A system which is capable of successful self-diagnosis and self-maintenance would have to know how all of its parts worked individually and as sub-systems and as a whole system. If this can be achieved electronically then it must be possible in the case of the universe. — universeness

I might disagree with you about the gods issue, but here I agree! If sub-systems collapse, I think the whole collapses. What is the whole though? If the spin inside the Schrödinger cat cage is measured the superimposed spin state is projected on one of the two states, up and down. Even for the observer observing the combined cat-observer state.

An event in physics is not actually an event. It's the time and position of a particle. — EugeneW

I think the 'event' label is a perfectly reasonable/logical one from the standpoint of natural human perception. Surely time and positional data are 'details of the event.' Why is such a distinction important?

If particles were devoid of charge all individualities of partìcles would be lost and the universe would spread out into a uniform mass in which nothing could be defined or have outlines. All would be one. — EugeneW

But is magnetism or repulsion/attraction the only reason for the existence of quanta?
If the universe is made up of multidimensional vibrating strings for example then an electron and its properties are merely due to a particular string state.

When particles interact, by their charges coupling to the omnipresent field of virtual particles, their evolving wavefunctions (which are, loosely speaking, the temporal cross sections of quantum fields) collapse every time upon an interaction. The standard view doesn't speak of collapse but the objective collapse approach does. — EugeneW

I get that an interaction between two electrons involves the exchange of a virtual photon from one to the other and this causes a change in momentum of the receiving electron and this causes them to repel each other. At least I got that from a question posed to a physicist on Quora. Is it the collapsing waveform that causes the repulsion or the change in momentum? Is the waveform collapse, similar to disturbed, undulating water, becoming still again?

So particles tract characteristics and identity because a relation with other particles. Their condensations in spacetime are relational. — EugeneW

I have no idea what this means.

There is a field of virtual particles in empty space. If a charged particle moves through space it couples to this field. How can they couple if they are point? Simply because they are no points. Their coupling to this field cause that field around them to change. Same for other particles. This means that if a particle enters a region of space where that virtual field is disturbed by another charge (say both charges are electrical, which couple to virtual photons only), it will not move the same as before (unchanging velocity, apart from the "Zitterbewegung"). It's accelerated because of the potential created by the other charge (which actually is a so-called virtual photon condensate). These interactions happen in measurements, and take place continuously to maintain individuality of the parts. Bosons though don't have individuality when in groups. — EugeneW

So space is therefore not empty, it's full of 'virtual particles.'
By 'coupling' do you simply mean 'connects to' or is 'affected by' or 'reacts to'?
What do you mean by 'Point'? a dimensionless point which has coordinates only or a tiny 'packet' or 'concentration of mass or energy?
So the charge/spin direction causes a disturbance in the 'virtual field' (why is the field virtual rather than real?) and the result is that the particle gets accelerated away? Am I understanding this correctly, so far?

The charges couple to this omnipresent virtual field. — EugeneW

So this virtual field must permeates all space if it is omnipresent, yes?
So why does the particle not accelerate forever if it encounters a constant expanse of 'virtual field'?

If the spin inside the Schrödinger cat cage is measured the superimposed spin state is projected on one of the two states, up and down. Even for the observer observing the combined cat-observer state. — EugeneW

Nope, sorry I don't think I understand this. Are you simply saying the cat is alive (spin up state) or dead (spin down state) Does spin up mean spin faster and spin down means spin slower? or does spin up mean 'starts to spin' and spin down mean 'stops spinning'?
The observer has to open the box to find out which possibility is true, I get that. If the box remains closed these both outcomes remain possible so one state is 'superimposed' on the other.
Are you saying that in your opinion, the structure and workings of the Universe are knowable, even though we are trying to discover such, as component parts, inside the universe we are trying to understand? Do we have to open all the Schrodinger style boxes and do all the measurements?

Nope, sorry I don't think I understand this. Are you simply saying the cat is alive (spin up state) or dead (spin down state) Does spin up mean spin faster and spin down means spin slower? or — universeness

No. I mean the direction of spin. It can be up and down. If they are in superposition there is no connection with a dead or alive cat. As long as the cat is in the cage it doesn't care about us or the superposition. Only when a spin up or down is measured (projected on an eigenstate) the cat will notice

Are you saying that in your opinion, the structure and workings of the Universe are knowable, even though we are trying to discover such, as component parts, inside the universe we are trying to understand? Do we have to open all the Schrodinger style boxes and do all the measurements? — universeness

Everything in the universe that interacts collapses, if we measure or not. All structural identities stem from interactions. When we measure or when we don't.

