Search FQXi


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.

Contests Home


Previous Contests

What Is “Fundamental”
October 28, 2017 to January 22, 2018
Sponsored by the Fetzer Franklin Fund and The Peter & Patricia Gruber Foundation
read/discusswinners

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 Fund.
read/discusswinners

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/discusswinners

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/discusswinners

It From Bit or Bit From It
March 25 - June 28, 2013
Contest Partners: The Gruber Foundation, J. Templeton Foundation, and Scientific American
read/discusswinners

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/discusswinners

Is Reality Digital or Analog?
November 2010 - February 2011
Contest Partners: The Peter and Patricia Gruber Foundation and Scientific American
read/discusswinners

What's Ultimately Possible in Physics?
May - October 2009
Contest Partners: Astrid and Bruce McWilliams
read/discusswinners

The Nature of Time
August - December 2008
read/discusswinners

Forum Home
Introduction
Terms of Use

Order posts by:
 chronological order
 most recent first

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

By using the FQXi Forum, you acknowledge reading and agree to abide by the Terms of Use

 RSS feed | RSS help
RECENT POSTS IN THIS TOPIC

Frank Martin DiMeglio: on 1/8/10 at 17:38pm UTC, wrote Hi Gil: How do you see the following? The most...

Edwin Klingman: on 11/5/09 at 0:30am UTC, wrote Dear Gil Jannes, I found your essay most enjoyable and informative. ...

Peter Morgan: on 10/10/09 at 2:35am UTC, wrote Hi Gil, I point out that there is a clear distinction to be made between...

Leshan: on 10/6/09 at 13:57pm UTC, wrote Dear Gil Jannes, My gravitation theory also is based on existence of atoms...

Gil Jannes: on 10/5/09 at 10:40am UTC, wrote Essay Abstract Are we moving in the right direction on the road to...


RECENT FORUM POSTS

Steve Dufourny: "after all like Borh has made,this universe and its spheres for me are like..." in Alternative Models of...

Steve Dufourny: "Thanks for sharing Georgina,it is nice.Friendly" in Alternative Models of...

Joe Fisher: "Today’s Closer To Truth Facebook page contained this peculiar piece of..." in First Things First: The...

Joe Fisher: "Today’s Closer To Truth Facebook page contained this peculiar piece of..." in First Things First: The...

Lorraine Ford: "With the “A.I. Feynman” software, Silviu-Marian Udrescu and Max Tegmark..." in Will A.I. Take Over...

Georgina Woodward: "Coin toss co-state potentials: With the measurement protocol decided, in..." in Schrödinger’s Zombie:...

Steve Dufourny: "If we correlate with the consciousness, can we consider that all is..." in Measuring Free Will: Ian...

Steve Dufourny: "Hi Ian Durham, Maybe still for the rankings and the links with this..." in Measuring Free Will: Ian...


RECENT ARTICLES
click titles to read articles

First Things First: The Physics of Causality
Why do we remember the past and not the future? Untangling the connections between cause and effect, choice, and entropy.

Can Time Be Saved From Physics?
Philosophers, physicists and neuroscientists discuss how our sense of time’s flow might arise through our interactions with external stimuli—despite suggestions from Einstein's relativity that our perception of the passage of time is an illusion.

Thermo-Demonics
A devilish new framework of thermodynamics that focuses on how we observe information could help illuminate our understanding of probability and rewrite quantum theory.

Gravity's Residue
An unusual approach to unifying the laws of physics could solve Hawking's black-hole information paradox—and its predicted gravitational "memory effect" could be picked up by LIGO.

Could Mind Forge the Universe?
Objective reality, and the laws of physics themselves, emerge from our observations, according to a new framework that turns what we think of as fundamental on its head.


FQXi FORUM
October 22, 2019

CATEGORY: What's Ultimately Possible in Physics? Essay Contest (2009) [back]
TOPIC: Emergent gravity and the spatiotemporal limits of knowledge by Gil Jannes [refresh]
Bookmark and Share
Login or create account to post reply or comment.

Author Gil Jannes wrote on Oct. 5, 2009 @ 10:40 GMT
Essay Abstract

Are we moving in the right direction on the road to quantum gravity? It seems to me that there is a serious conceptual problem with most current approaches. I discuss a simple guiding principle which I believe to be quite obvious, but which has nevertheless been largely neglected so far. This leads me to argue that the most relevant approach to quantum gravity might be a framework of emergent gravity based on insights from condensed matter physics. Within this framework, I discuss a thought experiment based on the idea to describe quantum gravity in a first approximation simply as a Minkowski spacetime containing nearly-point-like objects or `atoms' of spacetime, from which the geometry of our universe and its physics emerge as an effective, internal description based on collective excitations. Based on this thought experiment, I will try to convince you that there are strong spatiotemporal limits on the knowledge that we can possibly achieve with respect to quantum gravity.

