Francois Tremblay

I guess the contradiction I saw was due to the contradictory nature of the Copenhagen interpretation itself. I can't really get my mind to wrap around contradictions that easily.

echidna

I think this is the intuitive understanding and unfortunately QM is notoriously counter-intuitive.

Umm, if I understand this correctly, this is logically impossible. Under the CI a particle’s properties are indeterminate until it is observed (interacts). Experimentally verifying them is an observation. By definition it’s impossible to verify empirically.

Even when it is observed, under the Heisenberg Uncertainty Principle pairs of properties cannot be known simultaneously, the more precisely one measures position, the more fuzzy its momentum becomes, as though its momentum is somehow dependent on the observation and does not have a true value of its own.

AFAIC there’s some weird shit going down.

Franc, what’s the contradiction ? Perfectly circular as I see it.

tronvillain

I'm not sure that the Copenhagen interpretation actually says "wave functions are collapsed if and only if observed by a conscious observer." Still, let's grant that it does and look at the argument again:

P1.) Wave functions are collapsed if and only if observed by a conscious observer.
P2.) The universe is the result of a collapsed wave function.
C.) Therefore, intelligence was the inevitable result.

Despite what you seem to think, C does not follow from P1 and P2.

P1.) Wave functions are collapsed if and only if observed by a conscious observer.
P2.) The universe is the result of a collapsed wave function.
C.) Therefore, the universe was and is still being observed by at least one conscious observer.

Without an external observer to cause the initial collapse, nothing is explained. To get to anything resembling your conclusion, you have to modify P1 and and add another premise:

P1.) Wave functions are collapsed if observed by a conscious observer or if the collapse generates a conscious observer.
P2.) A universe is the result of a collapsed wave function.
P3.) No conscious observer exists or existed independent of the universe.
C.) Therefore, universes will always contain conscious observers.

Pretty similar to the strong athropic principle.

[ February 13, 2002: Message edited by: tronvillain ]</p>

David Gould

I do not understand the circularity that you are refering to (obviously!).

I am also unclear what you are saying cannot be empirically verified.

I am aware of the Heisenburg Uncertainty Principle.

(He was one of the Copenhagen adherents).

As far as I know, experiments that do not directly observe a wave function have confirmed that the wave function causes effects as if all the possible collapses have actually happened.

The specifics of this experiment involve detecting the flow of electricity going both ways simultaneously after giving an electron two choices in which to travel but not checking on it directly.

The electricity was detected by examining the magnetic fields caused by it.

Thus, the electron is in effect going both ways simultaneousl.

However, when they actually check on which way the electron is going directly, the magnetic detectors only detect the electricity flowing one way.

From this, I have looked at a Copenhagen cosmological model.

This assumes that the universe itself is a collapsed wave function.

Working backwards, the original wave function must have contained the possibility of a universe with intelligent life (we exist). (I also argue that it is impossible for a universe to form without intelligent life but that should be obvious from my other posts).

As the wave function contains this possibility, it acts as if this possibility has occurred. (electricity goes down both paths).

The wave function then must act as if it had been observed.

Thus, it collapses.

echidna

I think you’re right. I think the wave function collapse is officially triggered by an interaction. Then because there is no clear boundary for the quantum system, logical paradoxes such as Schroedinger’s Cat arise. Consciousness is an implication from the term "interaction".

That quantum events have macroscopic effects is beyond doubt, but given the problem’s still alive and kicking after 60 years, I’m guessing it’s not an easy one.

Can anyone explain "The TI For Dummies" ? (Bill ?)

I think it’s a choice between having a divine being or dumping chronological causality. Tough call.

David Gould

Hmm.

I still disagree on the divine being thing, based on the fact that things internal to the wave function have effects as if the wave function had collapsed in all ways possible.

I think that the revised premise is probably better - I guess I had it subsumed in my earlier ramblings.

Hopefully, my lecturer will get back to me about that experiment at some point.

tronvillain

David Gould:
Nothing about this experiment shows that a conscious observer is required.

David Gould

Sorry, this experiment was not to demonstrate that a conscious observer is required. That was the other one - I apologise for talking about two different ones.

This one was to show that the non-collapsed states of a wave function have an effect as if a collapse into all of the states simultaneously had actually occurred.

This is my basis for getting to your premises, which I agree with.

Again, I apologise for causing confusion.

echidna

But I think that measuring the magnetic field from an electron is again an observation of its properties (or the system’s) which would consequently collapse its wave function to affect its other properties.

This would be why the detector measures a real state and does not see a fuzzy probability field.

Do you have a reference for the experiment ? I would be interested if someone has really refuted the CI at last.

David Gould

I do not understand what you are getting at here. It does not refute CI, if by CI you mean Copenhagen.

The experiment detected that there are magnetic changes which indicate that the electron is travelling both ways around the circuit simultaneously.

When the electron is observed directly, it only travels one way.

Again, this is another experiment I will have to look up - this is another one from the course.

If my lecturer gets back to me about the other one, I will ask him about this one too.