Re: [asa] Brain and Determinism

Bill,

Topic 0: (software people always start counting with zero)

I am sorry the character for epsilon didn't translate in the cut and
paste. I cannot fix that in email other than to use something like an ascii
capital E for epsilon rather than a greek character.

Topic 1:

**Me** .... explain Polkinghorne? :)

rofl?

Not sure theres much chance of me understanding JP&NB, let alone explaining
them. What I can do is bring more of their explanation to the table. Would
that be sufficient?

Topic 2:

Elsewhere JP says something about it being the sharpness of a distribution
(first derivative) that rebuts Dawkins (as I recall that may have been in
the Cosmic Natural Selection section in appendix A?). But he does raise the
same issue that you do in your post. They just come to a different
conclusion.

You say "Ontologically, it must mean something like events occur for no
reason whatsoever, and yet they are statistically deterministic."

I don't know what that means. Isn't statistically deterministic an
oxymoron?

Maybe what's needed is a primer?

Topic 3:

>First, I don't understand the seemingly discontinuous comment about the
Planck length.

Do you mean the fact they start with the error being at the limit of
detectability and then use another example that has an error that is one
part in (fill in the blank with some arbitrarily large and fantastically
large number)?

Is that what you mean by discontinuous comment?

Regardless, I think I will include the calcium/synapse example. It is
relevant to arrival times and hypercomplex analog systems such as the
brain. the importance of JP&NB has to do with the mind.

Topic 4: Epistemological versus Ontological aspects.

I think it would be best to let JP and NB explain what they mean by that. I
will attempt to extract their comments. (This is where a wiki is of great
help organizing related topics).

Thanks,
 -Dave C

On Thu, Oct 1, 2009 at 8:14 AM, Bill Powers <wjp@swcp.com> wrote:

