Dear LizR, On Monday, January 20, 2014 10:04:38 PM UTC-5, Liz R wrote: > > A process which transforms information? >
Any! Define information as the distinction between a pair of things that makes a difference to a third. The "third" is the witness, it gives us a notion of 3p... > Ultimately, digital computation comes down to the NAND operation, I'm > told, which means it's a lot of "bit twiddling" which ultimately transforms > one lots of bits into another. I guess versions with non-binary data (like > DNA I assume?) can be reduced in principle to binary... > We could reduce everything to binary, but we would be very inefficient and might be making what are actually computable (with a wider definition of computable) into intractable ones. (Where did that idea come from, Stephen asks himself... Maybe P=NP after all...) > > Not sure about the entropy definition. Since nothing reduces entropy > globally, I assume you mean only locally... Or at the cosmic scale? The > expansion of the universe supposedly reduces entropy, or makes more states > available to matter at least (I think it increases the maximum available > entropy, as per Beckenstein, rather than reducing it). > There is an analogue of Thermodynamics within the computational vision: Encryption and decryption operations are not exactly invertible. A one time pad encryption, done correctly, transforms text into noise -randomness, making it the analogue of entropy. So we say that for closed computations noise, increases of is constant. > > Well, life does that, I guess, temporarily... > Indeed! > > > > On 21 January 2014 09:17, Alberto G. Corona <[email protected]<javascript:> > > wrote: > >> 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. >> >> -- >> 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] <javascript:>. >> To post to this group, send email to [email protected]<javascript:> >> . >> Visit this group at http://groups.google.com/group/everything-list. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > -- 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.
