[lightarrow]

Maybe, as I wrote, it's not exactly a matter of "complexity" but of irreversibility / loss of coherence (which is related to complexity but not the same thing).

Well yes, but that's just restating wavefunction collapse.

In my opinion, not, because it would provide a (generic) model for the collapse.

[dlorde]

...what I actually have in mind is that things can maybe maintain a certain amount of superpositions until it reaches a point where it's too hard to maintain them all, at which point some kind of simplification must occur.

OK; that sounds like an Objective Collapse model, which is fine as far as it goes, but for me, it needs some meat on its bones to reduce its arbitrariness.

What we'd need to test this idea though is a way to measure the total amount of complexity involved in order to see if there is some consistent level where a collapse of the wavefunction becomes more likely than not.

The problem here is that we only become aware of wavefunction collapse when we measure/observe the system, and increasing complexity means more interactions, which makes the complexity collapse model increasingly indistinguishable from the interaction collapse model.

I envisage real material as being outside the universe and merely contacting with it at a multiplicity of points, a bit like a spider with many legs hanging onto a web. Outside of the universe where the spiders reside there is no speed limit of c, but the movement of all the points of contact with the web are limited by c. Each leg continually multiplies into many new legs, following the waves in the web and maintaining an external, instant communication system between all these points. When the wavefunction has to collapse due to complexity, the spider simply lets go of the web with many of its legs and absorbs them back into itself.

Yes, I've thought about entangled particles being locally connected in a higher spatial dimension, which is fundamentally not so different from your spider, but I don't know whether this would be covered by locality in a dimensionally extended version of relativity, and I don't have the maths to find out. It's the kind of thing a physicist would think of, and I've not heard it proposed as a solution, so I'm guessing that either it is covered by locality, in which case Bell theorem invalidates it, or it just doesn't work.

[dlorde]

Well yes, but that's just restating wavefunction collapse.

In my opinion, not, because it would provide a (generic) model for the collapse.

But since wavefunction collapse is decoherence observed, saying that wavefunction collapse may be a matter of decoherence is not a particularly useful generic model.

Perhaps I've missed something - can you clarify?

[David Cooper]

What we really need to do is find experiments that allow us to push QM to the limits of how far it can sustain superpositions. I've found one that might fit the bill: http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser. The path to D0 can be kept very short while the other path to the D1, D2, D3, D4 cluster can be lengthened without limit, and the key point here is that it's what happens at this far end that dictates what "happened" a moment earlier at the D0 end. If the longer path can be stretched out to a year, you can appear to have backwards causation in time going back for a year. You can also bend the long path back on itself such that both ends are physically located right next to each other in the same lab.

Clearly it would be hard to stretch the path out to a year as the light would need to travel a whole lightyear to cover that distance, but a minute would probably be more than adequate, and a second might suffice. Even so, that's still going to be a long path. It may also be possible to slow down the light - I've read of materials in which it can be slowed down by 90% plus and even halted, so this could maybe enable very long time delays in a small space, hopefully without destroying the entanglements.

So, we have a setup in which there is a long delay between a future cause and its past effect, but I don't think there's really any backwards-in-time causation: what will actually happen is that the data received at D0 will be maintained in an state of superposition after it's been measured, and when the measurements are made later on at the far end, those states of the data can then simplify to remove the superpositions. However, if we take the data immediately after it's been taken generated at D0 and use it in complex calculations, we could maybe do something sufficiently complex with it to force it to lose its superpositions early, with the result that no interference patterns would be observed at the far end.

Addition to this post:-

To clarify a key feature of the experiment which I linked to, if you remove the beam splitter BSc, the interference patterns disappear at both ends of the experiment, so you can sit in a lab with the long path doubled back on itself (let's say a hour long) such that you can remove BSc and put it back in again and thereby dictate what happened at D0 an hour earlier.

[lightarrow]

In my opinion, not, because it would provide a (generic) model for the collapse.

