Artículos con la etiqueta ‘Entropía’

How do life, economy and other complex systems escape the heat death?

Por • 6 feb, 2014 • Category: Opinion

The primordial confrontation underlying the existence of our universe can be conceived as the battle between entropy and complexity. The law of ever-increasing entropy (Boltzmann H-theorem) evokes an irreversible, one-directional evolution (or rather involution) going uniformly and monotonically from birth to death. Since the 19th century, this concept is one of the cornerstones and in the same time puzzles of statistical mechanics. On the other hand, there is the empirical experience where one witnesses the emergence, growth and diversification of new self-organized objects with ever-increasing complexity. When modeling them in terms of simple discrete elements one finds that the emergence of collective complex adaptive objects is a rather generic phenomenon governed by a new type of laws. These ‘emergence’ laws, not connected directly with the fundamental laws of the physical reality, nor acting ‘in addition’ to them but acting through them were called by Phil Anderson ‘More is Different’, ‘das Maass’ by Hegel etc



Is the Information Entropy the Same as the Statistical Mechanical Entropy?

Por • 27 sep, 2012 • Category: Crítica

It is shown that the standard expression for the information entropy, originally due to Shannon, is only valid for a particular set of states. For the general case of statistical mechanics, one needs to include an additional term in the expression for the entropy as a function of the probability. A simple derivation of the general formula is given.



The different paths to entropy

Por • 19 sep, 2012 • Category: Ciencia y tecnología

In order to undestand how the complex concept of entropy emerged,we propose a trip towards the past reviewing the works of Clausius, Boltzmann, Gibbs and Planck. In particular, since the Gibbs’s work is not very well known, we present a detailed analysis, recalling the three definitions of the entropy that Gibbs gives. May be one of the most important aspect of the entropy is to see it as a thermodynamic potential like the other thermodynamic potentials as proposed by Callen. We close with some remarks on entropy and irreversibility.



A Model of Time

Por • 7 jul, 2012 • Category: Filosofía

Based on a mathematical model of quantum measurement we derive some properties of intuitive time.



An Entropic Story

Por • 25 sep, 2011 • Category: Leyes

A pedagogical account of entropy and its history.