Louis A. Girifalco
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780199228966
- eISBN:
- 9780191711183
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199228966.003.0008
- Subject:
- Physics, History of Physics
Modern science could not advance until the ideas of force and mass were understood. Newton provided this understanding by stressing the role of momentum and by creating his three laws of motion. But ...
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Modern science could not advance until the ideas of force and mass were understood. Newton provided this understanding by stressing the role of momentum and by creating his three laws of motion. But notions were not rigorously based and left much undefined until Mach gave a detailed operational method for defining mass and force. Newton's genius and insight was illustrated by the fact that he got everything right in spite of this. When force and mass were examined with rigorous logic, they were found to be in accord with Newton's intuition.Less
Modern science could not advance until the ideas of force and mass were understood. Newton provided this understanding by stressing the role of momentum and by creating his three laws of motion. But notions were not rigorously based and left much undefined until Mach gave a detailed operational method for defining mass and force. Newton's genius and insight was illustrated by the fact that he got everything right in spite of this. When force and mass were examined with rigorous logic, they were found to be in accord with Newton's intuition.
Mia de Kuijper
- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780195171631
- eISBN:
- 9780199871353
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195171631.003.0021
- Subject:
- Economics and Finance, Macro- and Monetary Economics
Looking for underlying drivers to make sense of the present and to foretell the future is a time-tested trick. That is why this chapter (and the book, in various other places) quotes Virgil's Aeneid, ...
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Looking for underlying drivers to make sense of the present and to foretell the future is a time-tested trick. That is why this chapter (and the book, in various other places) quotes Virgil's Aeneid, a 2000-year-old story about underlying drivers and inevitable trends. Like Virgil's Romans, we are in tempestuous circumstances. Humanity has often found itself in situations of rapid change before. And has learned that, with hindsight, the underlying drivers and the changes they caused were very clear. As largely unforeseen changes roil companies, industries, global economies and financial markets, it is possible to step back right now, in the midst of tumult, and discern the patterns that will later seem obvious with hindsight. Like Virgil, this book has argued that only by understanding the underlying forces can we recognize the source of power within a new era. And only then can we successfully profit from the momentum that these forces create. That is the logic flow of this book. Readers can benefit, right now, from applying this understanding to better anticipate the effects of transparency and to maximize returns for their companies or shareholders, and even to enhance the returns on their own human capital as well.Less
Looking for underlying drivers to make sense of the present and to foretell the future is a time-tested trick. That is why this chapter (and the book, in various other places) quotes Virgil's Aeneid, a 2000-year-old story about underlying drivers and inevitable trends. Like Virgil's Romans, we are in tempestuous circumstances. Humanity has often found itself in situations of rapid change before. And has learned that, with hindsight, the underlying drivers and the changes they caused were very clear. As largely unforeseen changes roil companies, industries, global economies and financial markets, it is possible to step back right now, in the midst of tumult, and discern the patterns that will later seem obvious with hindsight. Like Virgil, this book has argued that only by understanding the underlying forces can we recognize the source of power within a new era. And only then can we successfully profit from the momentum that these forces create. That is the logic flow of this book. Readers can benefit, right now, from applying this understanding to better anticipate the effects of transparency and to maximize returns for their companies or shareholders, and even to enhance the returns on their own human capital as well.
Robin Devenish and Amanda Cooper-Sarkar
- Published in print:
- 2003
- Published Online:
- January 2010
- ISBN:
- 9780198506713
- eISBN:
- 9780191709562
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198506713.001.0001
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
The book provides a self-contained account of deep inelastic scattering (DIS) in high energy physics. It covers the classic results that lead to the quark-parton model of hadrons and the ...