But since wavefunction collapse is decoherence observed, saying that wavefunction collapse may be a matter of decoherence is not a particularly useful generic model.
Perhaps I've missed something - can you clarify?

I added the concept of irreversibility, which is certainly far from being clarified in qm, but which is not simply decoherence.
But I admit I was quite criptic about it.

[dlorde]

I added the concept of irreversibility, which is certainly far from being clarified in qm, but which is not simply decoherence.

Ah, OK... so in what sense might the collapse of the wavefunction be a matter of irreversibility?  irreversibility of what?

[cheryl j]

What I've never understood is why the particle or wave question is linked to the actual act of choosing to observe or not observe and isn't a result of the system of measurement used to observe.

[dlorde]

What I've never understood is why the particle or wave question is linked to the actual act of choosing to observe or not observe and isn't a result of the system of measurement used to observe.

I don't quite follow you; whether you get particle or wave behaviour does depend on your measurement setup. The object itself has the properties of both a particle and a wave in some strange way (sometimes called a 'wavicle').

[lightarrow]

I added the concept of irreversibility, which is certainly far from being clarified in qm, but which is not simply decoherence.

Ah, OK... so in what sense might the collapse of the wavefunction be a matter of irreversibility?  irreversibility of what?

Making a measure means making a macroscopic registration of an event. Imagine a single photon hitting a fotomultiplier: something happens inside the macroscopic bulk of photo-sensitive metal, which then releases an electron, which then hits another electrode which releases 2 electrons and so on until a macroscopic current can be detected. I don't know what happens exactly, but certainly all the process is irreversible.
If, instead, a single photon hits a single atom and excites it, this proces is reversible. Maybe from the microscopic --> macroscopic some process becomes irreversible.

[dlorde]

... Imagine a single photon hitting a fotomultiplier: something happens inside the macroscopic bulk of photo-sensitive metal, which then releases an electron, which then hits another electrode which releases 2 electrons and so on until a macroscopic current can be detected. I don't know what happens exactly, but certainly all the process is irreversible.
If, instead, a single photon hits a single atom and excites it, this proces is reversible. Maybe from the microscopic --> macroscopic some process becomes irreversible.

OK. That sounds to me like statistical thermodynamics; all the underlying interactions are reversible, but entropy increases because disordered states are more likely than ordered states, hence the arrow of time, and macro irreversibility...

[yor_on]

You're perfectly correct Cheryl, although dlorde is too (a born diplomat, that's me)
As long as you add yourself as a part of the experiment, your observation of the setup defining the outcome, I hope we can agree on it. Remember that question if a tree falls in the wood, did it? If no one is there to see it? We are the ones observing outcomes, and our observations is what define them. You can use a lot of intricate logic and that way question a lot of outcomes. But in the end I expect it to come down to if a universe can be expected to 'work' without us, or not? I think it can, and in that way you should be right in that circumstances define outcomes.
=

either my spelling, or my fingers, sux
Corrected though.

[Bill S]

OK, go for it

Some people just don't know when to run for the hills.

Actually, this thread has given me the impetus to pull together some of the scattered notes I have made over a few years, so I guess it's done me some good.

[Bill S]

