Another way to say this is that if you start with a 0 (e.g., "nothing") and end up with a 1 (e.g., "something"), you can't do this unless somehow the 0 isn't really a 0 but is actually a 1 in disguise, even though it looks like 0 on the surface. — Roger
First of all, I balk at the word 'looking', since it makes it appear that humans or life forms play a preferred role. I can think of only one interpretation that suggests that, and even it was abandoned by its author (Wigner) due to it being driven to solipsism.What I meant is, why can't the Schrödinger cat actually collapse without someone looking, observing. — EugeneW
Does the term skeuomorphic ontology mean anything to you? Any sense can be applied to both of these words — Watchmaker
That's a poor representation of Rovelli's interpretation. It makes it sound like humans or things that 'observe' make any difference, which couldn't be further from what he says — noAxioms
Exactly, except I'd not have used the word 'observer'. Measurer maybe. — noAxioms
The universe (as a whole) doesn't need an origin story, lacking anything that measures the universe. That would require an external observer. Internal interaction only results in self-consistent state.
Rovelli says no system can measure itself, which doesn't mean I can't see my arms, but it means the cat in the box cannot collapse its own wave function relative to the observer outside the box. The live cat cannot measure dead parts despite being in superposition of being dead and alive. — noAxioms
An observer can measure, whether it's human or sensor, I think you are making an unimportant distinction here. — universeness
None of this is expressed as a relation, so the assertions of state are according to different interpretations. 'The superposition' is not an object which a photon can hit. If a measurement of the spin of some particle is taken, it usually involves information (photon?) traveling from the state being measured to the measurer, not the other way around.The bottle with poison breaks and kills the cat or not. If the superposition of, say, spin (thumb,) up and down interacts with a photon from outside, the photon can make it collapse to up (cat lives) or down (cat dies). Before the photon hits the superposition, the cat is just alive. — EugeneW
YouTube almost always uses human observers in their examples, and yet in real experiments, the human is often not present during any of the measurements, all of which are taken and recorded by inanimate equipment, say a screen upon which an interference pattern appears.It could well be that I was not attentive enough when watching Rovelli on YouTube. — universeness
According to quantum mechanics theory (rather than any metaphysical interpretation of that theory), there is no evidence that humans play a special role in physical waveform collapse. Humans do play a role in epistemological collapse: Even if somebody else watched, one particular lab guy isn't going to know where the photon was detected without at some point measuring the result, however indirectly. That doesn't mean that the photon didn't in fact get measured at a particular location.So, I assume you are saying that according to Rovelli, it's not the observer that's causing the waveform collapse it's the local interaction between x and y.
I'm balking at the connotations of using human verbs (like 'looking') when describing an interaction of any kind between two arbitrary systems. It is precisely that language usage that caused the naive readers back in the day to conclude that QM somehow provided evidence that humans were special. And, the 'oberver' need not be a sensor at all. It need not be anything designed with the purpose of specifically measuring the system. A photon can hit, instead of a photo-sensitive screen, just a black wall and be lost forever. The wavefunction is still collapsed relative to the system containing that wall.An observer can measure, whether it's human or sensor, I think you are making an unimportant distinction here.
Totally agree. Humans want this. How to explain the reality of whatever it is that you must assert to be objectively real to satisfy your desire for warm fuzziness. But the explanations always require dancing around an inevitable contradiction, and it seemed far simpler to not assert the objective reality in the first place.Humans desire an origin story for themselves and therefore for the Universe. I think that desire is significant even though I agree with all of Carl Sagan's great demotions.
By definition, there can be no such observer. Any such observer would be part of the universe.I understand your narration of Rovelli's view of Schrodinger's cat from the reference frame of the cat but you said earlier that only an observer from outside of the Universe can make measurements on the Universe that would reveal its true structure (is that what you are saying?).
I have no idea what I wrote that might suggest the outside observer could acquire knowledge concerning the state of the unmeasured cat.Does this not suggest that an observer outside of the box containing Schrodinger's cat should be able to know if the cat is dead or alive or is it merely the fact that the observer outside the box cannot see through the box?
Again, that would make the observer part of the universe, and not outside it.If so, then surely you are assuming that anything outside of the Universe would have an ability to interact with the Universe.
Cool. I'm a software engineer myself, hardly a cosmologist.As I have said before, my expertise is computing not cosmology but cosmology is of great interest to me.
The universe (as a whole) doesn't need an origin story, lacking anything that measures the universe. That would require an external observer. — noAxioms
By definition, there can be no such observer. Any such observer would be part of the universe.
I grant that similar to a simple quantum system in a thought experiment, the structure of the entire universe can be considered from 'outside', but that's different than measuring. No wave function collapse results from objective analysis of a wavefunction of some closed system. — noAxioms
If a measurement of the spin of some particle is taken, it usually involves information (photon?) traveling from the state being measured to the measurer, not the other way around. — noAxioms
Superposition is collapsed by a virtual photon. — EugeneW
That might be one way, especially for a realist interpretation.Superposition is collapsed by a virtual photon. An interaction is involved. — EugeneW
You have a reference for any of this? This seems to violate locality for one thing.A state of superposition remains superimposed without interaction. A superposition of spin up and down won't collapse by emission of a photon carrying info to the observer. Measuring the spin means placing the superposition in an external field. — EugeneW
I didn't mean that with that comment, which was specific to the relational interpretation.The universe (as a whole) doesn't need an origin story, lacking anything that measures the universe. That would require an external observer.
