Showing papers in "Physics Today in 2007"
TL;DR: Just one atom thick, this two-dimensional semiconductor does not resemble any known material as mentioned in this paper, and it has been shown that it can be used as a semiconductor for medical applications.
Abstract: Just one atom thick, this two-dimensional semiconductor does not resemble any known material.
739 citations
TL;DR: In this article, the need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience, and they must have efficient ways to convert photons into electricity, fuel, and heat.
Abstract: If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience.
618 citations
288 citations
TL;DR: The first full biography of Albert Einstein since all of his papers have become available was published by the author of the acclaimed bestseller "Benjamin Franklin" as mentioned in this paper, who explored how an imaginative, impertinent patent clerk became the mind reader of the creator of the cosmos, the locksmith of the mysteries of the atom and the universe.
Abstract: By the author of the acclaimed bestseller 'Benjamin Franklin', this is the first full biography of Albert Einstein since all of his papers have become available. How did his mind work? What made him a genius? Isaacson's biography shows how his scientific imagination sprang from the rebellious nature of his personality. His fascinating story is a testament to the connection between creativity and freedom. Based on newly released personal letters of Einstein, this book explores how an imaginative, impertinent patent clerk - a struggling father in a difficult marriage who couldn't get a teaching job or a doctorate - became the mind reader of the creator of the cosmos, the locksmith of the mysteries of the atom and the universe. His success came from questioning conventional wisdom and marveling at mysteries that struck others as mundane. This led him to embrace a morality and politics based on respect for free minds, free spirits, and free individuals. These traits are just as vital for this new century of globalization, in which our success will depend on our creativity, as they were for the beginning of the last century, when Einstein helped usher in the modern age.
266 citations
208 citations
TL;DR: The vapor-cell atomic clock finds application today in the global positioning system and telecommunications as discussed by the authors, and to improve and miniaturize the humble device for future applications will require a deeper understanding of atomic and chemical physics.
Abstract: The vapor-cell atomic clock finds application today in the global positioning system and telecommunications. To improve and miniaturize the humble device for future applications will require a deeper understanding of atomic and chemical physics.
180 citations
TL;DR: Topological defects, such as vortices and flux tubes, that arise during phase transitions in condensed-matter systems can serve as models for a far more elusive defect, cosmic strings formed in the early universe.
Abstract: Topological defects, such as vortices and flux tubes, that arise during phase transitions in condensed-matter systems can serve as models for a far more elusive defect—cosmic strings formed in the early universe.
151 citations
TL;DR: The once startling idea of a connection between quantum fluctuations and forces has by now been applied throughout physics as mentioned in this paper, but experimentalists and theorists alike still find challenges in the Casimir force.
Abstract: The once startling idea of a connection between quantum fluctuations and forces has by now been applied throughout physics. Nonetheless, experimentalists and theorists alike still find challenges in the Casimir force.
108 citations
107 citations
TL;DR: In this article, a window on the peculiar world of quantum mechanics is provided by electron confinement in ultrathin metal films, and the authors describe the process of quantum entanglement.
Abstract: Electrons confined in ultrathin metal films provide a window on the peculiar world of quantum mechanics.
100 citations
TL;DR: Icy solids in Earth's permafrost and deep ocean basins store an enormous reservoir of natural gas, and scientists' efforts to synthesize related molecular-storage compounds may help solve our energy problems as mentioned in this paper.
Abstract: Icy solids in Earth's permafrost and deep ocean basins store an enormous reservoir of natural gas. That reservoir, and scientists' efforts to synthesize related molecular-storage compounds, may help solve our energy problems.
TL;DR: Orientationally ordered soft matter is exceptionally responsive to a variety of excitations as discussed by the authors, and that is the basis for its great range of applications, such as medical applications and computer vision.
Abstract: Orientationally ordered soft matter is exceptionally responsive to a variety of excitations. That’s the basis for its great range of applications.
TL;DR: In this article, it was shown that at high temperatures, the ratio of shear stress to shear flow in the limit of vanishingly small driving force is proportional to exp (ΔE/kBT) with a temperature independent ΔE.
