If you are aware of an interesting new academic paper (that has been published in a peer-reviewed journal or has appeared on the arXiv), a conference talk (at an official professional scientific meeting), an external blog post (by a professional scientist) or a news item (in the mainstream news media), which you think might make an interesting topic for an FQXi blog post, then please contact us at forums@fqxi.org with a link to the original source and a sentence about why you think that the work is worthy of discussion. Please note that we receive many such suggestions and while we endeavour to respond to them, we may not be able to reply to all suggestions.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Please also note that we do not accept unsolicited posts and we cannot review, or open new threads for, unsolicited articles or papers. Requests to review or post such materials will not be answered. If you have your own novel physics theory or model, which you would like to post for further discussion among then FQXi community, then please add them directly to the "Alternative Models of Reality" thread, or to the "Alternative Models of Cosmology" thread. Thank you.

Contests Home

Current Essay Contest

*Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American*

Previous Contests

**Wandering Towards a Goal**

How can mindless mathematical laws give rise to aims and intention?

*December 2, 2016 to March 3, 2017*

Contest Partner: The Peter and Patricia Gruber Fnd.

read/discuss

**Trick or Truth: The Mysterious Connection Between Physics and Mathematics**

*Contest Partners: Nanotronics Imaging, The Peter and Patricia Gruber Foundation, and The John Templeton Foundation*

Media Partner: Scientific American

read/discuss • winners

**How Should Humanity Steer the Future?**

*January 9, 2014 - August 31, 2014*

*Contest Partners: Jaan Tallinn, The Peter and Patricia Gruber Foundation, The John Templeton Foundation, and Scientific American*

read/discuss • winners

**It From Bit or Bit From It**

*March 25 - June 28, 2013*

*Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American*

read/discuss • winners

**Questioning the Foundations**

Which of Our Basic Physical Assumptions Are Wrong?

*May 24 - August 31, 2012*

*Contest Partners: The Peter and Patricia Gruber Foundation, SubMeta, and Scientific American*

read/discuss • winners

**Is Reality Digital or Analog?**

*November 2010 - February 2011*

*Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American*

read/discuss • winners

**What's Ultimately Possible in Physics?**

*May - October 2009*

*Contest Partners: Astrid and Bruce McWilliams*

read/discuss • winners

**The Nature of Time**

*August - December 2008*

read/discuss • winners

Current Essay Contest

Previous Contests

How can mindless mathematical laws give rise to aims and intention?

Contest Partner: The Peter and Patricia Gruber Fnd.

read/discuss

Media Partner: Scientific American

read/discuss • winners

read/discuss • winners

read/discuss • winners

Which of Our Basic Physical Assumptions Are Wrong?

read/discuss • winners

read/discuss • winners

read/discuss • winners

read/discuss • winners

Forum Home

Introduction

Terms of Use

RSS feed | RSS help

Introduction

Terms of Use

*Posts by the author are highlighted in orange; posts by FQXi Members are highlighted in blue.*

RSS feed | RSS help

RECENT POSTS IN THIS TOPIC

**Alan Lowey**: *on* 3/19/11 at 11:03am UTC, wrote Dear Moshe, Congratulations on your dedication to the competition and your...

**Eckard Blumschein**: *on* 3/15/11 at 9:25am UTC, wrote Dear Vladimir, You might read what I replied to Georgina today in my...

**Moshe Rozali**: *on* 3/14/11 at 18:59pm UTC, wrote Thanks for your interest Yuri, I will take a look.

**Author Yuri Danoyan+**: *on* 3/12/11 at 9:21am UTC, wrote Dear Moshe Can this essay help to you for final answer? ...

**Moshe Rozali**: *on* 3/11/11 at 3:52am UTC, wrote Thanks very much Paul.

**Paul Halpern**: *on* 3/11/11 at 3:36am UTC, wrote Dear Moshe, Fascinating essay! Well-written and researched. Interesting...

**Moshe Rozali**: *on* 3/8/11 at 20:45pm UTC, wrote Thanks for your interest. I think that information is not likely to be...

**James Hoover**: *on* 3/8/11 at 19:20pm UTC, wrote Moshe, Great read. Do you think that black holes destroy information?...

RECENT FORUM POSTS

**Steven Andresen**: "James I'm on the tablet right now, clumsy to write on so I'll make it..."
*in* Alternative Models of...