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The book provides a self-contained account of deep inelastic scattering (DIS) in high energy physics. It covers the classic results that lead to the quark-parton model of hadrons and the establishment of quantum chromodynamics (QCD), through to the new vistas in the subject opened up by the electron-proton collider HERA. The extraction of parton momentum distribution functions, a key input for physics at hadron colliders such as the Tevatron and Large Hadron Collider (LHC), is described in detail. The challenges of the HERA data at low-x are described, and possible explanations in terms of gluon dynamics outlined. Other chapters cover: jet production at large momentum transfer and the determination of the strong coupling constant; electroweak probes at very high momentum transfers; the extension of deep inelastic techniques to include hadronic probes; a summary of fully polarised inelastic scattering and the spin structure of the nucleon; and a brief account of methods for searching for signals ‘beyond the standard model’.Less
The book provides a self-contained account of deep inelastic scattering (DIS) in high energy physics. It covers the classic results that lead to the quark-parton model of hadrons and the establishment of quantum chromodynamics (QCD), through to the new vistas in the subject opened up by the electron-proton collider HERA. The extraction of parton momentum distribution functions, a key input for physics at hadron colliders such as the Tevatron and Large Hadron Collider (LHC), is described in detail. The challenges of the HERA data at low-x are described, and possible explanations in terms of gluon dynamics outlined. Other chapters cover: jet production at large momentum transfer and the determination of the strong coupling constant; electroweak probes at very high momentum transfers; the extension of deep inelastic techniques to include hadronic probes; a summary of fully polarised inelastic scattering and the spin structure of the nucleon; and a brief account of methods for searching for signals ‘beyond the standard model’.
Martin Schöneld
- Published in print:
- 2000
- Published Online:
- May 2006
- ISBN:
- 9780195132182
- eISBN:
- 9780199786336
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0195132181.003.0003
- Subject:
- Philosophy, History of Philosophy
This chapter explores the text and contentions of Kant’s first book, Thoughts on the True Estimation of Living Forces (1747). Section 1 describes how Kant’s debut turned into a debacle. Section 2 ...
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This chapter explores the text and contentions of Kant’s first book, Thoughts on the True Estimation of Living Forces (1747). Section 1 describes how Kant’s debut turned into a debacle. Section 2 discusses Kant’s dynamic ontology, such as his ideas on substantial interaction and energetic space. Section 3 analyzes Kant’s experimental and kinematic appraisals, which form the bulk of his first book. Section 4 describes Kant’s proposed synthesis of Cartesian momentum and Leibnizian energy as “true estimation” of force.Less
This chapter explores the text and contentions of Kant’s first book, Thoughts on the True Estimation of Living Forces (1747). Section 1 describes how Kant’s debut turned into a debacle. Section 2 discusses Kant’s dynamic ontology, such as his ideas on substantial interaction and energetic space. Section 3 analyzes Kant’s experimental and kinematic appraisals, which form the bulk of his first book. Section 4 describes Kant’s proposed synthesis of Cartesian momentum and Leibnizian energy as “true estimation” of force.
Gary A. Glatzmaier
- Published in print:
- 2013
- Published Online:
- October 2017
- ISBN:
- 9780691141725
- eISBN:
- 9781400848904
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691141725.003.0001
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
This chapter presents a model of Rayleigh–Bénard convection. It first describes the fundamental dynamics expected in a fluid that is convectively stable and in one that is convectively unstable, ...
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This chapter presents a model of Rayleigh–Bénard convection. It first describes the fundamental dynamics expected in a fluid that is convectively stable and in one that is convectively unstable, focusing on thermal convection and internal gravity waves. Thermal convection and internal gravity waves are the two basic types of fluid flows within planets and stars that are driven by thermally produced buoyancy forces. The chapter then reviews the equations that govern fluid dynamics based on conservation of mass, momentum, and energy. It also examines the conditions under which the Boussinesq approximation simplifies conservation equations to a form very similar to that of an incompressible fluid. Finally, it discusses the key characteristics of the model of Rayleigh–Bénard convection.Less
This chapter presents a model of Rayleigh–Bénard convection. It first describes the fundamental dynamics expected in a fluid that is convectively stable and in one that is convectively unstable, focusing on thermal convection and internal gravity waves. Thermal convection and internal gravity waves are the two basic types of fluid flows within planets and stars that are driven by thermally produced buoyancy forces. The chapter then reviews the equations that govern fluid dynamics based on conservation of mass, momentum, and energy. It also examines the conditions under which the Boussinesq approximation simplifies conservation equations to a form very similar to that of an incompressible fluid. Finally, it discusses the key characteristics of the model of Rayleigh–Bénard convection.
