Table of contents

Spin is one of the most fundamental and mysterious phenomena in physics. All particles possess an amount of intrinsic angular momentum or "spin" that is completely separate from any angular momentum they might possess as a result of their motion. The effects of spin can be seen throughout physics and chemistry-in the energy levels of nuclei, in the electronic structure of atoms and molecules, in the periodic table, in magnetism and, most fundamentally, in the division of particles into fermions and bosons. And, as several articles in this issue report, the spin of atoms plays a crucial role in the behaviour of atomic gases at nanokelvin temperatures (p19, p31 and p37).

It is tempting to try to link Bose-Einstein condensation with the article on the physics of traffic flow (see p25). Indeed at least one respected journal has published a paper that makes such a link, and the different phases of traffic are often compared with the solid, liquid and gas phases of matter. However, recent experimental results have shown that current theoretical models are not capable of explaining many of the phenomena observed in real traffic data. And for the safety of all concerned, it is to be hoped that drivers behave as fermions and not as bosons!

The ability of physicists to control single quantum particles, such as individual atoms and photons, has improved greatly in recent years and has allowed many "thought experiments" to be actually performed in the laboratory Experimental techniques have now advanced to the stage where it is possible to repeatedly observe a single photon in a cavity without destroying it (G Nogues et al. l999 Nature 400 239).

Calculating the quickest route for a salesman to travel between cities is one of the most challenging problems in mathematics. Airlines face similar problems when scheduling flights between a large number of airports. The task becomes more difficult as more cities are added to the route. And in the worst case, the time needed to calculate the quickest route grows exponentially with the number of cities. In other cases, however, the computing time grows more slowly, based on a power law.

Gravitational-wave researchers have recently teamed up with high-energy physicists to explore how the world's largest particle accelerators could be used to detect the tiny ripples in space caused by gravitational waves. At a recent brainstorming meeting at CERN, researchers from both sides discussed whether the interaction between gravitational waves and accelerating sub-atomic particles could provide a new way of detecting the waves (www.cern.ch/Physics/Conferences/Cl 999/Thinkshop).

This summer is an exciting time for physicists working on neutrino experiments around the world. Installation work on Antares, an underwater neutrino telescope, is about to start off the French coast near Marseilles. In the US, construction of the MINOS neutrino oscillation experiment began in the Soudan underground mine in Minnesota last month. And at the end of June the K2K experiment in Japan detected its first neutrino. K2K is the world's first long-baseline neutrino oscillation experiment.

A new scheme funded by proceeds from the UK's National Lottery is to give money to physics research. NESTA, the National Endowment for Science, Technology and the Arts, will spend £10m a year to help the UK's scientists, artists and inventors develop novel ideas and bring their ideas to the marketplace. A project to develop superconducting quantum-computing devices is one of seven pilot schemes to be funded by NESTA.

It has been a summer of discontent for the US Department of Energy (DOE), an agency that funds much of the physics research in the US. The immediate cause of the problems was the revelation earlier this year that lax security at the department's Los Alamos National Laboratory had gained China access to American nuclear secrets over a period of several years. Then a recent study by the National Research Council – together with estimates by the Congressional general accounting office – pinpointed lax management in the department.

French physicists have helped to resolve a long-running mystery in the art world. They have shown that the painting Garden at Auvers is indeed a work by Vincent Van Gogh. Claims that the painting was a forgery sent its value plummeting after the current owners had bought it for FFr 55m (about £5.6m) in 1985, and there were no bidders when it was put up for auction 11 years later.

A new fellowship scheme to employ physicists in biomedical research has got off to a rocky start. The scheme is intended to allow physical scientists to use their quantitative skills in labs that come under the supervision of the Medical Research Council (MRC). But the first attempt to get the project off the ground has been unsuccessful – four physicists have turned down offers by the MRC to take up a fellowship. The reasons for the refusals have not been made public, and neither the MRC nor the Particle Physics and Astronomy Research Council (PPARC), who are co-funding the scheme with the MRC, would reveal the four names to Physics World.

The University of Glamorgan in Wales is to start a degree course in science and science fiction. Mark Brake, the physicist who is director of the course, hopes that the new degree will encourage more people to follow careers related to science and technology. Between 50 and 100 students will start the course in September.

One of the world's largest nuclear-energy businesses has appointed a physicist to be its next president. The French Cogema Group has put Anne Lauvergeon in charge following the success of the Greens in June's elections to the European parliament. Her job is to improve dialogue with environmentalists, and manage the group through a transition period as France tries to diversify its energy sources.

The UK government is planning a partial sale of British Nuclear Fuels Limited (BNFL), one of the world's largest nuclear-reprocessing firms. It wants to sell off 49% of the company to form what it calls a "public-private partnership". Stephen Byers, secretary of state for trade and industry, said that "this offers a new way to apply private-sector skills and finance to make a successful public-sector company".

