Liz, Richard: I´m not talking about global reduction of entropy neither of the universe neither a star, planet of black hole, but a local decrease of entropy at the cost of a (bigger) increase of entropy in the surroundings, so that the global entropy grows.
I mean local. A computation becomes whatever that permit the pumping of entropy from inwards to outwards and thus maintain the integrity of the entity that computes to do further computations. That is the definition of life in physical terms. so that life and computation are entangled in some way. The byproduct of this activity is an increase of entropy of the surroundings. No thermodynamical or any other physical law is violated. Within this definition, a computer alone does not perform computations a man that uses the computer to calculate his VAT declaration is performing a computation, because doing so the man has the information to deal with entropy increase produced by law enforcers. The semaphore system in a city perform computations when considering the system as the city as a whole. for the same reason. but also any living being computes as well. There hasn´t to be digital. analogic, chemical computations, for example, hormone levels can be part of a computation. Neurons are not digital. the activation potentials are not quantized to certains discrete levels. Digital computation, for example in DNA encoding-decoding or in the case of digital computers are good for storing and communicating information for a long time against environmental noise. Shannon law demonstrate why it is so. there is nothing magic about digital. But when noise is not a concern, analogical paths of chemical reactions with protein catalizers perform fine computations. More often than not, computation is analogic-digital. Living beings do it so. But also human systems, a car with a man inside, keeps entropy so there is a analogico-digital computation going on. So computation in this sense means not only computation as such but also perception or data input -or information intake- and a proper response (as result of the computation) in the physical world that keeps the internal entropy. 2014/1/20, Alberto G. Corona <[email protected]>: > Computation is understood as whatever made by a digital computer or > something that can be emulated (or aproximated) by a digital computer. > So everything is a computation. That is a useless definition. because > it embrace everything. > > Everything is legoland because everything can be emulated using lego > pieces? No, my dear legologist. > > What about this definition? Computation is whatever that reduces > entropy. In information terms, in the human context, computation is > whatever that reduces uncertainty producing useful information and > thus, in the environment of human society, a computer program is used > ultimately to get that information and reduce entropy, that is to > increase order in society, or at least for the human that uses it. > > A simulation is an special case of the latter. > > So there are things that are computations: what the living beings do > at the chemical, physiological or nervous levels (and rational, social > and technological level in case of humans) . But there are things that > are not computations: almost everything else. > > > -- > Alberto. > -- Alberto. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