Alan Corney
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780199211456
- eISBN:
- 9780191705915
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199211456.003.0003
- Subject:
- Physics, Atomic, Laser, and Optical Physics
This chapter derives the quantum mechanical wave functions which describe the energy levels of simple atoms. Schrödinger's equation is introduced as well and the angular part of the equation is ...
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This chapter derives the quantum mechanical wave functions which describe the energy levels of simple atoms. Schrödinger's equation is introduced as well and the angular part of the equation is solved for spherically symmetric potentials. The orbital angular momentum operator is defined and the concept of intrinsic spin is introduced. The extension of these results to atoms with several electrons using the central-field approximation is introduced. Spectroscopic notation for Russell-Saunders coupling is discussed.Less
This chapter derives the quantum mechanical wave functions which describe the energy levels of simple atoms. Schrödinger's equation is introduced as well and the angular part of the equation is solved for spherically symmetric potentials. The orbital angular momentum operator is defined and the concept of intrinsic spin is introduced. The extension of these results to atoms with several electrons using the central-field approximation is introduced. Spectroscopic notation for Russell-Saunders coupling is discussed.
Gary E. Bowman
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780199228928
- eISBN:
- 9780191711206
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199228928.003.0008
- Subject:
- Physics, Condensed Matter Physics / Materials
Angular momentum is one of the more abstract topics in quantum mechanics. This chapter begins with a review of classical angular momentum. Quantum-mechanical angular momentum is then introduced by ...
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Angular momentum is one of the more abstract topics in quantum mechanics. This chapter begins with a review of classical angular momentum. Quantum-mechanical angular momentum is then introduced by obtaining operators from their classical counterparts. The commutation relations amongst those operators and the corresponding uncertainty relations then follow. Eigenstates and eigenvalues of the angular momentum operators are then introduced (but not derived). From these follow the raising and lowering operators. Physical meaning is imparted to quantum angular momentum by considering predictions for sequential measurements, and by comparing the conceptual pictures of angular momentum in classical and quantum mechanics. Finally, quantum spin and orbital angular momenta, and the deep differences between them, are discussed.Less
Angular momentum is one of the more abstract topics in quantum mechanics. This chapter begins with a review of classical angular momentum. Quantum-mechanical angular momentum is then introduced by obtaining operators from their classical counterparts. The commutation relations amongst those operators and the corresponding uncertainty relations then follow. Eigenstates and eigenvalues of the angular momentum operators are then introduced (but not derived). From these follow the raising and lowering operators. Physical meaning is imparted to quantum angular momentum by considering predictions for sequential measurements, and by comparing the conceptual pictures of angular momentum in classical and quantum mechanics. Finally, quantum spin and orbital angular momenta, and the deep differences between them, are discussed.
Thomas J. Sargent
- Published in print:
- 2013
- Published Online:
- October 2017
- ISBN:
- 9780691158709
- eISBN:
- 9781400847648
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691158709.003.0003
- Subject:
- Economics and Finance, Economic History
This chapter examines several dramatic historical experiences that are consistent with the “rational expectations” view but that seem difficult to reconcile with the “momentum” model of inflation. ...
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This chapter examines several dramatic historical experiences that are consistent with the “rational expectations” view but that seem difficult to reconcile with the “momentum” model of inflation. The idea is to identify the measures that successfully brought drastic inflations under control in several European countries in the 1920s, namely: Austria, Hungary, Germany, and Poland, all of which experienced a dramatic “hyperinflation” in which, after the passage of several months, price indexes assumed astronomical proportions. The experience of Czechoslovakia is also considered. Within each of Austria, Hungary, Poland, and Germany, there occurred a dramatic change in the fiscal policy regime, which in each instance was associated with the end of a hyperinflation. Czechoslovakia deliberately adopted a relatively restrictive fiscal policy regime in order to maintain the value of its currency.Less
This chapter examines several dramatic historical experiences that are consistent with the “rational expectations” view but that seem difficult to reconcile with the “momentum” model of inflation. The idea is to identify the measures that successfully brought drastic inflations under control in several European countries in the 1920s, namely: Austria, Hungary, Germany, and Poland, all of which experienced a dramatic “hyperinflation” in which, after the passage of several months, price indexes assumed astronomical proportions. The experience of Czechoslovakia is also considered. Within each of Austria, Hungary, Poland, and Germany, there occurred a dramatic change in the fiscal policy regime, which in each instance was associated with the end of a hyperinflation. Czechoslovakia deliberately adopted a relatively restrictive fiscal policy regime in order to maintain the value of its currency.