The Infinite Cosmos      Part 5

  The apparently intrinsic indivisibility of infinity leads one to wonder if any “part” of infinity can be distinct from any other “part”.  Is it in any way meaningful to talk of parts of infinity?  If it is not, and if our Universe is “part” of this infinite cosmos, then we seem to have a problem.  However, the problem may not be as difficult to solve as it at first appears.  Consider the following possibility.  The cosmos is infinite; therefore every part of the cosmos is the cosmos.  Everything, including our apparently finite Universe, is infinite.  The birth of the Universe and perhaps its ultimate death exist together in infinity, along with all the things that “happen” between those two points.  It is all there, in eternity, in an all-embracing now.  We perceive spatial differences, and the passage of time, because our minds need to make sense of the partial image to which we are restricted.  This sounds like a recipe for predestination, but I am not suggesting that we should abdicate all responsibility for our actions; far from it.  In eternity, things are as they are, permanently.  However, we cannot entirely rule out the possibility that they are as they are, to some extent, because of the choices we seem to be making now.  Without time "to keep everything from happening all at once", our familiar concept of causality needs some re-thinking. We cannot hope to stretch our finite understanding around infinity and eternity.  Only if and when we realise the full potential of our oneness with everything in the cosmos could we hope to do that.  In the meantime, we can reason that the finiteness and change that we perceive occur only in our finite frames of reference, beyond which there is no change, and therefore no passage of, or through, time because everything just “is”. 

Julian Barbour writes of a realm – “Platonia” – in which movement and the apparent passage of time are illusions resulting from the way in which our minds interpret what he describes as a series of “snapshots” of a static, timeless cosmos.  It is a short step, if indeed it is a step at all, from Platonia to an infinite cosmos.  However, it would have to be acknowledged that in a truly infinite cosmos, the process of interpreting the snapshots, and the sequence of those snapshots, would also be illusions.  In a truly infinite realm every snapshot is every other snapshot; they exist together with no semblance of order or chronology.  We cannot move from one to another because there is no sequence and no passage of time in which to move.  If we live in an infinite cosmos, then every change we perceive, every movement we detect and every second that “ticks past” on our clocks must be an illusion.  Illusion is perhaps not the best word to use because if something exists in our reality, it is real for us.  In no way am I denying the reality of our Universe.  I am simply saying that our reality may not be "absolute" reality.

  What is, perhaps, even harder to comprehend is that, because no “part” of infinity can be distinct from any other “part”, then, any distinction which we, as individuals, perceive between ourselves and other individuals – past or present, living or dead – must also be an illusion, as must be the apparent distinction between ourselves and other creatures and objects.  Our individuality, our personality, that which we recognise as “I”, can be no more than an illusion created so that we may make sense of the limited perception which we have of “reality”. 

   Perhaps relativity is a more all pervading concept than we might imagine.  It has to be possible that, not only are time and space relative within our perception, but also that time and space exist only in our current frame of reference.  They are “real” within that frame of reference, but may be completely different, even non-existent, in another.  In fact, this is the way in which we have to look at the things I have just referred to as illusions.  It cannot be denied that they are real in our frames of reference, but reality is relative.

 In an infinite cosmos existence is infinite; everything that exists shares that same existence.  Each thing is everything.  There are no divisions or distinctions, only an all-pervading oneness.  Michael Talbot says this of the work of physicist David Bohm: “As he looked more carefully into the meaning of the quantum potential he discovered it had a number of features that implied an even more radical departure from orthodox thinking.  One was the importance of wholeness.  Classical science had always viewed the state of a system as a whole as merely the result of the interaction of its parts.  However, quantum potential stood this view on its ear and indicated that the behavior of the parts was actually organized by the whole.  This not only took Bohr’s assertion that subatomic particles are not independent ‘things’, but are part of an indivisible system one step further, but even suggested that wholeness was in some ways the more primary reality.”  This fits well with the idea that infinity is the primary reality, and that our seemingly finite existence is a mere shadow of that reality

What happens if we apply this reasoning to life, as, of course, we must?  If life is infinite, then it must be possessed by every “aspect” of the cosmos, whether or not we perceive it as being alive.  Talbot (1996) again refers to Bohm: “…he believes that dividing the universe up into living and nonliving things also has no meaning.  Animate and inanimate matter are inseparably interwoven, and life, too, is enfolded throughout the totality of the universe.  Even a rock is in some sense alive, says Bohm, for life and intelligence are present not only in all of matter, but in ‘energy,’ ‘space,’ ‘time,’ ‘the fabric of the entire universe,’ and everything else we abstract out of the holomovement and mistakenly view as separate things”.

