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Author | Topic: What is Time and Space | |||||||||||||||||||||||||||
cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
Typical, you're picking up on the "other" stuff about conciousness I wasn't really going there...
Penrose is not suggesting a new force, but he starts with the idea that our conciousness can come up with non/un-computable stuff like Godel Incompleteness, P/NP, etc and hence conciousness must be more than computation. He suggests quantum computation through the micro-tubule stuff. Now Roger's difficulties with classical emergence (collapse of the wave-function) have always confused me as he spent a reasonable amount of time with Chris Isham and should be satisfied with de-coherence as an excellent approach to the problem (Isham being a pioneer of this with Jim Hartle). But then Roger is a mathematician pretending to be a physicist unlike the rest of us who are physicists pretending to be mathematicians. To be honest, none of this is what I was discussing. I'm not so much interested in the origins of conciousness (for this particular debate) but rather the role of conciousness in "flow of time" - generating or merely observing. I'm at least 50% with generating... i.e. the "flow of time" is as much an observer dependent quantity as "red" or "Emaj7". That said, I am at least 25% convinced that conciousness is a necessary element of what we call existence (note, nothing of my religious beliefs intrudes here.)
If the universe must, according to some imbalance or difference in potential,move in a given direction as to effect an arrow of time is it necessary that we discover the mechanism as a consequence of the quantum physics or is the problwem of finding a suitable means of testing by experiment to settle the question? The arrow of time does not in itself imply a flow of time, merely an ordering of the fixed four dimensional solution. Statitsical, thermodynamic considerations lead to the arrow but they do not imply "flow".
Ionce read on the paradox about the wave particle duality and in that same book the author was implying that the wave aspect is simply a measure of the probability of a particle and the particle aspect was the actual matter point itself. NO! This is very naive and shows the lack of understanding by many who profess to know and then to teach! Neither description is correct, but both suffice in different situations. The particle is better described as a quite complex (quantum) excitation of a field. Edited by cavediver, : Does there have to be a reason?
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sidelined Member (Idle past 5908 days) Posts: 3435 From: Edmonton Alberta Canada Joined: |
cavediver
Neither description is correct, but both suffice in different situations. The particle is better described as a quite complex (quantum) excitation of a field. Ok so we have the wave or particle description of the quantum. Is it sufficient to say that these two measurements are similar to a description of a cone wherein if you use a "filter" that allows you to measure only the aspect of the cone that describes a triangular shape { a cone seen from one side } or a different filter that allows only the aspect of the cone that describes a circle {a cone seen from different perspective} ? Is the difficulty in the ability of our brains to concieve of a geometry that allows these two descriptions to co-exist without the seeming paradox?
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GDR Member Posts: 6202 From: Sidney, BC, Canada Joined: Member Rating: 1.9 |
Roger Penrose writes: Yes I think physicists would agree that the feeling of time passing is simply an illusion, something that is not real. It has something to do with our perceptions. Hi cavediver I'm hoping that you will comment on this quote from Penrose. Do you agree with him that most physicists would agree with his statement? What does he mean by illusion? If time is just a series of nows that are eternal I'm wondering if that would qualify as an illusion. Is Penrose's thinking on this consistent with Julian Barbour? How come all you guys that seem to write about this come from the UK? Edited by GDR, : typo Everybody is entitled to my opinion.
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jar Member (Idle past 394 days) Posts: 34026 From: Texas!! Joined: |
How come all you guys that seem to write about this come from the UK? Because New Market was founded in 1223 or there abouts. Aslan is not a Tame Lion
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Son Goku Inactive Member |
How come all you guys that seem to write about this come from the UK?
At least to my eyes, Oxford and Cambridge have a older and more pronounced culture of "learning for the sake of learning" in the sciences. They're one of the few universities where physics doesn't have a utilitarian edge to it. Even if you look at the undergraduate courses, they're far more "fluid" in what a student is allowed to do.