Thomas J. Sargent
- Published in print:
- 2013
- Published Online:
- October 2017
- ISBN:
- 9780691158709
- eISBN:
- 9781400847648
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691158709.003.0004
- Subject:
- Economics and Finance, Economic History
This chapter examines the methods adopted by British Prime Minister Margaret Thatcher and her French counterpart Raymond Poincaré to reduce the rate of inflation. Advocates of the two main groups of ...
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This chapter examines the methods adopted by British Prime Minister Margaret Thatcher and her French counterpart Raymond Poincaré to reduce the rate of inflation. Advocates of the two main groups of contemporary theories about inflation dynamics could have told Mrs. Thatcher that achieving that goal would be difficult. The first group consists of the “momentum” or “core inflation” theories, while the second group comprises the rational expectations-equilibrium theories. The chapter first provides an overview of the so-called Poincaré miracle before discussing Mrs. Thatcher's plan. It then considers the nature of the British government deficit, along with Britain's prospective revenues from North Sea oil that coincided with a simultaneous appreciation of the pound sterling. Finally, it compares Mrs. Thatcher's policies with respect to the coordination of monetary and fiscal policy with those of U.S. President Ronald Reagan.Less
This chapter examines the methods adopted by British Prime Minister Margaret Thatcher and her French counterpart Raymond Poincaré to reduce the rate of inflation. Advocates of the two main groups of contemporary theories about inflation dynamics could have told Mrs. Thatcher that achieving that goal would be difficult. The first group consists of the “momentum” or “core inflation” theories, while the second group comprises the rational expectations-equilibrium theories. The chapter first provides an overview of the so-called Poincaré miracle before discussing Mrs. Thatcher's plan. It then considers the nature of the British government deficit, along with Britain's prospective revenues from North Sea oil that coincided with a simultaneous appreciation of the pound sterling. Finally, it compares Mrs. Thatcher's policies with respect to the coordination of monetary and fiscal policy with those of U.S. President Ronald Reagan.
Helmut Hofmann
- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780198504016
- eISBN:
- 9780191708480
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198504016.003.0010
- Subject:
- Physics, Nuclear and Plasma Physics
Based on the Darwin-Fowler approximation various models for the many-body level density Ω are introduced, critically examined, and confronted with empirical parameterizations. This concerns both the ...
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Based on the Darwin-Fowler approximation various models for the many-body level density Ω are introduced, critically examined, and confronted with empirical parameterizations. This concerns both the macroscopic limit as well as the case where shell effects are included. Interpretations in the spirit of thermostatics are given. Implications for the use of the temperature concept and of the canonical ensemble are discussed in greater detail. Dependences of Ω on particle number and angular momentum are described. Theoretical approaches are sketched by which Ω can be treated on a microscopic basis, by applying functional integrals or the shell model Monte Carlo method (SMMC), for instance. Less
Based on the Darwin-Fowler approximation various models for the many-body level density Ω are introduced, critically examined, and confronted with empirical parameterizations. This concerns both the macroscopic limit as well as the case where shell effects are included. Interpretations in the spirit of thermostatics are given. Implications for the use of the temperature concept and of the canonical ensemble are discussed in greater detail. Dependences of Ω on particle number and angular momentum are described. Theoretical approaches are sketched by which Ω can be treated on a microscopic basis, by applying functional integrals or the shell model Monte Carlo method (SMMC), for instance.