Everything in the universe that interacts collapses — EugeneW

But two galaxies can interact by colliding and they don't collapse, they effectively merge!
Collisions within accretion disks merge into planets, I know my examples are of the very large rather than the very small but I still don't really understand.
I think I will just raise the white flag for now and keep watching Youtube cosmology vids and continue my reading on the subject until I can demonstrate more depth of understanding. I will continue to make some comments now and then however.

I think the 'event' label is a perfectly reasonable/logical one from the standpoint of natural human perception. — universeness

I think so to. That's why in physics it's a bit strange. An event is something that happens, a happening. A glass can't break at a point in time or space.

get that an interaction between two electrons involves the exchange of a virtual photon from one to the other — universeness

Photons are not exchanged. An electron doesn't emit or absorb photons. It couples to a virtual photon. On their own (so without charged particles) such photons are present through all of space (quantum bubbles). Charged Dirac fields couple to them, in accordance with the Hamiltonian (or Lagrangian) and charges. So it depends which energies and momenta of the virtual photons are needed (they have them all and independently, and give what the asymptotic conditions require).

What do you mean by 'Point'? a dimensionless point which has coordinates only or a tiny 'packet' or 'concentration of mass or energy?
So the charge/spin direction causes a disturbance in the 'virtual field' (why is the field virtual rather than real?) and the result is that the particle gets accelerated away? Am I understanding this correctly, so far? — universeness

A 0d point. Which causes misery. The field is virtual as opposed to real. Virtual fields have independent p and E. In a sense, a real particle is a virtual particle with p and E depending on each other and with a direction in time.

Yeah, definitely the white flag from me for now.

But two galaxies can interact by colliding and they don't collapse, they effectively merge! — universeness

Haha, yes! Of course. I meant their wavefunctions. The wavefunctions of both galaxies interact with other galaxies and will result in two collapsing wavefunctions of galaxies that merge. If the two galaxies were the only ones in an infinite flat space then in a very long time both galaxies would diffuse in space, like the wavefunction of a single non-interacting particle spreads.

I meant their wavefunctions — EugeneW

So do you mean all interacting wavefunctions (which produce actual waveform disturbances yes?) in the Universe collapse?

Yeah, definitely the white flag from me for now. — universeness

Let me put it in a different way. Consider a single virtual photon. Represented as a single circle in a Feynman diagram. One of the quantum "bubbles" (wrongly imagined in popular science to be a short appearance of a particle and its antiparticle). The virtual particles dont go in one time direction. They oscillate in time. Constantly and everywhere. Electrons couple to them. They "break" them open and from a circle they become a line (in Feynman diagrams) between two vertices (with associated vertex factors which quantify the coupling strength).

So do you mean all interacting wavefunctions (which produce actual waveform disturbances yes?) in the Universe collapse? — universeness

Rìght!

The virtual particles dont go in one time direction. They oscillate in time — EugeneW

is this mathematical modeling or something that actually happens?
Oscillate in time in what sense? Current/past or current/future?

All I really understand about Feynmann diagrams is they have inputs and outputs and nobody really understands what happens in the middle

So do you mean all interacting wavefunctions (which produce actual waveform disturbances yes?) in the Universe collapse?
— universeness

Rìght — EugeneW

I, like many people, I think, only understand wave interactions based on water waves, waves passing along strings from either end and meeting up with each other. Waves passing through prisms etc, peaks, troughs, frequencies, trig etc. Waves can interfere, cancel each other, merge etc.

When you say all interacting wavefunctions IN THE ENTIRE UNIVERSE collapse, what do you mean by collapse. I assumed that this means the function no longer produced a waveform.
So you get nothing when you try to measure what happened due to the interaction between system X and system Y because the action of trying to measure, stops the wavefunction from producing waveforms so you don't get the interference pattern you get in the double split experiment if you try to detect which slit each photon(massless) or electron(mass) went through. I thought this was the basics of 'the measurement problem,' yes/no?

I don't recall much mention of any philosophical aspects/consequences of his theories, that he discussed in his YouTube offerings but I was too busy trying to gain some understanding of his scientific musings. — universeness

Then the videos are likely to be of little use to me since it is precisely the philosophical implications that have a direct bearing on the OP question. I'm not going to disagree with the physics of those guys. I'm in the wrong league for that.
I have had direct communication with Tegmark and don't disagree with any of his physics, but there are some metaphysical points on which we disagree. The quantum suicide thing for instance makes some serious errors, and does not in fact constitute evidence of his favored interpretation.

My time is limited, and I've yet to get to the videos.

