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 <agoc...@gmail.com<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 everything-li...@googlegroups.com <javascript:>. >> To post to this group, send email to everyth...@googlegroups.com<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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
