Re: why can't we erase information?

From: Brent Meeker <meekerdb.domain.name.hidden>
Date: Sun, 09 Apr 2006 12:44:59 -0700

Wei Dai wrote:
> If we consider our observable universe as a computation, it's rather
> atypical in that it doesn't seem to make use of the erase operation (or
> other any operation that irreversibly erases information). The second law of
> thermodynamics is a consequence of this. In order to forget anything
> (decrease entropy), we have to put the information somewhere else (increase
> entropy of the environment), instead of just making it disappear. If this
> doesn't make sense to you, see Seth Lloyd's new book "Programming the
> Universe : A Quantum Computer Scientist Takes On the Cosmos" for a good
> explanation of the relationship between entropy, computation, and
> information.
>
> Has anyone thought about why this is the case? One possible answer is that
> if it were possible to erase information, life organisms would be able to
> construct internal perpetual motion machines to power their metabolism,
> instead of competing with each other for sources of negentropy, and perhaps
> intelligence would not be able to evolve in this kind of environment. If
> this is the case, perhaps there is reason to hope that our universe does
> contain mechanisms to erase information, but they are not easily accessible
> to life before the evolution of intelligence. It may be a good idea to look
> out for such mechanisms, for example in high energy particle reactions.
>
> However I'm not sure this answer is correct because there would still be
> competition for raw material (matter and energy) where intelligence can
> still be an advantage. Anyone have other ideas?

I guess you have in mind some kind of local (micrsoscopic) mechanism for erasing
information. The Copenhagen intepretation of QM assumed this, but couldn't
solve the problem of the Heisenberg cut. At a large scale, it is not yet
settled whether black holes erase information. With a few exceptions, like
t'Hooft, physicist assume that the unitary evolution of QM is fundamental. If
that's the case, the only place information gets "erased" is by expansion of the
universe.

Brent Meeker

--~--~---------~--~----~------------~-------~--~----~
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.domain.name.hidden
To unsubscribe from this group, send email to everything-list-unsubscribe.domain.name.hidden
For more options, visit this group at http://groups.google.com/group/everything-list
-~----------~----~----~----~------~----~------~--~---
Received on Sun Apr 09 2006 - 15:45:58 PDT

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:11 PST