Energy is the ability to do work. If at maximum entropy there is no energy available to do work, then effectively there is no energy on that definition. — Janus

The problem though is that there is a conservation law, and entropy does not actually decrease the amount of energy. So at maximum entropy there is still the same amount of energy, on that definition. All you have done is created a contradiction, saying that there is energy, but it's no longer the capacity to do work, when energy has already been defined as the capacity to do work. That's why i am sought to change the definition of energy. It's what would be needed to avoid the contradiction. But i am's definition is nonsense, and the definition of energy has already been established as you can see.

The "heat death" is just nonsense, it assumes that the universe has the characteristics of an artificial system, created by human beings. Then it describes the capacity of that system to do work, from the perspective of the human beings who created it, for a particular purpose. So it's nonsense because it requires that the universe is a system created by human beings.

Quantum mechanics provides conclusive evidence that the universe is not the type of system which is required for the heat death. That's why the many worlds interpretation is logically acceptable.

As he puts it, decoherence gives us quasi-classical worlds (branches) but not actual classical worlds. Which means that decoherence can be treated as irreversible and the worlds as classical for all practical purposes. Nonetheless interference between branches continues to happen in accordance with quantum mechanics. — Andrew M

Ok, I see!

The Andromeda Paradox is about the ambiguity of what time it is elsewhere, not about the state being definite. The former is a frame dependent thing and the latter is a statement of superposition of something unmeasured. I think you meant the former but your wording suggested the latter. — noAxioms

Yeah, sorry!

Totally agree. Two observers at the same place but different frames might disagree about what is going on at Andromeda, but they'll agree entirely about what has been measured. The light cone from that location is a frame independent thing. — NoAxioms

Yes! In Relativity the ordering of events in every light cone is an invariant (unless one accepts tachyons or any FTL influence). — boundless

I didn't say that. I said the set of events in a given light cone is frame independent. The ordering of those events is still quite frame dependent. — noAxioms

I am not sure I am following you. In fact, I just am saying that the cause precedes the effect in all reference frames without FTL. Isn't it right? :smile:

Interesting corollary for a presentist, who by definition cannot observe any existing thing. In 8 minutes, the thing I observe will not be the present state of the sun. It will be an observation of something nonexistent.
— noAxioms

Yep! Presentism is somewhat problematic in Relativity. I would say that 'global presentism' is simply incompatible with relativity of simultaneity. Maybe a form of 'local presentism' can be saved but it is surely counter-intuitive (I personally lean towards some form of presentism and I admit that I am troubled by this). — boundless

I have done an advocatus diaboli thread defending the compatibility of relativity and presentism, so I maintain that they're not incompatible. SR says that the preferred frame cannot be determined given the special case after which it is named. But inability to detect such a frame does not mean that there isn't a special one. Presentism doesn't even require it to be a inertial frame, and no presentist that knows their physics seems to assert that it corresponds to such a frame. The foliation is always bent, which has the interesting paradoxical implication that no two stationary observers are simultaneous in each other's inertial frames. I find that hilarious, but not paradoxical. — noAxioms

Ok, I see. Interesting, thanks! I wonder if this can be used to reconcile SR with pilot-wave theory... :smile:

Note, however, that the 'presentism' that I had in mind was somehow different. I am not sure of how to explain it - so, I'll leave it for now.

I simply meant that without the selection postulate, it seems that RQM implies the splitting.

Anyway, I agree with you. RQM seems simply silent on this point. — boundless

Maybe it's embarrassed. :yikes: — Wayfarer

Well, possibly! :razz: — boundless

This is why I resist describing RQM under presentist terms. If time is external to the structure that is the universe, then such selection is an objective act relative to this realm under which time exists, and it isn't really RQM anymore if such an objective action takes place.

With time being part of the structure, no event/state (something to which a relation can be made) 'flows' to a different event, necessitating such a selection. Thus there is no selection postulate.
This isn't an embarrassment, just an implication of a relative interpretation. — noAxioms

Ok, I can see the problem! Even the presentism you referred before as compatible with SR seems to imply a unique, well-defined state of the universe (the 'unicity' referred in the SEP article on Consistent Histories) :smile:

(as I said it was not exactly what I had in mind. But I think I'll leave it at least for now...)

I am not sure I am following you. In fact, I just am saying that the cause precedes the effect in all reference frames without FTL. Isn't it right? :smile: — boundless

Yes. With locality, which is essentially saying no FTL.

Ok, I see. Interesting, thanks! I wonder if this can be used to reconcile SR with pilot-wave theory... :smile:

Pilot wave is a form of Bohmian mechanics: Pro counterfactual definiteness (objective state) and denial of locality. So I wonder how they interpret spooky action at a distance using pilot waves. I don't know the official line on that. They certainly cannot reproduce spooky action using a classic pilot wave setup like they use for double slit.

