiments with the Zero Gradient Synchrotron at Argonne have revealed startling differences in the way protons of different spins scatter elastically. A group from the University of Michigan and Argonne National Lab led by Alan Krisch has found that for protons polarized normal to the scattering plane, elastic scattering at large momentum transfers is about four times more probable for spins parallel than anti-parallel.
Superlattices show quantum effects
Authors: Schwarzschild Bertram M.
Published: April 2009

Recent advances in controlling the epitaxial growth of semiconductor hetero-structures have made possible the observation of man-made quantum-size effects in such structures. By sandwiching a layer of gallium arsenide about 100 Å thick between confining layers of aluminum–gallium arsenide, one creates a potential well about 300 milli-electron volts deep in which confined, discrete energy levels can be observed for electrons above the conduction band edge. By expanding this sandwich to hundreds of GaAs layers, with interspersed AlxGa1−xAs layers of comparable thickness, one has created a superlattice, with an artificial periodicity one or two orders of magnitude longer than the atomic spacing, superposed on the natural periodicity of the crystal (see PHYSICS TODAY, August 1975, page 17). This results in a splitting of the conduction bands into mini-bands corresponding to the mini-Brillouin zones of the longer periodicity. When such a superlattice is doped with donor impurities, a pseudo-two-dimensional electron gas will be confined in each GaAs layer.
The state of the APS and of physics in 1978
Authors: Ramsey Norman F.
Published: April 2009

It has been a great honor to serve as President of The American Physical Society during the past year, but the honor is not an empty one. There are numerous duties attached, one of the last of them being to give this report on The American Physical Society, the physics profession, and physics.
Charge-density waves in transition-metal compounds
Authors: Di Salvo Francis J. , Rice T. Maurice
Published: April 2009

The vast majority of compounds crystallize into a regular form in which a unit cell is repeated indefinitely, except for generally localized defects, impurities and boundaries. In a few compounds, however, at sufficiently low temperatures interactions between electrons and ions across unit cells make this regular array unstable with respect to small distortions. The stable state is one in which the charge density, the spin density, or the ion positions display long-period modulations. The period of these modulations may be incommensurate with the spacing of the underlying lattice, so that the material is no longer truly periodic, having two unrelated periods. In this article we shall focus on charge-density waves, in which the electron density and also the ion positions exhibit a periodic variation.
Social currents in weak interactions
Authors: White D. Hywel , Sullivan Daniel
Published: April 2009

At the end of his concluding remarks, summarizing the reports at the 1962 International Conference on High Energy Physics at CERN, Victor Weisskopf referred to the excitement caused by experimental claims that the selection rule known as the ΔS = ΔQ rule did not hold and showed the New Yorker cartoon reprinted opposite.
Scanning acoustic microscopy
Authors: Schwarzschild Bertram M.
Published: April 2009

The resolving power of the scanning acoustic microscope now rivals that of the optical microscope. Since Calvin Quate and Ross Lemons reported building the first scanning acoustic microscope in 1974, Quate's group at Stanford has been able to improve the resolution of this instrument every year by about a factor of two; they now report they have achieved resolutions of about half a micron. Quate recently described his progress in an invited paper at the March meeting of The American Physical Society in Chicago. Quate's group has also recently reported the results of the first experiment with a photoacoustic microscope, a new instrument that generates sound waves by heating a sample with a pulsed laser.
Limit on space isotropy improves thousandfold
Authors: von Foerster Thomas
Published: April 2009

One of the fundamental postulates of the special theory of relativity is that the speed of light is uniform in all directions, and is independent of the motion of the emitter or the observer. A recent report from the Joint Institute for Laboratory Astrophysics (National Bureau of Standards and the University of Colorado) in Boulder has greatly increased the precision with which we know that the postulate agrees with experiment.
Cosmic background matches blackbody with deviations
Authors: Lubkin Gloria B.
Published: April 2009

Although last year's Nobel prize in physics honored the discovery of the cosmic background radiation in 1965, since then, because the observations are so difficult to make (especially at high frequency), it has only been possible to show that the spectrum is approximately that of a 3-K blackbody. Nevertheless, the evidence for a blackbody spectrum has been sufficiently compelling to convince most cosmologists that the Universe began with a big bang.
Magnetic refrigerator–heat pump
Authors: Schwarzschild Bertram M.
Published: April 2009