**James Putnam**: "Steven, I neglected to add your name to the beginning of my last message...."
*in* Alternative Models of...

**Georgina Woodward**: "Hi Pentcho, it is necessary to separate what is happening regardless of..."
*in* 2016: The Physics Year in...

**Lorraine Ford**: "Re Goals: “There are un-pleasurable, even painful aspects to pursuing..."
*in* FQXi Essay Contest 2016:...

**Pentcho Valev**: "Georgina, in a gravitational field photons accelerate like ordinary falling..."
*in* 2016: The Physics Year in...

**Lorraine Ford**: "This is my comment on H Chris Ransford’s essay “Where the Question..."
*in* FQXi Essay Contest 2016:...

**micheal le**: "thuốc bổ thận là bệnh hiếm gặp ở nam giới, tuy nhiên..."
*in* New Podcast: A MICROSCOPE...

**Joe Fisher**: "Dear Anonymous, If anybody wishes to know more about me, they are welcome..."
*in* Riding the Rogue Quantum...

RECENT ARTICLES

*click titles to read articles*

**Painting a QBist Picture of Reality**

A radical interpretation of physics makes quantum theory more personal.

**The Spacetime Revolutionary**

Carlo Rovelli describes how black holes may transition to "white holes," according to loop quantum gravity, a radical rewrite of fundamental physics.

**Riding the Rogue Quantum Waves**

Could giant sea swells help explain how the macroscopic world emerges from the quantum microworld? (Image credit: MIT News)

**Rescuing Reality**

A "retrocausal" rewrite of physics, in which influences from the future can affect the past, could solve some quantum quandaries—saving Einstein's view of reality along the way.

**Untangling Quantum Causation**

Figuring out if A causes B should help to write the rulebook for quantum physics.

RECENT FORUM POSTS

RECENT ARTICLES

A radical interpretation of physics makes quantum theory more personal.

Carlo Rovelli describes how black holes may transition to "white holes," according to loop quantum gravity, a radical rewrite of fundamental physics.

Could giant sea swells help explain how the macroscopic world emerges from the quantum microworld? (Image credit: MIT News)

A "retrocausal" rewrite of physics, in which influences from the future can affect the past, could solve some quantum quandaries—saving Einstein's view of reality along the way.

Figuring out if A causes B should help to write the rulebook for quantum physics.

FQXi FORUM

January 23, 2017

CATEGORY:
Is Reality Digital or Analog? Essay Contest (2010-2011)
[back]

TOPIC: Continuous Spacetime From Discrete Holographic Models by Moshe Rozali [refresh]

TOPIC: Continuous Spacetime From Discrete Holographic Models by Moshe Rozali [refresh]

We argue that discrete models of quantum gravity can be reconciled with continuous spacetime, and in particular with local Lorentz invariance. The fundamental discreteness cannot be manifested merely as a short distance cutoff. Rather it is expressed in subtle and non-local correlations, of the sort which are most familiar in the context of the quantum mechanics of black holes. Hence, holography is essential in reconciling any fundamentally discrete view of the universe with our continuous and local description thereof.

I am an associate professor in the department of Physics and Astronomy at the University of British Columbia, Vancouver, Canada. I was educated in Tel-Aviv University (degrees in Mathematics and in Physics) and in the University of Texas at Austin (PhD in Physics). Before joining the faculty at UBC, I was a postdoc in the University of Illinois at Urbana-Champaign, and in Rutgers University.

You wrote: "Nevertheless, to the author it seems clear that the discreteness

associated with quantum gravitational effects has little to do with any truncation of spacetime at short distances. Rather it is manifested in global correlations between the degrees of freedom making up spacetime."

I still don't see any proof of the above statement in the essay. Is this a speculation?

Thank you.

report post as inappropriate

associated with quantum gravitational effects has little to do with any truncation of spacetime at short distances. Rather it is manifested in global correlations between the degrees of freedom making up spacetime."

I still don't see any proof of the above statement in the essay. Is this a speculation?

