Comment on “Exact Expression for Radiation of an Accelerated Charge in Classical Electrodynamics”

It is shown that a newly derived “exact expression” for radiation of an accelerated charge in the recent literature is simply incorrect, having arisen because of a wrong relativistic transformation of the distance parameter. The ensuing claim that the newly derived expression alone satisfies the energy conservation for the electromagnetic radiation, is based on a wrong reasoning where a proper distinction between the time during which the radiation is received and the time for emission (retarded time of the charge) was not maintained.     

Classical interpretations of relativistic precessions

Relativists have exposed various precessions and developed ingenious experiments to verify those phenomena with extreme precisions. The Gravity Probe B mission was designed to study the precessions of the gyroscopes rotating round the Earth in a nearly circular near-Earth polar orbit to demonstrate the geodetic effect and the Lense-Thirring effect as predicted by the general relativity theory. In this paper, we show in a very simple and novel analysis that the precession of the perihelion of Mercury, the Thomas precession, and the precession data （on the de Sitter and Lense-Thirring precessions） collected from the Gravity Probe B mission could easily be explained from classical physics, too.     

Quantum Computing’s Classical Problem,Classical Computing’s Quantum Problem

Tasked with the challenge to build better and better computers, quantum computing and classical computing face the same conundrum: the success of classical computing systems. Small quantum computing systems have been demonstrated, and intermediate-scale systems are on the horizon, capable of calculating numeric results or simulating physical systems far beyond what humans can do by hand. However, to be commercially viable, they must surpass what our wildly successful, highly advanced classical computers can already do. At the same time, those classical computers continue to advance, but those advances are now constrained by thermodynamics, and will soon be limited by the discrete nature of atomic matter and ultimately quantum effects. Technological advances benefit both quantum and classical machinery, altering the competitive landscape. Can we build quantum computing systems that out-compute classical systems capable of some \(10^{30}\) logic gates per month? This article will discuss the interplay in these competing and cooperating technological trends.     

Radiation Energy Flux and Radiation Power of Schwarzschild Black Hole

Applying the entropy density near the event horizon, we obtained the result that the radiation energy flux of the black hole is always proportional to the quartic of the temperature of its event horizon. That is to say, the thermal radiation of the black hole always satisfies the generalized Stefan–Boltzmann law. The derived generalized Stefan–Boltzmann coefficient is no longer a constant. When the cut-off distance and the thin film thickness are both fixed, it is a proportional coefficient which is related to the black hole mass, the kinds of radiation particles and space–time metric near the event horizon. In this paper, we have put forward a thermal particle model in curved space–time. By this model, the result has been obtained that when the thin film thickness and the cut-off distance are both fixed, the radiation energy flux received by observer far away from the Schwarzschild black hole is proportional to the average radial effusion velocity of the radiation particles in the thin film, and inversely proportional to the square of the distance between the observer and the black hole.     

Classical dynamics of laser-driven D₃⁺

A classical model of the triatomic D?? molecule subjected to an intense, few-cycle laser pulse is introduced. The model is capable of describing the laser-induced correlated motion of both electrons and nuclei in three dimensions, and allows us to follow the motion of the two electrons and three deuterons from the initial field-free state, during the pulse, and until the bond breaking into the final fragments. By averaging over many trajectories, we calculate the relative yields of the ionization and dissociation channels, as well as the kinetic energy release (KER) from the fragment ions. A comparison with recent experimental KER spectra shows good qualitative agreement. In addition, we find a pathway in which an emitted electron recombines into a high-lying Rydberg state, resulting in D + D? + D? fragments with the same KER as in the D? + D? + D? channel.     

Kerr-Newman-Kasuya Black Hole Tunnelling Radiation

The radiation of black hole contributes to the shrinking of the event horizon such that the background spacetime should not be fixed. In this study we take into account the self-gravitation effect to study the radiation of Kerr Newman-Kasuya black hole as tunnelling. Using the facts of energy conservation and angular momentum conservation we derive the tunnelling rate and show that the spectrum of the radiation as tunnelling is not purely thermal.     