Author Bio

The author has studied electronical engineering, philosophy and fundamental physics at the universities of Leuven (Belgium) and Madrid (Spain), and has recently achieved a PhD in quantum gravity from a condensed-matter perspective.

Download Essay PDF File

Bookmark and Share



Leshan wrote on Oct. 6, 2009 @ 13:57 GMT
Dear Gil Jannes,

My gravitation theory also is based on existence of atoms of space-time. However, these atoms of space-time possess extension property, therefore they cannot be point-like objects. What you think, the space-time has a 'solid' structure or it is a 'soup' of fluctuating atoms? If atoms are virtual particles that disappear and appear continually, then a holes in space-time must exist. If an atom disappears, it creates a vacant place without space-time properties (a hole in space-time). Since a hole does not possess the extension and time properties, one collapses quickly. However, the lifetime of hole is non-zero because environment is not able to fill a hole instantly.

Since you admit the existence of atoms of space-time, you must admit also holes in space-time.

Sincerely, Leshan

Bookmark and Share
report post as inappropriate


Peter Morgan wrote on Oct. 10, 2009 @ 02:35 GMT
Hi Gil,

I point out that there is a clear distinction to be made between quantum fluctuations and thermal fluctuations, that the former are Lorentz invariant (in consequence of the Lorentz invariant definition of the vacuum state of a quantum field), while the latter are not. This difference is reflected in the difference of units between hbar and kT, action in contrast to energy. For a free quantum field, this can be laid out very clearly, as in my Phys. Lett. A 338, 8-12(2005) [arXiv:quant-ph/0411156]. It has not been clear to me that there is an analogue of Lorentz invariant fluctuations in the condensed matter analogue.

Bookmark and Share
report post as inappropriate


Edwin Eugene Klingman wrote on Nov. 5, 2009 @ 00:30 GMT
Dear Gil Jannes,

I found your essay most enjoyable and informative.

"Assume that there exists a condensed matter system of sufficient complexity such that it contains a whole internal universe."

I'm assuming that this condensed matter system has more the nature of a "perfect fluid" than a "bunch of particles".

Then you note, "A second motivation to take emergent gravity seriously, is that it has something sensible to say about the accelerated expansion of the universe, which seems to require the existence of some form of repulsive `dark energy'." This should follow from the original assumptions, at least in the ideal case.

I also liked your observation that "from a direct extrapolation to our universe, one would expect the vacuum energy of the universe to be approximately equal to the energy content of the matter component (baryonic or `normal' matter plus dark matter): a 50-50 distribution. Observations indicate that the distribution is in fact approximately 70% dark energy and 30% matter. By cosmological standards, 50-50 is an excellent prediction, certainly better than simply saying that the vacuum energy is a random value from a range of roughly 10**500 possibilities, as is sometimes claimed."

Although my essay does not directly support yours, I believe that they overlap in some areas. I invite you to read my essay and make any comments you feel appropriate. I also would say that, if you have the same trouble bringing consciousness into physics that many do, simply ignore the consciousness interpretation and focus on the pure physics implied by the existence of the gravi-magnetic field. I believe it may stimulate new ideas about quantum gravity that are not totally divorced from yours.

Edwin Eugene Klingman

Bookmark and Share
report post as inappropriate


Frank Martin DiMeglio wrote on Jan. 8, 2010 @ 17:38 GMT
Hi Gil: How do you see the following?

The most elemental/fundamental/deepest way (or manner) in which human thought is [comprehensively and consistently] enmeshed and interactive with physical (and this includes sensory, of course!)experience is the source of our deepest genius and of the deepest and broadest conclusions/unifications that are revealed (and possible) in physics.

This above is in keeping with the FACT that the ability of thought to describe OR reconfigure sense is ultimately dependent upon the extent to which thought is similar to sensory experience.

Electromagnetric space (e.g., photons and the Sun) is both larger and smaller than ordinary or typical space (such as the Earth). When space manifests as gravitational/electromagnetic energy, scale is then balanced, space is particle/wave, invisible/visible, and larger/smaller. Accordingly, space is both repulsive and attractive as well.

Essay author Frank Martin DiMeglio

Bookmark and Share
report post as inappropriate


Login or create account to post reply or comment.

Please enter your e-mail address:
Note: Joining the FQXi mailing list does not give you a login account or constitute membership in the organization.