Stochastic electrodynamics
Encyclopedia
In theoretical physics, Stochastic Electrodynamics (SED) is a variant of Classical Electrodynamics (CED) which posits the existence of a classical Lorentz Invariant radiation field having statistical properties similar to that of the electromagnetic zero-point field (ZPF) of Quantum Electrodynamics
(QED). Investigations of SED have been concerned with:
There is not universal agreement on the success of these endeavors.
in the (classical) Abraham-Lorentz-Dirac equation (see: Abraham–Lorentz–Dirac force), where the classical statistics of the electric and magnetic fields and quadratic combinations thereof are chosen to match the vacuum expectation values of the equivalent operators in QED. The field is generally represented as a discrete sum of Fourier components
each with amplitude and phase that are independent classical random variables, distributed so that the statistics of the fields are isotropic and unchanged under boosts. This prescription is such that each Fourier mode at frequency
is expected to have an energy of 
, equaling that of the ground state of the vacuum modes of QED. Unless cutoff
, the total field has an infinite energy density, with a spectral energy density (per unit frequency per unit volume) proportional to
where 
is Planck's constant. Consequently the background field is a classical version of the electromagnetic ZPF of QED, though in SED literature the field is commonly referred to simply as 'the ZPF' without making that distinction.
attempting to use the SED notion of a classical ZPF to explain inertial mass as due to a vacuum reaction.
In 2000, Trevor Marshall derived an experimental prediction of SED dubbed "spontaneous parametric up-conversion" (SPUC) as a dual process to the well-known spontaneous parametric down-conversion (SPDC). SPUC was tested in 2009 and 2010 with positive results.
In 2010, Cavalleri et al introduced SEDS ('pure' SED, as they call it, plus spin) as a fundamental improvement which they claim potentially overcomes all the known drawbacks to SED. They also claim SEDS resolves four observed effects that are so far unexplained by QED, i.e., 1) the physical origin of the ZPF, and its natural upper cutoff; 2) an anomaly in experimental studies of the neutrino rest mass; 3) the origin and quantitative treatment of 1/f noise; and 4) the high-energy tail (~
eV) of cosmic rays. Two double-slit electron diffraction experiments are proposed to discriminate between QM and SEDS
and the Dirac equation
and QED) for their explanation. It has also been used to motivate a classical ZPF-based underpinning for gravity and inertia. There is not universal agreement on the successes and failures of SED, either in its congruence with standard theories of quantum mechanics, QED, and gravity, or in its compliance with observation. The following SED-based explanations are relatively uncontroversial and are free of criticism at the time of writing:
The following SED-based calculations and SED-related claims are more controversial and some have been subject to published criticism:
, and claim to have computed a nonzero "z.p.f. momentum". This computation rests upon their claim to compute a nonzero "z.p.f. Poynting vector".
. NASA continues to make assessments: In the usual interpretation of vacuum energy it is not possible to use it to do work. However, SED takes a rather more literal, classical interpretation, and views the very high energy density of the electromagnetic vacuum as propagating waves, which must necessarily carry considerable energy and momentum flux, ordinarily not evident in the absence of matter, because the flux is isotropic.
". This follows speculation in (non-technical) papers by Haisch and Rueda on the control of inertia using SED principles.
Quantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
(QED). Investigations of SED have been concerned with:
- The degree to which this prescription might cause SED to mimic some behaviors traditionally considered to be the exclusive domain of Quantum MechanicsQuantum mechanicsQuantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
; and - A possible classical ZPF-based origin for gravity and inertia.
There is not universal agreement on the success of these endeavors.
The Classical Background Field
The background field is introduced as a Lorentz forceLorentz force
In physics, the Lorentz force is the force on a point charge due to electromagnetic fields. It is given by the following equation in terms of the electric and magnetic fields:...
in the (classical) Abraham-Lorentz-Dirac equation (see: Abraham–Lorentz–Dirac force), where the classical statistics of the electric and magnetic fields and quadratic combinations thereof are chosen to match the vacuum expectation values of the equivalent operators in QED. The field is generally represented as a discrete sum of Fourier components
Fourier series
In mathematics, a Fourier series decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions, namely sines and cosines...
each with amplitude and phase that are independent classical random variables, distributed so that the statistics of the fields are isotropic and unchanged under boosts. This prescription is such that each Fourier mode at frequency
is expected to have an energy of , equaling that of the ground state of the vacuum modes of QED. Unless cutoffCutoff frequency
In physics and electrical engineering, a cutoff frequency, corner frequency, or break frequency is a boundary in a system's frequency response at which energy flowing through the system begins to be reduced rather than passing through.Typically in electronic systems such as filters and...
