no quantum clones doesn't mean no for all intents and purposes clones

From: Tim May <>
Date: Tue, 24 Dec 2002 11:58:40 -0800

On Tuesday, December 24, 2002, at 11:02 AM, Stephen Paul King wrote:

>> I just can't see any basis for invoking quantum mechanics and "no
>> cloning" for why I am not you, or why I cannot plausibly experience
>> being you, and vice versa, and so on.
> [SPK]
> I did state that my argument is "hand waving"! But, you seem to
> have
> missed this. ;-)
> ...

> Woah! Since when does Nature have to wait for Mankind to figure out
> anything? YOur argument here is so grossly anthropocentric that I hope
> you
> would re-think what you are saying here! I am not thinking in terms of
> technical or engineering limits but instead I am trying to get at the
> "in
> principle" notions of "what could Nature do?"
> If, as I wrote before, our minds are classical computational
> machines,
> we should have no problems in "knowing what it is like to be" any
> entity
> that had a mind that required less computational power than that
> available
> to our brains. We might not be able to know "what it is like to be a
> bat"
> but surely we could "know what it is like to be an ameoba"!

Sorry, I misunderstood your chain of logic. I thought your paragraph
from the earlier post said that you were attempting to explain why we
_can't_ (as in "it is necessarily the case") simulate other minds or
have first-person experiences of their minds.

" The no cloning theoren of QM seems to have the "right flavor" to
how it is that we can not have first person experience of each other's
minds, whereas the UTM model seems to strongly imply that I should be
to know exactly what you are thinking."

I read the "how it is that we can not have" as your claim that we know
this to be the case.

I see you are saying something close to what I am saying, "It may be
the case" that minds cannot be simulated. And it may be the case, via
some hand-wavy arguments, that this is "because" to do so would violate
the no cloning theorem.

But, even on this claim, I am intensely skeptical. I don't believe that
any mind is critically dependent on a precise, perfect quantum state.

Consider this thought experiment. Suppose the no cloning theorem does
indeed mean that my mind in the state it is now in at this exact
instant cannot be exactly duplicated.

Well, would you settle for my mind as of a minute ago? A second ago?

(And the usual chestnuts about whether the "myself" of _right now_ is
the same person as a microsecond ago, an hour ago, etc.)

I can imagine some variant of the usual epsilon-delta arguments of
analysis to show that given any degree of closeness of states (possible
worlds), there exists some time delay which gives a simulation and
which still violates no theorems about cloned states. (I would guess
the time for biological systems is on the order of what Max Tegmark and
others have estimated for decoherence.)

In other words, no quantum clones doesn't mean no for all intents and
purposes clones.

--Tim May
Received on Tue Dec 24 2002 - 15:06:01 PST

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