A physicist has been nominated as the European Union's next commissioner for research. Philippe Busquin, a 58-year-old socialist from Belgium, has been nominated by Romano Prodi, the new president of the European Commission. Busquin will be in charge of the EU's fifth framework programme for research and development, a four-year project worth Euro l5bn. He should be confirmed as commissioner by the European parliament next month.

The latest mission of the space shuttle Columbia, which finally went into orbit as Physics World went to press last month, contained more than its share of pioneering moments. It was the first shuttle flight commanded by a woman. It was the first NASA mission run by an independent control centre. Aid it contained the largest and heaviest payload ever. For physicists, the interest focuses on that payload.

The US space agency NASA has announced new missions to Mercury and the comet Tempel 1 as part of its Discovery programme. The Deep Impact mission to Tempel I amounts to a rescue operation for the Champollion mission to the comet, which was cancelled in early July due to budgetary problems at NASA. Both missions were expected to cost $240m (about £ 150m). However, Champollion was being funded from NASA's New Millennium budget, where competition for funds is stiffer than in the Discovery programme. The Messenger mission to Mercury will cost $286m.

It was billed as a chance to "map a new future for science". But will the grandly titled World Conference on Science, which was held in Budapest at the end of June, make any difference? The answer, it seems, depends on whether the 1800 government officials, policy-makers and scientific activists who sat through six days of debate in the Hungarian capital can implement the high-minded ideals discussed by speaker after speaker. The only outcome of the conference was a decision by the 150 countries represented there to adopt two documents of "guidelines" and "principles": a Declaration on Science and a Framework for Action. Neither contains concrete measures or firm proposals, and neither is legally binding.

Four years ago, after having been a high-school teacher for some 10 years, I decided to take a job as an instructor on a university general-physics course. Naturally, I was scared. Would I be able to teach physics as well as a "real" physicist? Although my background in physics was equal to a master's degree and I had a doctorate in physics education, I had never done any physics research, and always considered myself to be a high-school teacher.

The forum article by André Lebeau (May pp15–16) proposes that more reliable scientific data are required before a proper course of action can be formulated concerning anthropogenic-induced climate change. This proposal is based on a serious misunderstanding of the situation and is totally unnecessary if not irresponsible. Politicians have already prevaricated for too long about this issue because the fossil-fuel industry has been extremely successful in convincing them that the economic consequences are far too negative-without providing any concrete evidence to validate this claim.

I enjoyed your excellent news story (July p8) about the outcome of the UK's recent "consensus conference", at which 15 members of the public discussed the problem of radioactive-waste management. This is clearly an important issue and it is pleasing to see that the report produced by the "citizens' panel" provides a balanced and penetrating view of some difficult and complex issues-quite a contrast to the near-hysterical views frequently paraded in the popular press.

Sonoluminescence (the conversion of sound into light by the extraordinary nonlinear pulsations of tiny bubbles of gas trapped in water) is a phenomenon that has attracted strong interest. The subject of sonoluminescence has also had an unusual history characterized by promising avenues of research being left unexplored following interesting and unexpected experimental results (see, for example, May 1998 pp38–42). Another example of sonoluminescence being discovered, only for the researcher to abandon this line of study, recently came to my attention.

While it may seem churlish to protest at Denys Wilkinson's insightful and generally favourable review of my book Making Physics:A Biography of Brookhaven National Laboratory (June pp49–5O), his negative remarks appear to be based on the unspoken assumption that a portrait of a laboratory community should be chiefly about science. But the life and work of a laboratory community is heavily shaped by political, social, economic and even psychological factors, which means that the canvas must include much more than science.

I was surprised to read such a complex solution to such a simple problem as slowing down the pace of a tennis match (June p19). Neither changing the balls, nor the rackets, nor the court size, is necessary Why not simply eliminate the second serve? This would mean that players have to increase the percentage of first serves they put in by slowing them down, as we can see with the second serve in the present game.

I must congratulate you on the elegant symmetry of your joke in the June issue of Physics World. I refer, of course, to Tom Wheldon's lateral thoughts article entitled "The accountant's delusion", which criticizes the belief that everything in life has a monetary value, and your editorial, which praises the fact that "theoretical physicists can create wealth" in the City. Like all the best jokes, it takes a few minutes to realize it is intended as one.

At the quantum level, particles behave very differently depending on whether their spin angular momentum is an integer or a half integer. Half-integer spin particles are known as fermions, and include all the constituents of atoms: electrons, protons and neutrons. Bosons, on the other hand, are particles with integer spin, such as photons.

An international team of astronomers has found the first direct evidence for fast-moving winds of charged particles high above the poles of Jupiter. These so-called electrojets carry ions in the opposite direction to the planet's rotation and transport a tremendous amount of energy, powering Jupiter's massive aurorae (D Rego et at. 1999 Nature 399 121). Furthermore, the researchers from the UK, France and the US found that these winds travel with velocities of over 3kms^-1–exceeding the speed of sound on the planet.

