Showing papers in "Physics Today in 2006"
TL;DR: This book guides the reader from the basics of string theory to recent developments, before describing modern developments, including D-branes, string dualities and M-theory, and concludes with Matrix theory, the AdS/CFT duality and its generalizations.
Abstract: String theory is one of the most exciting and challenging areas of modern theoretical physics. This book guides the reader from the basics of string theory to recent developments. It introduces the basics of perturbative string theory, world-sheet supersymmetry, space-time supersymmetry, conformal field theory and the heterotic string, before describing modern developments, including D-branes, string dualities and M-theory. It then covers string geometry and flux compactifications, applications to cosmology and particle physics, black holes in string theory and M-theory, and the microscopic origin of black-hole entropy. It concludes with Matrix theory, the AdS/CFT duality and its generalizations. This book is ideal for graduate students and researchers in modern string theory, and will make an excellent textbook for a one-year course on string theory. It contains over 120 exercises with solutions, and over 200 homework problems with solutions available on a password protected website for lecturers at www.cambridge.org/9780521860697.
824 citations
TL;DR: The remarkable 14-order-of-magnitude signal enhancement that can occur during Raman scattering from molecules on metallic nanostructures turns the normally weak inelastic-scattering effect into a single-molecule spectroscopic probe as discussed by the authors.
Abstract: The remarkable 14-order-of-magnitude signal enhancement that can occur during Raman scattering from molecules on metallic nanostructures turns the normally weak inelastic-scattering effect into a single-molecule spectroscopic probe.
405 citations
TL;DR: General Relativity: An Introduction for Physicists as mentioned in this paper provides a clear mathematical introduction to Einstein's theory of general relativity and presents a wide range of applications of the theory, concentrating on its physical consequences.
Abstract: General Relativity: An Introduction for Physicists provides a clear mathematical introduction to Einstein's theory of general relativity. It presents a wide range of applications of the theory, concentrating on its physical consequences. After reviewing the basic concepts, the authors present a clear and intuitive discussion of the mathematical background, including the necessary tools of tensor calculus and differential geometry. These tools are then used to develop the topic of special relativity and to discuss electromagnetism in Minkowski spacetime. Gravitation as spacetime curvature is then introduced and the field equations of general relativity derived. After applying the theory to a wide range of physical situations, the book concludes with a brief discussion of classical field theory and the derivation of general relativity from a variational principle. Written for advanced undergraduate and graduate students, this approachable textbook contains over 300 exercises to illuminate and extend the discussion in the text.
370 citations
TL;DR: In this article, the authors present a general classification of intermolecular interactions: direct electrostatic interactions, resonance interactions, exchange interactions, and nonadditive effects in long-range interactions.
Abstract: Preface. 1 Background Knowledge. 1.1 The Subject and its Specificity. 1.2 A Brief Historical Survey. 1.3 The Concept of Interatomic Potential and Adiabatic Approximation. 1.4 General Classification of Intermolecular Interactions. References. 2 Types of Intermolecular Interactions: Qualitative Picture. 2.1 Direct Electrostatic Interactions. 2.2 Resonance Interaction. 2.3 Polarization Interactions. 2.4 Exchange Interaction. 2.5 Retardation Effects in Long-Range Interactions and the Influence of Temperature. 2.6 Relativistic (Magnetic) Interactions. 2.7 Interaction Between Macroscopic Bodies. References. 3 Calculation of Intermolecular Interactions. 3.1 Large Distances. 3.2 Intermediate and Short Distances. References. 4 Nonadditivity of Intermolecular Interactions. 4.1 Physical Nature of Nonadditivity and the Definition of Many-Body Forces. 