# Re: why can't we erase information?

```We can observe a closed system at two points in time t0, t1 say. The
system is closed in between, but not at the point of observation,
obviously.```
```
The evolution of the system between the two observation points must

Cheers

On Mon, May 01, 2006 at 06:42:26PM -0700, 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"
> 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
> >
> > 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
>
>
>
>
>
--
----------------------------------------------------------------------------
A/Prof Russell Standish                  Phone 8308 3119 (mobile)
Mathematics                                    0425 253119 (")
UNSW SYDNEY 2052                         [EMAIL PROTECTED]
Australia                                http://parallel.hpc.unsw.edu.au/rks
International prefix  +612, Interstate prefix 02
----------------------------------------------------------------------------

--~--~---------~--~----~------------~-------~--~----~
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