For almost half a century low-temperature physicists have been exploiting the adiabatic demagnetization of paramagnetic materials to achieve temperatures near absolute zero. Until recently the potential utility of the magnetic cycle for refrigeration and heat pumping near room temperature has not been taken seriously for two reasons: First of all, the degree of magnetic order achievable in paramagnetic materials at practical field strength becomes very small at room temperature. Thus the entropy change that pumps heat when magnetic fields are applied and withdrawn becomes too small to be useful. Furthermore, by 20 K the lattice entropy changes of typical paramagnetic salts and the magnetic entropy changes from which they must be subtracted in a Carnot refrigeration cycle are comparable.
Uri Pestov develops high-resolution spark counter
Authors: Lubkin Gloria B.
Published: April 2009

A new kind of spark counter for high-energy physics is being developed by Uri Pestov and his collaborators at the Institute of Nuclear Physics in Novosibirsk. One model of the Pestov or planar counter was used a year ago as part of a picosecond time-of-flight spectrometer in experiments on the VEPP-2M electron–positron storage ring. Resolution time of the spark counter itself was 30 picosec.
Physics of rapidly rotating nuclei
Authors: Bohr Aage , Mottelson Ben R.
Published: April 2009

In recent years, a new field of nuclear research has been opened through the possibility of studying nuclei with very large values of the angular momentum. This development has been closely associated with the study of heavy-ion reactions, since collisions between two heavy nuclei are especially effective in producing metastable compound systems with large angular momenta. The study of such rapidly rotating nuclear systems provides the opportunity for exploring new aspects of nuclear dynamics. In figure 1 we show a multiple-coincidence spectrometer for studying gamma-ray cascades from the decay of these high-angular-momentum states. It comprises eighteen NaI detectors arranged around an on-line target; seven of the detectors and their photo-multipliers are visible in the photo. The arrangement gives high sensitivity to gamma-ray cascades, which in some cases exceed thirty consecutive gamma rays. The spectrometer was constructed at the Niels Bohr Institute and is being used in a Copenhagen-Darmstadt collaboration.
Jean Perrin and the reorganization of science
Authors: Weart Spencer
Published: April 2009

Around 1930 a new generation came to the leadership of science in France, determined to overhaul it from top to bottom. Already in their fifties or sixties by the time they achieved leading positions, they had long suffered under the direction of superannuated professors, and they had seen French physics, once first in the world, sink toward obscurity. It was their deeply feared rivals, the Germans, who had made and welcomed many of the exciting new discoveries in quantum theory and relativity. The new generation in France, led by the physicist Jean Perrin, now launched a campaign for science. Within a few years they managed to create an organization of a new kind—one that not only revived French science, but that also served as a model for science organizations in many other countries. The story of this effort is interesting not simply because it is an important part of the history of modern science, but also because it can help us to see the social and ideological forces that may help or hinder any reorganization of science.
Laser enrichment process called proliferation resistant
Authors: Lubkin Gloria B.
Published: April 2009

Although many technically advanced nations are attempting to develop laser isotope separation of uranium, detailed information has always been difficult to obtain. Much of the work is classified because of its potential weapons applications; still other work is considered “company confidential” by the industrial firms involved.
Update on free-electron lasers an applications
Authors: von Foerster Thomas
Published: April 2009

Lasers whose operating frequencies are not determined by energy levels in atoms or molecules have long been a goal of researchers in the field. Stimulated scattering by free electrons passing through spatially varying magnetic fields promises to meet that goal. Two years ago, a group at Stanford reported laser action from stimulated bremsstrahlung, and a collaborative effort of the Columbia University Plasma Lab and the Naval Research Lab has produced a laser based on stimulated Raman scattering by free electrons. These results have encouraged many other laboratories to investigate the construction and potential uses of free-electron lasers. Active research is now going on at Bell Labs, Los Alamos, The University of Trento, Frascati, Brookhaven, and the Lawrence Livermore Labs, among others. Much of the excitement is due to these lasers' promise of exceedingly high power levels at a low enough cost to make them useful suppliers of industrial process energy.
Crystallographic contributions to the energy problem
Authors: Wilkinson Michael K.
Published: April 2009

In every scientific discipline, attention has begun to turn toward the serious shortage of energy in the world as scientists ask themselves, “What can we do about it?” There is certainly no doubt that the problem exists, that it is growing more serious with time, and that it is not going to be solved easily and quickly.
Weak magnetic fields in human body
Authors: Schwarzschild Bertram M.
Published: April 2009

The ability of SQUID (Superconducting Quantum-Interference Device) magnetometers to measure magnetic fields weaker than 10−9 gauss has made possible the study of the very weak magnetic fields induced in human beings by biochemical current flow or by the presence of small quantities of ferromagnetic contaminants. The SQUID is basically a superconducting loop with a weak link that behaves as a Josephson junction. One can monitor the intrusion of individual flux quanta (h/e≈2×10−11 gauss-meters2) as they force their way through the weak link into the superconducting loop. The first SQUID magnetometers were built in 1967 by James Zimmerman and his colleagues at the Ford Scientific Research Lab.
Crystalline thin film grows on amorphous base
Authors: Schwarzschild Bertram M.
Published: April 2009

