Hi Brent and Stathis,
----- Original Message -----
From: "Brent Meeker" <meekerdb.domain.name.hidden>
To: <everything-list.domain.name.hidden>
Sent: Saturday, February 21, 2009 1:35 AM
Subject: Re: Personal Identity and Ethics
snip
>>
> There's no inconsistency between the universe being quantum mechanical,
> while human thought processes are essentially classical. The classical
> world emerges from the quantum in the limit of large action.
>
> Brent Meeker
Ok, my difficulty lies in the notion of "copying". If we are going to use a method X to derive a conclusion, does it not make sense that X must be sound? QM forbids the cloning or copying of states:
http://en.wikipedia.org/wiki/No_cloning_theorem
"The no cloning theorem is a result of quantum mechanics which forbids the creation of identical copies of an arbitrary unknown quantum state. It was stated by Wootters, Zurek, and Dieks in 1982, and has profound implications in quantum computing and related fields.
The state of one system can be entangled with the state of another system. For instance, one can use the Controlled NOT gate and the Walsh-Hadamard gate to entangle two qubits. This is not cloning. No well-defined state can be attributed to a subsystem of an entangled state. Cloning is a process whose end result is a separable state with identical factors.
.....
"No-cloning in a classical context
There is a classical analogue to the quantum no-cloning theorem, which we might state as follows: given only the result of one flip of a (possibly biased) coin, we cannot simulate a second, independent toss of the same coin. The proof of this statement uses the linearity of classical probability, and has exactly the same structure as the proof of the quantum no-cloning theorem. Thus if we wish to claim that no-cloning is a uniquely quantum result, some care is necessary in stating the theorem. One way of restricting the result to quantum mechanics is to restrict the states to pure states, where a pure state is defined to be one that is not a convex combination of other states. The classical pure states are pairwise orthogonal, but quantum pure states are not."
How does a limit of large action change this?
----- Original Message -----
From: "Stathis Papaioannou" <stathisp.domain.name.hidden>
To: <everything-list.domain.name.hidden>
Sent: Saturday, February 21, 2009 1:19 AM
Subject: Re: Personal Identity and Ethics
> The psychological criterion of personal identity is, or should be,
> agnostic on the question of how consciousness is actually generated.
> It says simply that if I am destroyed here and a copy of me with the
> same psychological properties is created there, then I will suddenly
> find myself there. It is possible to accept this criterion but deny
> that the right sort of psychological properties could be duplicated in
> a computer, or by any physical means at all if there is a supernatural
> element involved in consciousness. What I find incoherent is the idea
> that the psychological properties might be able to be duplicated but
> nevertheless there is no continuity of identity because the soul
> cannot be duplicated.
>
>
> --
> Stathis Papaioannou
In the Wiki article
http://en.wikipedia.org/wiki/No_cloning_theorem we find:
"Imperfect cloning
Even though it is impossible to make perfect copies of an unknown quantum state, it is possible to produce imperfect copies. This can be done by coupling a larger auxiliary system to the system that is to be cloned, and applying a unitary transformation to the combined system. If the unitary transformation is chosen correctly, several components of the combined system will evolve into approximate copies of the original system. Imperfect cloning can be used as an eavesdropping attack on quantum cryptography protocols, among other uses in quantum information science."
Does this allow us to recover our method X? No, because unless the copy is "identical", not just "approximate", we can not conclude that any notion of continuance of consciousness might obtain.
Onward!
Stephen
--~--~---------~--~----~------------~-------~--~----~
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?hl=en
-~----------~----~----~----~------~----~------~--~---
Received on Sat Feb 21 2009 - 15:25:38 PST