Tuesday, July 10, 2012

Barr on quantum mechanics

Over at Big Questions Online, physicist Stephen Barr addresses the question of the relationship between quantum physics and theology.  Take note of the discussion board attached to the article, to which Barr has contributed.  (And if you haven’t watched Barr’s lecture on “Physics, the Nature of Time, and Theology” from the Science and Faith Conference at Franciscan University of Steubenville last December, you should.)

28 comments:

Eduardo said...

Uhh I can see Paisley popping up any time now XD.

So Dr, I see that Dr. Barr is also talking about philosophy, I mean at least to me how we interpret data is completely philosophical. I remember you said something that misterianism doesn't work, but I wonder, what would happen if we were to choose that ... you know, say that shit just happens and really put oneself in a mystery position. Something like, strong sgnosticism about the subject.

* and a bit of an excuse like, the science haven't yet got there so we must wait and not judge *

reighley said...

I was a little disappointed that he set it up as a distinction between copenhagen and many worlds. I want a non-local hidden variable theory. Is that so wrong?

Eduardo said...

Perhaps talking about that was too hardcore for the average reader n_n?

reighley said...

The fact that the average reader will accept undiluted hand waving in their quantum theory, but not admit of something they cannot easily see, is what is wrong with the world today.

rank sophist said...

I too prefer non-local hidden variables, as strange and paradoxical as they may be. Still an interesting article--and a very amusing takedown of the materialists who support Copenhagen.

Eduardo said...

well wasn't really thinking about acception of ideas XD.

The world should be more critical ?

can't really say anything against that n_n

BeingItself said...

Feser should go after some of that Templeton money. All you have to do is write something cozy about science and your particular superstition.

The cash will start pouring in, but credibility and respect go out the door.

Edward Feser said...

Say what you will about BeingItself, he's got his talking points down!

reighley said...

@BeingItself,
I have to know : do you think that wave functions actually collapse, and do you think that something causes them to do that? If so, what?

Eduardo said...

Dr, I suppose people around these parts deserve a better target xD!

PatrickH said...

I think BI is right, Ed. You should go for the Templeton money. As for its effect on your credibility, the people who would disrespect you for getting Templeton loot don't like you anyway. You can laugh at them all the way to the bank.

Anonymous said...

"All you have to do is write something cozy about science and your particular superstition."

1) So asserts the person who has yet to give a cogent reason why Christianity is a superstition.

2) This statement applies to everything written by Dawkins, Harris, Hitchens, Dennett, Stenger, Hawking, Atkins, et al.

DNW said...

" ... And if you haven’t watched Barr’s lecture on “Physics, the Nature of Time, and Theology” from the Science and Faith Conference at Franciscan University of Steubenville last December, you should.)"


I think he made a couple of interesting and relevant points which tracked along many of the exchanges and comments here.

Specifically:


A, the logical implication of (what he claims is) the Augustinian conception of time as an artifact of the universe rather than a preexisting field in which the universe is expressed.

Maybe I appreciated it because it also implies, as he says it implies, that the puerile infinite-series objections we have seen trotted out here again and again, and the witless objection to a Creator as implying a god standing next to a powder keg he is about to light off to get the universe started, are the result of fundamental mis-conceptions which were philosophically dealt with long ago.

Several commenters here, not to mention the author of this blog, have repeatedly made the same points.

Whatever the fact situation may be, the concepts are clearly distinguishable.


B, Barr's assertion concerning the lack of meaningful conceptual individuation in electrons however, is not something I had recognized as important before; but which is also quite interesting to contemplate from a logical point of view.

Gyan said...

Prof Barr does not really engage with the point made as to the validity of the hypothesis of the wavefunction of the entire universe (WEU)

At most, he grants that the wavefunction may be postulated for physical universe, assuming the minds to be unphysical.

Now the point is the WEU is supposed to exist because the universe is build up of electrons, protons and other fundamental particles and is entirely reducible to fundamental particles.
That is, the assumption of WEU conflicts with the Thomist position that the whole is not reducible to the parts and the parts themselves are known only in relation to the whole.

