unification?

[mathematic]

Has there been any progress in recent years to unify relativity with quantum theory?  I have the impression that both string theory an loop quantum gravity have not made any progress recently,

[StringJunky]

The present situation in quantum theory and its merging with general relativity - arxiv 2017 paper

[mathematic]

It sounds awfully offbeat as far as quantum theory is concerned.

[MSD]

I think the unification is beyond the relativity. The unification is deeper and it encompasses every single physical theory. I encourage you to read this e-book that's against the rules for me to advertise

Edited November 25, 2019 by Phi for All
No advertising, please

[mathematic]

2 hours ago, MSD said:

I think the unification is beyond the relativity. The unification is deeper and it encompasses every single physical theory. I encourage you to read this e-book that's against the rules for me to advertise

Reference cannot be accessed.

[Bufofrog]

19 hours ago, MSD said:

I think the unification is beyond the relativity. The unification is deeper and it encompasses every single physical theory. I encourage you to read this e-book that's against the rules for me to advertise

That cracked me up.

[Schmelzer]

On 7/3/2019 at 3:58 AM, StringJunky said:

The present situation in quantum theory and its merging with general relativity - arxiv 2017 paper

Khrennikov is not really a good source for this. 

Quote

1. Nonrelativistic QM versus relativistic QFT were just steps towards real QT which have not yet been constructed.

 

Khrennikov has his own ideas about developing QT, and I don't think they are reasonable. The majority thinks that it is GR which creates the problem, and here I follow the mainstream. 

Quote

4. Foundational output of violation of Bell’s inequality - existence of action at a distance, has to be translated to the QFT-language.

No need for this. In fact, it is well-known that the Bell inequality is violated in QFT too. 

There is some truth in his claim that non-relativistic QM and QFT live separate from each other, with all the foundational discussions localized in non-relativistic QM.  But this is not really an issue, because both have the same abstract QT as the base.  

This abstract QT is essentially non-relativistic.  QFT solves this by emphasizing only those parts where the non-relativistic character is less visible. So there is simply silence about the other parts. Those other parts are discussed in non-relativistic QM.  A reason is that many, in fact all realist interpretations also need the Schrödinger equation with  

Relativistic field theories have a similar structure, but those who care about the foundational questions sometimes don't even know this, while others don't want to consider the infinities of field theories so they prefer to restrict themselves to the non-relativistic case.   

Another problem with the infinities is that there are simple regularizations, like lattice regularizations - but those regularizations destroy relativistic symmetry.  This is quite trivial, even in Euclidean space a lattice regularization destroys rotational symmetry.  But for those who consider relativistic symmetry as something fundamental, such a breaking of relativistic symmetry is unacceptable.  That's why they cannot accept that the theories we have work only for large distances and below some critical length there will be some other theory without relativistic symmetry.  

[Conjurer]

It really makes me wonder why they can't just take the limit and find the derivative of QFT to find the area under the curve of the theory to get rid of all the infinities...  Did they just fail at calculus or something?

[Markus Hanke]

4 hours ago, Schmelzer said:

4. Foundational output of violation of Bell’s inequality - existence of action at a distance

Violation of Bell’s inequalities does not imply such as thing as “action at a distance” - which is in itself a meaningless concept. Quantum entanglement is simply a statistical correlation between measurement outcomes; there is no causative “action” involved. 

1 hour ago, Conjurer said:

It really makes me wonder why they can't just take the limit and find the derivative of QFT to find the area under the curve of the theory to get rid of all the infinities..

I’m afraid this is completely meaningless.

[Conjurer]

14 minutes ago, Markus Hanke said:

I’m afraid this is completely meaningless.

Why is that?  A function can have an infinite value in it, but the area under the curve of that function isn't always infinite.  Then it could potentially provide real numbers to deal with instead of infinities, which represent the same function.  I really don't know why that method has not been attempted or mentioned publicly.  It is really the only well known way to get rid of infinities...