4.2 Manifestations of Nonadditive Effects. 4.3 Perturbation Theory and Many-Body Decomposition. 4.4 Many-Body Effects in Atomic Clusters. 4.5 Atom-Atom Potential Scheme and Nonadditivity. References. 5 Model Potentials. 5.1 Semiempirical Model Potentials. 5.2 Determination of Parameters in Model Potentials. 5.3 Reconstructing Potentials on the Basis of Experimental Data. 5.4 Global Optimization Methods. References. Appendix 1: Fundamental Physical Constants and Conversion Table of Physical Units. Appendix 2: Some Necessary Mathematical Apparatus. A2.1 Vector and Tensor Calculus. A2.1.1 Definition of vector the addition law. A2.1.2 Scalar and vector products triple scalar product. A2.1.3 Determinants. A2.1.4 Vector analysis gradient, divergence and curl. A2.1.5 Vector spaces and matrices. A2.1.6 Tensors. A2.2 Group Theory. A2.2.1 Properties of group operations. A2.2.2 Representations of groups. A2.2.3 The permutation group. A2.2.4 The linear groups. The three-dimensional rotation group. A2.2.5 Point groups. A2.2.6 Irreducible tensor operators. Spherical tensors. References. Appendix 3: Methods of Quantum-Mechanical Calculations of Many-Electron Systems. A3.1 Adiabatic Approximation. A3.2 Variational Methods. A3.2.1 Self-consistent field method. A3.2.2 Methods taking into account the electron correlation. A3.2.2.1 r12-dependent wave functions. A3.2.2.2 Configuration interaction. A3.2.2.3 Coupled cluster method. A3.2.2.4 Density functional theory approach. A3.3 Perturbation Theory. A3.3.1 Rayleigh-Schr odinger perturbation theory. A3.3.2 Moller-Plesset perturbation theory. A3.3.3 Operator formalism and the Brillouin-Wigner perturbation theory. A3.3.4 Variational perturbation theory. A3.3.5 Asymptotic expansions Pade approximants. References. Index.
206 citations
TL;DR: In this paper, the authors identify universal properties of turbulence and relate them to broken symmetries, which confound any simple attempts to understand them, but physicists have succeeded in identifying some universal properties.
Abstract: Turbulent flows, with their irregular behavior, confound any simple attempts to understand them. But physicists have succeeded in identifying some universal properties of turbulence and relating them to broken symmetries.
190 citations
TL;DR: In this paper, the dynamical equations of water waves, viscosity, and vortices have been studied, and they include the following: 1. Water waves 2. Viscosity 3. Vortices 4. Instability 5. Turbulence 7. Drag and lift
Abstract: 1. The dynamical equations 2. Water waves 3. Viscosity 4. Vortices 5. Instability 6. Turbulence 7. Drag and lift
169 citations
TL;DR: Theoretical Models for Photonic Crystals- Models for Infinite Crystals - Models for Finite Crystals, Quasi-Crystals and Archimedean Tilings- Specific Features of Metallic Structures- Optical Properties of Photonic Crystal Fibres- Three-Dimensional Structures in Optics- Microwave and Terahertz Antennas and Circuits as discussed by the authors.
Abstract: Theoretical Models for Photonic Crystals- Models for Infinite Crystals- Models for Finite Crystals- Quasi-Crystals and Archimedean Tilings- Specific Features of Metallic Structures- Optical Properties of Photonic Crystals- Control of Electromagnetic Waves- Refractive Properties of Photonic Crystals and Metamaterials- Confinement of Light in Zero-Dimensional Microcavities- Nonlinear Optics with Photonic Crystals- Fabrication, Characterization and Applications of Photonic Bandgap Structures- Planar Integrated Optics- Microsources- Photonic Crystal Fibres- Three-Dimensional Structures in Optics- Microwave and Terahertz Antennas and Circuits- Conclusion and Perspectives
157 citations
TL;DR: To address the misconceptions that students typically hold concerning quantum mechanics, instructors should couple computer-based visualizations with research-based pedagogical strategies.
Abstract: To address the misconceptions that students typically hold concerning quantum mechanics, instructors should couple computer-based visualizations with research-based pedagogical strategies.
152 citations
TL;DR: As China implements its plan to improve scientific innovation, it will need to solve such political and economic problems as finding the proper balance between indigenous efforts and engagement with the global community as discussed by the authors.