When a thin film is epitaxially grown on a crystalline substrate, the crystal lattice pattern of the substrate surface acts as a kind of atomic template for the crystal growth of the overlayer film. Until recently it has not been possible to deposit oriented single-crystal layers on amorphous substrates, where no such regular atomic template is present.
Analyses of historical data suggest Sun is shrinking
Authors: Lubkin Gloria B.
Published: April 2009

At high noon on every clear day since 1750, astronomers at the Royal Greenwich Observatory have been measuring the diameter of the Sun. The quantity is a by-product of a more fundamental measurement, which is to determine the precise position of the center of the Sun with respect to the stars. To do this, they record the time at which each limb of the Sun crosses the fixed meridian wire of an instrument. From the same data one can then calculate the horizontal solar diameter from the known rotation rate of the Earth.
Mixed reception for magnetic monopole announcement
Authors: Lubkin Gloria B.
Published: April 2009

The possibility that a fundamental magnetic charge might exist has intrigued physicists over the years. After the quantum theory of the magnetic monopole was developed in 1931 by P. A. M. Dirac, experimenters began looking for them. They have searched in cosmic rays, at particle accelerators, in iron ore, ocean sediment, meteorites and lunar rock.
Encouraging progress with Livermore mirror machine
Authors: Rothenberg Marian S.
Published: April 2009

The 2XIIB mirror device at Lawrence Livermore Laboratory has produced plasma temperatures of 10–14 keV, more than four times higher than temperatures reached in an earlier version of the device. Simultaneous with this achievement of reactor-level temperatures in a dense plasma was a tenfold increase in plasma confinement time, to about five milliseconds. Although these new results are not being taken to mean that magnetic-mirror confinement has suddenly become the favorite for producing a practical fusion reactor, they do show that the plasma produced in such a device continues to follow classical energy scaling at high temperatures. Confinement time, that is, does increase with energy, indicating that most of the plasma losses are caused by collision between plasma particles rather than by the more serious effects of internal instabilities. Moreover, notes Frederic Coensgen, leader of the California experimental group, the temperature reached was just that predicted two-and-one half years ago, and success was achieved within the predicted time and for the predicted cost. Other members of the experimental team are Thomas Simonen, William Cummins, Grant Logan, Arthur Molvik, William Nexsen Jr, Barry Stallard and William Turner.
Structure analysis of solid surfaces
Authors: Rhodin Thor N. , Tong David S. Y.
Published: April 2009

An accident that occurred at Bell Laboratories in 1925 started Clinton Davisson and Lester Germer on an historical series of experiments. While studying the backscattering of slow electrons from a polycrystalline nickel target, they observed that the angular distribution of the electrons changed completely when the surface was inadvertently oxidized at a high temperature. The consequent study of diffraction phenomena in electrons scattered from the (111) face of a nickel crystal confirmed the de Broglie hypothesis of the wave nature of electrons. But Davisson and Germer also predicted that this type of experiment would provide a valuable approach to the important problem of defining the precise position of atoms in the surfaces of crystalline solids. This suggestion has been pursued diligently by scientists both in the US and abroad. Now, fifty years after Davisson and Germer demonstrated the coherent scattering of electrons by a crystalline solid, the goal of studying surface structure with this technique is becoming a reality. In this article we will discuss some of the major advances of the past few years that are making this achievement possible.
Highly excited atoms excite interest in many labs
Authors: Scott John T.
Published: April 2009

“Since I'm an atom as big as bacterias I've got to take microwaves serious. No matter what I do, I'll be cryin'… After they hit me, I'll be an ion.” So begins a poem written last year by Peter Koch of Yale, during the stresses of preparing his PhD thesis. With James Bayfield, Koch had been studying highly excited atoms (often called “atoms in high Rydberg states,” or even simply “Rydberg atoms”); the interesting behavior of such atoms has become the subject of current experimental and theoretical work at many centers around the world.
Two-level atom shows photon antibunching
Authors: Lubkin Gloria B.
Published: April 2009

What happens to a two-level atom in an intense laser field? The system resembles the hydrogen atom in its relative simplicity, but only in the last couple of years have experiments shed much light on its behavior. Intensity-dependent resonant light scattering has been studied in two-level atoms by looking at the spectrum and more recently, by observing the time development of fluorescence—photon antibunching. Such scattering is one of the few electromagnetic phenomena that apparently cannot be described by semiclassical arguments; a quantum field theoretical approach appears essential.
Neutrons and fission
Authors: Michaudon André
Published: April 2009

