13,961 research outputs found
Derivation of the Blackbody Radiation Spectrum from a Natural Maximum-Entropy Principle Involving Casimir Energies and Zero-Point Radiation
By numerical calculation, the Planck spectrum with zero-point radiation is
shown to satisfy a natural maximum-entropy principle whereas alternative
choices of spectra do not. Specifically, if we consider a set of
conducting-walled boxes, each with a partition placed at a different location
in the box, so that across the collection of boxes the partitions are uniformly
spaced across the volume, then the Planck spectrum correspond to that spectrum
of random radiation (having constant energy kT per normal mode at low
frequencies and zero-point energy (1/2)hw per normal mode at high frequencies)
which gives maximum uniformity across the collection of boxes for the radiation
energy per box. The analysis involves Casimir energies and zero-point radiation
which do not usually appear in thermodynamic analyses. For simplicity, the
analysis is presented for waves in one space dimension.Comment: 11 page
Darwin-Lagrangian Analysis for the Interaction of a Point Charge and a Magnet: Considerations Related to the Controversy Regarding the Aharonov-Bohm and Aharonov-Casher Phase Shifts
The classical electromagnetic interaction of a point charge and a magnet is
discussed by first calculating the interaction of point charge with a simple
model magnetic moment and then suggesting a multiparticle limit. The Darwin
Lagrangian is used to analyze the electromagnetic behavior of the model
magnetic moment (composed of two oppositely charged particles of different mass
in an initially circular orbit) interacting with a passing point charge. The
changing mangetic moment is found to put a force back on a passing charge; this
force is of order 1/c^2 and depends upon the magnitude of the magnetic moment.
It is suggested that in the limit of a multiparticle magnetic toroid, the
electric fields of the passing charge are screened out of the body of the
magnet while the magnetic fields penetrate into the magnet. This is consistent
with our understanding of the penetration of electromagnetic velocity fields
into ohmic conductors. Conservation laws are discussed. The work corresponds to
a classical electromagnetic analysis of the interaction which is basic to
understanding the controversy over the Aharonov-Bohm and Aharonov-Casher phase
shifts and represents a refutation of the suggestions of Aharonov, Pearle, and
Vaidman.Comment: 33 page
Blackbody Radiation and the Scaling Symmetry of Relativistic Classical Electron Theory with Classical Electromagnetic Zero-Point Radiation
It is pointed out that relativistic classical electron theory with classical
electromagnetic zero-point radiation has a scaling symmetry which is suitable
for understanding the equilibrium behavior of classical thermal radiation at a
spectrum other than the Rayleigh-Jeans spectrum. In relativistic classical
electron theory, the masses of the particles are the only scale-giving
parameters associated with mechanics while the action-angle variables are scale
invariant. The theory thus separates the interaction of the action variables of
matter and radiation from the scale-giving parameters. Classical zero-point
radiation is invariant under scattering by the charged particles of
relativistic classical electron theory. The basic ideas of the matter
-radiation interaction are illustrated in a simple relativistic classical
electromagnetic example.Comment: 18 page
Study of basic bio-electrochemistry Sixth monthly progress report, 1-31 Aug. 1963
Contribution of hydrogen peroxide to electrode reaction in electrochemical cell by considering effect of catalyst on cell curren
L\'evy-like behavior in deterministic models of intelligent agents exploring heterogeneous environments
Many studies on animal and human movement patterns report the existence of
scaling laws and power-law distributions. Whereas a number of random walk
models have been proposed to explain observations, in many situations
individuals actually rely on mental maps to explore strongly heterogeneous
environments. In this work we study a model of a deterministic walker, visiting
sites randomly distributed on the plane and with varying weight or
attractiveness. At each step, the walker minimizes a function that depends on
the distance to the next unvisited target (cost) and on the weight of that
target (gain). If the target weight distribution is a power-law, , in some range of the exponent , the foraging medium induces
movements that are similar to L\'evy flights and are characterized by
non-trivial exponents. We explore variations of the choice rule in order to
test the robustness of the model and argue that the addition of noise has a
limited impact on the dynamics in strongly disordered media.Comment: 15 pages, 7 figures. One section adde
Classical interpretation of the Debye law for the specific heat of solids
We derive the Debye law for the specific heat of solids within the realm of stochastic electrodynamics (i.e., classical electrodynamics with the assumption of a real zero-point field). Random lattice vibrations are generated by the Planck radiation including zero point, which is absorbed by the ions. The equilibrium is accomplished by a fluctuation-dissipation mechanism due to the emission of radiation by the ions in accelerated motion
Modification of energy shifts of atoms by the presence of a boundary in a thermal bath and the Casimir-Polder force
We study the modification by the presence of a plane wall of energy level
shifts of two-level atoms which are in multipolar coupling with quantized
electromagnetic fields in a thermal bath in a formalism which separates the
contributions of thermal fluctuations and radiation reaction and allows a
distinct treatment to atoms in the ground and excited states. The position
dependent energy shifts give rise to an induced force acting on the atoms. We
are able to identify three different regimes where the force shows distinct
features and examine, in all regimes, the behaviors of this force in both the
low temperature limit and the high temperature limit for both the ground state
and excited state atoms, thus providing some physical insights into the
atom-wall interaction at finite temperature. In particular, we show that both
the magnitude and the direction of the force acting on an atom may have a clear
dependence on atomic the polarization directions. In certain cases, a change of
relative ratio of polarizations in different directions may result in a change
of direction of the force.Comment: 29 pages, 3 figure
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