Abstract: As China implements its plan to improve scientific innovation, it will need to solve such political and economic problems as finding the proper balance between indigenous efforts and engagement with the global community
TL;DR: The search for a large-scale, error-free quantum computer is reaching an intellectual junction at which semiconductor physics, knot theory, string theory, anyons, and quantum Hall effects are all coming together to produce quantum immunity as discussed by the authors.
Abstract: The search for a large-scale, error-free quantum computer is reaching an intellectual junction at which semiconductor physics, knot theory, string theory, anyons, and quantum Hall effects are all coming together to produce quantum immunity.
TL;DR: The role of water as reaction product, proton shuttle, and asphyxiant in fuel cells has been discussed in this paper, where the authors argue that fuel cells are to do for the 21st century what combustion engines did for the 19th and 20th.
Abstract: If fuel cells are to do for the 21st century what combustion engines did for the 19th and 20th, designers must wrestle with the complex role of water—as reaction product, proton shuttle, and asphyxiant.
TL;DR: In this article, the relativistic Dirac equation also describes how electrons move in a unique two-dimensional condensed matter system, graphene, and is used to describe the dynamics of the electron motion in the system.
Abstract: Traditionally found in particle-physics and cosmology contexts, the relativistic Dirac equation also describes how electrons move in a unique two-dimensional condensed matter system, graphene.
TL;DR: Problems at the interface between biology and physics offer unique opportunities for physicists to make quantitative contributions to biology and enrich the discipline of physics by challenging its practitioners to think in new ways.
Abstract: Problems at the interface between biology and physics offer unique opportunities for physicists to make quantitative contributions to biology. Equally important, they enrich the discipline of physics by challenging its practitioners to think in new ways.
TL;DR: Two centuries after seminal work by Pierre-Simon Laplace and Thomas Young, capillarity's modern applications arise in fields ranging from biology and oceanography to propulsion, materials science, and novel devices as mentioned in this paper.
Abstract: Two centuries after seminal work by Pierre-Simon Laplace and Thomas Young, capillarity’s modern applications arise in fields ranging from biology and oceanography to propulsion, materials science, and novel devices.
TL;DR: The chemical and physical interactions of radioactive compounds are key to understanding how they can contaminate the environment and, more importantly, how best to remove them as mentioned in this paper, which is the most relevant work to ours.
Abstract: The chemical and physical interactions of radioactive compounds are key to understanding how they can contaminate the environment and, more importantly, how best to remove them.
TL;DR: Frayling as mentioned in this paper explored the genealogy of the film scientist in films made in Western Europe, and especially in Hollywood after the 1930s, showing how in film the scientist has often been used to represent the prevailing phobias of the time In the 1950s, films were dominated by the fear of botched atomic research, and were a showcase of mutated, outsized creatures and radioactive zombies.
Abstract: Since its origin cinema has had an uneasy relationship with science and technology: scientists are almost always impossibly mad or impossibly saintly, and technology is nearly always very bad for you In "Mad, Bad and Dangerous", Christopher Frayling explores the genealogy of the film scientist in films made in Western Europe, and especially in Hollywood after the 1930s, showing how in film the scientist has often been used to represent the prevailing phobias of the time In the 1950s, for example, films were dominated by the fear of botched atomic research, and were a showcase of mutated, outsized creatures and radioactive zombies Since Hitchcock's "The Birds", however, the role of the scientist has been less straightforward, and by the 1970s damage to the environment and the spread of diseases were the predominant consequences of science gone wrong Scientists - and the corporations that controlled them - became the 'baddies' The author also examines in parallel the portrayal of real-life scientists in the movies, noting how they are in the main depicted as misfits, immersed in their work, sacrificing any normal life to the interests of science, yet distrusted by the scientific establishment Interestingly, the cinematic portrayal of fictional and real-life scientists follow very similar dramatic conventions, and Frayling concludes that the mad scientist and the saintly one are two sides of the same Hollywood coin
TL;DR: The form and chemical composition of their lavas add to our growing understanding of where on Earth volcanoes can form as discussed by the authors and how they form and evolve over the course of their lifetime.
