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Cosmology, Quantum Mechanics & Consciousness Message Board › The mechanism within quantum mechanics. What actually happens?

The mechanism within quantum mechanics. What actually happens? Collapse or no collapse?

A former member
Post #: 166
Thanks again Will for your further comments, particularly that amusing and not-at-all offensive one about my previous post. You portray me like a politician failing to address a question. Spot on, and I am probably going to do it again!

 I don't think there is any difference between Ian and me on the wave-like nature of a photon in transit. I am not saying that a photon starts off its journey as a particle and then turns into a wave en route. I am saying that the photon simply comprises the two physical events of emission from one electron and absorption by another, with a non-physical wave in between.  Don't we all have to agree about that? Perhaps where we would differ on the photon is merely in the use of English, where I would say that the emission and absorption events are particle-like and maybe (?) Ian would not. 

The dispute between us, at least with regard to more substantial things than photons, is that Ian thinks everything is wave-like at all times and I don't. Admittedly this debate is splitting hairs, because we know that quantum physics has a feature called wave/particle duality and we also know that there is a particle description of quantum field theory which is equivalent to the wave description.

The miracle is how a quantum wave which, as you said, effectively spreads over the entire universe, just as readily disappears down the tiny sink- hole of what is commonly called a particle.   Decoherence, which is the process of a well-defined wave breaking up and dissipating into the environment, does not come anywhere near to explaining that and I am happy to note this further angle on this question. 

I am not interested in splitting hairs in the philosopher's corner of this Message Board so that's all I want to say for now. I have answered Ian's question to my own satisfaction and also with a satisfying conciseness that has apparently left him lost for words!
A former member
Post #: 56
I am saying that the photon simply comprises the two physical events of emission from one electron and absorption by another, with a non-physical wave in between. Don't we all have to agree about that?

Not me, I don’t think ‘non-physical wave’ means anything outside mathematics.

The dispute between us, at least with regard to more substantial things than photons, is that Ian thinks everything is wave-like at all times and I don't. Admittedly this debate is splitting hairs, because we know that quantum physics has a feature called wave/particle duality and we also know that there is a particle description of quantum field theory which is equivalent to the wave description.

Wave/particle duality, as I understand it, is not a physical description; trying to think of stuff as wave and particle will give you a headache. There are handy classical descriptions of behaviour of lumps of matter which the behaviour of tiny little bits can be made to mimic, but it doesn’t follow that these little bits are either of these things. So let me push on with that idea that a photon is, like every particle, a tiny knot of big bang stuff that would much rather untangle (pardon the anthropomorphizing; it’s a common enough device in Fairy-tales). It is held in place primarily by it’s partners in a system, other quarks for instance, every one of which is a knot of the same big bang stuff and is desperately trying to unravel itself. As a knot it has some of the properties of a particle, as it moves the pressure it exerts rises and falls exactly as a sine wave describes, but it is actually neither of those things.

The miracle is how a quantum wave which, as you said, effectively spreads over the entire universe, just as readily disappears down the tiny sink- hole of what is commonly called a particle.

I don’t believe in miracles. In my book superposition is replaced with the idea that a knot that isn’t being held in place is a source of pressure in the field; the particle isn’t in any state, eigen or otherwise, it doesn’t exist. Under the right conditions the knot will re-tie somewhere.

I have answered Ian's question to my own satisfaction and also with a satisfying conciseness that has apparently left him lost for words!

Have no fear he’ll make up some new ones.

Just teasing, Ian. Thanks for the tip vis a vis realism and sorry to be hopelessly vague. To be honest I can’t be bothered to defend any particular epistemology. What I really mean is I just take everything at face value until I have a reason not, but I acknowledge that, as you intimate, that is the instant you give it any thought.
A former member
Post #: 167
My comment: “............ the photon simply comprises the two physical events of emission from one electron and absorption by another, with a non-physical wave in between. Don't we all have to agree about that?”

Your reply, Will: “Not me, I don’t think ‘non-physical wave’ means anything outside mathematics.”

Fair enough, perhaps I should not use such a phrase, though I quite like it. I cannot argue with your analogies of knots or the more frivolous bunnies because you are using these ideas as an aid to visualisation, not as a new explanation of quantum physics. Please don’t be offended but I prefer Einstein’s view: he had the strong intuition that the mathematical basis of quantum physics cannot be the complete explanation of the universe and that there must be at least one level of sub-quantum reality that we cannot perceive because of the limitations of our own physics. To use the accepted vernacular, this would be a hidden variables explanation. So Bell’s theorem applies - any hidden variables theory must be non-local - meaning that our notions of ‘near’ and ‘far’ cannot apply in the sub-quantum reality. I have no problem with that: it fits with other features such as (a) the quantum wave function applying over all space and (b) time and distance disappearing (in special relativity) to nil at light speed. We already know that quantum physics is weird and so it must follow that the sub-quantum world (if it does exist) is itself weird – very weird indeed. Whilst Bell’s theorem (and other theoretical results) place constraints on the nature of any supposed sub-reality, the possibility of such an explanation for QM does remain open.

