Freethought & Rationalism Archive

tronvillain · 02-13-2002, 03:05 PM

Good. Quantum phenomena can be weird, but I've never heard of that one.

Christopher Lord · 02-13-2002, 03:34 PM

My own way of thinking of this is as follows. Correct me if I'm way off.

An 'observation' is impacting the electron cloud with something (lets say a photon). This gives the photon a vector dependant on the state of the cloud at the moment of impact.

at the macro-level, these impacts average out so that we see 'atoms' and other particles.

Since our only method of seeing atoms is by shining a stream of particles at them and observing the reflected and deflected particles, we can not observe without collapsing the state of the target to one state.

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

David Gould · 02-13-2002, 03:58 PM

I do not think it is quite that simple.

The photon itself is a quantum particle with a wave function.

Also, photons are zipping around into electrons all over the palce. Copenhagen interpretation says that this does not collapse any wave functions because they are unobserved.

I have emailed my old lecturer (well, he's not that old) about the experiment I discuss above. Hopefully, he will get back to me with some info on it.

echidna · 02-13-2002, 04:23 PM

My loose understanding of QM (not that there seems to be any other type of understanding) is that the CI is only the oldest of several interpretations of "spooky action at a distance".

The irony of the CI, is that it seems to make a very strong scientific case for the necessity of a omniscient consciousness to realise the universe, as outlined in Paul Davies� "God and the New Physics". Actually tron, I was under the impression that under the CI, it was consciousness which was necessary to collapse the wave function, only that this creates an impossible set of systems in systems, conciousnesses perceiving consciousnesses etc.

As in the case of Schroedinger�s Cat, the Greek philosopher�s tree falling in the empty forest makes no sound until there is a consciousness to observe it. Counter-intuitive, but frustratingly difficult to prove.

Hence the desperation to find alternatives, of which the Transactional Interpretation seems the strongest currently � no god necessary, but quantum communication is necessary backwards in time.

Either way, there�s some weird shit going down.

David, I think your lecturer is correct that at this stage no one can objectively prove the correctness of any of the interpretations since they all fit the empirical data. But I�m suspicious of the validity of your dice experiment. CI isn�t humanocentric BTW, it�s consciounesscentric (my spellchecker just went into orbit � must have perceived a problem).

David Gould · 02-13-2002, 04:35 PM

I agree that at the moment no empirical data can distinguish the interpetations.

However, I disagree that Coenhagen points to a omniscient consciousness.

As I have outlined, human consciousness (hell, any consciousness, as you have said) will be enough.

All it needs to be is a possible part of the wave function and then one of the possible parts will be realised.

I think Copenhagen says that if universes in general result from a collapsed wave function then all of them must contain intelligences.

Of course, if the universe is not the result of a collpased wave function then this is all moot anyway...

The experiment that I have outlined was given as evidence for the observer being important. However, it can also be used for backwards in time causality, many universes, blah blah blah.

Christopher Lord · 02-13-2002, 04:37 PM

Quote:

Also, photons are zipping around into electrons all over the palce. Copenhagen interpretation says that this does not collapse any wave functions because they are unobserved.

It is truely the 'tree in the forest' problem. since these collisions are not observed, no one can say if they made a sound. The most reasonable response would be to say that in the absence of an observer, the events typically associated with the event (sound), would occur but go unheeded.

David Gould · 02-13-2002, 04:47 PM

Unfortunately, reasonable responses and quantum mechanics do not go well together.

Apparantly, it is pretty much accepted that unless observed they do not collapse. Instead, the wave function of an electron and the wave function of a photon would merge into a wave function of a photon/electron collision.

Thus, there are many possible results of the collision (as you would expect, with the photon being in many possible places and the electron being in many possible places). Many of these possible results are that the particles do not collide at all (this is obvisous when you think about it).

I do not understand QM (I have read the Bohrs quote on this!). However, the mathematics on it are pretty tight I am told and the theory is the most succesful predicative theory we have ever had.

tronvillain · 02-13-2002, 04:55 PM

Part of the problem here may be that no "official" verson of the Copenhagen Interpretation exists. The versions of it that emphasize consciousness strike me as ridiculous and unecessary.

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

David Gould · 02-13-2002, 05:03 PM

If the wave function exists then something must trigger its collapse.

What is this trigger?

If it is some mechanical detection, then anything and everything triggers the collapse.

For example, a photon striking an electron is a mechanical detection. Thus, it must trigger the collapse.

However, all particles are interacting with other particles at all times.

Thus, if mechanical detection is all that is required the wave function can never actually exist.

As Qm is based on the wave function and the mathematics to go with it, this seems kind of difficult to reconcile...

Copenhagen says that the observation is the trigger and the observer must be conscious.

As far as I can tell, this is not mystical, anymore than consciousness itself is mystical.

Conscious things are different qualitively from non conscious things.

Why can not one of those differences be the ability to collapse wave functions?

There is nothing more mystical in that than the ability to self identify.

Christopher Lord · 02-13-2002, 05:17 PM

But wouldnt the chaos of normal impacts average out as well?

The observer actually sends a directed, non-random particle at the desired target. this would be what collapses.

I highly doubt a mind is required to collapse these. Minds can create order, however, and this would have to be ruled out before moving on to such an exotic sugestion.

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02-13-2002, 03:05 PM	#11
tronvillain Veteran Member Join Date: Oct 2000 Location: Alberta, Canada Posts: 5,658	Good. Quantum phenomena can be weird, but I've never heard of that one.