The advent of the double-hump fission barrier that occurred about a decade ago was one of the great steps forward not only in fission but also in nuclear physics in general. This new development brought the two disciplines into much closer contact after years of independence. The double-hump shape of the fission barrier (figure 1) provided the clue to a unified explanation of a number of experimental results. Among these are fission isomerism, the phenomenon whereby a heavy nucleus can exist in a relatively long-lived excited state decaying by fission, and the appearance of several types of structure in the fission cross sections of many nuclei as a function of incident neutron energy.
Electron diffraction: fifty years ago
Authors: Gehrenbeck Richard K.
Published: April 2009

An article that appeared in the December 1927 issue of Physical Review, “Diffraction of Electrons by a Crystal of Nickel,” has been referred to in countless articles, monographs and textbooks as having established the wave nature of the electron—in principle, of all matter. Now, fifty years later, it is fitting to look back at the events that led up to this historical discovery and at the discoverers, Clinton Davisson and Lester Germer. Figure 1 shows them in their lab in 1927, together with their assistant Chester Calbick.
Evolution of red-giant stars
Authors: Sweigart Allen V.
Published: April 2009

Theorists are paying a lot of attention nowadays to the structure and evolution of highly luminous stars with low surface temperatures. These stars, referred to as “red giants” because of their color and large radii, are believed to be in an advanced phase of their evolution. Most stars pass through at least one such phase, late in their lifetimes—as will our Sun.
Dimuons at Fermilab suggest new form of hadronic matter
Authors: Lubkin Gloria B.
Published: April 2009

Neutrino experiments at Fermilab conducted over the past two years, in which pairs of muons are produced, appear to show the existence of a new form of hadronic matter. The discovery suggests that matter carrying a new quantum number has been observed. This quantum number is often generically referred to as “charm.”
Shuttle studies to include atmospheres and plasmas
Authors: Bennett Floyd C.
Published: April 2009

The Science Definition Working Group associated with the Atmospheres, Magnetospheres and Plasmas-in-Space Payload has identified scientific objectives for the project. The group has named outstanding problems in each of the three areas and reviewed possible experimental techniques to be used with the Payload, which is to be placed in orbit by means of NASA's Spacelab–Shuttle system.
Slow positrons in gases
Authors: Massey Sir Harrie
Published: April 2009

The study of the behavior of slow positrons in gases has recently become a very lively field. New fast counting techniques are making it possible to enlarge much further the base already established in earlier work, as well as bringing into practical possibility measurements that previously seemed unattainable. (Typical of the recent experimental systems is the apparatus shown in the photograph, figure 1, and diagrammatically in figure 2.) For collisions with helium atoms at energies below the positronium formation threshold the position appears very well established, and the prospect is now opened for interpreting, in more detail, positron collisions with more complex systems.
Sun appears to be oscillating at many frequencies
Authors: Lubkin Gloria B.
Published: April 2009

Last year Henry Hill and his collaborators reported seeing normal modes of oscillation in the Sun, with periods ranging from 6–70 minutes. By now the group says they have seen oscillations at a minimum of 20 different frequencies. Recently a group at the Crimean Astrophysical Observatory reported a period of 160 minutes, which was also observed by a group at the University of Birmingham, England (who also reported two shorter periods).
Group meets in USSR on Very Big Accelerator
Authors: Lubkin Gloria B.
Published: April 2009

This month, beginning on 17 May, an international study group will meet in Serpukhov in the Soviet Union, to discuss the prospects and possibilities of constructing a “Very Big Accelerator” by a world collaboration among many different countries. It would be a machine with much higher energy than any accelerator being planned by an individual nation.
Light sources
Authors: Kressel Henry , Ladany Ivan , Ettenberg Michael , Lockwood Harry
Published: April 2009

The selection of a system for optical communications is largely governed by the availability of the necessary components. Although through-the-atmosphere systems have some applicability, they are generally restricted to small installations where their inherent limitations are tolerable. The optical transmission medium of greater importance for the future is a glass or plastic fiber, and therefore the properties of these fibers—their absorption, dispersion, mechanical strength, and so on—are all-important.
Integrated optics
Authors: Conwell Esther M.
Published: April 2009

