Hi Lawrence,

nice to meet you again.

Regarding thermal gravitational waves, give a look to this paper by C. Sivaram and Kenath Arun: http://arxiv.org/abs/1005.3431.

I recently accepted it for publication in TOAAJ.

Cheers,

Ch.

Dear Christian

An excellent essay. If we are to find an acceptable route for reality to permeate physics then this will certainly be a strong candidate.

My own work has taken a more physical view but seems otherwise almost entirely equivalent. It is really a case of defining how this 'intrinsic' curvature is manifested in nature at the quantum level. Perhaps I have gone too far too soon, but have been seduced by the trail of 'magic bullets' followed.

I'd be very appreciative of your views on my own essay, http://fqxi.org/community/forum/topic/803 and in particular of your opinion on the relevance of the extended field equations to the physical process described from the empirical evidence.

Best wishes

Peter

    Dear Dr. Juan R. González-Álvarez,

    thanks for your comments.

    My best wishes for further developing your approach in extending General Relativity.

    Best regards,

    Ch.

    Dear Dan,

    thanks for your kind words.

    I do not know if I have written a definite winner, this will be judged by the expert panel of judges which will be instructed and I have a total respect in FQXi's merit system.

    I have read your Essay and I find it interesting. In particular, I appreciate your relating the cosmological application of GR to the Mach's Principle through FPC and your intuitive-geometric vision of the Universe. Some suggestions: you should try to derive the model in a more rigorous way and send it to a peer-reviewed international journal in order to have a concrete scientific feedback. More, you should improve the references. For example, there are more rigorous reference than Wikipedia on the Friedmann-Lemaître-Robertson-Walker Model, examples are L. Landau and E. Lifsits, Classical Theory of Fields (3rd ed.), London: Pergamon (1971) and C. W. Misner , K. S. Thorne, J. A. Wheeler, "Gravitation", Feeman and Company (1973).

    You cold be interested also in two recent works of mine, where, together with my friend H. J. Mosquera Cuesta, we find ways to remove both of the BH's and Universe's Sigularities. These are Mod. Phys. Lett.A25, 2423-2429 (2010) and Astropart. Phys. 34, 7, 587 (2011).

    I wish you a lot of luck in the contest.

    Cheers,

    Ch.

    Dear Dr. Juan R. González-Álvarez,

    I would like to invite you to submit your next papers on your approach to extend General Relativity to The Open Astronomy Journal, see http://bentham.org/open/toaaj/index.htm, and/or to The Hadronic Journal, see http://www.hadronicpress.com/edit_board.htm.

    These are two international peer-reviewed journal in which I am Editor in Chief.

    Best regards,

    Ch.

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    • Post #14

    Dear Dr. Corda,

    Thanks, for your reply and I greatly appreciate your feedback. I'll be the first to admit that my model needs a more rigorous treatment and that some of my references were somewhat weak. I am presently working on just such a revision, among other things. My rough draft started with over 60000 characters, so it went through a major overhaul and the Wikapedia references were last minute additions, requested by FQXI, that I should have taken more seriously. This is my first attempt at writing a scientific paper. Having a support group would have been helpful, as I do want to be considered seriously. Do peer review journals accept papers from anyone? It was my assumption, that you need to be affiliated with a academic institution to obtain consideration.

    I look forward to reading your latest works, they sound intriguing. My greatest concern with General Relativity has always been the uncomfortable acceptance of singularities, assuming that QG will someday resolve the issue.

    Thanks again and best wishes,

    Dan

    Dear Dan,

    actually, it is not needed to be affiliated with ab academic institution to obtain consideration.

    Even if such an affiliation is, of course, a vantage, what is really important is to write good research papers.

    I would like to invite you to submit your technical papers on your approach to Cosmology to The Open Astronomy Journal, see http://bentham.org/open/toaaj/index.htm, and/or to The Hadronic Journal, see http://www.hadronicpress.com/edit_board.htm.

    These are two international peer-reviewed journal of which I am Editor in Chief.

    Cheers,

    Ch.

    Dear Christian,

    Your essay is very interesting and really innovative. In general I agree with the outcome: from analog to digital. In your essay I have found more concepts that seem to support my own (the details in my essay ). For example you claim: "Dark Energy and Dark Matter have to be considered like pure effects of the presence of an intrinsic space-time curvature in the Universe. Considering this point of view, one can think that gravity is different at various scales because of the existence of the intrinsic space-time curvature, which changes at different scales, and there is room for alternative theories." I am happy - for the first time I have read such innovative view in a public paper. And it is fully compatible with my own view. There are also strong differences. For example I try to prove that gravitational waves do not exist. Moreover in my concept the gravity is an emergent and not fundamental interaction. But I have started out from different assumptions albeit based on geometry as well.