02-13-2002, 03:34 PM	#12
Christopher Lord Senior Member Join Date: Feb 2001 Location: Toronto Posts: 808	My own way of thinking of this is as follows. Correct me if I'm way off. An 'observation' is impacting the electron cloud with something (lets say a photon). This gives the photon a vector dependant on the state of the cloud at the moment of impact. at the macro-level, these impacts average out so that we see 'atoms' and other particles. Since our only method of seeing atoms is by shining a stream of particles at them and observing the reflected and deflected particles, we can not observe without collapsing the state of the target to one state. [ February 13, 2002: Message edited by: Christopher Lord ]</p>

02-13-2002, 03:58 PM	#13
David Gould Senior Member Join Date: Jun 2001 Location: Australia Posts: 759	I do not think it is quite that simple. The photon itself is a quantum particle with a wave function. Also, photons are zipping around into electrons all over the palce. Copenhagen interpretation says that this does not collapse any wave functions because they are unobserved. I have emailed my old lecturer (well, he's not that old) about the experiment I discuss above. Hopefully, he will get back to me with some info on it.

02-13-2002, 04:23 PM	#14
echidna Veteran Member Join Date: May 2001 Location: Melbourne, Australia Posts: 2,832	My loose understanding of QM (not that there seems to be any other type of understanding) is that the CI is only the oldest of several interpretations of "spooky action at a distance". The irony of the CI, is that it seems to make a very strong scientific case for the necessity of a omniscient consciousness to realise the universe, as outlined in Paul Davies� "God and the New Physics". Actually tron, I was under the impression that under the CI, it was consciousness which was necessary to collapse the wave function, only that this creates an impossible set of systems in systems, conciousnesses perceiving consciousnesses etc. As in the case of Schroedinger�s Cat, the Greek philosopher�s tree falling in the empty forest makes no sound until there is a consciousness to observe it. Counter-intuitive, but frustratingly difficult to prove. Hence the desperation to find alternatives, of which the Transactional Interpretation seems the strongest currently � no god necessary, but quantum communication is necessary backwards in time. Either way, there�s some weird shit going down. David, I think your lecturer is correct that at this stage no one can objectively prove the correctness of any of the interpretations since they all fit the empirical data. But I�m suspicious of the validity of your dice experiment. CI isn�t humanocentric BTW, it�s consciounesscentric (my spellchecker just went into orbit � must have perceived a problem).

02-13-2002, 04:35 PM	#15
David Gould Senior Member Join Date: Jun 2001 Location: Australia Posts: 759	I agree that at the moment no empirical data can distinguish the interpetations. However, I disagree that Coenhagen points to a omniscient consciousness. As I have outlined, human consciousness (hell, any consciousness, as you have said) will be enough. All it needs to be is a possible part of the wave function and then one of the possible parts will be realised. I think Copenhagen says that if universes in general result from a collapsed wave function then all of them must contain intelligences. Of course, if the universe is not the result of a collpased wave function then this is all moot anyway... The experiment that I have outlined was given as evidence for the observer being important. However, it can also be used for backwards in time causality, many universes, blah blah blah.

02-13-2002, 04:47 PM	#17
David Gould Senior Member Join Date: Jun 2001 Location: Australia Posts: 759	Unfortunately, reasonable responses and quantum mechanics do not go well together. Apparantly, it is pretty much accepted that unless observed they do not collapse. Instead, the wave function of an electron and the wave function of a photon would merge into a wave function of a photon/electron collision. Thus, there are many possible results of the collision (as you would expect, with the photon being in many possible places and the electron being in many possible places). Many of these possible results are that the particles do not collide at all (this is obvisous when you think about it). I do not understand QM (I have read the Bohrs quote on this!). However, the mathematics on it are pretty tight I am told and the theory is the most succesful predicative theory we have ever had.

02-13-2002, 04:55 PM	#18
tronvillain Veteran Member Join Date: Oct 2000 Location: Alberta, Canada Posts: 5,658	Part of the problem here may be that no "official" verson of the Copenhagen Interpretation exists. The versions of it that emphasize consciousness strike me as ridiculous and unecessary. [ February 13, 2002: Message edited by: tronvillain ]</p>

02-13-2002, 05:03 PM	#19
David Gould Senior Member Join Date: Jun 2001 Location: Australia Posts: 759	If the wave function exists then something must trigger its collapse. What is this trigger? If it is some mechanical detection, then anything and everything triggers the collapse. For example, a photon striking an electron is a mechanical detection. Thus, it must trigger the collapse. However, all particles are interacting with other particles at all times. Thus, if mechanical detection is all that is required the wave function can never actually exist. As Qm is based on the wave function and the mathematics to go with it, this seems kind of difficult to reconcile... Copenhagen says that the observation is the trigger and the observer must be conscious. As far as I can tell, this is not mystical, anymore than consciousness itself is mystical. Conscious things are different qualitively from non conscious things. Why can not one of those differences be the ability to collapse wave functions? There is nothing more mystical in that than the ability to self identify.

02-13-2002, 05:17 PM	#20
Christopher Lord Senior Member Join Date: Feb 2001 Location: Toronto Posts: 808	But wouldnt the chaos of normal impacts average out as well? The observer actually sends a directed, non-random particle at the desired target. this would be what collapses. I highly doubt a mind is required to collapse these. Minds can create order, however, and this would have to be ruled out before moving on to such an exotic sugestion.

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