The appearance of “Integrated Optics: An Introduction” by Stewart E. Miller in the September 1969 Bell System Technical Journal signalled the birth of an activity that now occupies thousands of researchers. Bell Labs, among others, had been concerned with optical communications for some time, encouraged in this activity by the advent of the laser. Miller pointed out that the then typical optical telephone repeater, involving a laser, modulator, detector, lenses, and so on, spread out on an optical bench, was a form of extremely short-range radio communication and as such suffered from a number of difficulties. The apparatus was sensitive to ambient temperature gradients, to temperature changes, to mechanical vibrations of the separately mounted parts. The elegant solution to these problems proposed by Miller was to combine the separate components on the same substrate or chip, connecting them by miniature transmission lines or waveguides. Because the size of the components need only be of the order of the wavelength of light in one, and possibly two, dimensions, the substrate could be quite small—centimeters or less. He proposed calling such an assembly of components an “integrated optical circuit,” in view of its analogy to the assembly of electrical components on an integrated circuit chip.
Separating isotopes by multiphoton dissociation
Authors: Lubkin Gloria B.
Published: April 2009

Collisionless dissociation of polyatomic molecules was a topic of great interest at the Conference on Laser-Induced Chemistry in Steamboat Springs, Colorado in February. Laser-induced multiphoton dissociation has been used in the separation of sulfur, nitrogen, silicon, chlorine and osmium isotopes. Publicly reported work has concentrated on SF6, although of course the primary interest is in separating uranium isotopes.
Strongest superconducting magnet installed in Japan
Authors: Lubkin Gloria B.
Published: April 2009

A 175-kG superconducting magnet was recently installed at the Japanese National Research Institute for Metals in Tsukuba Science City, an hour's ride from Tokyo. Built by Intermagnetics General Corp of Guilderland, New York, the magnet is the highest-field completely superconducting magnet in the world. The previous record, established two years ago, was held by an IGC magnet with a field of 158 kG, built for the Mullard Cryogenic Laboratory at Oxford University.
The formation of interstellar molecules
Authors: Herbst Eric , Klemperer William
Published: April 2009

The expanding universe is 1010 years old and has a radius of 1010 light years or 1028 cm. Matter in the universe, distributed in a highly non-uniform manner, is concentrated largely in galaxies, which occupy only a minute fraction (10−7) of the volume of the universe. In addition to stars, most galaxies contain diffuse, low density interstellar matter. Because interstellar matter is most easily studied in our own galaxy, the discussion here will focus on it, although this discussion should be pertinent to other galaxies as well.
FIFTY YEARS OF SPIN: Personal reminiscences
Authors: Uhlenbeck George E.
Published: April 2009

In a one-page Letter to the Editor of Naturwissenschaften dated 17 October 1925, Samuel A. Goudsmit and I proposed the idea that each electron rotates with an angular momentum ℏ/2 and carries, besides its charge e, a magnetic moment equal to one Bohr magneton,  eℏ/2mc. (Here, as usual, ℏ is the modified Planck constant, m the mass of the electron and c the speed of light.) Sam, in his accompanying article, tells something of those times, fifty years ago. We have often talked about the circumstances that led to our idea, but it was mainly Goudsmit's recollections that have appeared in print before now—they are, however, not readily accessible in English. Although I gave a short account of the discovery of the spin as a part of my inaugural address for the Lorentz professorship in Leiden in 1955, it therefore appears to be my turn to reminisce.
Kondo methods may work for quarks and gluons too
Authors: Lubkin Gloria B.
Published: April 2009

Methods developed for solving problems in statistical mechanics and in solving the Kondo problem are showing promise that they might explain how at the same time quark effects can be observed at high energies and appear to be infinitely bound when observed at low energies. Once again some beautiful work in one field may have an impact in another.
Stabilization problem threatens future of Scyllac
Authors: Lubkin Gloria B.
Published: April 2009

Facing a deadline of September 1977, fusion physicists at Los Alamos are working hard to demonstrate that they can stabilize the plasma in Scyllac, one of the three major approaches in ERDA's magnetic confinement effort. Recently Robert Hirsch, ERDA's new assistant administrator for solar, geothermal and advanced energy systems said (PHYSICS TODAY, June, page 69) that a real question exists as to the future of Scyllac if present trends are not reversed. Meanwhile Los Alamos is studying alternative schemes for the laboratory to pursue if Scyllac work is terminated.
Intense neutron sources for fusion studies
Authors: Bennett Floyd C.
Published: April 2009

Steady-state sources of intense neutrons are under way at two US laboratories. They would be used to study radiation damage produced in controlled-fusion reactors. If funds are appropriated for the Los Alamos Scientific Laboratory's $25.4-million Intense Neutron Source, it would be expected to produce fluxes of 2×1014 14-MeV neutrons/cm2-sec after it became operational near the end of fiscal 1980. Meanwhile, Rotating-Target Neutron Source II, under construction at the Lawrence Livermore Laboratory, may begin initial operation leading to a maximum 14-MeV-neutron flux of 1.5×1013 neutrons/cm2-sec as early as March of 1978; total cost of the RTNS-II is estimated at $5 million.
75 years of physics at NBS
Authors: Ambler Ernest
Published: April 2009