Thank you.

report post as inappropriate

"The difference between space and time manifests itself in the difference between boosts and rotations"

How about when this is a screw motion?

report post as inappropriate

How about when this is a screw motion?

report post as inappropriate

Shalom Moshe

Your statement below describes a model I have been thinking about for some years - a face-centered-cubic universal lattice:

You wrote: "To see the tension between this requirement [Lorentz invariant at the Planck scale] and fundamental discreteness, imagine at first the most naive possible discrete model, the assumption that our space is arranged into a cubic lattice of sides whose length is precisely lp. It is immediately clear that this statement depends on your reference frame, your friend in possession of the latest spaceship model will zoom by this lattice and will see it Lorentz contracted. The principle of relativity is clearly at odds with this very naive picture."

My short response is that the cubic lattice will not be seen from the spaceship, let alone contract because it is not itself made of matter nor does the lattice constitute a frame of reference! The lattice has no background in which it is embedded - it itself creates space, matter and everything else. My other observation about this very basic and important picture you conjured is that in such a lattice the spaceship will not move as if it were in an inertial frame, but will self-convolute as a soliton pattern leap-frogging across the field of lattice nodes, as I have outlined in my original Beautiful Universe paper on which my present fqxi paper is based.

I hope this makes sense and that it helps. Vladimir

report post as inappropriate

Your statement below describes a model I have been thinking about for some years - a face-centered-cubic universal lattice:

You wrote: "To see the tension between this requirement [Lorentz invariant at the Planck scale] and fundamental discreteness, imagine at first the most naive possible discrete model, the assumption that our space is arranged into a cubic lattice of sides whose length is precisely lp. It is immediately clear that this statement depends on your reference frame, your friend in possession of the latest spaceship model will zoom by this lattice and will see it Lorentz contracted. The principle of relativity is clearly at odds with this very naive picture."

My short response is that the cubic lattice will not be seen from the spaceship, let alone contract because it is not itself made of matter nor does the lattice constitute a frame of reference! The lattice has no background in which it is embedded - it itself creates space, matter and everything else. My other observation about this very basic and important picture you conjured is that in such a lattice the spaceship will not move as if it were in an inertial frame, but will self-convolute as a soliton pattern leap-frogging across the field of lattice nodes, as I have outlined in my original Beautiful Universe paper on which my present fqxi paper is based.

I hope this makes sense and that it helps. Vladimir

report post as inappropriate

Moshe,

Thanks for a first rate essay. Your classification of operators is a super great way to put things in perspective. And your expert explanation of Lorentz Invariance hopefully will correct a lot of misconceptions among relativity doubters (who seem to be more abundant in these forums than elsewhere)about the role of "empty space."

If you don't mind a little side observation, I like the way your philosophy and results smoothly descend from Leiniz down to contemporary researchers such as Hermann Weyl and Gregory Chaitin. Appealing to Leibniz's continuity principle, Weyl wrote in 1949*, "Only in the infinitely small may we expect to encounter the elementary and uniform laws, hence the world must be comprehended through its behavior in the infinitely small."

Good luck.

Tom

* Philosophy of Mathematics and Natural Science, Princeton.

report post as inappropriate

Thanks for a first rate essay. Your classification of operators is a super great way to put things in perspective. And your expert explanation of Lorentz Invariance hopefully will correct a lot of misconceptions among relativity doubters (who seem to be more abundant in these forums than elsewhere)about the role of "empty space."

If you don't mind a little side observation, I like the way your philosophy and results smoothly descend from Leiniz down to contemporary researchers such as Hermann Weyl and Gregory Chaitin. Appealing to Leibniz's continuity principle, Weyl wrote in 1949*, "Only in the infinitely small may we expect to encounter the elementary and uniform laws, hence the world must be comprehended through its behavior in the infinitely small."

Good luck.

Tom

* Philosophy of Mathematics and Natural Science, Princeton.

report post as inappropriate

Hello,

I the conclusion of your paper you state: "Nevertheless, to the author it seems clear that the discreteness associated with quantum gravitational effects has little to do with any truncation of spacetime at short distances. Rather it is manifested in global correlations between the degrees of freedom making up spacetime. This is the best way to avoid the tension between

Lorentz invariance and the underlying discreteness of quantum gravity."

A much more serious problem is the experimentally demonstrated non-locality in quantum mechanics. Even if you can find a mathematical way to reconcile quantum gravity with Lorentz invariance, something that it is not demonstrated in the paper, the issue still remains: relativity obeys locality and in quantum mechanics you have nonlocality confirmed by the existence of Greenberger-Horne-Zeilinger relations. These two theories cannot be reconciled physically. One must be fundamentally wrong in the sense that it is not a true theory of nature but only an instrument for making predictions. I don't know which but in my opinion, trying to invent some way to keep both is like having the cake and eating it too.

