4,249 research outputs found
Teaching the third law of thermodynamics
This work gives a brief summary of major formulations of the third law of
thermodynamics and their implications, including the impossibility of perpetual
motion of the third kind. The last sections of this work review more advanced
applications of the third law to systems with negative temperatures and
negative heat capacities. The relevance of the third law to protecting the
arrow of time in general relativity is also discussed. Additional information,
which may useful in analysis of the third law, is given in the Appendices.
This short review is written to assist lecturers in selecting a strategy for
teaching the third law of thermodynamics to engineering and science students.
The paper provides a good summary of the various issues associated with the
third law, which are typically scattered over numerous research publications
and not discussed in standard textbooks.Comment: 22 pages, 5 figure
Symmetric and antisymmetric forms of the Pauli master equation (for interaction of matter and antimatter quantum states)
When applied to matter and antimatter states, the Pauli master equation (PME)
may have two forms: time-symmetric, which is conventional, and
time-antisymmetric, which is suggested in the present work. The symmetric and
antisymmetric forms correspond to symmetric and antisymmetric extensions of
thermodynamics from matter to antimatter --- this is demonstrated by proving
the corresponding H-theorem. The two forms are based on the thermodynamic
similarity of matter and antimatter and differ only in the directions of
thermodynamic time for matter and antimatter (the same in the time-symmetric
case and the opposite in the time-antisymmetric case). We demonstrate that,
while the symmetric form of PME predicts an equi-balance between matter and
antimatter, the antisymmetric form of PME favours full conversion of antimatter
into matter. At this stage, it is impossible to make an experimentally
justified choice in favour of the symmetric or antisymmetric versions of
thermodynamics since we have no experience of thermodynamic properties of
macroscopic objects made of antimatter, but experiments of this kind may become
possible in the future.Comment: 12 pages, 2 figure
Intransitivity in Theory and in the Real World
This work considers reasons for and implications of discarding the assumption
of transitivity, which (transitivity) is the fundamental postulate in the
utility theory of Von Neumann and Morgenstern, the adiabatic accessibility
principle of Caratheodory and most other theories related to preferences or
competition. The examples of intransitivity are drawn from different fields,
such as law, biology, game theory, economics and competitive evolutionary
dynamic. This work is intended as a common platform that allows us to discuss
intransitivity in the context of different disciplines. The basic concepts and
terms that are needed for consistent treatment of intransitivity in various
applications are presented and analysed in a unified manner. The analysis
points out conditions that necessitate appearance of intransitivity, such as
multiplicity of preference criteria and imperfect (i.e. approximate)
discrimination of different cases. The present work observes that with
increasing presence and strength of intransitivity, thermodynamics gradually
fades away leaving space for more general kinetic considerations.
Intransitivity in competitive systems is linked to complex phenomena that would
be difficult or impossible to explain on the basis of transitive assumptions.
Human preferences that seem irrational from the perspective of the conventional
utility theory, become perfectly logical in the intransitive and relativistic
framework suggested here. The example of competitive simulations for the
risk/benefit dilemma demonstrates the significance of intransitivity in cyclic
behaviour and abrupt changes in the system. The evolutionary intransitivity
parameter, which is introduced in the Appendix, is a general measure of
intransitivity, which is particularly useful in evolving competitive systems.
Quantum preferences are also considered in the Appendix.Comment: 44 pages, 14 figures, 47 references, 6 appendice
Asymptotic properties of Arnold tongues and Josephson effect
A three-parametrical family of ODEs on a torus arises from a model of
Josephson effect in a resistive case when a Josephson junction is biased by a
sinusoidal microwave current. We study asymptotics of Arnold tongues of this
family on the parametric plane (the third parameter is fixed) and prove that
the boundaries of the tongues are asymptotically close to Bessel functions.Comment: 21 pages, 1 figur
Competition of Color Ferromagnetic and Superconductive States in a Quark-Gluon System
The possibility of color ferromagnetism in an SU(2) gauge field model is
investigated. The conditions allowing a stable color ferromagnetic state of the
quark system in the chromomagnetic field occupying small domains are
considered. A phase transition between this state and the color superconducting
state is considered. The effect of finite temperature is analyzed.Comment: 21 pages, 4 Postscript figure
- …