I have no idea what you mean by this? A rock can take a measurement? in what sense? I assume you don't mean this literally

I mean it very literally. It is the effect end of a cause-effect relationship. Any superposition of the measured system is lost relative to the rock. Some molecule of Napoleon's dying breath interacts with the rock, changing the state (the momentum perhaps) of at least one particle of the rock. The rock is now different than it would have been without that measurement, thus Napoleon exists relative to that rock (as if he didn't already, but it's this particular measurement we're using in the example). The world cannot be measured to be in the state of that rock's exact state, but with Napoleon never having been.

I don't know how EugeneW would have expressed that since he seems to assert the necessity of a two-way 'virtual' interaction, which implies that Napoleon cannot exist relative to me (I cannot have measured Napoleon) unless I also exist relative to him (Napoleon has measured me, which violates locality).

That you have no idea about this means you need to spend more time learning physics from reviewed textbooks and not pop videos and articles, which almost always focus on the more relatable humans, their actions, and the epistemological aspects of knowledge of a system instead of the actual metaphysical state of a system.

Well, a wave function will produce a waveform, will it not?

It is a description of a system (somewhere) from a point of view. It doesn't necessarily 'produce' anything, but the future state of the system in question, if closed, can be described by evolving the wavefunction over time using Schrodinger's equation. Not sure if you'd consider that the production of a waveform. So maybe it's an atom with a half-life, and the wavefunction will give the state of the unmeasured system at any time. Upon measurement, the wavefunction collapses into a simpler state (typically decayed or not) instead of the superposition of all possible states of <decayed maybe>.

and all waveforms moving in 3D space will produce a worldline as it traverses space from its origin.

No. Wavefunctions are not objects that move around. They're descriptions.

Like a drop of water in an ocean that will cause only a localised disturbance and then settle as it dissipates its energy. It does not affect the entire ocean. I don't know what you mean by the wavefunction of a distant system relative to 'here' is nevertheless 'here'.

EugeneW worded it that way, giving a wavefunction the location of the point-of-view in question, hence measurements here collapse the local wavefunction here that describes the non-local system elsewhere. This makes sense in a local interpretation (of which RQM is one). If I measure one particle of an entangled pair, it doesn't physically make any change to the other particle elsewhere. No local interpretation supports 'spooky action at a distance' the way that non-local interpretations do. No reverse causality, with actions now having effects billions of years ago. There are very much interpretations that suggest otherwise.

light waves from a distant star still have to traverse the distance between here and its origin, which is why we see what was, not what is. maybe I am being a bit dense here but I am not following your logic very well.

Agree with this. Say the star is a light year away (impossible of course). To word it differently, only the state of the distant star a year ago is in our past light cone, and thus the wavefunction of that star from the point of view of Earth is collapsed only to its year-old state, and its present state is not in any way fact, relative to us. Likewise, a star sufficiently distant (say 50 GLY) doesn't meaningfully exist at all relative to Earth. Unmeasured state is not meaningful to a local interpretation. That's a very hard pill to swallow, but I find it an even harder pill to abandon locality, that information can travel backwards in time or anywhere else outside its future light cone.

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.

I cannot understand EugeneW, so I don't think an explanation of what I mean is going to come from him.

You stated that observers cant fully understand a system that they are a part of so it's that which I disagree with.

I don't think I disagreed with that either. I said a system cannot collapse its own wavefunction. Superposition would be nonexistent if it were otherwise.

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

In standard QM this is actually the case. — EugeneW

Are you agreeing with me or disagreeing?

An event in physics is not actually an event. It's the time and position of a particle. If particles were devoid of charge all individualities of partìcles would be lost and the universe would spread out into a uniform mass in which nothing could be defined or have outlines. All would be one. When particles interact, by their charges coupling to the omnipresent field of virtual particles, their evolving wavefunctions (which are, loosely speaking, the temporal cross sections of quantum fields, collapse every time upon an interaction. The standard view doesn't speak of collapse but the objective collapse approach does.

So particles tract characteristics and identity because a relation with other particles. Their condensation in spacetime are relational.

None of this seems at all relevant to my comment quoted above.

Waveforms certainly exist in electronics, but in Quantum theory they may be in abstract spaces where collapse of wavefunctions occur. What is actually physically happening vs probability measures, etc. At least that's how I see it - and I'm probably off track.

None of this seems not at all relevant to my comment quoted above. — noAxioms

None seems not at all relevant? So all seems relevant?

It depends how you view the wavefunction. In the standard Copenhagen view it's a mathematical aid. A complex function in Hilbert space. The square, a real number, represents the probability of finding a particle. Contrary to a dice, this probability has no determining substrate. That's the difference with etymological chance, where chance is due to lack of knowledge. The standard says there is nothing to know.

