Physica Scripta is published by the IOP on behalf of the Royal Swedish Academy of Sciences for the Science Academies and the Physical Societies of the Nordic Countries.
Paper of the Week – Laue: right or wrong? In 1912, Laue spots were discovered in x-ray scattering 'photograms' of crystals, which were amongst the most consequential experimental findings of the 20th century. Laue, a protégé of Planck and a wave-optics expert, had theoretically predicted these spots, and promptly won the Physics Nobel Prize for 1914. The prize did not come easy: executing his experimentum cruces, over the judgments of Sommerfeld and Wien, required force of will and a certain amount of diplomacy. Besides, his explanation for missing spots and x-ray diffraction were proven wrong by Moseley, Darwin and the two Braggs. Yet, Laue stimulated countless breakthroughs: Nobel Prizes and scientific innovations, with an enduring legacy of inspiration a century later.
Highlights of 2014
Don't miss our new collection of papers, celebrating the research that was published with us last year. All the papers are free to read until 31 December 2015.
Proceedings of Quantum Theory: Advances and Problems - QTAP, Linnaeus University, Sweden, June 10-13, 2013
The proceedings of this conference that was held in Sweden in June 2013, are now available as a Topical Issue of Physica Scripta. The articles in this issue will be free to read online until the end of March 2015.
ASOS-11 special issue now available
Selected papers from the Eleventh International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas (Mons, Belgium, 5-9 August 2013) are now available as a special section of Physica Scripta
Virtual issue: Emerging technologies and the future of humanity
This virtual issue of Physica Scripta grew out of the one-day meeting 'Emerging technologies and the future of humanity' that took place on March 17, 2014, at the Royal Swedish Academy of Sciences. The backdrop of the discussions at the meeting is the realization that technologies developed in the next few decades can have profound influence on the future of humanity.
Photonica'13 Topical Issue now available
Papers from the 4th International School and Conference on Photonics (PHOTONICA'13) that took place in the Serbian Academy of Sciences and Arts in Belgrade, Serbia, from 26–30 August 2013, are now available as a Topical Issue of Physica Scripta. A selection of the best work has been made free to read until the end of January 2015.
Crystallography and the Gregori Aminoff Prize
To mark the fact that 2014 has been designated the 'International Year of Crystallography', Physica Scripta will be publishing a virtual issue containing Invited Comments on the history of crystallography, as well as autobiographical articles from some of the current and previous winners of the Gregori Aminoff Prize. You can read the first papers published in this virtual issue here.
In the last 30 days
Kaj Sotala and Roman V Yampolskiy 2015 Phys. Scr. 90 018001
Many researchers have argued that humanity will create artificial general intelligence (AGI) within the next twenty to one hundred years. It has been suggested that AGI may inflict serious damage to human well-being on a global scale (‘catastrophic risk’). After summarizing the arguments for why AGI may pose such a risk, we review the fieldʼs proposed responses to AGI risk. We consider societal proposals, proposals for external constraints on AGI behaviors and proposals for creating AGIs that are safe due to their internal design.
D J Dunstan and D J Hodgson 2014 Phys. Scr. 89 068002
Many gardeners and horticulturalists seek non-chemical methods to control populations of snails. It has frequently been reported that snails that are marked and removed from a garden are later found in the garden again. This phenomenon is often cited as evidence for a homing instinct. We report a systematic study of the snail population in a small suburban garden, in which large numbers of snails were marked and removed over a period of about 6 months. While many returned, inferring a homing instinct from this evidence requires statistical modelling. Monte Carlo techniques demonstrate that movements of snails are better explained by drift under the influence of a homing instinct than by random diffusion. Maximum likelihood techniques infer the existence of two groups of snails in the garden: members of a larger population that show little affinity to the garden itself, and core members of a local garden population that regularly return to their home if removed. The data are strongly suggestive of a homing instinct, but also reveal that snail-throwing can work as a pest management strategy.
Sukang Bae et al 2012 Phys. Scr. 2012 014024
Since the first isolation of graphene in 2004 by mechanical exfoliation from graphite, many people have tried to synthesize large-scale graphene using various chemical methods. In particular, there has been a great number of advances in the synthesis of graphene using chemical vapor deposition (CVD) on metal substrates such as Ni and Cu. Recently, a method to synthesize ultra-large-scale (~30 inch) graphene films using roll-to-roll transfer and chemical doping processes was developed that shows excellent electrical and physical properties suitable for practical applications on a large scale. Considering the outstanding scalability/processibility of roll-to-roll and CVD methods as well as the extraordinary flexibility/conductivity of graphene films, we expect that transparent graphene electrodes can replace indium tin oxide in the near future.
Garry Robinson and Ian Robinson 2013 Phys. Scr. 88 018101
In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball.
Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results.
