The Wigner/Von Neumann interpretation explicitly brings consciousness into it. It has not been disproven. It really is a matter of opinion. Most do not like this interpretation, but there is nothing inherently wrong with it. It's basically equivalent to a kind of solipsism. Like I said, it boils down to a semantic dispute over whether you allow unconscious things to be observers (copenhagen interpretation) or if you require conscious observers (Wigner's interpretation).

What I meant was a virtual graviton is not the same thing as a virtual photon, at least afaik.

How would we explain this reversibility/retroactivity?

to be honest im no expert on the matter. i dont think anyone at this point in time knows the details of this.

i was just taking a stab at the idea and the reasoning i used was that gravitational fields have to have some kind of force carying particle which we know propgates at the speed of light

the only thing that can move at the speed of light is photons. like the old saying if it walks like a duck and quacks like a duck then its a duck.

but no one really knows. i dont think weve even verified gravitons exist, its purely a theoretical idea

We could just as easily say the fundamental thing is the graviton, then if that were the case. You are right though that they have not detected gravitons in the same way. However, I will say that the theory suggests that any massless particle at all must move at the speed of light, so calling it the speed of light is kind of a misnomer. It's more like the speed of information propagation. My point is that none of the fundamental particles we see today are the fundamental building blocks because at higher energies, different forces and particles existed, and perhaps at the grand unification energies, an entirely different kind of building block existed. A photon is solely an excitation of the electromagnetic field. As far as I know, the other bosons are not made of photons, and only relate to them in the sense that, at high energies, the forces all become unified. There is also the matter of time and space emerging from more fundamental things, as I posted before, with the new amplituhedron research.
https://en.wikipedia.org/wiki/Amplituhedron

As I said, it is much weirder than we might think, and it isn't light that is the "fundamental building block".

So are you saying the universe didn't exist before humans? How did humans evolve in the first place then?
Do monkeys collapse the wave function? What about dogs? Frogs? Amoebas? At what point in the intelligence scale does it become an "observation"?
Why does a lump of cells inside a spherical bone cavity have such a powerful effect on physical reality, as opposed to everything else?
How did the first conscious being come about? There wouldn't be any conscious being to observe anything in the first place, nothing would exist.
Or are you saying you are the only consciousness in the universe and everybody else is a p-zombie? If you are taking this solipsistic view, then why did the experimenters who performed QM experiments manage to collapse wave functions, since they aren't conscious? How were you born, since there wasn't anyone to experience reality in the first place?
How do you know your memory is reliable, and you just didn't hallucinate everything and matter is actually continuous and not made of particles?
Why are you biologically so similar to other humans, but conveniently you are the only one who has this non-falsifiable, non predictive element you call consciousness?
Why is this consciousness thing so correlated to what happens to that lump of cells we call brain? Why does shutting down these cells cause your consciousness to have a gap?
I could go on, but you see how ridiculous it gets. If you deny your consciousness being a by-product of physical reality and not the other way, then you have far worse epistemological problems to solve before even worrying about quantum mechanics.

what i meant when i said the photon is most fundamental building block is that everything is electromagnetic radiation, the differences have to do with different energy levels and different orientation in space-time.

I'm saying that under Wigner's interpretation, that is essentially the case. The universe practically doesn't exist until an observer observes it. It sounds silly, and it is, but that's solipsism for you. Penrose made the same argument against it, but in the end, it is still logically defensible. I am a Copenhagen guy myself, for the record. I just bring this up to show that the argument is rooted around interpretation.

Everything is not electromagnetic radiation. Also, if you go here:

https://en.wikipedia.org/wiki/Electroweak_interaction

You will see that the photon actually emerges from other bosons at the unification energies.

I really don't think it's a matter of interpretation. Maybe if you only consider quantum mechanics experiments it seems that way, but if you consider a wider range of observations, then the materialists interpretations that don't involve consciousness have a far better predictive power for the same amount of information (bits). And that's really what science is about, choosing the most succinct theory that adequately explains all the available observations.

It's not as ridiculous as it seems. In fact, the nature of the arrow of time, and the very ways we observe our laws suggests a particular special preference to what are known as "IGUS", information gathering and utilizing systems (which are, for all intents and purposes, conscious observers). The very nature of science is always written as a model in the point of view of observers. We cannot ever really say how anything "really" is. Where this all breaks down is that the consciousness itself seems to be part of the system, and that is not easily resolved (not by Copenhagen either, since observers are given preferential treatment). In fact, all observers are themselves part of the quantum system and are affected by the interaction as well. There is no satisfactory theory to really address this, and it is swept under the rug.