— noAxioms
I took this to mean that only an external observer of the Universe could make measurements/perform experiments on the Universe (as a whole) and by doing so, discover its structure and workings. — universeness
I forget the context of when I said that. Data necessary for what again?I took it that you were basing this view on your other view that internal measurers (human or electronic sensor) cannot gain the necessary data as they are part of the Universe.
By definition, given the relational (or any non-counterfactual) interpretation, nothing external (or even sufficiently distant) can exist since it cannot be measured. But given a different definition of 'exists', the rules might be different.By definition, there can be no such observer. Any such observer would be part of the universe.
I grant that similar to a simple quantum system in a thought experiment, the structure of the entire universe can be considered from 'outside', but that's different than measuring. No wave function collapse results from objective analysis of a wavefunction of some closed system.
— noAxioms
Are you using the argument that no observer can exist 'outside' of our Universe?
There is no origin story. Only a realist interpretation requires an origin story to explain the reality of whatever is asserted to be real. Positing an 'outside observer' doesn't change that.are you saying we can never know the origin story of the universe based on the points you make that an outside observer would be needed ...
Totally agree. So if it interacts, it is not outside. If it's outside, it can't interact.If an observer can be conceived as 'outside' of the Universe then how would they be part of it?
That makes no sense to me.
I'm not suggesting it necessarily is. The wavefunction of the universe is supposedly by definition closed, and thus an analysis of 'the universe' (defined as that wavefunction) would be an analysis of a closed system, but open systems can also be objectively analyzed.What evidence are you calling upon that demonstrates that objective analysis of a waveform is a closed system?
Objective is an adjective which I am using in opposition to 'relative'. Objective existence is realism: The ontological property of existence even in the absence of observation. Relative existence is a relation: A exists to B, but A might not exist to C.hat are you defining as 'objective' and 'closed'?
I'm not trying to convey Rovelli's views. I've not read the work you name. But the view is at least loosely based on his concept, but driven to its logical conclusion.I am trying to follow a smooth line of logic in your narration of 'The structure and workings of the Universe,' as suggested by Carlo Rovelli.
Or not... Not sure if I'd score better than you on a test of his works.I have tried to narrate the basics of his viewpoint as I conceive it, based on the youtube videos he offers. You may have a better understanding of his viewpoint than I do.
I'm not trying to convey Rovelli's views. I've not read the work you name. But the view is at least loosely based on his concept, but driven to its logical conclusion. — noAxioms
That's a poor representation of Rovelli's interpretation — noAxioms
I've not read the work you name — noAxioms
It says 'loosely based'. Rovelli certainly has the physics part down, but not having read his works, I don't know if he's explored the philosophical implications of his ontology, such as that of identity for example.I'm not trying to convey Rovelli's views. I've not read the work you name. But the view is at least loosely based on his concept, but driven to its logical conclusion.
— noAxioms
I think we have been mostly talking past each other. I thought you were narrating Rovelli's views — universeness
I restored some of the context. That reply of mine referred to your usage of "act of observation" which sounds like a pop wording at best, and not how a physicist might have put it.your first response to me stated:
The collapse of the wave function due to the act of observation?
— universeness
That's a poor representation of Rovelli's interpretation
— noAxioms
With that we seem to both agree. It implies that a wavefunction has a location (which I would not have intuitively suggested), and that a wavefunction of a distant system relative to 'here' is nevertheless 'here'.I think Rovelli's posit that the measurement problem and waveform collapse is a localised phenomena which only occurs between interacting systems X and Y and is not a 'Universal/objective effect,' is very interesting. The waveform does not collapse from the reference point of the whole Universe.
Did I suggest anything along those lines?I don't think Rovelli has ever suggested that the structure and fundamental workings of the Universe are unknowable
Perhaps you can recommend some Rovelli vids, even though I don't usually get my science from videos. Then I can point out places where I might not agree with Rovelli.I have WATCHED his youtube videos, his lectures and his discussions with Sean Carroll etc.
I haven't READ any of his publishings.
It says 'loosely based'. Rovelli certainly has the physics part down, but not having read his works, I don't know if he's explored the philosophical implications of his ontology, such as that of identity for example. — noAxioms
A rock can take a measurement and collapse the wave function of some non-rock system just fine, all without actually observing or knowing anything. — noAxioms
With that we seem to both agree. It implies that a wavefunction has a location (which I would not have intuitively suggested), and that a wavefunction of a distant system relative to 'here' is nevertheless 'here'. — noAxioms
I would not have said that spatially systems can 'interact' since I consider a system to be essentially an event and not say a worldline like Rovelli implies. We obviously differ on this point, but I can drive the worldline view to contradiction, a philosophical problem which seems not to concern Rovelli, being a physicist mostly interested in empirical consistency.
Two events cannot 'interact' since that would require each to be in the other's past light cone — noAxioms
Did I suggest anything along those lines? — noAxioms
Perhaps you can recommend some Rovelli vids, even though I don't usually get my science from videos. Then I can point out places where I might not agree with Rovelli. — noAxioms
Act' makes it sound like some action or intent is required, and 'act of observation' makes it sound like a human is required to be involved in the act. — noAxioms
I think I understand your words but then how do particles 'interact.' Perhaps ↪EugeneW can explain to me what you mean more clearly. I often turn to him, regarding cosmology stuff that I dont fully grasp. — universeness
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