Abstract: © 2007 American Institute of Physics, S-0031-9228-0702-210-7 Often, when we physicists ask the right questions, we realize that even the most commonplace parts of our world remain deeply puzzling. In its 125th anniversary issue, Science magazine asked many such questions.1 My eye was caught by, “What is the nature of the glassy state? . . . Where and why does liquid end and glass begin?” I chuckled, partly because I knew the editors had made a perceptive choice, but also because I had just wandered inadvertently into that field of research and was beginning to appreciate its depth and subtlety. I also was learning that glass physics is a highly contentious subject—a sure sign that there is still a lot to learn about it. My curiosity-driven excursion through glass physics started more than a decade ago with fracture and earthquake dynamics. I decided to look at amorphous solids because I thought their liquidlike structure would make them easier to understand than crystals; I would have no dislocations or grain boundaries to worry about. Then I moved from fracture to plasticity because I wanted to understand how molecules rearrange themselves near advancing crack tips; so I found myself in the mysterious world of glass dynamics. A molten glass doesn’t suddenly solidify when cooled; it gradually becomes more and more viscous. If we put a drop of sufficiently hot molten glass on a flat surface, it quickly spreads like a liquid. A drop ten degrees or so cooler does the same thing but may take minutes or hours. If we cool it more, it will retain its shape for years or centuries, or perhaps for longer than the age of the universe. We ought to understand what is happening here—but we don’t. We don’t know what kind of transformation occurs when a liquid becomes a glass or even whether that familiar change of state is actually a thermodynamic phase transition like condensation or solidification, or something completely different. Consider a supercooled, glassforming liquid that somehow has escaped crystallization, and assume that this liquid consists of molecules interacting only via short-ranged forces. Those forces must be such that longrange crystalline order is frustrated; that is, the energetically preferred local arrangements of the molecules don’t fit neatly together to fill all space in a periodic array. As a result, the molecular structure of the system resembles a liquid even at low enough temperatures that the material behaves like a solid. Now forget about complicated phenomena such as fracture. Instead, think about simple linear viscosity, in other words, the ratio of shear stress to shear flow in the limit of vanishingly small driving force. Irreversible motion of this kind, as opposed to reversible elastic deformation, requires molecules to change positions relative to one another. At low temperatures T, the rearrangements must be thermally activated. The energy barrier that they must overcome to move around each other, say ΔE, is larger than kBT, where kB is Boltzmann’s constant; thus the predicted viscosity has what is called an Arrhenius form, which means it is proportional to exp (ΔE/kBT) with a temperature-independent ΔE. At yet lower temperatures, say T less than some TA, an Arrhenius fit to the viscosity requires that ΔE grows with decreasing T and appears to become infinite at some nonzero temperature T0. Below T0, the material seems to be completely frozen, so much so that it is in a state of “broken ergodicity,” which means it violates Josiah Willard Gibbs’s assumption that such systems explore statistically significant fractions of their possible states on experimental time scales. Indeed, apart from the thermal jiggling of molecules in their local environments, the glassy molecular configurations seem to be stuck forever near just one of those configurational states. How can that happen? And what is happening at higher temperatures between T0 and TA? Apparently, as T falls below TA, increasingly large cooperative motions requiring increasing activation energies ΔE are needed to achieve local rearrangements. What are those motions? What features of the molecular dynamics are responsible for such behavior?
TL;DR: A self-contained introduction to quantum information and computation for physicists, mathematicians and computer scientists can be found in this paper, where a step-by-step introduction to the quantum bit (qubit) and its main properties are presented.
Abstract: Quantum information and computation is a rapidly expanding and cross-disciplinary subject. This book, first published in 2006, gives a self-contained introduction to the field for physicists, mathematicians and computer scientists who want to know more about this exciting subject. After a step-by-step introduction to the quantum bit (qubit) and its main properties, the author presents the necessary background in quantum mechanics. The core of the subject, quantum computation, is illustrated by a detailed treatment of three quantum algorithms: Deutsch, Grover and Shor. The final chapters are devoted to the physical implementation of quantum computers, including the most recent aspects, such as superconducting qubits and quantum dots, and to a short account of quantum information. Written at a level suitable for undergraduates in physical sciences, no previous knowledge of quantum mechanics is assumed, and only elementary notions of physics are required. The book includes many short exercises, with solutions available to instructors through solutions@cambridge.org.
TL;DR: Stately dolphins and flittering bats both use biosonar for navigating and for catching prey, but the details of their echolocation systems have evolved to reflect their different physiologies and environments.
Abstract: Stately dolphins and flittering bats both use biosonar for navigating and for catching prey. The details of their echolocation systems, though, have evolved to reflect their different physiologies and environments.
TL;DR: A 1931 result that lay in obscurity for decades, Bethe's solution to a quantum mechanical model now finds its way into everything from superconductors to string theory as discussed by the authors, and it has been used in many applications.
Abstract: A 1931 result that lay in obscurity for decades, Bethe’s solution to a quantum mechanical model now finds its way into everything from superconductors to string theory.
TL;DR: In this paper, GLS can reveal the fine structure of such features as faults, landslides, and drainage patterns, and produce surface maps at sub-meter resolution, even over heavily forested terrain.
Abstract: Producing surface maps at submeter resolution, even over heavily forested terrain, GLS can reveal the fine structure of such features as faults, landslides, and drainage patterns.
TL;DR: Greenberg's "Science for Sale" as mentioned in this paper reveals that campus capitalism is more complicated and less profitable than media reports would suggest, and that the temptations of money will always be a threat, and they can only be countered through the vigilance of scientists, the press, and the public.
