From: wjp <wjp@swcp.com>

Date: Tue Jun 30 2009 - 10:01:52 EDT

Date: Tue Jun 30 2009 - 10:01:52 EDT

Iain:

This is an interesting point, and it seems to me that, in part, it depends

upon your interpretation of QM.

We can take the noncommutability of variables as ontological or epistemological.

That is, is the incompatibility of "measuring" certain variables "simultaneously"

a matter of our ability to know them or is it a feature of the possibilities of

reality.

(It is possible, it seems to me, that it is a merely a theoretical feature,

one which forces our empirical results to be interpreted in this way, but I

won't discuss this.)

Many physicists today believe that it is a settled issue that it is ontological.

If this is the case, then is it possible for anyone (perhaps even God) to

establish initial conditions? Quantum mechanically can we even speak of initial

conditions. The system would be, supposedly, in a huge complex mass of entangled

states. Is it possible to establish these entangled states?

On the other hand, there are, supposedly, a huge number of possible QM states

associated with a given macro "state." Otherwise, we couldn't build buildings

or fly planes. So perhaps a designer need not establish such entangled states,

but something far more coarse.

If we say that it is a issue of measuring (e.g., collapse of the wave function,

or dechorence, whatever), it still seems that in order to establish an initial

condition one would have to be able to, in some sense, measure it.

Epistemological interpretations of QM suggest that the problem is our measuring

techniques, even the possible measuring techniques available to us in this

universe, something akin to Heisenberg's microscope example. If this is the

case, then one could presumably say that an electron is located at position X

and with velocity V. It's just that we couldn't physically know it.

Such statements presume that electrons are localizable entities, which they

may not be -- we don't, for example, speak of waves in this manner, but then again

I've never been able to get my mind around waves that don't wave anything, just

another example of the ghostly world we supposedly inhabit.

Another way to look at the epistemological question is whether there are

hidden variables. In this sense QM is incomplete, where complete would

mean that it would be classically deterministic.

So what of so-called physical parameters? Why believe that they don't

suffer the same difficulties as other measurements?

Physical considerations would suggest that we can measure nothing

exactly. And that makes us wonder whether this is an epistemological

property or an ontological one.

If it is ontological then we can speak of nothing having an exact value.

If physical parameters can be, indeed must be, exact, then do they serve

as something like hidden variables? Or are physical parameters theoretical

artifacts. We speak of them as if they are absolutes, as properties of our

universe. I must presume, then, that theoretically the combination of variables

associated with parameters commute, for if they did not, theoretically they

could have no value.

Enough of this confused speculation.

bill

On Tue, 30 Jun 2009 07:35:46 +0100, Iain Strachan <igd.strachan@gmail.com> wrote:

*> Hi, Don,
*

*>
*

*> OK, so in this particular case (Lorenz) it is a poor analogy.
*

*> However, the point I was trying to make still, I think, stands. One
*

*> may think of chaotic systems that are sensitive to initial conditions
*

*> and also to other mathematical parameters of the system. George's
*

*> point (as I understand) is that the accuracy of specification of
*

*> initial conditions (e.g. momentum, position) is limited by the
*

*> uncertainty principle. My point was that the values of fundamental
*

*> constants were not subject to that limitation.
*

*>
*

*> It occurs to me also that the original point was about whether the
*

*> specification of the initial conditions of the universe amounted to a
*

*> designer's input of information. However, it would perhaps be better
*

*> to say that the specification of fundamental constants is an input of
*

*> information (if one wants to argue front-loading - which I'm not sure
*

*> I do). On the one hand, it could be said that the Lorenz attractor is
*

*> sensitive to initial conditions. But on the other hand, you could
*

*> just as well say that in terms of the behaviour of the system, even
*

*> though it's not predictable microscopically, it always ends up on the
*

*> Lorenz strange attractor - in terms of the general behaviour, provided
*

*> rho is fixed at 28 (which it certainly is in the simulations that
*

*> generate the attractor). In real life, rho, as you say, can vary -
*

*> but in order to demonstrate the attractor in a simulation, the
*

*> programmer has to choose precisely the value to make that happen. A
*

*> fine-tuning ID advocate might well argue that Planck's constant, fine
*

*> structure constant, ratio of gravity to EM force etc were also
*

*> deliberately chosen to make life inevitable.
*

*>
*

*> Iain
*

*>
*

*> On Tue, Jun 30, 2009 at 2:16 AM, Don Nield<d.nield@auckland.ac.nz> wrote:
*

*>> Sorry, Iain, but you are off the beam. The parameter rho that appears in
*

*> the
*

*>> Lorenz equations is not a fundamental constant that can be thought
*

*> of as
*

*>> being fine tuned. Rather, it is a parameter like a Reynolds number that
*

*> can
*

*>> be varied continuously. In the original Lorenz paper on convection in
*

*> the
*

*>> atmosphere it appears as a sort of Rayleigh number that measures the
*

*> ratio
*

*>> of factors associated with the causes of convection (a temperature
*

*>> difference between the top and bottom a layer of fluid, expansion ,
*

*>> gravity) and properties. of the fluid that hinder convection (viscosity,
*

*>> conduction). For small values of rho one has no convection, for
*

*> intermediate
*

*>> values one has laminar convection, and for large values one has
*

*> turbulence.
*

*>> The value 28 (in conjunction with the values of sigma and beta) is a
*

*> typical
*

*>> value for the the transition to turbulence.
*

*>> Don N.
*

*>>
*

*>>
*

*>> Iain Strachan wrote:
*

*>>>
*

*>>>
*

*>>> Ah yes, of course I'd forgotten the quantum uncertainty. But that
*

*>>> only applies to things like position and momentum (which would of
*

*>>> course apply to my Lorenz Attractor example - initial conditions).
*

*>>> However it would not apply to the fine-tuning of the constants of the
*

*>>> universe. Hence there are constants in the Lorenz attractor (this
*

*>>> from the Wikipedia page):
*

*>>>
*

*>>> ## Lorenz Attractor equations solved by ODE Solve
*

*>>> ## x' = sigma*(y-x)
*

*>>> ## y' = x*(rho - z) - y
*

*>>> ## z' = x*y - beta*z
*

*>>> function dx = lorenzatt(X,T)
*

*>>> rho = 28; sigma = 10; beta = 8/3;
*

*>>> dx = zeros(3,1);
*

*>>> dx(1) = sigma*(X(2) - X(1));
*

*>>> dx(2) = X(1)*(rho - X(3)) - X(2);
*

*>>> dx(3) = X(1)*X(2) - beta*X(3);
*

*>>> return
*

*>>> end
*

*>>>
*

*>>> Note that the line starting rho = 28 specifies not the initial
*

*>>> conditions, but the constants of the system. One might imagine there
*

*>>> is much greater scope for fine adjustments of these. Different values
*

*>>> of rho give very different behaviour of the system.
*

*>>>
*

*>>> So generalising to the Universe, maybe the Creator has much more fine
*

*>>> choice over things such as Planck's constant , or the Fine Structure
*

*>>> Constant than would be allowed by Quantum uncertainty.
*

*>>>
*

*>>> Iain
*

*>>>
*

*>>>
*

*>>> To unsubscribe, send a message to majordomo@calvin.edu with
*

*>>> "unsubscribe asa" (no quotes) as the body of the message.
*

*>>>
*

*>>
*

*>>
*

*>>
*

*>
*

*>
*

*>
*

*> --
*

*> -----------
*

*> Non timeo sed caveo
*

*> (\__/)
*

*> (='.'=)
*

*> (")_(") This is a bunny copy him into your signature so he can gain
*

*> world domination
*

*> -----------
*

*>
*

*>
*

*> To unsubscribe, send a message to majordomo@calvin.edu with
*

*> "unsubscribe asa" (no quotes) as the body of the message.
*

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Received on Tue Jun 30 10:03:06 2009

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