The year 1901, just two years after the founding of The American Physical Society, saw the founding of the National Bureau of Standards as the US reference laboratory for measurements and standards. Physics is indispensable to the fulfillment of this function, and the two organizations have enjoyed a close working relationship in these seventy-five years.
Japanese synchrotron yields 10-GeV protons
Authors: Lubkin Gloria B.
Published: April 2009

The first accelerator for high-energy physics in the Far East was recently dedicated at the KEK laboratory in Tsukuba science city, 60 km northeast of Tokyo. The proton synchrotron, whose construction began in 1971, has exceeded its initial design energy of 8 GeV on 19 March, when it reached over 10 GeV. After the main ring power supply and cooling capacity are modified, the machine is expected to reach a peak energy of 12 GeV.
Neutrinos and atoms shed light on neutral currents
Authors: Lubkin Gloria B.
Published: April 2009

Over the past three years, evidence for the existence of neutral currents has grown ever stronger. Such currents are generally required by various gauge theories that have been developed in an attempt to unify the weak and electromagnetic interactions. Many observations of neutrino interactions are consistent with the model proposed a decade ago by Steven Weinberg and by Abdus Salam. However, two experiments cast a small shadow of doubt on the minimal model: the so-called “high-y anomaly” in antineutrino inelastic scattering and preliminary results on parity violation (or lack of it) in atomic physics.
Laser frequency switching studies coherent phenomena
Authors: Lubkin Gloria B.
Published: April 2009

A simple way of observing coherent transient effects in the visible and ultraviolet regions has been developed by Richard G. Brewer and Azriel Z. Genack (IBM Research Laboratory, San Jose). The technique, called “laser frequency switching,” simplifies the observation of a class of coherent phenomena in atoms, molecules and solids, analogous to the wide-ranging applications of pulsed nuclear-magnetic-resonance techniques. The IBM pair reported their results in Phys. Rev. Letters and at the International Tunable Lasers and Applications Conference in Loen, Norway in June.
Amorphous semiconductors
Authors: Tauc Jan
Published: April 2009

In recent years the physics of amorphous semiconductors has developed into a field so extensive and ramified that it is difficult to review in one paper. Various researchers emphasize different achievements; my choice of these is based on an attempt to give the reader an idea of the breadth of the research—from fundamental questions on electron states and atomic motions to the principles underlying some of the applications. The main difficulty with such a presentation of a more or less consistent picture is that there will necessarily be an inadequate discussion of alternative interpretations, so that the reader may get the mistaken impression that the suggested models were uniquely deduced from the experimental data. Unfortunately, crucial experiments that distinguish between different interpretations are still scarce. Nevertheless, experimental and theoretical work in the last five years have shown that some previously suggested plausible assumptions were incorrect, and the field has achieved, besides its extensive growth, significant progress in the understanding of the fundamental physics.
Treatment of sewage by electrons and gammas
Authors: Bennett Floyd C.
Published: April 2009

The use of high-energy electrons in the treatment of sewage sludge for return to the land as fertilizer is undergoing technical and economic assessment under actual conditions in Boston. The project constitutes a joint effort by MIT's High-Voltage Research Laboratory, High-Voltage Engineering Corp (suppliers of the electron accelerator) and the State and municipal commissions in charge of the treatment plant. Another program, conducted at Sandia Laboratories in Albuquerque, N.M., is concerned with the scientific practicality of decontaminating sewage wastes by exposure to radioactive cesium.
Congressional interactions at very small impact parameter
Authors: Horwitz Paul
Published: April 2009

T HIS IS A REPORT to the members of The American Physical Society on some recent data obtained from the ongoing Congressional Fellow Deep Inelastic Scattering Experiment. This experiment, which was initiated by the APS and other scientific and engineering societies three years ago, represents a first attempt to probe the nature of the US Congress. The concept is very simple: a strongly focused beam of high-energy Congressional Fellows is directed at the Congress and allowed to interact. An analysis is then made of the final state of the system (which may be either a free Fellow or a bound Fellow-Congress pair) and, in this way, insight is gained into the nature of the unknown scattering center and its interactions. A more ambitious goal is to learn to use and perhaps even modify these interactions for some practical purpose—this goal is still a long way off, and at present very little is known about the fundamental nature of either the Congress or that larger entity of which it is a part, the Federal Government.
The early years
Authors: Serber Robert
Published: April 2009