, the total field has an infinite energy density, with a spectral energy density (per unit frequency per unit volume) proportional to
where is Planck's constant. Consequently the background field is a classical version of the electromagnetic ZPF of QED, though in SED literature the field is commonly referred to simply as 'the ZPF' without making that distinction.Brief history
Stochastic Electrodynamics is a term for a collection of research efforts of many different styles based on the ansatz that there exists a Lorentz-Invariant random electromagnetic radiation. The basic ideas have been around for a long time; but Marshall (1963) and Brafford seem to have been the originators of the more concentrated efforts starting in the 1960s. Thereafter, Boyer (for reviews see Boyer 1975, 1980, 1985) and de la Pena & Cetto (1996, 2005) were perhaps the most prolific contributors to SED in the 1970s and beyond. Others have made contributions, alterations and proposals concentrating on the application of SED to problems in QED. A separate thread has been the investigation of an earlier proposal by Walther NernstWalther Nernst
Walther Hermann Nernst FRS was a German physical chemist and physicist who is known for his theories behind the calculation of chemical affinity as embodied in the third law of thermodynamics, for which he won the 1920 Nobel Prize in chemistry...
attempting to use the SED notion of a classical ZPF to explain inertial mass as due to a vacuum reaction.
In 2000, Trevor Marshall derived an experimental prediction of SED dubbed "spontaneous parametric up-conversion" (SPUC) as a dual process to the well-known spontaneous parametric down-conversion (SPDC). SPUC was tested in 2009 and 2010 with positive results.
In 2010, Cavalleri et al introduced SEDS ('pure' SED, as they call it, plus spin) as a fundamental improvement which they claim potentially overcomes all the known drawbacks to SED. They also claim SEDS resolves four observed effects that are so far unexplained by QED, i.e., 1) the physical origin of the ZPF, and its natural upper cutoff; 2) an anomaly in experimental studies of the neutrino rest mass; 3) the origin and quantitative treatment of 1/f noise; and 4) the high-energy tail (~
eV) of cosmic rays. Two double-slit electron diffraction experiments are proposed to discriminate between QM and SEDSScope of SED
SED has been used in attempts to provide a classical explanation for effects previously considered to require quantum mechanics (here restricted to the Schrödinger equationSchrödinger equation
The Schrödinger equation was formulated in 1926 by Austrian physicist Erwin Schrödinger. Used in physics , it is an equation that describes how the quantum state of a physical system changes in time....
and the Dirac equation
Dirac equation
The Dirac equation is a relativistic quantum mechanical wave equation formulated by British physicist Paul Dirac in 1928. It provided a description of elementary spin-½ particles, such as electrons, consistent with both the principles of quantum mechanics and the theory of special relativity, and...
and QED) for their explanation. It has also been used to motivate a classical ZPF-based underpinning for gravity and inertia. There is not universal agreement on the successes and failures of SED, either in its congruence with standard theories of quantum mechanics, QED, and gravity, or in its compliance with observation. The following SED-based explanations are relatively uncontroversial and are free of criticism at the time of writing:
- The Casimir force
- The Van der Waals forceVan der Waals forceIn physical chemistry, the van der Waals force , named after Dutch scientist Johannes Diderik van der Waals, is the sum of the attractive or repulsive forces between molecules other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral...
- DiamagnetismDiamagnetismDiamagnetism is the property of an object which causes it to create a magnetic field in opposition to an externally applied magnetic field, thus causing a repulsive effect. Specifically, an external magnetic field alters the orbital velocity of electrons around their nuclei, thus changing the...
- The Unruh effectUnruh effectThe Unruh effect , was first described by Stephen Fulling in 1973, Paul Davies in 1975 and Bill Unruh in 1976. It is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none...
The following SED-based calculations and SED-related claims are more controversial and some have been subject to published criticism:
- The ground state of the harmonic oscillatorQuantum harmonic oscillatorThe quantum harmonic oscillator is the quantum-mechanical analog of the classical harmonic oscillator. Because an arbitrary potential can be approximated as a harmonic potential at the vicinity of a stable equilibrium point, it is one of the most important model systems in quantum mechanics...
