On 07-10-2015 07:20, Brent Meeker wrote:
On 10/6/2015 8:11 PM, smitra wrote:
On 07-10-2015 02:04, Brent Meeker wrote:
On 10/6/2015 4:35 PM, smitra wrote:
On 07-10-2015 00:06, Bruce Kellett wrote:
On 7/10/2015 7:51 am, Brent Meeker wrote:
On 10/6/2015 1:18 PM, Stathis Papaioannou wrote:
I'm not sure I understand what you are getting at. I meant that
if the normal sequence of brain states is s1-s2-s3 with
corresponding mental states m1-m2-m3 and s2 is omitted, there is
nothing in m3 to give any indication of the discontinuity. Of
course, normally s2 is necessary in order to generate s1, but
that doesn't change the argument.
But I think that's wrong. Brains are not like ideal von Neumann
computers or Turing machines that have "brain states"
corresponding to "mental states". If you simulated a brain using
a computer you would find that an enormous number of "brain
states" were required to instantiate a single conscious thought
and furthermore the brains states necessary for one thought
overlapped with those necessary for the next thought. So this
overlap at the low level is part of the physical continuity needed
for consciousness. The fact that the physics can be simulated by
discrete computation doesn't imply that the conscious states are
discrete.
I think that is an important insight, Brent. One thing that it
means
is that two brains can, by chance, be in the same physical state at
one instant, but those two brains might be supporting quite
different
thought processes. The consequence is that there is one person per
brain -- the same person can't be spread over several brains.
Bruce
That's impossible, two identical physical states within an isolated
system will yield the same (statistical) results when measured. So,
if one person would be experiencing something different compared to
the other person at that very instant then, by definition, they were
not in the same physical state at that very moment, because that's
how we define physical states to begin with.
No, the contention is that a physical state, a state that obtains at
a
single moment (Planck time?), does not instantiate a thought or an
experience. A thought or experience requires a sequence many
physical
states and having two sequences share some subsequence of states is
not enough to make the two experiences the same. Consider an
airport:
the fact that two runways cross doesn't make them the same runway.
Brent
Yes, this is the "observer moment problem" discussed a long time ago
in this list, but the requirement of needing a sequence of states is
also problematic, because at any given time I'm a conscious being.
This paradox is related to the well known paradox where one argues
that you can map the states of the brain of a person as it evolves in
time to that of a clock and then ask why the clock isn't conscious.
Of course, the clock doesn't perform any computations,
Sure it does. It computes the time.
but to see this you have to consider the counterfactual inputs and the
corresponding counterfactual outputs.
Right. The problem is not that it doesn't compute anything, it's that
it doesn't interact with its environment so it has nothing to be
conscious of, except the time.
Then as I've argued here one or two years ago, a much better solution
is to invoke the MWI. Given your conscious experience, your brain can
still be in an astronomically large number of states. So, instead of
identifying yourself with the single branch, you should consider the
very large bundle branches that contain the same macroscopic
information.
The superposition of these states describes a person that is entangled
with the environment. This entanglement contains the counterfactuals
that you need to define what computation is performed at any given
moment.
I agree with that. But the hypothetical being argued was the inverse:
Suppose two persons/brains were is exactly same state.
But invoking the environment makes this a messy way out, a better way
i.m.o. is to include one computational step, you identify the
operator:
O = sum over inputs i of |output(i)><i|
as your observer moment . The summation is over states that fall
within your resolution,
But doesn't that just move the problem to determining which states are
"yours".
Well, the idea is that your observer moment at any time is an algorithm
in a well defined computational state, so to define it requires
specifying a list of inputs and their corresponding outputs, which
cannot be done in classical mechanics. But in quantum mechanics,
physical states are generically correlated states and it's not a problem
to specify a physical state representing a well defined computation that
nevertheless is defined at a specific moment in time.
The classical picture leading to paradoxes is fundamentally flawed
precisely because you only get classical behavior due to entanglement
with the environment.
Saibal
Brent
and this then partially defines a computation.
Saibal
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