So, when I refer to the ‘non-physical wave’ of the photon I mean that, to my mind, photon transmission is a process of the sub-quantum reality, not a process at our level of physical reality.
A former member
Post #: 168
PS just to emphasise that I am referring here to single photons. Clearly electromagnetic waves are real and physical, but they are composed of billions of photons. The fun starts when we try to understand these little critters one at a time!
A former member
Post #: 57
I cannot argue with your analogies of knots or the more frivolous bunnies because you are using these ideas as an aid to visualisation, not as a new explanation of quantum physics.

Well, the bunnies are a visual aid for the idea of knots in a field which is at least as old as Lord Kelvin’s knot theory of 1867. I don’t believe in ‘knots’ as such, as a visual aid I think of a box of Catherine Wheels that some joker dropped match into. It’s mayhem in there, but I can ‘see’ some of the fireworks trapped in symbiotic dances. Given the spinning nature of the image, I’d like to think it has some parallels with Roger Penrose’s Twistor theory, but given our relative facility with maths, I’m afraid I have no way of telling. The idea of an expanding field is more or less the same as the inflaton proposed to account for Alan Guth’s inflation period. If there is a difference it’s that I don’t think it has stopped expanding and that it is this continued expansion that is the source of all the energy.

Please don’t be offended but I prefer Einstein’s view:

Of course I’m not offended, that’s Einstein we’re talking about.

he had the strong intuition that the mathematical basis of quantum physics cannot be the complete explanation of the universe and that there must be at least one level of sub-quantum reality that we cannot perceive because of the limitations of our own physics.

I think so too. For all that mathematics can describe the universe (and an effectively infinite number of other universes), the actual one we find ourselves in is, I suspect, a physical thing that really exists.

(Gotta go to work, might carry on later.)
A former member
Post #: 170
So we are agreed then. That's a fairly boring state of affairs: I wonder if someone else will come in and disagree.

Meanwhile I just noticed that the Nobel Prize for physics this year went to people for working in quantum mechanics but not for the Higgs project. I looked at the CERN site and found that physicists there are taking it for granted that the Higgs boson has been found - ie what was was found in July is not anything other than the Higgs - but are stilll waiting for the final verdict from the 'jury' around December. So I do expect to claim on our wager!
lan B.
user 10895495
London, GB
Post #: 267

Sorry for the protracted delay in reply! Meanwhile, although this ain't the proper place -- maybe we need a "Forthcoming Fixtures/Talks of Possible Interest" threaad -- and sorry the notification is a little on the late side, how about this for consideration?


Monday, 12 November 2012, 7:00 pm

Conway Hall (South Place Ethical Society)


Conway Memorial Lecture 2012: Are We Seeing Signals from Before the Big Bang?

Speaker: Professor Sir Roger Penrose, Mathematical Physicist, Emeritus Rouse Ball Professor of Mathematics, Mathematical Institute, Emeritus Fellow of Wadham College, University of Oxford & Member, British Humanist Association

Chair: Professor Michael Rowan-Robinson, Professor of Astrophysics, Astrophysics Group, Imperial College London & former President, Royal Astronomical Society (2006-2008)

In this year’s Conway Memorial Lecture, Sir Roger Penrose, Emeritus Professor of Mathematics at Oxford University, will put forward an alternate view of the history and origin of the universe. Current cosmology takes the origin of the entire universe to be that overreaching explosion referred to as the Big Bang. There is indeed much evidence for the actual occurrence of such an event, but was it the actual beginning? The proposal of conformal cyclic cosmology (CCC) takes what we currently regard as the entire history of the Universe, from its Big Bang origin (but without an “inflationary phase”) to its final exponential expansion, to be but one aeon of a continual succession of such aeons. The big bang of each is taken to be a continuation of the exponentially expanding remote future of the previous one via an infinite rescaling of space and time. Events involving supermassive black hole encounters in the aeon previous to ours would have important observational implications for CCC, detectable within the ubiquitous cosmic microwave background. Some intriguing new evidence for this will be presented.

Free by Registration

Contact:
Sid Rodrigues (Programme Co-Ordinator)
Email: sid@ethicalsoc.org,uk
Tel: 0207 061 6744

Location:
Main Hall
Conway Hall
25 Red Lion Square
Holborn
London
WC1R 4RL
A former member
Post #: 171
Thanks for that comment Ian but what about the following:

Your mention of this very interesting idea of Penrose on cosmology is, as you admit, completely irrelevant to the topic of this thread which is about wave collapse in QM.

I pointed to exactly the same idea no less than two years ago on the thread labelled Cosmology.

It took you a whole year to reply to my posting and even then your discussion meandered onto the sailing of yachts. Perhaps this latest posting of yours deserves a similar treatment. We could talk about the Euro or something. What do you think?

And anyway, a few observations have prompted the hypothesis than whenever you express a point of view ( such as on the role of decoherence) but find yourself unable to respond to critical analysis of your point of view then you go silent for a couple of weeks then change the subject with some totally irrelevant comment. This is not the first time. Don't you think it would show a bit more integrity if you were to concede that you were wrong instead of hoping that not many people will notice the evident failure of your arguments?





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