Andrew P. Ingersoll
- Published in print:
- 2013
- Published Online:
- October 2017
- ISBN:
- 9780691145044
- eISBN:
- 9781400848232
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691145044.003.0008
- Subject:
- Environmental Science, Climate
This chapter examines the effect of winds on Jupiter's weather. The Great Red Spot is an atmospheric structure—a storm—that is free to move about under the laws of fluid dynamics. On Earth, these ...
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This chapter examines the effect of winds on Jupiter's weather. The Great Red Spot is an atmospheric structure—a storm—that is free to move about under the laws of fluid dynamics. On Earth, these laws lead to turbulence, chaos, and limited predictability. By comparison, the Red Spot is well behaved. It stays in one latitude band, rolling like a ball bearing between two conveyor belts—a westward current to the north and an eastward current to the south. All the large-scale features are remarkably constant. Atmospheric scientists during the Voyager encounter were surprised by the areas outside the Red Spot and the three white ovals—formerly featureless areas that had become turbulent convective regions. The chapter first provides an overview of long-range weather forecasting on Jupiter before discussing the dynamics of rotating fluids, momentum transfer by eddies, stability of zonal jets, geostrophic balance, vorticity, and abyssal weather.Less
This chapter examines the effect of winds on Jupiter's weather. The Great Red Spot is an atmospheric structure—a storm—that is free to move about under the laws of fluid dynamics. On Earth, these laws lead to turbulence, chaos, and limited predictability. By comparison, the Red Spot is well behaved. It stays in one latitude band, rolling like a ball bearing between two conveyor belts—a westward current to the north and an eastward current to the south. All the large-scale features are remarkably constant. Atmospheric scientists during the Voyager encounter were surprised by the areas outside the Red Spot and the three white ovals—formerly featureless areas that had become turbulent convective regions. The chapter first provides an overview of long-range weather forecasting on Jupiter before discussing the dynamics of rotating fluids, momentum transfer by eddies, stability of zonal jets, geostrophic balance, vorticity, and abyssal weather.
Alice H. Amsden
- Published in print:
- 1992
- Published Online:
- November 2003
- ISBN:
- 9780195076035
- eISBN:
- 9780199870691
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0195076036.003.0004
- Subject:
- Economics and Finance, Development, Growth, and Environmental, South and East Asia
Late industrialization is characterized by three facets of growth, as South Korea exemplifies. The first relates to diversification, or entrepreneurial decisions concerning penetration of new ...
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Late industrialization is characterized by three facets of growth, as South Korea exemplifies. The first relates to diversification, or entrepreneurial decisions concerning penetration of new industries – which ones to penetrate, when, and with what size investment. The second relates to stabilization or short‐run macroeconomic policies to maintain the level of economic activity. The third relates to the growth momentum itself. Once underway, growth gains a momentum whose properties are distinct depending on the presence or absence of new technological discoveries. This chapter is divided into three parts, each devoted to one of these facets of growth.Less
Late industrialization is characterized by three facets of growth, as South Korea exemplifies. The first relates to diversification, or entrepreneurial decisions concerning penetration of new industries – which ones to penetrate, when, and with what size investment. The second relates to stabilization or short‐run macroeconomic policies to maintain the level of economic activity. The third relates to the growth momentum itself. Once underway, growth gains a momentum whose properties are distinct depending on the presence or absence of new technological discoveries. This chapter is divided into three parts, each devoted to one of these facets of growth.
Louis A. Girifalco
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780199228966
- eISBN:
- 9780191711183
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199228966.003.0006
- Subject:
- Physics, History of Physics
The law of gravitation could not be proved and could not be applied unless the basic laws of motion were understood. Newton realized this and in an amazing intellectual tour de force, he formulated ...
