In a general sense, if we (the observer) are outside of the system, there is a definition of "closed system" which allows output from the system, even though there is no input into the system, *if such a configuration is possible*. If there is no output, I agree with you that the system is unknowable.
If the observer is inside (part of) the closed system, that's when things get very mystifying. In this case there are non-trivial limits to what we can know about the system, even though we are in it, since our framework of "knowing" is also part of the system. (For instance, I maintain that in this case we cannot know if information is being erased.) But I don't think that's what your question was referring to. Tom John M wrote: > Tom: one excerpt I try to address: > > "Closed system (Principia Cybernetica): An isolated > system having no > interaction with an environment. A system whose > behavior is entirely > explainable from within, a system without input..." > (I skip the rest, including the mathematical closure > as irrelevant for my reply). > > How do you know about such system? > What I mean is: if NO interaction reaches or leaves > the 'system', (it includes 'information as well) it > does > not even 'exist' for us. It is more than a 'black > hole' which is said to be receptive. A 'closed > no-thing'? > > John M > > > ----- Original Message ----- > From: "Tom Caylor" <[EMAIL PROTECTED]> > To: "Everything List" > <everything-list@googlegroups.com> > Sent: Monday, May 01, 2006 6:18 PM > Subject: Re: why can't we erase information? > > > > > Bruno Marchal wrote: > > Le 25-avr.-06, à 17:37, Tom Caylor a écrit : > > > > > > > > In fact, "closed system" and "meta element" seem > to be contradictory. > > > > Not necessarily. It could depend of what you mean > exactly by "closed". > > Closure for the diagonalization procedure is the > key. Diagonalization > > is the key of the "heart of the matter". I will come > back on this > > later. > > > > Closed system (Principia Cybernetica): An isolated > system having no > interaction with an environment. A system whose > behavior is entirely > explainable from within, a system without input... > > Mathematically, a closed system contains its boundary, > or it contains > its limit points. In other words, anything > expressable with the given > axioms/language is itself a member the system. > ...SKIP > Tom --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---