By my understanding, in PWT the pilot wave controls the velocity of the particle. And that velocity depends not only on the position of the particle, but also the positions of all the particles it is entangled with; and that information is all available instantaneously to the pilot wave which controls the velocity of the particle. I don't see how that can be reconciled with SR.

Is there a way to block somebody in this forum? — i aM

It can be frustrating, when you are trying to interact sensibly with an ignorant or stupid person who is being willfully ignore-ant or deliberately obtuse, or just plain stubbornly ignorant and/ or doltish.

It can be frustrating to realize that no matter how much you try to reason with them and encourage them to engage with relevance and rationality with what you are presenting, even if only to cogently criticize it, that there is nothing you can do to stop them coming up with ever more distortions of what you have said, empty rationalizations, evasions and other tactics designed to avoid admitting they are wrong, or seeing that their position is actually ill-informed or even totally vacuous.

Often such people will never stop, they always want to have the last word, no matter how empty that word might be. It can be frustrating to have to admit to yourself that you are powerless to help such people, powerless to stop their flow of bullshit, and it is not always easy to admit that enough is enough, and any further responses from you will just be a waste of time.

There does come a time, though, and hopefully we learn from our wasted efforts and abstain from future interactions with such people altogether (at least insofar as they continue with their ignorant claims or evasive tactics). Unfortunately, I haven't been able to find any 'ignore' function on this site.So it's down (or up) to you! Your brain has an 'ignore' function, although it's not always that easy to actuate and sustain, but definitely worth the effort sometimes. :zip:

On the positive side; there is probably more value in learning to exercise your own 'ignore' function in cases which warrant it, than there would be in electronically avoiding having to see such annoying responses at all. I'm a slow learner; it has taken me a long time to learn to ignore, and even now I still get sucked back in from time to time. :gasp:

Yes. With locality, which is essentially saying no FTL. — noAxioms

Ok! Fine, then we agree :smile:

Pilot wave is a form of Bohmian mechanics: Pro counterfactual definiteness (objective state) and denial of locality. So I wonder how they interpret spooky action at a distance using pilot waves. I don't know the official line on that. They certainly cannot reproduce spooky action using a classic pilot wave setup like they use for double slit. — noAxioms

Considering that the 'wave-function' is a 3N-dimensional (N being the number of particles) object and the theory predicts that the 'influence' is instantaneous, I do not think that there can be an explanatory dynamical model like - say - the one that uses mediators.

(As an aside, I prefer using the term 'de Broglie-Bohm theory' or 'pilot-wave theory' for various reasons. Among these, 'Bohmian mechanics' is actually the preferred term of a specific sub-school of the dBB-supporters and also downplays the role of de Broglie. It gained success and maybe it is the most used term in literature... :smile: YMMV )

By my understanding, in PWT the pilot wave controls the velocity of the particle. And that velocity depends not only on the position of the particle, but also the positions of all the particles it is entangled with; and that information is all available instantaneously to the pilot wave which controls the velocity of the particle. I don't see how that can be reconciled with SR. — i aM

Well, there have been attempts to reconcile SR and PWT. To my knowledge, they involve the use of preferred foliations of space-time or retro-causality. Of course, this is different from saying that PWT can be reconciled with SR in its standard formulation, but the point is that apparently it can be reconciled with Lorentz symmetry.

I was however referring to this way of reconciling SR and PWT via this defense of presentism proposed by NoAxioms:

I have done an advocatus diaboli thread defending the compatibility of relativity and presentism, so I maintain that they're not incompatible. SR says that the preferred frame cannot be determined given the special case after which it is named. But inability to detect such a frame does not mean that there isn't a special one. Presentism doesn't even require it to be a inertial frame, and no presentist that knows their physics seems to assert that it corresponds to such a frame. The foliation is always bent, which has the interesting paradoxical implication that no two stationary observers are simultaneous in each other's inertial frames. I find that hilarious, but not paradoxical. — noAxioms

https://erlichdallc.wordpress.com/2019/04/11/my-current-understanding-in-a-nutshell-of-everetts-relative-state-formulation-of-qm/

Isn't a core idea of SR "relativity of simultaneity", i.e. simultaneity of events is entirely dependent on the reference frame of the observer?

https://erlichdallc.wordpress.com/2019/04/11/my-current-understanding-in-a-nutshell-of-everetts-relative-state-formulation-of-qm/ — i aM

Nice!

Isn't a core idea of SR "relativity of simultaneity", i.e. simultaneity of events is entirely dependent on the reference frame of the observer? — i aM

I believe that it depends on how you define SR. In the usual definition, both preferred foliation of spacetime and retro-causality are incompatible with SR.

Yet, I think that they are both compatible with Lorentz symmetry.