Abstract: In recent years, the news media have been awash in stories about increasingly close ties between college campuses and multimillion-dollar corporations. Our nation's universities, the story goes, reap enormous windfalls patenting products of scientific research that have been primarily funded by taxpayers. Meanwhile, hoping for new streams of revenue from their innovations, the same universities are allowing their research - and their very principles - to become compromised by quests for profit. But is that really the case? Is money really hopelessly corrupting science? With "Science for Sale", acclaimed journalist Daniel S. Greenberg reveals that campus capitalism is more complicated - and less profitable - than media reports would suggest. While universities seek out corporate funding, news stories rarely note that those industry dollars are dwarfed by government support and other funds. And, while many universities have set up technology transfer offices to pursue profits through patents, many of those offices have been financial busts. Meanwhile, science is showing signs of providing its own solutions, as highly publicized misdeeds in pursuit of profits have provoked promising countermeasures within the field. But just because the threat is overhyped, Greenberg argues, doesn't mean that there's no danger. From research that has shifted overseas so corporations can avoid regulations to conflicts of interest in scientific publishing, the temptations of money will always be a threat, and they can only be countered through the vigilance of scientists, the press, and the public. Based on extensive, candid interviews with scientists and administrators, "Science for Sale" will be indispensable to anyone who cares about the future of scientific research.
TL;DR: In this paper, a new set of recommended values of the basic constants and conversion factors of physics and chemistry has been published, which is based on the results of a recent survey.
Abstract: Incorporating recent data, a new set of recommended values of the basic constants and conversion factors of physics and chemistry has just been issued.
TL;DR: The field of surface physics is evolving to include molecular-scale studies of nanoparticle surfaces, as well as single-crystal surfaces in contact with liquids or high-pressure gases as discussed by the authors.
Abstract: The field of surface physics is evolving to include molecular-scale studies of nanoparticle surfaces, as well as single-crystal surfaces in contact with liquids or high-pressure gases.
TL;DR: Applying the techniques of nonlinear dynamics to cardiac arrhythmias sheds light on their genesis and suggests new strategies for preventing them.
Abstract: Applying the techniques of nonlinear dynamics to cardiac arrhythmias sheds light on their genesis and suggests new strategies for preventing them.
TL;DR: Three-dimensional mapping of starling flocks could shed light not only on the birds' collective behavior but also on a broad range of other aggregate systems as mentioned in this paper. But it is difficult to obtain a detailed 3D model of the starling population.
Abstract: Three-dimensional mapping of starling flocks could shed light not only on the birds' collective behavior but also on a broad range of other aggregate systems.
TL;DR: In this article, the authors present a representation of quantum states in phase space, where the environment is watching and the quantum state states are represented as a set of points in a box.
Abstract: 1. Unveiling the quantum 2. Strangeness and power of the quantum 3. Of spins and springs 4. The environment is watching 5. Photons in a box 6. Seeing light in subtle ways 7. Taming Schrodinger's cats 8. Atoms in a box 9. Entangling matter waves Appendix: Representation of quantum states in phase space
TL;DR: In this paper, a set of structural and dynamical problems combining physics and geometry are studied for deforming thin surfaces, and the authors propose a solution to each of them by combining geometry and physics.
Abstract: Deforming thin surfaces creates a rich set of structural and dynamical problems combining physics and geometry.
TL;DR: A newly synthesized mineral is perhaps the most promising material yet to realize a hypothetical state with exotic behavior as mentioned in this paper, and it has been shown to be a promising material for many applications.
Abstract: A newly synthesized mineral is perhaps the most promising material yet to realize a hypothetical state with exotic behavior.
TL;DR: It's coming again, the new collection that this site has, and the favorite an introduction to systems biology design principles of biological circuits book as the choice today.
Abstract: It's coming again, the new collection that this site has. To complete your curiosity, we offer the favorite an introduction to systems biology design principles of biological circuits book as the choice today. This is a book that will show you even new to old thing. Forget it; it will be right for you. Well, when you are really dying of an introduction to systems biology design principles of biological circuits, just pick it. You know, this book is always making the fans to be dizzy if not to find.
TL;DR: The physics of water beneath Earth's surface is the basis of groundwater hydrology, a multifaceted discipline that continues to challenge theorists and experimentalists alike as mentioned in this paper, and it has been studied as early as the mid-19th century.
Abstract: Studied as early as the mid-19th century, the physics of water beneath Earth's surface is the basis of groundwater hydrology, a multifaceted discipline that continues to challenge theorists and experimentalists alike.
TL;DR: In this paper, the world in a Grain of Sand in the Space of All Possible Theories is described as a "world in a grain of sand in the space of all possible theories".
Abstract: What Makes the World Tick Electromagnetism The Vacuum Is the Medium Let There Be Light Heroic Age: The Struggle for Quantum Theory Quantum Reality What Is Charge? The Zen of Rotation Yang-Mills Field: Non-Commuting Charges Photons Real and Virtual Creation and Annihilation The Dynamical Vacuum Elementary Particles The Fall of Parity The Explosion of Particles Quarks All Interactions Are Local Broken Symmetry Quark Confinement Hanging Threads of Silk The World in a Grain of Sand In the Space of All Possible Theories.