Insights Does the Block Universe of Physics Mean Time is an Illusion?

[jbriggs444]

If it is not true how may we make meaning from it?

You may want to step over to the mathematics forum to debate this. Good work has been done in mathematics to establish a reasonable and useful definition for "true" that is independent of physical reality.

In mathematics, for instance, we have the Euclidean and non-Euclidean geometries. In Euclidean geometry we have the parallel postulate. In non-Euclidean geometries that postulate cab be falsified. Yet we can prove that if Euclidean geometry is consistent then so is non-Euclidean geometry.

We can prove theorems and do geometry either way.

Which is "true"? It depends on the model. There are useful models where Euclidean geometry is "true". There are useful models where non-Euclidean geometry is "true".

Similar for the continuum hypothesis and the axiom of choice. We can take them or leave them.

 

[MacCrimmon]

Any system of math using a set of postulates may express a contradiction to another system of math using a different set of postulates. (or may not) but any system of math used may not be valid if it contradicts its own postulates.
The math topic was introduced by the mentor.

 

[PeterDonis]

if it contains no self-contradiction and employs an accepted more fundamental truth (time) in its construct then the more fundamental truth employed is also accepted.

You are saying that, because time is "an accepted more fundamental truth", then it cannot be an illusion. But this argument (a) has nothing whatever to do with the Block Universe, and (b) is circular, since you are basically assuming your conclusion ("accepted more fundamental truth" is basically equivalent to "is not an illusion").

 

[jbriggs444]

Any system of math using a set of postulates may express a contradiction to another system of math using a different set of postulates.

Yes. I thought I'd just given an example of such.

(or may not) but any system of math used may not be valid if it contradicts its own postulates.

If you can prove a contradiction, you have an inconsistent system. That's a bit stronger than "may not be valid".

None of this has anything to do with "illusion", whatever that means.

 

[MacCrimmon]

Thank you Peter. I think your correction of my phrase "more fundamental truth" is justified. And from that point it is also becomes a circular argument. Is it better if I say simply that Block Universe employs some concept of time in its construct as you asserted it uses the concept of spacetime?

 

[PeterDonis]

Is it better if I say simply that Block Universe employs some concept of time in its construct as you asserted it uses the concept of spacetime?

That would be fine, yes.

 

[Sunil]

Not at all. Most physicists who use the term "quantum gravity" mean finding a quantum theory that has classical GR as an approximation in some appropriate limit. Discussion of such proposed theories belongs in the Beyond the Standard Model forum.

Ok, I have started a discussion at https://www.physicsforums.com/threads/will-qg-leave-gr-unchanged-or-qt.996228/

You have already been told, in another thread, that Lorentz Ether Theory, as an alternate interpretation of SR, is off limits for discussion at PF.

Theories such as Schmelzer's, considered as possible extensions of existing theories (i.e., possibly making different predictions in some domain), should be discussed in the Beyond the Standard Model forum.

Correct, but my question was not about discussing them, but simply referencing them if this is necessary to support simple existence claims with a reference to scientific literature. (I have no problem to add myself a remark where those referenced theories resp. quantum interpretations have to be discussed.

But not referencing papers which are relevant for the question discussed is a reason, say, for referees to ask for modifications of papers. Today in "publish or perish" physics it is quite common that the authors simply don't know all the relevant literature, so it is also common that they are asked to add some references. This does not mean that one is obliged to discuss them, one can simply write "we will not discuss here [...]", but a reference has to be given if it is relevant.

And even if postings in a forum are something quite different, I think that what would be obligatory in a scientific article should not be forbidden in a scientific forum. To give correct information about the alternatives is, last but not least, even a moral obligation.

You didn't answer that question.

I disagree, but I think this is a minor quibble not worth further consideration in detail.

You talked about how what you call "realistic" theories explain violations of the Bell inequalities. That has to do with quantum theory, not GR. This is the relativity forum, not the QM forum.

Given that realistic interpretations require absolute time, but other interpretations don't, I think it is obligatory to refer to them (but not to discuss them) if absolute time is considered.