The other approach, which I use here, is that there is a layer of determination beneath the chance: hidden variables. These are real features. The wavefunction describes them. So the particle has a well determined position but hops around in space due ti the hidden variables. You could say the hidden variables are the space-sauce around the particles. If there is no interaction, the particles get lost in space.

None seems not at all relevant? So all seems relevant? — EugeneW

Thx. Double negative fixed.

It depends how you view the wavefunction. In the standard Copenhagen view it's a mathematical aid.

True. Copenhagen is/was an epistemological interpretation, and as such, the only way anybody is going to learn about the state of some system (like the existence of Napoleon and TutCommon, the latter being the more ordinary brother of Tutankhamun) is to take a measurement (like read a history book) which collapses your knowledge from <maybe either> to <yes Napoleon, no TutCommon>.
As such, an act (reading a book, getting a sunburn) is required to change your knowledge.
It's like the shell game: the ball is under one of three shells and you don't know which until you life the shells. But not knowing where the ball is is absolutely not the same thing as the ball being in superposition of those three places. That's a metaphysical state which means (for the purpose of this discussion) that a real possibility exists for it to be anywhere instead of in fact under the left shell, unbeknownst to you. Superposition (QM definition this time) means that those three states can be made to interfere with each other in some way, which would be a metaphysically different state.

I am admittedly, in my posts, talking about metaphysical wavefunction collapse (or lack thereof) which narrows the interpretation choices to the metaphysical ones (which includes a metaphysical version of Copenhagen in which humans once again play no role).

The other approach, which I use here, is that there is a layer of determination beneath the chance: hidden variables. These are real features.

You've been speaking of locality before, and now there's hidden variables, used only by interpretations which abandon locality.

For the most part, and for purposes of this topic, I don't care. My observation was that RQM is an elegant solution to the origin problem. I really don't care that the other interpretations don't solve the problem the same way, or don't solve it at all. There are no hidden variables in RQM, and humans do not play any preferred role.

Many seem to know some (textbook) physics but, as this thread amply shows, very few demonstrate that they actually understand the speculative implications of major physicists' rival interpretations of the currently prevailing theories. How tedious ...

My observation was that RQM is an elegant solution to the origin[al] problem. I really don't care that the other interpretations don't solve the problem the same way, or don't solve it at all. There are no hidden variables in RQM, and humans ["consciousness"] do not play any preferred role. — noAxioms

:up:

Many seem to know some (textbook) physics but, as this thread amply shows, very few demonstrate that they actually understand the speculative implications of major physicists' rival — 180 Proof

Especially you... Tedious indeed... :fire:

There are no hidden variables in RQM, and humans do not play any preferred role. — noAxioms

How do you know there are no hidden variables? It's the only solution that solves the problems, and the nature of space.

It's like the shell game — noAxioms

It's not like the shell game.

You've been speaking of locality before, and now there's hidden variables, used only by interpretations which abandon locality. — noAxioms

Locality and non-locality can co-exist. Only the hidden variables are non-local.

is this mathematical modeling or something that actually happens?
Oscillate in time in what sense? Current/past or current/future — universeness

"In Feynman's language, such creation and annihilation processes are equivalent to a virtual particle wandering backward and forward through time"

So, a virtual particles have no direction in time. They just go up and down. Since the beginning of time and before.

An ad hominem via projection of him who hears his name without it even being mentioned. You tell on yourself, EW. :smirk:

Haha.

Who said I heard my name 180Booze? I defend those who don't understand... according to you. They might understand after all...

I guess you D-Kers gotta stick together. :sweat:

Wtf are D-kers?

Wtf are D-kers? — EugeneW

:lol:

Wtf????

Then the videos are likely to be of little use to me since it is precisely the philosophical implications that have a direct bearing on the OP question. — noAxioms

Perhaps you would be more interested in offerings from Carlo such as:


I have not watched this one myself but I probably will do at some point.

I'm not going to disagree with the physics of those guys. I'm in the wrong league for that. — noAxioms

That you have no idea about this means you need to spend more time learning physics from reviewed textbooks and not pop videos and articles — noAxioms

I think we are in a 'similar' league when it comes to command of physics. If by 'pop' you mean popular then I think there is value in using any source of physics-based facts or musings. I am happy with my own attempts to improve my knowledge of physics and philosophy and require no advice from you on how I could best progress.

I have had direct communication with Tegmark and don't disagree with any of his physics, but there are some metaphysical points on which we disagree. — noAxioms

That's good to hear! There you go @EugeneW, some of these guys will enter a discourse with us humblebums! I have mixed emotions when it comes to the term 'metaphysical.' Definintions like 'after physics' or 'beyond physics' don't help but I normally do find some value when I read/view 'metaphysical' discussions.