The development of heat engines has been overshadowed by technological advances founded in quantum mechanics and condensed-matter physics for most of this century. Indeed, over the past few decades the prominence of classical thermodynamics in university curricula has faded to make room for more modern subjects.

How do you measure the wavelength of an electromagnetic wave? The standard technique is to split the beam into two partial waves, allow these waves to travel independently for a time, and then measure their interference as a function of the phase difference between the two paths. This technique uniquely determines the wavelength of an electromagnetic wave, and the result is independent of the quantum state of the wave. However, this seemingly obvious result is not so obvious if we look at the definition of wavelength from a quantum-mechanical point of view.

The fantastic progress in the miniaturization of electronic devices that has taken place in the past few decades has largely been made possible by perfecting a century-old technique called lithography. Devices are built up layer by layer, the pattern on each layer being defined by a lithographic "mask". In this "top-down" approach we start with a large, uniform chunk of semi-conducting material and finish with a device that can have features that measure a fraction of a micron across. Forty years ago Richard Feynman proposed an alternative, "bottom-up" approach in which electronic devices would assemble themselves from individual atoms and molecules. Although such "self-assembly" sounds like science fiction, it can work in practice. All the plants and animals in the natural world are the result of self-assembly!

Traffic jams are a fact of life for many car drivers. Every morning millions of drivers around the world sit motionless in their vehicles for long periods of time as they try to get to work, and then repeat the experience on their journeys home in the evening. The same thing often happens when they are driving to the coast for the weekend or to the airport to go on their holidays. They blame other drivers, increasing volumes of traffic and, inevitably, roadworks. So what has any of this got to do with physics?

Soon after the invention of the laser in the late 1950s many dubbed the discovery as "a solution in search of a problem". Nowadays lasers are used in an enormous range of scientific and technological applications, thanks to their high intensity and their ability to emit light in an extremely narrow range of wavelengths. Indeed, the laser has revolutionized the whole field of optics and now plays a central role in the world's communications networks. The market for lasers, optical amplifiers and other optoelectronic components is worth billions of dollars every year.

Bose-Einstein condensation is a macroscopic quantum phenomenon that was first predicted by Albert Einstein in the 1920s, at a time when quantum theory was still developing and was being applied to microscopic systems, such as individual particles and atoms. Einstein applied the new concept of Bose statistics to an ideal gas of identical atoms that were at thermal equilibrium and trapped in a box. He predicted that at sufficiently low temperatures the particles would accumulate in the lowest quantum state in the box, giving rise to a new state of matter with many unusual properties.

The Massachusetts Institute of Technology (MIT) has no shortage of "futurologists" for the information age. First came Nicholas Negroponte in 1995 with his book Being Digital. Michael Dertouzos was next in 1997 with What Will Be. And now we have Neil Gershenfeld with When Things Start to Think.

At the age of two, John Desmond Bernal was taken by his American mother from their farm in Ireland to see his grandmother in California. He amazed other passengers on the steamship by talking in both English and French. Later on, when he was at Cambridge, his fellow undergraduates would nickname him "Sage" because of his seemingly limitless knowledge.

Not too long ago one had to look very hard to find physics, astrophysics or astronomy books intended for the layman that could actually he understood and appreciated by even an educated non-scientist. The great purveyors and translators of the language of the scientist for the public could he counted on one's fingers. However, things have changed since then. The writers have become more numerous and more skilled, while, at the same time, the demands on them to present complex, abstract and strange ideas have become more formidable. Narlikar is one of the stronger members of this new breed.

CTI-Cryogenics has introduced a range of water pumps designed to increase water-vapour pumping speed in turhopumped applications. During vacuum pumpdown, the light gases – nitrogen, oxygen and hydrogen – are pumped quickly regardless of the pumping scheme. Water vapour becomes the dominant gas load. Increasing the water-vapour pumping speed has a direct effect on pumpdown times and the ability to achieve ultimate base pressures. The new ThinLine and LowProfile pumps add significant water-vapour pumping speed to turbopumped systems, while remaining compact and offering easy integration. The core of the water pump is a closed-loop refrigeration system using helium gas as the refrigerant. The pump mounting flange is only 25 mm thick for ISO configurations and 39 mm for metal seal. This allows easy installation into the pumping stack. Both pump designs are available in a range of sizes.

I'm hot, sunburnt, tired, sweats my feet hurt and I'm thirsty-but most of all I'm scared. "This is all going to end badly," I thought. I have a PhD in semiconductor spectroscopy. My natural habitat is a darkened optics laboratory filled with bath cryostats, transfer siphons and argon-ion lasers. How on Earth did I end up hiking into the Kenyan bush with four Maasai elders, looking for water samples?