 If all this is right, it might be tempting to say: “We are the cosmos”.  However, the term “we” implies distinction, therefore it would be more correct to say: “I am the cosmos”, recognising, of course, that every “I” in the cosmos can rightly make the same claim.  Talbot brings together two quotes from Whitman’s “Mystical Life” when he talks of “…feeling that ‘everything is everything’ and ‘I am that’.”             

Can we talk about dimensions in infinity?  Apparently some scientists feel that we can.  Some of the current cosmological theories relating to dimensions suggest that our Universe has more than four dimensions, but that we are able to detect only three of space and one of time.  Among the explanations offered for the fact that we are not aware of these other spatial dimensions is that they might be rolled up so tightly that our instruments cannot detect them.  It is even claimed that these dimensions might be rolled so tightly as to be infinitely small.  I have yet to find a definition of infinitely small that is able to distinguish it from non-existent.  However, that is another matter.  An alternative concept – the one that lets in the idea of dimensions of infinity – is that ours is a four dimensional Universe embedded in a higher dimensional cosmos, and that this cosmos might have infinite (sometimes stated as an infinite number of) dimensions.

 Any attempt to calculate the dimensions of infinity must be a matter of conjecture.  The most logical assumptions would seem to be that it might have infinite dimensions; or, perhaps, one infinite dimension.  The latter possibility seems the more likely; because, if infinity had more than one dimension, each of the dimensions would have to be all of the others, and one has to wonder how this would differ from having just one dimension.  The possibility must also be considered that dimensions are features of finite, temporal realms, and cannot be applied to infinity.  Thus, infinity would be timeless and dimensionless.  Those who have read Edwin Abbott’s “flatland” will undoubtedly notice a similarity between this interpretation of infinity and “Pointland”; although, it would have to be said that the occupant of “Pointland” was heard to be talking, which would indicate that “Pointland” must not have been timeless. 

[dlorde]

I'm afraid I found that post confused, confusing, and somewhat incoherent. Confusion between a subjective and an objective view, unsubstantiated assertions, and leaps to unjustified conclusions...

For example:

The apparently intrinsic indivisibility of infinity leads one to wonder if any “part” of infinity can be distinct from any other “part”.  Is it in any way meaningful to talk of parts of infinity?

Why does it seem apparently intrinsically indivisible to you? It seems to me that infinity is divisible into any number of parts, including an infinite number of parts. In any division, there will be at least two infinite parts. Consider a road that stretches away from you to infinity in either direction. You can paint a line across it and divide it into two infinite lengths, then paint another line across, making two infinite lengths and one finite length. You can do this an infinite number of times in either direction.

It is all there, in eternity, in an all-embracing now.

It's not an 'all embracing now', because you're outside of time in that perspective; 'now' is a subjective experience of observers traversing the time dimension.

This sounds like a recipe for predestination, but I am not suggesting that we should abdicate all responsibility for our actions; far from it.  In eternity, things are as they are, permanently.  However, we cannot entirely rule out the possibility that they are as they are, to some extent, because of the choices we seem to be making now.

These are two sides of the same coin in a 4D Parminidean block universe. Part of the future is dependent on the 'choices' we make now, but those choices are deterministic events like all others, from the 4D viewpoint. That we see them subjectively as free choices is a reflection of our ignorance of all the deterministic influences involved, including the processes in our own brains (and, of course, we can't see the future). Even in a deterministic universe we will act as if we have free will - we have no choice 

In a truly infinite realm every snapshot is every other snapshot; they exist together with no semblance of order or chronology.

Chronology is temporal order. But I don't see how it follows that infinity must be disordered. Consider the integers - a truly infinite extent of numbers in the plus and minus directions, and definitively ordered. All the evidence suggests that there is an ordering to time, at least at a macro scale; causality, statistical thermodynamics. There may be uncertainties at the quantum scale (see what I did there?), but they generally don't affect our subjective experience of chronology. The logical implication of your suggestion is that if we have chronology in this universe (which we appear to), it can't be infinite... I'm not averse to it being finite, but it ought to be for some coherent reason.