Some molecule of Napoleon's dying breath interacts with the rock, changing the state (the momentum perhaps) of at least one particle of the rock. The rock is now different than it would have been without that measurement, thus Napoleon exists relative to that rock — noAxioms

I may have garnished more value from this if you had typed something like 'Some molecule of Napoleans consciousness (not his dying breath), as his physical body starts to disassemble, after his death...interacts with a rock.' I personally think this idea is nonsense and that such an interaction would leave the rock completely unchanged. I think it's much more likely that disassembled component parts of a dead human consciousness (whatever such quanta might be) could only 'interact' with a live conscience or a forming fetus in a woman or perhaps any living creature, but not a rock.

It is a description of a system (somewhere) from a point of view. It doesn't necessarily 'produce' anything, but the future state of the system in question, if closed, can be described by evolving the wavefunction over time using Schrodinger's equation. Not sure if you'd consider that the production of a waveform. — noAxioms

Thank you for this one. It made me search the internet with 'Wave function and the quantum world.'
I clicked on wikipedia for 'wave-function' and read about A wave function in quantum physics. I think I have been confusing wave function and wave equation. Wikipedia states:

"A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system. The wave function is a complex-valued probability amplitude, and the probabilities for the possible results of measurements made on the system can be derived from it."

and

The wave function is a function of the degrees of freedom corresponding to some maximal set of commuting observables. Once such representation is chosen, the wave function can be derived from the quantum state.
For a given system, the choice of which commuting degrees of freedom to use is not unique, and correspondingly the domain of the wave function is also not unique. For instance, it may be taken to be a function of all the position coordinates of the particles over position space, or the momenta of all the particles over momentum space; the two are related by a Fourier transform. Some particles, like electrons and photons, have nonzero spin, and the wave function for such particles include spin as an intrinsic, discrete degree of freedom; other discrete variables can also be included, such as isospin.

and

According to the superposition principle of quantum mechanics, wave functions can be added together and multiplied by complex numbers to form new wave functions and form a Hilbert space. The inner product between two wave functions is a measure of the overlap between the corresponding physical states and is used in the foundational probabilistic interpretation of quantum mechanics, the 'Born' rule, relating transition probabilities to inner products. The Schrödinger equation determines how wave functions evolve over time, and a wave function behaves qualitatively like other waves, such as water waves or waves on a string, because the Schrödinger equation is mathematically a type of wave equation. This explains the name "wave function", and gives rise to wave–particle duality. However, the wave function in quantum mechanics describes a kind of physical phenomenon, still open to different interpretations, which fundamentally differs from that of classic mechanical waves.

I also used the linked pop-ups for more info on terms such as 'degrees of freedom and 'commuting observables' as used in quantum physics. I think I now understand more about the term wave function as used in quantum physics.

and all waveforms moving in 3D space will produce a worldline as it traverses space from its origin.
No. Wavefunctions are not objects that move around. They're descriptions. — noAxioms

I was referring to waveforms not the term wavefunction as I now conceive it based on the wikipedia stuff above. I was referring to something like a light wave with traditional peaks, troughs, wavelength, frequency etc, physically traveling through 3D space. All such will produce a 'worldline' based on my understanding of the term. I base this on a comment made by a physicist on Quora:
"the worldline of light behaves as ligtht-like curves in spacetime"

To word it differently, only the state of the distant star a year ago is in our past light cone, and thus the wavefunction of that star from the point of view of Earth is collapsed only to its year-old state, and its present state is not in any way fact, relative to us. Likewise, a star sufficiently distant (say 50 GLY) doesn't meaningfully exist at all relative to Earth. Unmeasured state is not meaningful to a local interpretation. That's a very hard pill to swallow, but I find it an even harder pill to abandon locality, that information can travel backwards in time or anywhere else outside its future light cone. — noAxioms

Yes, so the picture of hubble deepest field image (I have a very large framed print of it in my bedroom)
mainly contains objects which probably don't exist anymore.

I cannot understand EugeneW, so I don't think an explanation of what I mean is going to come from him. — noAxioms

He has been quite patient with me when I have demonstrated my limited knowledge of physics. He has demonstrated his deeper grasp of the topic and has not 'dismissed' me as 'not worth his efforts.' As a retired school teacher myself, I appreciate and celebrate his approach and passion for physics and I prefer it to the more pretentious and unwarranted, almost sad, aloof attitudes of other members of this forum, be the thread philosophical, scientific, religious or political. Thankfully, such attitudes are also in the minority on this forum.