THE YEARS 1925 TO 1929 were great years in physics. They saw the development of the quantum theory: the Schrödinger equation, the Dirac equation, field theory and quantum electrodynamics. That it was so completely a European effort illustrates the weakness and provincialism of theoretical physics in the United States at the time. Within fifteen years the situation was drastically changed and American theoretical physics was becoming comparable to the best. A very important element in this change was the influence of Robert Oppenheimer. The alumni of the great school of theoretical physics he established at Berkeley played a large part in the subsequent growth of American physics and also in enabling us to meet the demands of the war years.
Public service and human contributions
Authors: Seaborg Glenn T.
Published: April 2009

MUCH HAS BEEN SAID and written about Robert Oppenheimer by the many friends and students with whom he shared his life—his knowledge, wisdom and the wealth of his personal warmth and wide range of worldly interests. Thus I would like to begin with my personal recollections of him. I was fortunate enough to have known and worked with him over a long period of time—particularly in the early years of nuclear discovery and development when we shared some of the excitement of those historic days.
Wide-Range Device Measures Electron and Proton Energies
Authors: Lewis Michael L.
Published: April 2009

Scientists at Rice University, Houston, Tex., have developed a single instrument that can measure electrons and protons over the energy range of 50 to 100 000 eV. Code named SPECS (Switched Proton Electron Channeltron Spectrometer) the device is suitable for space missions because of its small mass (0.9 or 1.6 kg) and low power requirements (about 1 watt). 18-point differential-energy-spectrum measurements for both electrons and protons include parts of the lower ends of the spectra that have been relatively neglected by plasma and penetrating-radiation physicists.
Phimsy
Authors: Ellis R. Hobart
Published: April 2009

Everyone knows it's obvious; G is for Giga and Geneva; We made the Readers' Guide; How to handle “Books”; The melody of relativity.
Oxford Laboratory Mixes Physics and Archeology
Authors: Ellis R. Hobart
Published: April 2009

If an archeologist sat down to dinner with a physicist, their conversation might stir up ways to pursue the two sciences together. Such a meeting happened once at the University of Oxford and the resulting laboratory, established in 1955 by C. F. C. Hawkes and Viscount Cherwell, is now carrying on what is probably the world's most intense program of physics applied to archeology. The present director is E. T. Hall.
A correction
Authors: Courtoy C.
Published: April 2009

I would like to call your attention to two small historical mistakes in your September issue.

On page 45: It was not Marcel de Broglie, but Maurice de Broglie, who attended the Solvay Congress.

On page 121: Georges Lemaître did not go to Louvain to study humanities. The Collège du Sacré-Coeur is in Charleroi, where Lemaître was born.
Bad luck in attempts to make scientific discoveries
Authors: Gorter C. J. , Boorse Henry A.
Published: April 2009

WHEN THE Committee for the Fifth Fritz London Award asked me to give my recipient's address a somewhat personal nature, I hesitated about how to combine the modest review that I could give of certain recent advances made in the Kamerlingh Onnes Laboratory with this request. Not finding a satisfactory solution, I remembered that from time to time I am asked why I have just missed making certain discoveries. Since I have received a favorable reaction from the committee chairman, Dean Boorse, to my enquiry about whether it would be admissible to drop all discussion of recent work and to speak only on apparent bad luck in my attempts to make certain scientific discoveries, I shall do so in the hope of satisfying once and for all those who have asked or would like to ask me about these matters. I shall talk mainly on attempts to observe nuclear and electron magnetic resonances, gamma anisotropy after orienting atomic nuclei, anisotropy of beta emission, and flux quantization in superconductors.
Dust-cloud moons of the earth
Authors: Simpson J. Wesley
Published: April 2009

THE EARTH HAS three moons, two of them very different from the familiar one. They are cosmic dust clouds first reported in 1961 by Kazimierz Kordylewksi, the Polish astronomer. The clouds are found at two of the five points in the earth-moon system where a small mass is expected to be in dynamic equilibrium with the massive earth and moon revolving about their common center of mass. The existence of such points is most simply understood when viewed from the rotating coordinate system of the two heavy masses. Then the five equilibrium positions, known as libration points, are the places at which the gravitational forces just balance the centrifugal force on the small mass. We have been studying the two clouds for nearly three years to determine experimentally the dynamic behavior of matter at the libration points. Recently we have successfully developed techniques for photographing the libration clouds.
Van de Graaff, the man and his accelerators
Authors: Burrill E. Alfred
Published: April 2009

LAST SUMMER Robert J. Van de Graaff received the 1966 Tom W. Bonner Prize “for his contribution to and continued development of the electrostatic accelerator, a device that has immeasurably advanced nuclear physics.” The occasion was the banquet ceremony of the American Physical Society meeting in Mexico City, held jointly with the Mexican and Canadian Physical Societies.
Pre-college: Harvard Project Physics
Authors: Holton Gerald
Published: April 2009