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
Is it sufficient to say that these two measurements are similar to a description of a cone... Yes, a good analogy, and closer to the truth that you realise. When I ask, "what is the position of the particle?" I am projecting the wave-function in a particular way that gives me a position-like answer. When I ask about the momentum of the particle, I am projecting the wave-function in a different way, just like your "side" or "end-on" projections of your cone. Notice how the two projected aspects, position and momentum, cannot possibly be observed simulataneously by the same observer...
Is the difficulty in the ability of our brains to concieve of a geometry that allows these two descriptions to co-exist without the seeming paradox? It probably plays a large part, yes. We are so used to "things" sitting in space and "processes" applied to "things" at our length scale. This is so unlike the quantum field picture.
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
Do you agree with him that most physicists would agree with his statement? Well I agree with his statement, and I think most physicists in our field would as well. Outside our field, I wouldn't be so sure.
What does he mean by illusion? If time is just a series of nows that are eternal I'm wondering if that would qualify as an illusion. The illusion is the "time-flow", or passing of time. To me, every moment exists, it is just my conciousness only revealing a slice at a time.
Is Penrose's thinking on this consistent with Julian Barbour? In general, yes. But my description depicts a static 4d universe, with all the time layers neatly ordered. Barbour sees a collection of possible states of 3d spaces that are brought together or picked out to form the 4d universe.
How come all you guys that seem to write about this come from the UK? It's the tea Too bad you chucked all of yours into the sea a while back
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GDR Member Posts: 6202 From: Sidney, BC, Canada Joined: Member Rating: 1.9 |
cavediver writes: It's the tea Too bad you chucked all of yours into the sea a while back That would be our good friends to the south. We kept the tea and the Queen. Thanks
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
That would be our good friends to the south I was going to excuse myself by saying I thought I was replying to Sidelined, then just checked his location So... what is it that makes the Canucks ask all the awkward questions?
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GDR Member Posts: 6202 From: Sidney, BC, Canada Joined: Member Rating: 1.9 |
cavediver writes: So... what is it that makes the Canucks ask all the awkward questions? If I'm representative it would be because I'm a lot better with questions than I am with answers. Incidently in sidelined location of Edmonton there is a physicist named Don Page. (By the way he is Christian as well.)He's worked closely with Hawking and even lived with him for a while. He is quoted in the material about Barbour that he believes that not only will we eventually find that time is an illusion but so is space. It seems that the more you guys find out the curiouser it gets. Nothing is as it appears. Everybody is entitled to my opinion.
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
Yeah, I know Don a little He was Hawking's sidekick before my time so I only ever met him on his visits. He's done some interesting work in his time.
not only will we eventually find that time is an illusion but so is space This is very much the picture from something as "mundane" as classic string theory, when looked at from the relativist/mathematical viewpoint (as opposed to the particle physicists). In this case, reality is only two dimensional and our 4d universe and everything in it inlcuding us is a projection.
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Son Goku Inactive Member |
"cavediver" writes:
Sorry to ask something off topic, but I heard today that in String Theory one considers the coupling constant as a dynamic field. Rather than just a variable which depends on the energy scale. This is very much the picture from something as "mundane" as classic string theory, when looked at from the relativist/mathematical viewpoint (as opposed to the particle physicists). In this case, reality is only two dimensional and our 4d universe and everything in it inlcuding us is a projection.Is that true? Edited by Son Goku, : Clearer message title.