> Merv & David:
>
> A few comments.
>
> First, I don't understand the seemingly discontinuous comment about the
> Planck length.
>
> Second, I don't follow the argument. It seems to me that from beginning to
> end they are discussing epistemological uncertainty and not ontological
> uncertainty. In fact, it seems to me that the Heisenberg uncertainty can be
> similarly interpreted.
>
> Since I don't consider the Heisenberg uncertainty to really get at the
> matter (it can be viewed as merely the result of not attempting to measure
> an eigenvalue), consider instead something like the decay of a radioactive
> nucleus.
>
> We are told that if one were to ask why this particular nucleus decayed at
> this instance that the "appropriate" answer is that there is no reason.
> Yet, we are also told that the statistical decay of a host of such atoms
> has such a small variance that we can make extremely accurate atomic clocks
> from them.
>
> The situation is analogous to tossing an honest penny. If one were to try
> to predict whether this penny on this toss would be a head or a tail, our
> knowledge would be completely uncertain. All we could say is that it will
> be either a head or a tail. And this is why we in Bayesian fashion say that
> the result is 50-50, a measure of complete ignorance. Yet, were we to toss
> 10^23 such coins we could predict with extraordinary accuracy the fraction
> of coins that are heads and the fraction that are tails.
>
> In this analogical story would we say that there was no reason that the
> flip of a single coin came up heads? I don't think so. Such a story was
> well known long befor QM came along, and no one was led to argue that we
> live in a random universe. Well, maybe not no one. It was probably a
> common belief prior to the advent of modern science.
>
> I know that what I'm suggesting seems to lead to hidden variables. I've
> just never quite understood the claim that we live in a random universe,
> which appears to imply what?
>
> Is a random universe that is unpredictable? That's epistemological.
> Ontologically, it must mean something like events occur for no reason
> whatsoever, and yet they are statistically deterministic. This appears to
> me, at least, to be a paradox. Does ontological randomness entail that
> events occur without any antecedent conditions, not just unobservable, but
> none whatsoever. Even with the pennies there are antecedent condtions: the
> penny must be tossed.
>
> In summary, I don't get Polkinghorne's argument. Please, explain.
>
> thanks,
>
> bill
>
> On Thu, 1 Oct 2009, mrb22667@kansas.net wrote:
>
> My comments injected below...
>>
>> Quoting David Clounch <david.clounch@gmail.com>:
>>
>>
>>> Polkinghorne and Beale write about determinism and the
>>> brain1<#sdfootnote1sym>
>>>
>>>
>>> Consider a single nitrogen molecule in the air you are now breathing. On
>>> average it is traveling 450 m/s and bounces off about 7 billion other air
>>> molecules every second, thus 7,000 every microsecond. Suppose you knew
>>> the
>>> exact position and momentum of every one of these particles (even though
>>> this is impossible by Heisenberg's uncertainty principle), then perhaps
>>> you
>>> could, at least in principle, predict exactly where that nitrogen
>>> molecule
>>> would be one microsecond later. Of course there are all kinds of
>>> complications, such as electrostatic forces, angular momentum, and so on,
>>> but lets make it simple and pretend that these were all perfect spheres
>>> and
>>> Newton's laws exactly applied – the kind of eighteenth-century
>>> worldview
>>> that shaped the Enlightenment and still influences much of our thinking.
>>> But
>>> suppose a tiny error is introduced in the angle at which this air
>>> molecule
>>> is traveling, for any reason at all. A little bit of uncertainty about
>>> the
>>> position of an electron, say. Call this error ï ¥(epsilon). After one
>>> collision, the error is 2 ï ¥; after two collisions 4 ï ¥, and so forth.
>>> Each
>>> microsecond this error will increase by 2^7000, or roughly 10^2100. The
>>> situation is clearly hopeless even if the initial error corresponds to a
>>> Planck length (1.6 x 10 ^ -35 m – the smallest possible length, at
>>> which
>>>
>>> conventional physics breaks down) per meter, after just 97 collisions the
>>> uncertainty will be enough for the position of the molecule to be out by
>>> more than the diameter of a nitrogen molecule (6.2 x 10^-10m), which
>>> means
>>> it will miss the 98th target. This will happen in less than a 70th of a
>>> microsecond. And making the error one Planck length in the size of the
>>> observable universe (about 3 x 10 ^23 m) just means it will miss the
>>> 176thmolecule. So even with the unrealistic assumptions of a perfect
>>> Newtonian
>>> world elsewhere, exact determinism is dead.
>>>
>>
>> It isn't the error amplification (chaos theory) that kills determinism.
>> Because
>> the original 18th century thought assumed up front that such knowledge was
>> impossible anyway, they had already premised their speculation as being so
>> *in
>> principle* since they knew nobody could know all this. And that caveat
>> allows
>> them (and us now even with Chaos theory) to reduce the initial state error
>> *in
>> principle* to zero (infinitely smaller than a Planck length). So it is
>> only the
>> Heisenberg uncertainty as mentioned below that actually drives the real
>> stake
>> into the heart of determinism. Yet for all this, it doesn't prevent some
>> from
>> still thinking deterministically about the universe as a strictly causal
>> domain.
>> Since my mind can't fully fathom the nature of our ontological
>> uncertainty, I
>> find myself in this deterministically minded camp at least every other
>> Thursday.
>> Maybe the atoms in my brain will happen to bounce that way today.
>>
>> --Merv
>>
>> In fact, of course, we use
>>> statistical mechanics to describe the behavior of gases and liquids and
>>> do
>>> not try to predict the behavior of individual small molecules. But many
>>> people think of the indeterminacy in statistical mechanics as simply a
>>> limitation on our knowledge rather than a reflection of real
>>> indeterminacy
>>> as in the quantum world. This kind of argument strongly suggests, to our
>>> satisfaction at least, that in cases like the movement of molecules in
>>> air
>>> the indeterminacy is real.
>>>
>>>
>>> They go on to describe calcium ions in te synapses in the brain, and use
>>> a
>>> similar analysis. They conclude:
>>>
>>>
>>> We will see later that this entirely destroys the idea that the brain is
>>> a
>>> fully deterministic system.
>>>
>>>
>>>
>>> 1 <#sdfootnote1anc>Questions of Truth, pp. 126-127
>>>
>>>
>>
>>
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>

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Received on Thu Oct 1 12:50:09 2009