X-Message-Number: 3774
Date: 29 Jan 95 18:54:21 EST
From: "Steven B. Harris" <>
Subject: SCI.CRYONICS Uploading
Dear Cryonet:
Perhaps because I'm a physics novice (no grad courses) the
Clark/Zimov debate mystifies me somewhat. I cannot see what
exchange forces (Pauli forces) have to do with anything, since
these are (as both debate participants must know) NOT an automa-
tic consequence of quantum identity. For one thing, such forces
operate only between "identical" members of one class of partic-
les (fermions), and but not "identical members" of the other
class. I remind all that condensation into the same quantum
state in the absence of exchange forces between bosons is why we
get fun things like superfluid liquid helium-4, lasers, and those
in-phase radiowaves from any radio station (i.e., all the photons
cuddled up together without our working very hard to get them
that way).
I accept the idea of quantum identity for other reasons (see
the index of Frank Tippler's last book _The Physics of
Immortality_, section D, for the real-world consequences if
quantum identity did NOT operate, Pauli forces aside). However,
I still do not see how it applies to the problem of identity. In
quantum mechanics, two things are identical if they are composed
of the identical particles, and are in the same quantum energy
state. However, being quantum-identical in quantum mechanics
does *not* guarantee identical behavior. Any two ground-state
carbon-14 atoms, for instance, are absolutely identical, and this
fact could even be proved by showing that they interfere with
each other in experiments with beams of carbon-14 atoms (I don't
know if this has been done with carbon-14 specifically, but it
has been done with much larger atoms). However, being quantum-
identical does not suggest that two carbon-14 atoms will decay at
the same time-- in fact we expect they won't. The differences in
decay time are not due to the environment, either, including what
place each atom occupies in the environment. We know this,
because decay probability is relatively independent of locality
or many other physical factors. Two carbon-14 atoms, according
to the best science, decay at different times for NO REASON AT
ALL (here we use "reason" in the sense of a reference to simpler
underlying causal mechanisms).
Now, two brains, even if composed of the identical numbers of
identical atoms in the same arrangement and with the whole in the
same quantum state (i.e., same energy distributed through the
same bounded volume in the same way), then the two may be quantum
identical for an instant-- sort of like the carbon-14 atoms.
After that, however, they will evolve to different quantum
states, simply by the same random quantum (Schroedinger
wavefunction collapse) processes which make one atom decay now
and another identical one continue in stability for the next
million years. Brains are much more complex and unstable with
regard to state-change than carbon-14 atoms, of course, and
quantum-identical brains will thus begin to diverge insofar as
quantum state immediately as soon as we start our "clock."
Location of the brains is largely irrelevant (i.e., irrelevant to
the extent that the brains are bounded in potential wells or
closed "volumes" so that we can even talk meaningfully about
quantum states!). Anyway, two identical brains become quantum
non-identical with great rapidity: the minimum time to change
quantum states is on the order of 2R/c, where 2R is brain
diameter and c is the speed of light (on the order of tenths of a
nanosecond). They become personality non-identical with the same
rapidity, if "personal identity" results from thoughts and
feelings, which in turn are the product of brain physical state
(i.e., brain quantum state-- what else).
Of course it may be that thoughts and feelings are only
crudely the product of brain quantum state. In other words, many
quantum states may result in EXACTLY the same thoughts and
feelings, which are the product of discontinuous discrete "neural
states." If personality is the product of a much more grainy
brain neural states which are more resistant to quantum
differences, then such states will not diverge until quantum
differences get large enough. I don't think this saves us from
the quantum problem, though, for I submit they surely WILL get
large enough. The quantum level is not that far below the
physical level of brain operation, and even such things as ion-
channel opening and closing in neural membranes is a heavily
quantum-influenced process. In a short time (I don't know how
short-- fractions of a second, probably), I suspect quantum
effects will make some neuron fire in one brain and not the
other. Then more differences will follow in cascade. At that
point, mental state is at risk of changing, and in fact I cannot
see how it can escape (brains, being analog devices, are NOT like
computers in this kind of behavior). At some further point in
the future, mental state will have diverged enough to change
behavior.
Behavior? How can my long-term behavior depend on random
quantum events and have the result (whatever happens) still be
ME? Please note that this is the same problem that all of us are
faced with every single day. Pick a time 0 and say "This is ME."
At some time after time zero, and probably not a long time, you
will be thinking and feeling things which are significantly
different than you would have done if your quantum state had
evolved differently, which it could well have done (and perhaps
is doing in some parallel universe-- who knows?). Wait long
enough and you are a different person in that sense FOR NO REASON
(existentialists will hate that). This is counterintuitive, but
would be more clear if you had a duplicate of you in duplicate
surroundings to watch.
There are several possible responses to this idea. The first
is for a person to say: "I *feel* like *essentially* the same
person I was years ago, so all this quantum nonsense obviously
makes no difference to personal identity. I'd feel like the same
person even if for quantum reasons I had said, did, and thought
something different, as I well might have." This approach
supposes either a soul or a brain "self-circuit" so robust and so
well beta-tested that it stands up to the slings and arrows of
outrageous Schroedinger collapses, with scarcely a screen-
flicker. It does so for a lifetime, it does so through a cryonic
suspension (maybe even a bad one), and it will do so though a
resurrection and a zillion lifetimes after. It leaps tall
buildings in a single bound....
I'm making fun here, but in a sense this is a matter of
taste, as I remarked before. If Joe Blow still insists he
*feels* like Joe Blow, even though all his former friends no
longer recognize him, because he doesn't look, feel, or act
particularly like Joe Blow-- who's to say "Joe," with his tough
self-circuit which takes a licking and keeps on ticking, is
wrong? Yes, of course, the courts may have some problems in this
case with wills and possessions, and divorces will be messier,
too. Declaring someone "dead" (saying the person or identity is
degraded past some arbitrary extent) is always a social decision.
In the future it's going to get REALLY tough.
The other approach to long-term identity changes due to
quantum randomness and other annoyances (aging, dementia,
freight trains, etc, etc), is the Arthur C. Clarke approach,
already mentioned in this thread. This approach views identity
as a fuzzy concept, with varying degrees of survival of identity
possible-- not only after cryonic suspension, but even throughout
the course of normal life, let alone an extended one. A
restatement of this idea is even more difficult to conceptualize,
for it says that there is actually no such THING as a "person"
which is then considered to "partly survive," but rather that the
very concept of one "person" surviving across any stretch of time
longer than a few nanoseconds (or minutes or days), is an
artificial one, and one not strictly honest to the facts (again,
see Korzybski). I myself feel that my own identity as a "person"
has "survived" the last decade only in the same sense that the
"Roman Catholic Church" has "survived" the last millennia. In
both cases the concept is concrete enough to talk about, and
certainly to be useful, but in both cases damned hard to pin down
when you want to think about exactly what happened.
Steve
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