- The ground state of the hydrogen atomHydrogen atomA hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively-charged proton and a single negatively-charged electron bound to the nucleus by the Coulomb force...
- de Broglie waves
- InertiaInertiaInertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to...
- GravitationGravitationGravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
- Non-locality and tests of Bell's theoremBell's theoremIn theoretical physics, Bell's theorem is a no-go theorem, loosely stating that:The theorem has great importance for physics and the philosophy of science, as it implies that quantum physics must necessarily violate either the principle of locality or counterfactual definiteness...
The work of Haisch and Rueda
According to Haisch and Rueda, inertia arises as an electromagnetic drag force on accelerating particles, produced by interaction with the zero-point field. In their 1998 Ann. Phys. paper (see citations), they speak of a "Rindler flux", presumably meaning the Unruh effectUnruh effect
The Unruh effect , was first described by Stephen Fulling in 1973, Paul Davies in 1975 and Bill Unruh in 1976. It is the prediction that an accelerating observer will observe black-body radiation where an inertial observer would observe none...
, and claim to have computed a nonzero "z.p.f. momentum". This computation rests upon their claim to compute a nonzero "z.p.f. Poynting vector".
Zero Point Energy Details
The proposals of Haisch and Rueda for zero point energy might ultimately provide no cost "energy from the vacuum", thereby solving many current problems in contemporary human society. Others claim that the work of Haisch, Rueda, and Puthoff holds out hope of developing a reactionless driveReactionless drive
A reactionless drive is a fictional or theorized method of propulsion where thrust is generated without any need for any outside force or net momentum exchange to produce linear motion...
. NASA continues to make assessments: In the usual interpretation of vacuum energy it is not possible to use it to do work. However, SED takes a rather more literal, classical interpretation, and views the very high energy density of the electromagnetic vacuum as propagating waves, which must necessarily carry considerable energy and momentum flux, ordinarily not evident in the absence of matter, because the flux is isotropic.
Fictional References
Arthur C. Clarke describes a "SHARP drive" (for Sakharov, Haisch, Rueda and Puthoff) in his 1997 novel "3001: The Final Odyssey3001: The Final Odyssey
3001: The Final Odyssey is a science fiction novel by Sir Arthur C. Clarke. It is the fourth and final book in Clarke's Space Odyssey series.-Plot summary:...
". This follows speculation in (non-technical) papers by Haisch and Rueda on the control of inertia using SED principles.
See also
- Casimir effectCasimir effectIn quantum field theory, the Casimir effect and the Casimir–Polder force are physical forces arising from a quantized field. The typical example is of two uncharged metallic plates in a vacuum, like capacitors placed a few micrometers apart, without any external electromagnetic field...
- Vacuum energyVacuum energyVacuum energy is an underlying background energy that exists in space even when the space is devoid of matter . The concept of vacuum energy has been deduced from the concept of virtual particles, which is itself derived from the energy-time uncertainty principle...
- Zero-point energyZero-point energyZero-point energy is the lowest possible energy that a quantum mechanical physical system may have; it is the energy of its ground state. All quantum mechanical systems undergo fluctuations even in their ground state and have an associated zero-point energy, a consequence of their wave-like nature...
- Andrei SakharovAndrei SakharovAndrei Dmitrievich Sakharov was a Soviet nuclear physicist, dissident and human rights activist. He earned renown as the designer of the Soviet Union's Third Idea, a codename for Soviet development of thermonuclear weapons. Sakharov was an advocate of civil liberties and civil reforms in the...
- Bernard HaischBernard HaischBernard Haisch is a German-born American astrophysicist who has done research in solar-stellar astrophysics and stochastic electrodynamics. He has developed with Alfonso Rueda a speculative theory that the non-zero lowest energy state of the vacuum, as predicted by quantum mechanics, might provide...
- Harold E. PuthoffHarold E. PuthoffHarold E. Puthoff is an American physicist who, earlier in his career was involved in research on paranormal topics. In 1967, Puthoff earned a Ph.D. from Stanford University...
External links
- California Institute for Physics and Astrophysics, a physics organization founded by Bernard HaischBernard HaischBernard Haisch is a German-born American astrophysicist who has done research in solar-stellar astrophysics and stochastic electrodynamics. He has developed with Alfonso Rueda a speculative theory that the non-zero lowest energy state of the vacuum, as predicted by quantum mechanics, might provide...
- H. E. Puthoff, Quantum Vacuum Fluctuations: A New Rosetta Stone of Physics?