As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first year university students in physics and engineering and, with the guidance of teachers, good final year secondary school students. The trajectory results included may be useful to sporting personnel with no formal training in physics.
Seth D Baum 2014 Phys. Scr. 89 128004
Some emerging technologies promise to significantly improve the human condition, but come with a risk of failure so catastrophic that human civilization may not survive. This article discusses the great downside dilemma posed by the decision of whether or not to use these technologies. The dilemma is: use the technology, and risk the downside of catastrophic failure, or do not use the technology, and suffer through life without it. Historical precedents include the first nuclear weapon test and messaging to extraterrestrial intelligence. Contemporary examples include stratospheric geoengineering, a technology under development in response to global warming, and artificial general intelligence, a technology that could even take over the world. How the dilemma should be resolved depends on the details of each technology’s downside risk and on what the human condition would otherwise be. Meanwhile, other technologies do not pose this dilemma, including sustainable design technologies, nuclear fusion power, and space colonization. Decisions on all of these technologies should be made with the long-term interests of human civilization in mind. This paper is part of a series of papers based on presentations at the Emerging Technologies and the Future of Humanity event held at the Royal Swedish Academy of Sciences on 17 March 2014.
K S Novoselov and A H Castro Neto 2012 Phys. Scr. 2012 014006
Graphene is just one example of a large class of two-dimensional crystals. These crystals can either be extracted from layered three-dimensional materials or grown artificially by several different methods. Furthermore, they present physical properties that are unique because of the low dimensionality and their special crystal structure. They have potential for semiconducting behavior, magnetism, superconductivity, and even more complex many-body phenomena. Two-dimensional crystals can also be assembled in three-dimensional heterostructures that do not exist in nature and have tailored properties, opening an entirely new chapter in condensed matter research.
Roland E Allen and Suzy Lidström 2015 Phys. Scr. 90 028002
Fundamental physics, as exemplified by the recently discovered Higgs boson, often appears to be completely disconnected from practical applications and ordinary human life. But this is not really the case, because science, technology, and human affairs are profoundly integrated in ways that are not immediately obvious. We illustrate this by defining a ‘Higgs number’ through overlapping activities. Following three different paths, which end respectively in applications of the World Wide Web, digital photography, and all modern electronic devices, we find that most people have a Higgs number of no greater than 3.
T Brehm et al 2015 Phys. Scr. 90 035802
The electrorheological (ER) effect is known as the change in the apparent viscosity upon the application of an external electric field perpendicular to the flow direction. In this work we present the electrorheological behaviour of suspensions in silicone oil of two different dispersed phases: foams of liquid crystal 4-n-penthyl-4′-cyanobiphenyl (5CB) encapsulated in polyvinyl alcohol (PVA) and nano/microspheres of 5CB encapsulated in silica. We will present the viscosity curves under the application of an electric field ranging between 0 and 3 kV mm −1. The ER effect was observed for the suspensions of 5CB/PVA but not in the case of 5CB/silica. For the case of the suspensions of 5CB/PVA, the effect of the viscosity of the continuum phase and the concentration of the dispersed phase was analysed, showing that the enhancement of the viscosity of the suspension increases with the concentration, as expected, however the continuum phase viscosity has no significant effect, at least in the investigated viscosity range.
David A Keen 2014 Phys. Scr. 89 128003
X-ray crystallography was initiated by physicists in the early 20th century. However—as is common with many developments in physics—the subject quickly moved beyond the confines of physics to produce key advances in chemistry, biology, mineralogy and materials science. This article discusses the role of physics in developing crystallography over the last 100 years and the relevance of crystallography to physics today. It is concluded that although crystallography has become somewhat hidden within physics departments it is still a key component of modern condensed matter physics.
B Cameron Reed 2014 Phys. Scr. 89 108003
The Manhattan Project was the United States Army’s program to develop and deploy nuclear weapons during World War II. In these devices, which are known popularly as ‘atomic bombs’, energy is released not by a chemical explosion but by the much more violent process of fission of nuclei of heavy elements via a neutron-mediated chain-reaction. Three years after taking on this project in mid-1942, the Army’s Manhattan Engineer District produced three nuclear bombs of two different designs. Two of these devices were fueled with the 239 isotope of the synthetic element plutonium, while the third employed the rare 235 isotope of uranium. One of the plutonium devices, code-named Trinity, was detonated in a test in southern New Mexico on 16 July 1945; this was the world’s first nuclear explosion. Three weeks later, on 6 August, the uranium bomb, Little Boy, was dropped on the Japanese city of Hiroshima. On 9 August the second plutonium device, Fat Man, was dropped on Nagasaki. Together, the two bombings killed over 100 000 people and were at least partially responsible for the Japanese government’s 14 August decision to surrender. This article surveys, at an undergraduate level, the science and history of the Manhattan Project.