Stochastic electrodynamics

Stochastic electrodynamics (SED) is an extension of the de Broglie–Bohm interpretation of quantum mechanics, with the electromagnetic zero-point field (ZPF) playing a central role as the guiding pilot-wave. The theory is a deterministic nonlocal hidden-variable theory. It is distinct from other more mainstream interpretations of quantum mechanics such as QED, a stochastic electrodynamics of the Copenhagen interpretation and Everett's many-worlds interpretation. SED describes energy contained in the electromagnetic vacuum at absolute zero as a stochastic, fluctuating zero-point field. The motion of a particle immersed in this stochastic zero-point radiation generally results in highly nonlinear, sometimes chaotic or emergent, behaviour. Modern approaches to SED consider the quantum properties of waves and particles as well-coordinated emergent effects resulting from deeper (sub-quantum) nonlinear matter-field interactions.The background field is introduced as a Lorentz force 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 (f) is expected to have an energy of hf/2, equaling that of the ground state of the vacuum modes of QED. Unless cut off, the total field has an infinite energy density, with a spectral energy density (per unit frequency per unit volume) f3 where h 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. Any finite cutoff frequency of the field itself would be incompatible with Lorentz invariance. For this reason, some researchers prefer to think of cutoff frequency in terms of the response of particles to the field rather than as a property the field itself.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 Timothy Boyer, Luis de la Peña and Ana María Cetto were perhaps the most prolific contributors 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 Nernst attempting to use the SED notion of a classical ZPF to explain inertial mass as due to a vacuum reaction.SED has been used in attempts to provide a classical explanation for effects previously considered to require quantum mechanics (here restricted to the Schrödinger equation 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 no 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: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 effect, 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'.Arthur C. Clarke describes a 'SHARP drive' (for Sakharov, Haisch, Rueda and Puthoff) in his 1997 novel '3001: The Final Odyssey'.