[Carrock]

4 hours ago, Markus Hanke said:

Violation of Bell’s inequalities does not imply such as thing as “action at a distance” - which is in itself a meaningless concept. Quantum entanglement is simply a statistical correlation between measurement outcomes; there is no causative “action” involved.

I wonder if this is a definition issue. I always assumed action in this context was energy*time as I believe Einstein or whoever invented the term intended. That action need not be cause and effect.

However from https://en.wikipedia.org/wiki/Action_at_a_distance#Einstein

Quote

If 'action' is defined as a force, physical work or information, then it should be stated clearly that entanglement cannot communicate action between two entangled particles

which seems to be avoiding the issue. Action does seem to be defined vaguely in other refs too, except for Planck's constant (action or Js).

I couldn't quickly find a good reference but I'm sure there are some.

If you have entangled photons, each pair with the same (random) polarisation and the distant measurement outcome is the photons are reflected by a polarised filter with orthogonal orientation to a local polariser, giving it kinetic energy, then the action for a given time of that filter is greater than if you have parallel filters with fewer photons reflected.

No cause and effect, just a correlation.

[Markus Hanke]

10 hours ago, Conjurer said:

Why is that?

1. A QFT is not a function.
2. “Derivative of QFT” is a meaningless term.
3. In any case, derivatives don’t measure the area under a curve.
4. “Curve of the theory” is a meaningless term.

4 hours ago, Carrock said:

No cause and effect, just a correlation.

Yes, that is what I was getting at.

[Conjurer]

44 minutes ago, Markus Hanke said:

1. A QFT is not a function.
2. “Derivative of QFT” is a meaningless term.
3. In any case, derivatives don’t measure the area under a curve.
4. “Curve of the theory” is a meaningless term.

I meant the integral could be taken, and it could remove the infinity.  Then the derivative could be taken after that to renormalize the equation back to the original.  Although, it would mean that you would be missing variables, but one of the goals of unification is to have a short equation which can describe anything.

Why is QFT not a function?  Couldn't GR be considered as an area of higher dimensional spacetime?  Then GR could have the infinities taken out of it?  Couldn't you consider the area of the hyperspace around a black hole to to remove the infinities while it is even a stand alone theory?  

Edited January 18, 2020 by Conjurer

[Strange]

17 minutes ago, Conjurer said:

I meant the integral could be taken, and it could remove the infinity.  Then the derivative could be taken after that to renormalize the equation back to the original.  Although, it would mean that you would be missing variables, but one of the goals of unification is to have a short equation which can describe anything.

Why is QFT not a function?  Couldn't GR be considered as an area of higher dimensional spacetime?  Then GR could have the infinities taken out of it?  Couldn't you consider the area of the hyperspace of a black hole to to remove the infinities while it is even a stand alone theory?  

!

Moderator Note

Please stop posting your nonsensical comments in the science sections of the forum. Any further comments like this will be removed.

 

[Markus Hanke]

11 hours ago, Conjurer said:

Why is QFT not a function?

QFT stands for “quantum field theory”; it’s a mathematical framework that describes the dynamics of quantum fields. It’s not a function.

11 hours ago, Conjurer said:

I meant the integral could be taken, and it could remove the infinity.  Then the derivative could be taken after that to renormalize the equation back to the original.  Although, it would mean that you would be missing variables, but one of the goals of unification is to have a short equation which can describe anything.

 

11 hours ago, Conjurer said:

Couldn't GR be considered as an area of higher dimensional spacetime?  Then GR could have the infinities taken out of it?  Couldn't you consider the area of the hyperspace around a black hole to to remove the infinities while it is even a stand alone theory?  

I do not mean to be rude, but little of what you write makes any sense - it seems obvious that you have not actually studied things like GR and QFT, and thus are not familiar with these models. It is not generally very wise to comment on things one does not understand.