Abstract: The form and chemical composition of their lavas add to our growing understanding of where on Earth volcanoes can form.
TL;DR: The axion is a hypothetical particle with a mass possibly a trillion times lighter than an electron and exceedingly small couplings to ordinary matter as discussed by the authors, and experiments may soon detect its presence, either as dark matter or as a component of solar flux.
Abstract: The axion is a hypothetical particle with a mass possibly a trillion times lighter than an electron and exceedingly small couplings to ordinary matter. Yet experiments may soon detect its presence, either as dark matter or as a component of solar flux.
TL;DR: The atomic force microscope has gradually evolved into an instrument whose spatial resolution is now fine enough to image subatomic features on the scale of picometers as mentioned in this paper, and it has been used to perform a variety of experiments.
Abstract: Over its 20-year history, the atomic force microscope has gradually evolved into an instrument whose spatial resolution is now fine enough to image subatomic features on the scale of picometers.
TL;DR: Greenhouse gases make Earth’s surface hotter than it would be if the planet were simply a blackbody radiator as mentioned in this paper and that additional warming is an important driver of hurricanes.
Abstract: Greenhouse gases make Earth’s surface hotter than it would be if the planet were simply a blackbody radiator. That additional warming is an important driver of hurricanes.
TL;DR: In a recent article as discussed by the authors, the authors discuss the future of time itself and the need to say farewell to leap seconds, which are the occasional one-second adjustments of our clocks that are made to maintain harmony between the astronomical and atomic time scales.
Abstract: W wishing to cause unnecessary distress, I would like to call attention to a couple of issues concerning time. The first is merely calendraic but the second concerns the future of time itself. The first issue is that we may have to say farewell to leap seconds. Leap seconds, as you might recall, are the occasional one-second adjustments of our clocks that are made to maintain harmony between the astronomical and atomic time scales. Personally, I would be sorry to see leap seconds go because that would cost me the pleasure of mulling over the best way to spend my next one. Although a mere second might seem to be too short to cause jubilation, I believe any gift of time deserves to be treasured. Also, one second is not really that short. It is long enough to record a few million high-energy scattering events, and in femtosecond physics, one second is virtually an eternity. Also, one second is sufficient for a word or quick kiss that might change your life. The argument about whether to retain leap seconds is reminiscent of the argument about standard time versus daylight savings time: What is convenient for one community can be inconvenient for another. City dwellers generally favor daylight savings time and farmers generally oppose it. Astronomers favor leap seconds because they keep clocks in synchrony with the orientation of the Earth. Synchronization is helpful in deciding where to point telescopes and in interpreting the data in astronomical records. Celestial navigators—that vanishing breed—also like leap seconds. The Global Positioning System, however, cannot tolerate time jumps and employs a time scale that avoids leap seconds. Moreover, all large-scale systems that require precise synchronization are likely to have trouble with leap seconds. For instance, any attempt to introduce a one-second hiccup in the phasing of North American power grids would likely cause a hemispheric blackout.
TL;DR: Franklin's work on electricity and lightning earned him worldwide fame and respect as mentioned in this paper,ideal assets for brokering aid from France during the American Revolution, and his work on lightning and electricity became a symbol of dynamism and dynamism.
Abstract: Franklin’s work on electricity and lightning earned him worldwide fame and respect—ideal assets for brokering aid from France during the American Revolution.
TL;DR: The need to augment Newtonian mechanics to encompass systems more complex than collections of point masses engendered a century-long dispute about conservation principles as discussed by the authors, leading to the need for conservation principles.
Abstract: The need to augment Newtonian mechanics to encompass systems more complex than collections of point masses engendered a century-long dispute about conservation principles.
TL;DR: Light trucks cannot safely coexist with passenger cars under existing conditions as mentioned in this paper, and the problem becomes particularly urgent as more and more light trucks are used simply as car substitutes, which makes it difficult for them to be used as transportation vehicles.
Abstract: Light trucks cannot safely coexist with passenger cars under existing conditions. The problem becomes particularly urgent as more and more light trucks are used simply as car substitutes.