Classical space–times from the S-matrix

We show that classical space–times can be derived directly from the S-matrix for a theory of massive particles coupled to a massless spin two particle. As an explicit example we derive the Schwarzchild space–time as a series in _GN$G_N$. At no point of the derivation is any use made of the Einstein–Hilbert action or the Einstein equations. The intermediate steps involve only on-shell S-matrix elements which are generated via BCFW recursion relations and unitarity sewing techniques. The notion of a space–time metric is only introduced at the end of the calculation where it is extracted by matching the potential determined by the S-matrix to the geodesic motion of a test particle. Other static space–times such as Kerr follow in a similar manner. Furthermore, given that the procedure is action independent and depends only upon the choice of the representation of the little group, solutions to Yang–Mills (YM) theory can be generated in the same fashion. Moreover, the squaring relation between the YM and gravity three point functions shows that the seeds that generate solutions in the two theories are algebraically related. From a technical standpoint our methodology can also be utilized to calculate quantities relevant for the binary inspiral problem more efficiently then the more traditional Feynman diagram approach.     

A Classical Formulation of Quantum Theory?

We explore a particular way of reformulating quantum theory in classical terms, starting with phase space rather than Hilbert space, and with actual probability distributions rather than quasiprobabilities. The classical picture we start with is epistemically restricted, in the spirit of a model introduced by Spekkens. We obtain quantum theory only by combining a collection of restricted classical pictures. Our main challenge in this paper is to find a simple way of characterizing the allowed sets of classical pictures. We present one promising approach to this problem and show how it works out for the case of a single qubit.     

“Quantal” Behavior in Classical Probability

A number of phenomena generally believed characteristic of quantum mechanics and seen as interpretively problematic—the incompatibility and value-indeterminateness of variables, the non-existence of dispersion-free states, the failure of the standard marginal-probability formula, the failure of the distributive law of disjunction and interference—are exemplified in an emphatically non-quantal system: a deck of playing cards. Thus the appearance in quantum mechanics of incompatibility and these associated phenomena requires neither explanation nor interpretation.     

Wavefunction of Coupled Quantum—Classical Oscillator

Considering classical environment to be a classical oscillator,we describe the dynamics of a system consisting of a quantum oscillator coupled to classical oscillator.Using the Born-Oppenheimer approximation and the method of adiabatic invariants,we derive the classically effective Hamiltonian describing the complete dynamics of the system and the wavefunction of quantum part of the system.We also present a new method for investigating the dynamics of the quantum system in classical environment.     

Radiation characteristics of intermittence exhaust noise

1 IntroductionBecause of noise fluctuation value, exhaust noise may be divided into three classes: steadynoise, periodic noise and intermittent noise. The value of steady noise, such as the exhaustnoise produced by a gas tank in an air compression station does not change remarkably in thecourse of exhaust, the high frequency portions of noise being dominant[1]. The periodic exhaustnoise, such as the exhaust noise generated by an totemal combustion engine, means the noisewhose value changes per…     

Radiation Heat Waves in Gold Plasma

Eight beams 0.35μm laser with pulse duration of about 1.0ns and energy of 260J per beam was injected into a cylindrical cavity to generate intense x-ray radiation on the “Shengguang Ⅱ“ high power laser facility.Gold foils with a thickness in the range of 0.09-0.52μm were attached on the diagnostic hole of the cavity and ablated by the intense x-ray radiation.The propagating radiation heat wave in the high-Z gold plasma was observed clearly.For comparison,we also simulated the experimental results.     

Polarization Properties of Quantum Cyclotron Radiation

We present a simplified formulae system describing the polarization properties of the quantum cyclotron radiation by a nonrelativistic thermal electron in a very strong magnetic field. In this system, each of the derived quantities, including the Einstein coefficients, the absorption cross sections, and scattering cross sections, as well as the absorption coefficients by plasma, is divided into the perpendicularly and parallelly polarized components. The results, especially the absorption and scattering cross sections of resonant frequency photons, are potentially important in x-ray and γ-ray astronomy, particularly in the study of gamma-ray bursts and pulsars.