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The law of gravitation could not be proved and could not be applied unless the basic laws of motion were understood. Newton realized this and in an amazing intellectual tour de force, he formulated his famous three laws of motion that govern all of mechanics. All mechanics, from falling bodies, rotating machinery and automobiles, to aircraft and planetary motion; in short everything that moves and is subject to forces, are governed by Newton's laws of motion. This was the most important and far-reaching achievement in the history of physical science. It superseded all previous attempts to understand motion, and has never been surpassed. These laws properly stressed the importance of inertia, momentum, and reaction forces for the first time.Less
The law of gravitation could not be proved and could not be applied unless the basic laws of motion were understood. Newton realized this and in an amazing intellectual tour de force, he formulated his famous three laws of motion that govern all of mechanics. All mechanics, from falling bodies, rotating machinery and automobiles, to aircraft and planetary motion; in short everything that moves and is subject to forces, are governed by Newton's laws of motion. This was the most important and far-reaching achievement in the history of physical science. It superseded all previous attempts to understand motion, and has never been surpassed. These laws properly stressed the importance of inertia, momentum, and reaction forces for the first time.
A.F. Borghesani
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780199213603
- eISBN:
- 9780191707421
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199213603.003.0007
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter deals with the discovery that ions interact with hydrodynamic structures of the superfluid in a way that can be explained only by assuming that the flow patterns in the superfluid are ...
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This chapter deals with the discovery that ions interact with hydrodynamic structures of the superfluid in a way that can be explained only by assuming that the flow patterns in the superfluid are quantized. Vortex lines and vortex rings capture the ions and the electron bubbles to produce charged vortex rings and lines which appear to be quantized. The fundamentals of semiclassical vortex hydrodynamics are described. The chapter also discusses experiments that unequivocally show that the relationship between momentum, impulse, and energy of such charged ion-vortex complexes confirm the picture of quantized hydrodynamic structures occurring in the superfluid.Less
This chapter deals with the discovery that ions interact with hydrodynamic structures of the superfluid in a way that can be explained only by assuming that the flow patterns in the superfluid are quantized. Vortex lines and vortex rings capture the ions and the electron bubbles to produce charged vortex rings and lines which appear to be quantized. The fundamentals of semiclassical vortex hydrodynamics are described. The chapter also discusses experiments that unequivocally show that the relationship between momentum, impulse, and energy of such charged ion-vortex complexes confirm the picture of quantized hydrodynamic structures occurring in the superfluid.
J. C. Garrison and R. Y. Chiao
- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780198508861
- eISBN:
- 9780191708640
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198508861.003.0004
- Subject:
- Physics, Atomic, Laser, and Optical Physics
The cavity-mode quantization conjecture of Chapter 2 is replaced by local commutation relations — which are independent of the size and shape of the cavity — between field-operator components. This ...
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The cavity-mode quantization conjecture of Chapter 2 is replaced by local commutation relations — which are independent of the size and shape of the cavity — between field-operator components. This step eliminates the previous dependence on the classical boundary conditions at the ideal cavity wall. The cavity annihilation and creation operators are respectively replaced by the positive- and negative-frequency parts of the vector potential. A simple ad hoc model provides similar results for quantized fields in a passive, linear dielectric. It is shown that the total electromagnetic angular momentum cannot, in general, be expressed as the sum of well defined orbital- and spin-parts. The chapter ends with a discussion of localizability for photons, in which it is shown that there is no photon position operator, no position-space photon wave function, and no local photon number operator.Less
The cavity-mode quantization conjecture of Chapter 2 is replaced by local commutation relations — which are independent of the size and shape of the cavity — between field-operator components. This step eliminates the previous dependence on the classical boundary conditions at the ideal cavity wall. The cavity annihilation and creation operators are respectively replaced by the positive- and negative-frequency parts of the vector potential. A simple ad hoc model provides similar results for quantized fields in a passive, linear dielectric. It is shown that the total electromagnetic angular momentum cannot, in general, be expressed as the sum of well defined orbital- and spin-parts. The chapter ends with a discussion of localizability for photons, in which it is shown that there is no photon position operator, no position-space photon wave function, and no local photon number operator.
Hersh Shefrin
- Published in print:
- 2002
- Published Online:
- November 2003
- ISBN:
- 9780195161212
- eISBN:
- 9780199832996
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0195161211.003.0007
- Subject:
- Economics and Finance, Financial Economics
The third theme of behavioral finance is inefficient markets. In recent years scholars have produced considerable evidence that heuristic‐driven bias and frame dependence cause markets to be ...