If we live in an infinite cosmos, then every change we perceive, every movement we detect and every second that “ticks past” on our clocks must be an illusion. Illusion is perhaps not the best word to use because if something exists in our reality, it is real for us.

So what are you saying? It isn't an illusion?  And surely saying 'if something exists in our reality, it is real for us' is tautologous - what does it mean? what is 'our reality' but what is real for us?

no “part” of infinity can be distinct from any other “part”

Why? what makes you think so?

In no way am I denying the reality of our Universe.  I am simply saying that our reality may not be "absolute" reality.

If reality is what is real to us, what is 'absolute reality'? what do you mean by it?

Perhaps relativity is a more all pervading concept than we might imagine.  It has to be possible that, not only are time and space relative within our perception, but also that time and space exist only in our current frame of reference.  They are “real” within that frame of reference, but may be completely different, even non-existent, in another.

Relativity is totally pervasive. Time and space are different for every observer. You could even say that from the 'point of view' of a particle travelling at light speed, there is no time or space (though how useful that would be isn't clear to me  ).

What happens if we apply this reasoning to life, as, of course, we must?

Why?

If life is infinite, then it must be possessed by every “aspect” of the cosmos, whether or not we perceive it as being alive.

What does 'if life is infinite' mean? and why does it imply that it must be a property of every aspect of the cosmos? Two different things can be infinite without one necessarily being an attribute of the other.

if infinity had more than one dimension, each of the dimensions would have to be all of the others...

Why?

[Bill S]

Dlorde, thanks for your response.  One of the great things about being able to share ideas is that others usually think of things in a different way and add new perspectives.

Sorry you found the last post "confused and confusing".  I've just had a look back through it, and I agree on both counts, although much less so if it is taken in conjunction with preceding posts. 

As I mentioned, these posts are pulled together from scattered notes.  It would undoubtedly have been better if I had spent more time organising them, but time is a bit short.  There should be one more "Part" to come, which may touch on some of your questions, but I will address each of them separately, anyway.   

[Pmb]

I was wondering if anyone here has read The Philosophy of Quantum Mechanics: The Interpretations of Quantum Mechanics in Historical Perspective by Max Jammer (Dec 3, 1974)? I was told my a physics historian friend of mine that it's an excellant book on the philosophy of quantum mechanics. If you're really interested in this subject then this is a must read on your list of books to consider buying and reading.

[dlorde]

Looks interesting; the question is how to find a copy...

[Bill S]

There's one on Amazon UK at a little over £790! I think I might try the local Library.

[Bill S]

The Infinite Cosmos      Part 6        (Final Part)

What happens in infinity?  Popular science books often point out that, in eternity, everything that can happen, must happen.  Few, if any, take this to its logical conclusion.  Because there can be no succession of events in eternity, everything that can happen, and must happen, must be now.  Even the assertion that it must be happening now is misleading, because, to say that something is happening implies that it is undergoing a process of occurring, which requires a passage of time.

  Consider events A, B and C.  In linear time these might occur, one after the other, in that order.  In eternity, though, they would all be present together.  There could not have been a point in eternity when, for example, A had happened, but not B or C.  The whole of eternity must contain A, B and C, in their entirety, for all eternity.

If the past - the period up to now - is infinite, then A, for example, has already happened, an infinite number of times, as have B and C.  What sense does it make to claim that, because they occur in the sequence: A- B- C, there must have been a point at which A had happened more times than B or C? 

If that were the case, it must be that if we had selected a point in the past as our "now", there would have been a chance that we opted for a point at which A had happened more times than B or C.  This would mean that they had not happened an infinite number of times.  Manifestly, this is not possible if the past is infinite, and if in infinity everything that can happen must happen an infinite number of times.