All the best.

report post as inappropriate

I the conclusion of your paper you state: "Nevertheless, to the author it seems clear that the discreteness associated with quantum gravitational effects has little to do with any truncation of spacetime at short distances. Rather it is manifested in global correlations between the degrees of freedom making up spacetime. This is the best way to avoid the tension between

Lorentz invariance and the underlying discreteness of quantum gravity."

A much more serious problem is the experimentally demonstrated non-locality in quantum mechanics. Even if you can find a mathematical way to reconcile quantum gravity with Lorentz invariance, something that it is not demonstrated in the paper, the issue still remains: relativity obeys locality and in quantum mechanics you have nonlocality confirmed by the existence of Greenberger-Horne-Zeilinger relations. These two theories cannot be reconciled physically. One must be fundamentally wrong in the sense that it is not a true theory of nature but only an instrument for making predictions. I don't know which but in my opinion, trying to invent some way to keep both is like having the cake and eating it too.

All the best.

report post as inappropriate

Dear Efthimios,

you said "These two theories cannot be reconciled physically. One must be fundamentally wrong in the sense that it is not a true theory of nature but only an instrument for making predictions. I don't know which but in my opinion, trying to invent some way to keep both is like having the cake and eating it too."

Yum indeed. I propose a solution in my essay. Your opinion is most welcome.

report post as inappropriate

you said "These two theories cannot be reconciled physically. One must be fundamentally wrong in the sense that it is not a true theory of nature but only an instrument for making predictions. I don't know which but in my opinion, trying to invent some way to keep both is like having the cake and eating it too."

Yum indeed. I propose a solution in my essay. Your opinion is most welcome.

report post as inappropriate

Thanks everyone for the encouragement and the interesting comments, lots of food for thought.

Holographic type of discreteness can prove with Holometer

http://holometer.fnal.gov/ and my non-standart idea

http://www.fqxi.org/community/forum/topic/946

report post as inappropriate

http://holometer.fnal.gov/ and my non-standart idea

http://www.fqxi.org/community/forum/topic/946

report post as inappropriate

Efthimios you said " These two theories cannot be reconciled physically. One must be fundamentally wrong in the sense that it is not a true theory of nature but only an instrument for making predictions. I don't know which but in my opinion, trying to invent some way to keep both is like having the cake and eating it too. "

That is exactly right. GR and QM both 'work' but both are based on irreconcilable assumptions. In my paper here I have traced these assumptions to two of Einstein's arbitrary and experimentally unfounded ideas: 1- the constancy of the speed of light. 2- a photon being a point object . The first worked brilliantly in SR but vastly complicated GR. The second led to the unnecessary confusions of explaining QM in terms of probability. Unless physics is restructured without these two concepts it will never be unified in a simple and direct way close to nature.

report post as inappropriate

That is exactly right. GR and QM both 'work' but both are based on irreconcilable assumptions. In my paper here I have traced these assumptions to two of Einstein's arbitrary and experimentally unfounded ideas: 1- the constancy of the speed of light. 2- a photon being a point object . The first worked brilliantly in SR but vastly complicated GR. The second led to the unnecessary confusions of explaining QM in terms of probability. Unless physics is restructured without these two concepts it will never be unified in a simple and direct way close to nature.

report post as inappropriate

Dear Vladimir,

You might read what I replied to Georgina today in my thread 833.

Regards,

Eckard

report post as inappropriate

You might read what I replied to Georgina today in my thread 833.

Regards,

Eckard

report post as inappropriate

Moshe,

Your essay was a good reading, and I gave it a good score. My essay discusses the issue of conformal completion and quotient group with AdS.

http://fqxi.org/community/forum/topic/810

Further down the discussion list is a reply of mine to Tejindar Singh, where I indicate something about noncommutative geometry in quantum gravity.

Cheers LC

report post as inappropriate

Your essay was a good reading, and I gave it a good score. My essay discusses the issue of conformal completion and quotient group with AdS.

http://fqxi.org/community/forum/topic/810

Further down the discussion list is a reply of mine to Tejindar Singh, where I indicate something about noncommutative geometry in quantum gravity.