    I think I shall read your essey once more to fully understand it.

    I look forward to reading your publications and finding out a development of your concepts.

    Good luck Christian!

    Jacek

    http://fqxi.org/community/forum/topic/883

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    • Post #17

    Dear Dr. Corda,

    Thanks for you invitation and advice. It may take some time to get my paper up to professional standards, but I look forward to the challenge. I'm currently working on another essay for a different contest, but the two ideas are complementary so I may have enough material for two papers. I'll work on getting the first one acceptable before I proceed.

    You have been most helpful,

    Dan

    Dear Peter,

    thanks for your kindness.

    It is a big problem defining how this 'intrinsic' curvature is manifested in nature at the quantum level. I realized such a quantization only within the linearized (i.e. at first order) theory in my papers Eur. Phys. J. C 65 1-2, 257 (2010), Astropart. Phys. 30, 209 (2008), Mod. Phys. Lett. A 22, 35, 2647 (2007), Gen. Rel. Grav. 42, 1323 (2010), AIP Conf. Proc. 966, 257 (2008), and Mod. Phys. Lett. A 22, 15, 1097 (2007). I reported the main results in page 9 of my Essay. A better definition implies the quantization of the extended field equations (2) of my Essay, which, based on the strong non linear character of these equations, is a goal very very difficult to realize .

    I have read your Essay, it is interesting.

    The relevance of the extended field equations is important to the physical process described from the empirical evidence which happen on scales larger than the Solar System scales. Examples are Dark Matter and Dark Energy. In fact, General Relativity is very very well tested within the Solar System. Thus, variations from General Relativity have to be very weak in order to be consistent with the Solar System tests. In my geometric approach this means that the spacial hypersurfaces of the intrinsic curve space-time should have a curvature which manifests only on scales larger than the Solar System scales.

    Cheers,

    Ch.

    Dear Jacek,

    thanks for your kind words.

    I read your Essay and I agree with you that there are strong differences with respect to mine. In particular, your claiming that gravitational waves do not exist in the way they are conventionally defined is very strong. Actually, gravitational waves are solutions of both the linearized and full Einstein Field Equations in both of Standard General Relativity and Extended Theories of Gravity.

    On the other hand, you also claim, verbatim, that "the spacetime has elastic properties". But in that case I think that heavy masses with acceleration should radiate gravitational waves based on such elastic properties. What do you think on this issue?

    In any case, I wish you a lot of luck in the contest.

    Cheers,

    Ch.

      Dear Dan,

      be free to call me merely Christian without any suffix.

      Take your time for getting your papers up to professional standards, we are not in a hurry. What other different contest are you attending?

      Cheers,

      Ch.

      Dear Dr. Corda,

      Welcome to the essay contest. Since Dr. Elliot McGucken and you are my neighbors in the essays list, therefore I must visit these pages first.

      All attempts to quantize gravity have utterly failed, and your attempt to quantize gravity will have the same fate; There are a lot of different Extended Theories of Gravity, including yours, which tries to enlarge the Einstein scheme through an addition of corrective terms, but all these theories are not able to explain inertia, mass and the curvature of spacetime. The complete theory of gravitational interaction must be able to explain inertia, mass, and the curvature of spacetime in the same model. Also the true theory of gravitation must be able to unify gravity with the other forces. Since your variant of Extended Theory of Gravity is not able to do it, then your approach also is wrong and even the quantization of the extended Einstein field equations can not help you.

      I agree with you that the intrinsic space-time curvature may be important for Gravity, but not ''by adding an intrinsic space-time curvature to the model''. Instead you must examine how an intrinsic space-time curvature appears and how it works. In other words, you must look for physical solutions rather than for mathematical.

      Also, your essay do not show, if you are in the digital or analog party. In general, I don't found any proofs in your essay that the reality is digital, analog, or digital-analog.

      Sincerely

      Constantin

      Dear Mr. Leshan,

      actually, I do not attempt to quantize gravity. I limit myself to discuss intermediate steps like the extension of General Relativity and/or the quantization of Extended Theories in the weak field approximation.

