arXiv subjects

Miroslav Holeček

Publications and source records attributed to Miroslav Holeček.

3 recordsLinked to original sources

arXiv2022

Information form of the second law of thermodynamics

An essential role of information in microscopic thermodynamics (e.g. Maxwell's demon) opens a challenging question if there exists a formulation of the second law of thermodynamics based only on pure information ideas. Here, such a formulation is suggested for unitary processes by introducing information as a full-valuable physical quantity defining an (objective) microscopic information entropy as 'information about microstate'. We show that various forms of entropy (Boltzmann, Shannon, Clausius) are in fact only a special cases of information entropy whose general form is found out. An observer plays here the role of a special (information) reference frame (IRF) towards which the entropy is defined. Some paradoxes or misunderstandings connected with the concept of entropy or the content of the second law arise by describing a situation without specifying a concrete IRF. Typically, the Boltzmann statistical approach cannot be symmetrically used towards the past as towards the future in one IRF. The information second law is full usable at meso- or microscopic scales: the information form of the generalized second law is found out too.

cond-mat.stat-mech↗

arXiv2022

Information break of time symmetry in the macroscopic limit

The evident contrast between the time symmetry of fundamental microscopic laws and the time asymmetry of macroscopic processes is a challenging physical problem. The observation of unitary evolution of a general physical system by an idealized observer whose recording and processing information is time neutral is studied in a full information context. In the macroscopic limit, a contradiction between observations and predictions done at different times appears. It implies that the observer cannot read records performed at times when the entropy of the system is larger.

cond-mat.stat-mech↗

arXiv2018

Work as a Memory Record

The possibility of a controlled manipulation with molecules at the nanoscale allows us to gain net work from thermal energy, although this seems to be in contradiction to the Second Law of thermodynamics. Any manipulation, however, causes some memory records somewhere in the system's surroundings. To complete the thermodynamic cycle, these records must be reset, which costs energy that cancels the previous gain. The question is, what happens when this memory (information) is recorded only in the work reservoir? Then it cannot be reset because the record means nothing but the work gain itself (e.g., the result position of a weight in the gravity field). Is this a violation of the Second Law? To answer the question, we study in this theoretical work an exchange of energy between a physical (possibly microscopic) system that is thermalized at the beginning and another (possibly microscopic) system -- the work reservoir -- during a deterministic process in an autonomous arrangement, including also an auxiliary device controlling the process. This arrangement is suitable for deriving some equalities which express the Second Law in a form incorporating explicitly relevant memory records (and related information). We use these equalities in studying a hypothetical process including many cycles in which the only non-reset memory record is that in the work reservoir during each cycle. The results show that either the work gain is canceled in following cycles (and the work reservoir fluctuates and cannot accumulate energy), or there exists an information flow from the system (an information engine), or the system cannot work in an expected way for a purely dynamic reason (this reveals a deeper connection of the studied questions with the concept of adiabatic accessibility).

cond-mat.stat-mech↗