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GDR Member Posts: 6202 From: Sidney, BC, Canada Joined: Member Rating: 1.9 |
cavdiver writes: Replace "illusion" with "emergent property" and you pretty much have our current understanding. I don't think "illusion" is too far off the mark. The "flow" seems to require a conciousness to exist to appreciate it. Other than for conciousness, everything is just a static 4 dimensional construct as General Relativity has told us for the past 100 years... I keep trying to sort out the relationship between time space and consciousness. I'm not clear on what you mean by emergent property. This is where my basic logic is taking me. The flow of time requires consciousness in order to perceive that flow. If all consciousness stopped everything would just exist in the eternal now without change. (At least that is if I understand you correctly.) The problem I have with that is as distance = space x time, then if time is non-existent or zero then distance must also be zero. In other words how if time doesn't exist, can distance or space exist? If space becomes meaningless then aren't we right back to the initial singularity. Incidentally all of this has made me look at the size of our universe in a totally different way. The universe seems so immense but it seems to me that it has to be "perceived" that way. If we lived in a three dimensional universe then it would require an edge or a boundary. Once time is factored in for our 4D universe there can be no boundary, in just the same way that aside from mountains etc we can continually move in any given direction from any given point on the surface of our planet. Just as it is true that the last statement is true regardless of the size of our planet it should hold true that the size of our universe is an irrelevancy and beyond our comprehension. My universe has shrunk. Everybody is entitled to my opinion.
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sidelined Member (Idle past 5908 days) Posts: 3435 From: Edmonton Alberta Canada Joined: |
cavediver
When I ask, "what is the position of the particle?" I am projecting the wave-function in a particular way that gives me a position-like answer. When I ask about the momentum of the particle, I am projecting the wave-function in a different way, just like your "side" or "end-on" projections of your cone. Notice how the two projected aspects, position and momentum, cannot possibly be observed simulataneously by the same observer... If the cone is established from the integration of the circle aspect with the trianglular aspect is there a geometry yet discovered that allows for a simultaneous conjuction of these two aspects of quantum mechanics in the same way as the 2 dimensional properties of the circle and triangle can be resolved as a 3 dimensional cone? Or am I just spitting into a blind alley here?
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GDR Member Posts: 6202 From: Sidney, BC, Canada Joined: Member Rating: 1.9 |
cavediver writes: So there is no time variable that montonically increases... there is just a fixed, possibly infinite, time dimension. Part of the four dimensional mess of matter that makes up the universe are these sub-structures that we call humans, although we are more familiar with dealing with single cross-sections of these humans. These strcutures are sufficiently complex that somehow (don't ask me how) this thing known as conciousness arises, and appears as a dynamic 3-d process within the static 4d structure. How this conciousness makes sense of a temporal order is difficult to determine but certainly the thermodynamic arrow of time is involved. I’ve re-read this thread and others, re-read Brian Greene’s “Fabric of the Cosmos”, bought Penrose’s “Road to Reality” and skimmed it but it was mostly over my head. I also read books by Hawking, Randall and others. I’m trying to get my head around some of these concepts but there is one thing, (among a zillion others) that really has me puzzled right now. I understand that space/time is absolute and that space and time are tightly linked. I understand that time is broken up into quantum moments that probably last just one unit of Planck time. (10 to the 43rd moments every second which kinda takes your breath away.) As we mentioned earlier Julian Barbour goes so far as to suggest that each one of those moments is a separate eternal universe. (I’m a long way from getting my head around that.) Other physicists talk about there being an infinite number of universes. That really has me curious. Frankly I’m not clear at all as to what they mean by a universe in that context and I’d be interested in a definition. OK. Here’s the problem. SR tells us that we all have our own time. Time does not pass for me at the same rate as it does for my wife. We live in different time zones so to speak. (I’m definitely not going any further with that concept. ). If space and time are so tightly linked, then it seems to me that if our passage through time is different, then as space/time is absolute, our space vector (if that is the correct term), must be different as well, in order to balance off our time variation so that our space/time is equal. So, as I see it then, our passage through space/time is the same because space/time is absolute but we occupy different points in both space and in time. I have some understanding of what it means to occupy different points in time but I’m not sure what it means when applied to space. I assume that it means something more than the fact that we occupy different 3d locations as we could do that even when our time vector is equal. Does this mean that we live in different universes? (I sure hope my wife doesn’t see this. ) When physicists talk about infinite universes could it mean that each one of us live in our own personal universe? Honest, I don’t do drugs but I admit I have friends who are starting to wonder about that. Everybody is entitled to my opinion.
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