Перегляд вихідного коду сторінки Deception, Deceptions As Well As Downright Lies Concerning SCH727965

Importantly, Gibbs formula provides an informational reinterpretation of the second law of thermodynamics as follows: our information about an isolated system can never increase since spontaneous processes always entail a loss of information (Rothstein, 1951). Hence, according to Gibbs, a gain of entropy equals to a decrease of our information about the system. Negentropy (brillouin) As mentioned above, physical free energy is [http://en.wikipedia.org/wiki/Ramoplanin Ramoplanin] described by Helmholtz formula  (Equation 1). Critically, Brillouin (1953) coined the term negentropy and linked this concept to information. He unified both, information and physical entropy under the same equation. Below, we have applied the same short reasoning as Brillouin's (1953) paper to deduce the formula. First, we consider a system with P0 different equiprobable structures  (states). If we obtain information I about the system and we use it, as Maxwell's demon did with the gas, the number of possible structures is reduced to P1. Taking the natural logarithm of the ratio as a measure of information, this yields to I = K?ln(P0/P1), where K? is a constant. For example, by choosing K? = log2(e) we would be measuring the information I = log2(P0/P1) in bits. By choosing K? = k (i.e., the Boltzmann constant), applying Boltzmann formula [S = kln(P)] and rearranging terms, the following relationship is obtained: S1=S0?I (9) where I corresponds to the negentropy term. Brillouin's idea of considering information and physical entropy as two interchangeable quantities has been widely accepted (Prigogine, 1978; Plenio and Vitelli, 2001; Maruyama et al., 2009). Remarkably, with Brillouin's equation, a generalization of the second law of thermodynamics can be formulated with the inclusion of an information term: (S0 ? I) �� 0, for every isolated system (Brillouin, 1953). Furthermore, the latter statement entails a deeper result, namely that Shannon's source coding theorem and the second law are intrinsically related in the sense that a violation of one may be used to  violate the other. Processing information Szilard (1929) proved that the act of acquiring information from a system generates entropy, or equivalently, it has an energetic cost due to the very nature of the procedure. He showed that the minimum amount of energy required to determine one bit of information is kTln(2) J or equivalently, an increase of entropy of kln(2) J/K. Later, Landauer (1961) studied the same phenomena in computation and found that the same minimum amount of heat is generated to erase one bit of information, e.g., in disk formatting. As an interesting fact, the generation of heat is the main reason that prevents modern computers from processing faster, and, in fact, these are still far from attaining Landauer's limit.