HARVARD PROJECT PHYSICS is developing a new one-year physics course to meet the contemporary needs of high schools and junior colleges. Physicists and science educators for some time have wanted a coherent, tested course for national use alongside other previously developed courses. Moreover there is a desire among physics educators to halt and reverse the decline in physics enrollment. New course materials and organization are necessary to exploit effectively recent developments in educational philosophy and techniques. In particular the trend toward recognition and response to individual differences as well as availability of films, transparencies, film strips, film loops, programed student guides and new laboratory equipment and experiments require changes in course structure for best utilization.
Pre-College: The Nuffield project
Authors: Rogers Eric M.
Published: April 2009

IN 1962, THE NUFFIELD FOUNDATION, one might say the British equivalent of the Ford Foundation, started a project to discuss, renew, and bring up to date the teaching of physics, chemistry and biology in British grammar schools. These schools take the top 20 to 40%, varying with locality, of the high-school population, graded by academic ability. The initial project in physics was to offer schools and teachers a new curriculum for the standard course taken by many students. Unlike the one-year courses in American high schools, the corresponding teaching in England is spread over five years in each science starting at age 1112 and leading to external “Ordinary” or “O-level” examinations at 16 or 17. The project has born fruit and is now extending into other levels of science teaching with a total endowment of over a million pounds from the foundation.
College: Teaching from Feynman
Authors: Stabler Howard P.
Published: April 2009

THE FEYNMAN LECTURES on physics are widely recognized as invaluable source books for teachers and prospective textbook authors, but there is less unanimity regarding suitability of the published lectures as textbooks for students. (For example, two excellent reviews and a different evaluation have appeared.) I am reporting on the two years at Williams College during which my introductory course students and I worked with the first volume. I had the privilege of attending Richard Feynman's lectures at Cal Tech before volume 1 existed, and my perspective is inevitably affected by this experience and the fact that I adopted as textbook for the present term “Mechanics,” Volume 1 of the Berkeley Physics Course. This text was adopted primarily to effect smoother transition to “Electricity and Magnetism” by E. M. Purcell (volume 2 of the Berkeley series), which had just been selected for the sophomore course.
College: The Berkeley course
Authors: Helmholz A. Carl
Published: April 2009

THE BERKELEY PHYSICS COURSE is intended to present introductory physics to students in engineering and the physical sciences in a new and fresh way, to give them the flavor of the way in which practicing physicists use the subject. It consists of five volumes (“Mechanics,“Electricity and Magnetism,” “Waves and Oscillations,” “Quantum Physics” and “Statistical Physics”) and a new laboratory manual. Since the course is designed to acquaint the student with the basic principles and ideas of the physics of today, it does not survey all of physics; rather it selects topics that characteristically illustrate the basic elements of physical reasoning. Consideration of the subjects common in present-day physics has influenced the choice of many of these topics.
College: Baccalaureate science
Authors: Parsegian V. Lawrence
Published: April 2009

ALTHOUGH COMBINED EFFORTS of “armies” of physicists, chemists, engineers and other technological specialists change the textbooks and habits of the nation without letup, their instructional programs are primarily designed to turn out problem-solving specialists for each profession. Unfortunately there is little interest in educating philosopher-scientists, whom we need and whom our society can easily support.
Enrollment trends
Authors: Ellis Susanne D.
Published: April 2009

A PHYSICIST CAN BE defined on many bases, and so far no unique definition has been agreed upon. Yet it can probably be said with certainty that a large fraction of the physics community consists of individuals who have a bachelor's, master's or doctor's degree in physics. Most of those physics-degree holders were undergraduate physics majors at one time or other. Therefore an analysis of those college juniors and seniors who have declared themselves physics majors should give the reader a comprehensive view of what has happened to the physics profession and where it is headed if no drastic changes occur. At the same time the analysis may suggest desirable changes or the strengthening of existing policies in the present educational structure to accomplish various goals set by the physics profession.
CP-Violation Experiments: Superweak Theory is Out
Authors: Lubkin Gloria B.
Published: April 2009

Since a Princeton group (James Christenson, James Cronin, Val Fitch and Rene Turlay) found the first violation of CP in 1964, high-energy physicists have been eagerly looking for the source of the violation. Of the four classes of theories proposed, at least one and a half classes seem to be ruled out by recent experiments at CERN (by Jean-Marc Gaillard, F. Krienen, W. Galbraith, A. Hussri, M. R. Jane, N. H. Lipman, G. Manning, T. Ratcliffe, P. Day, A. G. Parham, B. T. Payne, A. C. Sherwood, H. Faissner and H. Teithler) and at the Princeton-Pennsylvania Accelerator (by James Cronin, Paul Kunz, Winthrop Risk and Paul Wheeler).