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The third theme of behavioral finance is inefficient markets. In recent years scholars have produced considerable evidence that heuristic‐driven bias and frame dependence cause markets to be inefficient. Scholars use the term “anomalies” to describe specific market inefficiencies. For this reason, Eugene Fama characterizes behavioral finance as “anomalies dredging.” This chapter discusses what behavioral finance implies about picking stocks and beating the market. Market efficiency is a direct challenge to active money managers, because it implies that trying to beat the market is a waste of time. Why? Because no security is mispriced in an efficient market, at least relative to information that is publicly available. Inside information may be another story. The chapter discusses whether the stock recommendations made by brokerage houses have beaten the market, and a series of effects discussed in the literature: the winner–loser effect, momentum, the size effect, the book‐to‐market effect, the effect of a change in analysts' recommendations.Less
The third theme of behavioral finance is inefficient markets. In recent years scholars have produced considerable evidence that heuristic‐driven bias and frame dependence cause markets to be inefficient. Scholars use the term “anomalies” to describe specific market inefficiencies. For this reason, Eugene Fama characterizes behavioral finance as “anomalies dredging.” This chapter discusses what behavioral finance implies about picking stocks and beating the market. Market efficiency is a direct challenge to active money managers, because it implies that trying to beat the market is a waste of time. Why? Because no security is mispriced in an efficient market, at least relative to information that is publicly available. Inside information may be another story. The chapter discusses whether the stock recommendations made by brokerage houses have beaten the market, and a series of effects discussed in the literature: the winner–loser effect, momentum, the size effect, the book‐to‐market effect, the effect of a change in analysts' recommendations.
Hersh Shefrin
- Published in print:
- 2002
- Published Online:
- November 2003
- ISBN:
- 9780195161212
- eISBN:
- 9780199832996
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0195161211.003.0008
- Subject:
- Economics and Finance, Financial Economics
Mispricing is complicated. Sometimes mispricing results in reversals, while at other times it results in momentum. Momentum and reversals co‐exist, despite lying at diametrically opposite ends of the ...
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Mispricing is complicated. Sometimes mispricing results in reversals, while at other times it results in momentum. Momentum and reversals co‐exist, despite lying at diametrically opposite ends of the spectrum. The academic scholars participating in the market efficiency debate have been grappling with what this co‐existence means. Proponents of market efficiency view these phenomena as nothing more than random deviations from efficient prices. Proponents of behavioral finance view them as systematic departures from efficient prices. To shed additional light on the co‐existence issue, this chapter is devoted to post‐earnings‐announcement drift, a phenomenon that involves both reversals and momentum.Less
Mispricing is complicated. Sometimes mispricing results in reversals, while at other times it results in momentum. Momentum and reversals co‐exist, despite lying at diametrically opposite ends of the spectrum. The academic scholars participating in the market efficiency debate have been grappling with what this co‐existence means. Proponents of market efficiency view these phenomena as nothing more than random deviations from efficient prices. Proponents of behavioral finance view them as systematic departures from efficient prices. To shed additional light on the co‐existence issue, this chapter is devoted to post‐earnings‐announcement drift, a phenomenon that involves both reversals and momentum.
Michele Maggiore
- Published in print:
- 2007
- Published Online:
- January 2008
- ISBN:
- 9780198570745
- eISBN:
- 9780191717666
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198570745.003.0001
- Subject:
- Physics, Particle Physics / Astrophysics / Cosmology
This chapter discusses how gravitational waves emerge from general relativity, and what their properties are. The most straightforward approach is ‘linearized theory’, where the Einstein equations ...