  It is not possible to envisage a “part” of eternity that does not contain everything that is contained in eternity.  I have been using the term “eternity” rather than “infinity” in order to stress the “everlasting” aspect, but we must not lose sight of the fact that it is only our time- and space-bound perception that persuades us that we should distinguish between space-like and time-like infinities.  What applies to eternity applies equally to infinity.               
 
We started by trying to apply rational thought to the origin of the cosmos and the position that our Universe might occupy within that cosmos.  We are still left with one fundamental question:  Is there any way in which we can work out whether our Universe was created, or whether it is simply part of an eternal cosmos?  First, we have to ask if the cosmos was created, or if it is eternal.

If the cosmos was created, it must form part of the infinite realm of the creator.  As discussed above, this implies that it has always been part of that realm; it, too, is eternal.

If the cosmos is eternal, and the Universe forms part of the cosmos, it follows that the Universe has always been part of the cosmos; the Universe is also eternal. 

We seem to have reached a juncture at which we are saying that arguing about whether or not the Universe was created is totally pointless.  If there can never have been a time when there was nothing, something must be eternal, and therefore infinite.  Our Universe must be part of that infinite something, and therefore, according to the above reasoning, must be infinite. 

Now I seem to be arguing that the Universe is finite, and infinite, at the same time.  The logical way round this must, surely, be to assume that the Universe, and the whole cosmos, are infinite, and that our perception of differentiation of space, the “passage” of time and of any change is simply an illusion resulting from our very restricted viewpoint. 

We should look briefly at the idea of the holographic universe.  What is the holographic universe?  Does it imply that the Universe is a hologram?  I shall assume sufficient knowledge of holograms to make a description unnecessary.

When scientists, such as David Bohm, and authors, such as Michael Taylor describe the Universe as a hologram I very much doubt that they are suggesting that some other-worldly being is projecting laser images with an incredibly gigantic projector to produce what we experience as the Universe.  I suspect that it would be more appropriate to say that the three-dimensional images we can produce with laser technology are as near as we can come to producing an effect that, to some extent, mimics the way in which our Universe works. 

The kind of holographic image with which most people are familiar is that which is viewed by reflected light and produces a very limited three-dimensional image when observed directly.  However, the kind of holographic image that is of interest in terms of the holographic universe model is that which is not directly observable simply by looking at the plate on which it is captured.  Viewed by reflected light the plate seems to contain only vague, swirling the marks of interference.  The true image can be seen only when the plate is illuminated by transmitted light.  The image then stands out from the plate, forming a three-dimensional image that can be viewed from any angle.  The object may appear real, but any attempt to touch it will reveal that it is not there, it is simply a product of the ability of our brains to interpret electromagnetic frequencies.  One remarkable thing about these holographic plates is that if you cut one in half, each half will produce the same, complete, image.  In fact, how ever many times you divide the plate, each fragment will produce the whole image.  Only the quality of the reproduction will deteriorate as the fragments get smaller.  The best explanation for this must be that the entire image is contained in every part of the plate.  It is this quality of the holographic image that makes it particularly significant in the context of a possibly infinite universe.  If our Universe is actually infinite, then the entire Universe is contained in every atom of what we perceive as a collection of divisible entities.  William Blake’s “….World in a Grain of Sand” is no longer just poetic imagery; it is a small step towards seeing things as they really are. 

When we talk of the holographic Universe we are suggesting two things.  The first is that, as with the holographic images produced by lasers, it is our brains that interpret the “frequencies” of the Universe to produce the images we see and the reality we perceive around us.  The second point is that every part of the Universe is, in a very real sense, the whole Universe, “….and I am that”.     

Sighs of relief all round - it's over!   Later I'll try to tackle some of the questions.   

[Pmb]

There's one on Amazon UK at a little over £790! I think I might try the local Library.

If they don't have it ask them about an inter-library loan.