Go to 31:50 to see a dude much smarter and more knowledgeable than me about these things talk about this dichotomy between observer and system.
"So that tells you that there are no measurements of any sort in the interior of a region of space and time that can belong as precise properties of the world. Those cannot be the things that laws of physics are about!"


https://arxiv.org/pdf/gr-qc/0403001.pdfarticle by Hartle is kind of cool and talks about the evolution of IGUS and the reason we might perceive an arrow of time.

Also LOL at Von Neumann actually not having anything to do with the Wigner interpretation.
It was weird seeing a so well known name being associated with that crankish stuff.
Also, apparently even Wigner himself changed his mind later in his life.

(sourcehttps://physics.stackexchange.com/qu...-got-that-name)

Edit: ok I'll check it out

thats some heavy dope. i interpret that as saying the photon is a specific range and orientation of energy.

Go hop on your son’s electric dirt bike and go

It's not crankish...

It is a perfectly valid, but weird interpretation of QM and was his resolution to his "Wigner's friend" thought experiment, which is a very cool experiment. No need to hate on him. Also, I am pretty sure Von-Neumann did adopt that interpretation. I remember reading about it in one of his things. It's just an interpretation and has no effect on the physics.

https://motls.blogspot.com/2015/06/v...ation-was.html

You can read more about it here. It treads into the realm of philosophy. As I said, the physics are the same. It isn't crankish. Perhaps it's not any more useful than Copenhagen, but it's fine to accept it if you like it.

It is hard to visualize what the "fundamental stuff" is, but whatever it is, space and time themselves may even emerge from it...which is a total mindphuck.

You and that liberal crap you preach

agree/10

nature is bazaar

Not my preaching brah. Check that vid I linked.



Really awesome discussion. He was able to simplify these really complicated expressions which would take forever to compute by basically computing the area of a simple fuking object in a weird space without any explicit reference to virtual particles, and not seeming to depend on time or space, and he believes this object can shed light on how space and time emerge.

I like you breh but your liberal agenda zucks

This is just ignorant speculation, but I think it has to do with this:

https://en.wikipedia.org/wiki/Lazy_evaluation

It's almost as if the universe was optimized to reduce unnecessary computations.

This is a great thread. I'm not formally trained in physics beyond the classes I took in college, but it is a huge personal interest of mine. Especially quantum physics. Most nights when I lie in bed, I watch lectures on physics. I especially like Nima Arkani-Hamed's lectures, like the one you posted. You've posted a lot of good stuff in this thread, most of which I agree with. However, the Wigner/Von-Neumann interpretation is considered a fringe interpretation of the measurement problem, and is pretty widely disregarded by experts in the field. I have no problem with you bringing it up, however, as it does address the issue of consciousness in regard to wave function collapse that was discussed in this thread. I did see that you are a Copenhagen guy yourself, which still seems to be the most common accepted version among physicists, however this is apparently decreasing as time goes on.

My main issue with Copenhagen is that none of the math of QM indicates a wave function collapse. The many worlds interpretation explains this in an interesting way, and is the second most preferred among experts. Decoherence interpretations seem to make more intuitive sense to me. DeBroglie-Bohm pilot wave theory is also interesting and perhaps makes the most intuitive sense, however we obviously must be careful in applying "intuitive" reasoning to QM. It also has not been successfully integrated with special relativity. I think the question is incredibly interesting, and enjoy reading about it.

As far as the discussion of photons and virtual photons, my understanding is more in line with what wincel posted. Not all virtual particles are virtual photons, and particles such as the higgs are not virtual photons at all. They are in fact neither virtual (they are real particles) nor photons.

For people interested in these things, but who don't necessarily want to watch lectures, my favorite youtube series BY FAR is PBS's Space Time. I highly, highly recommend it, and multiple episodes address QM. If you go to their page, there is a whole series on QM. Here are some relevant videos to the discussion at hand:

The reality is you are a goldfish trying to understand the Iphone X.

You are Chestbrah trying to understand Quantum physics.

It's not going to happen.


If the Universe could speak to you in English and you asked it this very question, it's answer would likely be something along the lines of....

I created it.

not this chit again, son that experiment was first done back in the 1800s, now what do you do with this information son? you don't do JACK CHIT,

i'll smack your mouth sonny boy

life is real, exactly as we see it

you piss smacker

There is no free will in a simulation.

Yeah. Makes sense to me.

Yeah brah. Agreed. Copenhagen doesn't fix the problem of how to deal with observers as Nima pointed out. The observer is itself a quantum system. As Lubos Motl said in his blog, the Wigner interpretation is really just defining where you draw that line for that measurement. It's a matter of philosophy and doesn't affect the physics at all.

You are right that Bohm's deterministic model hasn't been made compatible with QFT. Many worlds is interesting, but there are some issues with it. A lot of physicists are very passionate about their pet interpretation. As Nima has pointed out, it may well be that all of them are the wrong way to look at things.