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This chapter discusses how gravitational waves emerge from general relativity, and what their properties are. The most straightforward approach is ‘linearized theory’, where the Einstein equations are expanded around the flat Minkowski metric. It is shown how a wave equation emerges and how the solutions can be put in an especially simple form by an appropriate gauge choice. Using standard tools of general relativity such as the geodesic equation and the equation of the geodesic deviation, how these waves interact with a set of test masses is detailed. The energy and momentum carried by GWs are then computed and discussed. This chapter approaches the problem from a geometric point of view, identifying the energy-momentum tensor of GWs from their effect on the background curvature. Finally, GW propagation in curved space is discussed.Less
This chapter discusses how gravitational waves emerge from general relativity, and what their properties are. The most straightforward approach is ‘linearized theory’, where the Einstein equations are expanded around the flat Minkowski metric. It is shown how a wave equation emerges and how the solutions can be put in an especially simple form by an appropriate gauge choice. Using standard tools of general relativity such as the geodesic equation and the equation of the geodesic deviation, how these waves interact with a set of test masses is detailed. The energy and momentum carried by GWs are then computed and discussed. This chapter approaches the problem from a geometric point of view, identifying the energy-momentum tensor of GWs from their effect on the background curvature. Finally, GW propagation in curved space is discussed.
Michael Munowitz
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195167375
- eISBN:
- 9780199787104
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195167375.003.0004
- Subject:
- Physics, History of Physics
The Moon — caught in an exact balance of attractive and repulsive forces — orbits the Earth with flawless regularity, never faltering. A ball rolls predictably down a slope of a certain grade, always ...
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The Moon — caught in an exact balance of attractive and repulsive forces — orbits the Earth with flawless regularity, never faltering. A ball rolls predictably down a slope of a certain grade, always passing the same landmarks in the same sequence of times. There are no surprises in the macroscopic world of classical mechanics, a world where to know the present is to predict the future and retrace the past. Observations may differ superficially according to individual frames of reference, but there is always agreement on the larger issues. Energy is conserved. Momentum is conserved. Differences in coordinates and velocities, along with perceptions of motion and rest, are all reconciled, and Newton’s deterministic equations of motion are the law of the land.Less
The Moon — caught in an exact balance of attractive and repulsive forces — orbits the Earth with flawless regularity, never faltering. A ball rolls predictably down a slope of a certain grade, always passing the same landmarks in the same sequence of times. There are no surprises in the macroscopic world of classical mechanics, a world where to know the present is to predict the future and retrace the past. Observations may differ superficially according to individual frames of reference, but there is always agreement on the larger issues. Energy is conserved. Momentum is conserved. Differences in coordinates and velocities, along with perceptions of motion and rest, are all reconciled, and Newton’s deterministic equations of motion are the law of the land.
A.J. Leggett
- Published in print:
- 2006
- Published Online:
- January 2008
- ISBN:
- 9780198526438
- eISBN:
- 9780191711954
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198526438.003.0006
- Subject:
- Physics, Condensed Matter Physics / Materials
After a brief review of the properties of the normal state of liquid 3He and its description in terms of Landau Fermi-liquid theory, this chapter extends the BCS theory of pairing to the superfluid ...
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After a brief review of the properties of the normal state of liquid 3He and its description in terms of Landau Fermi-liquid theory, this chapter extends the BCS theory of pairing to the superfluid phase, where in contrast to classical superconductors it is believed that the pairs form with nonzero relative orbital angular momentum (“anisotropic Fermi superfluidity”). The generalization of the Ginzburg-Landau formalism to this case is presented, as is a possible physical mechanism (spin-fluctuation-induced feedback) for the stabilization of more than one anisotropic superfluid phase. The concept of spontaneously broken spin-orbit symmetry is introduced and used to explain the anomalous spin dynamics of this system. Finally, some topological properties unique to the superfluid phases of 3He are reviewed.Less
After a brief review of the properties of the normal state of liquid 3He and its description in terms of Landau Fermi-liquid theory, this chapter extends the BCS theory of pairing to the superfluid phase, where in contrast to classical superconductors it is believed that the pairs form with nonzero relative orbital angular momentum (“anisotropic Fermi superfluidity”). The generalization of the Ginzburg-Landau formalism to this case is presented, as is a possible physical mechanism (spin-fluctuation-induced feedback) for the stabilization of more than one anisotropic superfluid phase. The concept of spontaneously broken spin-orbit symmetry is introduced and used to explain the anomalous spin dynamics of this system. Finally, some topological properties unique to the superfluid phases of 3He are reviewed.