Cheers LC

report post as inappropriate

Thanks for your interest and for your comments Lawrence, I'll take a look.

Moshe,

Great read.

Do you think that black holes destroy information? Some speak of holograms to explain that BHs don't.

Do you have details on this?

Jim

report post as inappropriate

Great read.

Do you think that black holes destroy information? Some speak of holograms to explain that BHs don't.

Do you have details on this?

Jim

report post as inappropriate

Thanks for your interest. I think that information is not likely to be lost, and the point of my last section is trying to learn from possible ways information can be preserved in black hole physics. For quantum mechanical black holes you'd expect discrete spectrum and finite entropy, and one might instinctively attempt to explain this fact by assuming that the horizon is made of tiny discrete bits at short distances. In this example at least, this is unlikely that things work this way, because any such discretization would be at odds with the principle of equivalence and the experience of the infalling observer. We need the holographic principle to make things work while avoiding the problems that would follow from making spacetime discrete. Maybe there is a lesson there for more general situations.

If you want to read more on the holographic principle and black hole physics, I'd recommend Lenny Susskind's books: "The Black Hole War" for non-technical exposition, and "An Introduction To Black Holes, Information And The String Theory Revolution: The Holographic Universe" for semi-technical exposition.

If you want to read more on the holographic principle and black hole physics, I'd recommend Lenny Susskind's books: "The Black Hole War" for non-technical exposition, and "An Introduction To Black Holes, Information And The String Theory Revolution: The Holographic Universe" for semi-technical exposition.

Dear Moshe,

Fascinating essay! Well-written and researched. Interesting speculations about the black hole energy spectrum.

Best wishes,

Paul

Paul Halpern, The Discreet Charm of the Discrete

report post as inappropriate

Fascinating essay! Well-written and researched. Interesting speculations about the black hole energy spectrum.

Best wishes,

Paul

Paul Halpern, The Discreet Charm of the Discrete

report post as inappropriate

Thanks very much Paul.

Dear Moshe

Can this essay help to you for final answer?

http://www.fqxi.org/community/forum/topic/946

report post as inappropriate

Can this essay help to you for final answer?

http://www.fqxi.org/community/forum/topic/946

report post as inappropriate

Thanks for your interest Yuri, I will take a look.

Dear Moshe,

Congratulations on your dedication to the competition and your much deserved top 35 placing. I have a bugging question for you, which I've also posed to all the potential prize winners btw:

Q: Coulomb's Law of electrostatics was modelled by Maxwell by mechanical means after his mathematical deductions as an added verification (thanks for that bit of info Edwin), which I highly admire. To me, this gives his equation some substance. I have a problem with the laws of gravity though, especially the mathematical representation that "every object attracts every other object equally in all directions." The 'fabric' of spacetime model of gravity doesn't lend itself to explain the law of electrostatics. Coulomb's law denotes two types of matter, one 'charged' positive and the opposite type 'charged' negative. An Archimedes screw model for the graviton can explain -both- the gravity law and the electrostatic law, whilst the 'fabric' of spacetime can't. Doesn't this by definition make the helical screw model better than than anything else that has been suggested for the mechanism of the gravity force?? Otherwise the unification of all the forces is an impossiblity imo. Do you have an opinion on my analysis at all?

Best wishes,

Alan

report post as inappropriate

Congratulations on your dedication to the competition and your much deserved top 35 placing. I have a bugging question for you, which I've also posed to all the potential prize winners btw:

Q: Coulomb's Law of electrostatics was modelled by Maxwell by mechanical means after his mathematical deductions as an added verification (thanks for that bit of info Edwin), which I highly admire. To me, this gives his equation some substance. I have a problem with the laws of gravity though, especially the mathematical representation that "every object attracts every other object equally in all directions." The 'fabric' of spacetime model of gravity doesn't lend itself to explain the law of electrostatics. Coulomb's law denotes two types of matter, one 'charged' positive and the opposite type 'charged' negative. An Archimedes screw model for the graviton can explain -both- the gravity law and the electrostatic law, whilst the 'fabric' of spacetime can't. Doesn't this by definition make the helical screw model better than than anything else that has been suggested for the mechanism of the gravity force?? Otherwise the unification of all the forces is an impossiblity imo. Do you have an opinion on my analysis at all?

Best wishes,

Alan

report post as inappropriate

Login or create account to post reply or comment.