This sort of undercuts the WEU claims. But Prof Barr is straightforwardly a conventional physicist and has no desire for Thomist adventures.

grodrigues said...

@Gyan:

"That is, the assumption of WEU conflicts with the Thomist position that the whole is not reducible to the parts and the parts themselves are known only in relation to the whole."

I am not understanding this, as postulating a WEU is *precisely* a vindication of the claim that the whole is not reducible to its parts.

An analogy is with particle entanglement, say electrons. The state space is the Hilbert space tensor product, but the state of the pair of entangled particles is *not* of the form u tensor v but rather a linear combination of states of these form -- but this is just a reflection that the whole (the entangled pair) is more than its parts (the two electrons).

Anonymous said...

At times like these, I wish I'd been a math or physics major, so that I could follow this bloody conversation and understand reality more deeply. "Hilbert space tensor product"? How am I to wrap my mind around such a mystical entity?

Eduardo said...

Don't worry Anon half the stuff someone talks in Particle physics is actually some kind of mathetical property, or some special quantum; it never never fails to be one of the two.

Eduardo said...

"some special quantum property"

U_U Must learn to preview

Justin said...

So, with respect to Dr. Barr's point about the nature of the wave function and determined probabilities at observation, I have a question.

The Geiger counter could be modeled as part of the wave function of the system (modeling decay) being observed, and the wave function will not give anything but a probabilistic result, but Bob can observe that the Geiger counter has definitely registered or not registered the decay.

If Sue does not know what Bob has observed, but she is capable of describing an even larger wave function including the particle, the Geiger counter and Bob, I take it the wave function would still not give a 0% or 100% probability? This assumes, of course, that we could even describe the wave functional of all the particles in a Geiger counter, much less Bob.

acucucuuc said...

I think this is the Schrodinger's cat scenario, with Bob being the cat (a bobcat?).

E.H. Munro said...

"Hilbert space tensor product"? How am I to wrap my mind around such a mystical entity?

In Soviet Russia Hilbert Space Tensor Product wraps self around your mind! (Sorry, someone had to do it.)

Gyan said...

grodrigues,
You make a valid point. QM is not reductionist.

But the only reason to postulate WEU is the belief that the universe is fully describable as a collection of fundamental particles, thereby assuming a non-Thomist view.

grodrigues said...

@Gyan:

"But the only reason to postulate WEU is the belief that the universe is fully describable as a collection of fundamental particles, thereby assuming a non-Thomist view."

This is incorrect. First, as a statement of fact as positing a WEU does not entail a belief "that the universe is fully describable as a collection of fundamental particles". For one, one may need other natural, non-particle entities such as space-time. How this can go about is not important, but even a cursory glance at LQG should disabuse you of the notion. More argumentation is needed to read off ontological conclusions from physical theories (and non-existent ones at that), otherwise we will soon be saying that a Lagrangian or a Feynman diagram is "real".

note: all this quite apart from the fact whether a theory of Quantum Gravity, if we ever get there, does indeed postulate a WEU.

Second, and more importantly, positing a WEU would be a part of a *physical theory* and as such, it can hardly refute Thomist metaphysics. You must have missed the recent post of Dr. Feser about the relations between physics, philosophy of nature and natural theology.

Omer said...

Professor Feser,

Thanks for posting this illuminating talk by Barr.

I am a Muslim and I believe that the Qur'an is outside time as the Qur'an indicates.

I was looking for some information to show how process theology and so on is not in harmony with modern cosmology of space-time.

Thanks again for sharing this.

Eduardo said...

What is ... process Theology again?

Casey said...

So has any argument been made that perhaps quantum mechanics justifies an Aristotelian ontology? Seeing things as existing in potential when they are wave functions and then collapsing when they meet the actuality of observation?

Basil said...

Casey,

Yes, see "The Quantum Enigma" by Wolfgang Smith.

Alan Aversa said...

Yes, Barr's lecture was awesome.