      On the other hand, I agree with you that the complete theory of gravitational interaction must be able to explain inertia, mass, and the curvature of space-time in the same model. I also agree with you that the true theory of gravitation must be able to unify gravity with the other forces. But, surely, I am not so arrogant and presumptuous to claim that I can find, alone, the complete theory of gravitational interaction. If Albert Einstein and others world's greatest scientists did not find this theory in about 100 years of scientific research, I am absolutely sure that I will not find it being alone!!

      I limit myself to try to give small contributions towards such a goal by following a way that could be the correct one.

      On the other hand, I am not so arrogant and presumptuous to claim that the reality is digital, analog, or digital-analog. Even in this case, I recall you that Albert Einstein and others world's greatest scientists did not find the correct answer to this issue in about 100 years of scientific research. Thus, I prefer limit myself to suggest a potential detectable signal, i.e. the relic gravitational waves, which could clarify the digital rather than analog feature of the gravitational interaction.

      This is absolutely sufficient for me.

      I wish you a lot of luck in the contest.

      Best regards,

      Ch.

      I clarify my reply to Mr. Leshan on the question "Is Reality Digital or Analog?".

      In my opinion, at the present time and at the present status of our scientific knowledge, nobody can claim, with an absolute certainty, that Reality is surely Digital, or surely Analog or surely Digital-Analog. Of course, people have various opinions on this fundamental issue and I respect all the various opinions. I have an opinion too, but I think this is NOT really important. What I think to be really important, at the present status of our scientific knowledge, is the way in which one attempts to arrive to a potential answer to the question, not the question itself.

      I interpreted this beautiful Essay Contest in this spirit and with this spirit I wrote my Essay.

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      • Post #24

      Dear Christian,

      I read that a non-academic received an honorable mention in the 2009 Gravity Research Foundation Essay Contest and that has encouraged me to submit an entry on black holes. The entry deadline is April 1, which is quickly approaching. I believe that I have seen your name listed there, at least once, so undoubtably you're familiar with them.

      Sincerely,

      Dan

      Dear Cristian,

      You write

      ---"As distinct from other field theories, like the Electromagnetic Theory, General Relativity is very difficult to quantize. This fact rules out the possibility of treating gravitation like other quantum theories and precludes the unification of gravity with other interactions. At the present time, it is not possible to realize a consistent Quantum Gravity Theory which leads to the unification of gravitation with the other forces."---

      If a universe is to create itself without any outside intervention, then its particles must create themselves, each other. If (the properties of) particles then are as much the product as the source of their interactions, their energy exchange, then so is the force between them. This means that a force, in principle, cannot be either attractive or repulsive. That is, particles can only exist, have properties (attract/repulse) if they have some kind of backbone so they can, within limits, absorb energy in an increase of their kinetic energy rather than in a change of identity. That said, if the rest energy of particles ultimately is as much the effect as the cause of their energy exchange, their interactions, of a continuing evolution, then interaction energies never can become infinite at infinitesimal distances, so there's no need for string theory. A universe which finds a way to create itself without any outside intervention can hardly stop doing so: gravity, the contraction of masses and the related expansion of spacetime between the mass concentrations they form, is the expression of this continuing creation process, and hence differs fundamentally from the 'other' forces.

      Since according to our present, simplistic ideas particles only are the source of their fields, they either attract or repulse, so the strength of the force between them solely depends on their distance. This belief led to the question how protons can fit in atomic nuclei despite their huge electric repulsion, which is said to be 10^38 times stronger than gravity between them. However, a force never can exceed the counter force it is able to evoke, that is, than the opposition the particles offer to that force: than their inertia. So if we may interpret Einstein's equivalence principle to say that every influence which brings the inertia of a particle to expression as a counter force can be called 'gravity', then there's only gravity. As attractive as it is repulsive, it is much stronger than the weak gravity pulling at Newton's apple, as gravity which is powered by the continuous creation process inherent to a self-creating universe. For details, see my essay the UPDATE 1 post about the strong nuclear force.

      Regards, Anton

      Dear Anton,

      thanks for your comments.

      There are two points of view concerning gravitation: the Einstein's geometric point of view and the Feynman's particle point of view. The Quantum Gravity Theory, if it will be ultimately find, should be the definitive synthesis of them.

      In any case, Einstein's Equivalence Principle is purely geometric as it implies that test masses (particles) have to follow the space-time curvature during their motion. In this geometric vision only mass-energy and curvature are strictly needed. In my attempt to extend General Relativity mass-energy should be produced by variations of an intrinsic space-time curvature. Can this be conciliated with your vision that gravity has to be powered by the continuous creation process inherent to a self-creating universe?

      Best regards,

      Ch.