Can Gravity Be Quantized? by Vesselin Petkov

Dear Vesselin Petkov,

I loved reading your essay, and not only because I fully agree with what you wrote, but because you expressed very clearly and logical, and also with originality, some of the reasons why semi-classical gravity may be enough. The essay reduced the arguments to their essence, which can be understood from basic general relativity. Indeed, the geodesic hypothesis implies that there is no gravitational interaction, at least not of the same type as for the other forces. Also, I think your emphasis on the non-existence of gravitational energy is also important. I agree that this is true locally, which from my viewpoint means that it is true. Probably the appearance of gravitational interaction and energy loss may be due to the unavoidable of use non-inertial charts.

I expressed in a previous FQXi essay the viewpoint that QFT and the Standard Model on (classical) curved spacetime may be enough. Part of this position is because I think that quantum fields are more classical than they may appear, and this may arise from a unitary interpretation of QM. While I think that the quantum fields are more like classical fields than we expect, I do not deny that perturbative expansions and path integrals are powerful tools, if not for bringing understanding, at least for calculations. So, why not, maybe perturbative methods may work for gravity too. We don't know for sure what is quantization, but GR seems to me on a very good position.

Recently I found that by trying to understand singularities in GR we see that they are not harmful, and even they may help in making gravity renormalizable (see my essay).

Best regards,

Cristi Stoica

Dear

Your paper is very interesting. What you are discussing is same in my paper http://gsjournal.net/Science-Journals/Research%20Papers-Relativity%20Theory/Download/2310

My paper is entitled "THE RELATIVISTIC QUANTIZED FORCE: NEWTON'S SECOND LAW,

INERTIAL AND GRAVITATIONAL"

Dear Vesselin Petkov,

Quite a fascinating essay! I want to believe some of your conclusions and I resist others. Like so many other essays here, this one calls for some careful re-thinking.

You write clearly and well and, for the most part, convincingly, and I will have to re-read your essay and give it more thought.

In one place you remark that "there is no tensorial measure of the gravitational field in general relativity, since it can always be transformed away in the local inertial frame." If, as several other authors suggest, there *is* a 'preferred frame of reference', would this still be true?

Thanks for your essay and for your answer.

Edwin Eugene Klingman

Vesselin Petkov,

You used to claim that "the wavelength of a photon in the gravitational redshift experiment cannot change along with its frequency" and that "both frequency and velocity change in this experiment":

http://arxiv.org/pdf/gr-qc/9810030v12.pdf

Vesselin Petkov: "It has been overlooked that the wavelength of a photon in the gravitational redshift experiment cannot change along with its frequency (...) As both frequency and velocity change in this experiment the measurement of a change in a photon frequency is in fact an indirect measurement of a change in the photon local velocity. (...) The very existence of the gravitational redshift, however, shows that it is the local velocity of a photon that changes along with the change of its frequency. (...) In such a way the gravitational redshift essentially shows that two photons emitted at points of different gravitational potential have different local velocities at the same observation point..."

Did you know then that the invariability of the wavelength and the variability of the speed of light put an end to Einstein's relativity? Do you know it now?

Pentcho Valev pvalev@yahoo.com

Dear Vesselin Petkov,

As gravity is not a physical interaction between point-like particles, I think, quantization of gravity is possible only with string theory predictions in that restructuring of atomic analogy is inevitable and emergence of new physics in accordance with the existing physics is expectative.

With best wishes,

Jayaker

If, as you used to claim, "the wavelength of a photon in the gravitational redshift experiment cannot change along with its frequency", that marks the end of Einstein's relativity. Let me ask you a concrete question (I have already asked it to James Putnam and Israel Perez):

The top of a tower of height h emits light with frequency f, speed c and wavelength L (as measured by the emitter):

f = c/L

An observer on the ground measures the frequency to be f'=f(1+gh/c^2), the speed of light to be c' and the wavelength to be L':

f' = c'/L'

The questions: c' = ? ; L' = ?

My answers: c'=c(1+gh/c^2) ; L'=L

Pentcho Valev pvalev@yahoo.com

Don't forget that, as judged from a local inertial (free-falling) system, the observer on the ground is racing upwards toward the falling light. If, at the moment of reception of the light, his speed is v (as judged from the free-falling system), then the speed of light this observer measures is:

c' = c(1 gh/c^2) = c v

This puts an end to Einstein's relativity doesn't it? Perhaps my initial question was not so irrelevant.

Pentcho Valev pvalev@yahoo.com

If the masses of fundamental objects, comprising 99.99...% of mass in the universe, were reasonably discrete and quantized, would not gravitational interactions between them automatically be quantized?

Hello Mr. Petkov,

I believe that I found humbly. Of course I must test and expermiment.But my equations can help.The gravitational waves have several answer. The quantum gravitation can be linked with my spheres and their rotations more their volumes. The quantum theory of fields and the GR converge when we insert two different main senses of rotations differenciating the bosons and fermions.

Good luck in this contest

Dear Petkov

Wonderful and well written essay. I enjoyed it a lot and I would not hesitate to put it in the list of the top scores. I agree with your view in the physical foundations of gravity. In this respect, my essay, essentially points out the physical source of the puzzle in contemporary physics.

You said: relativists who are more accustomed to solving technical problems than to examining the physical foundation of general relativity which may involve no calculations.

I sympathize with this view, I hold that philosophical reasoning should not be disregarded in physics as a tool to understand the foundations of physical phenomena.

From your essay I could figure out that you realize that the falling of a body is not caused by a force. Indeed, it is easy to conclude from careful analysis and observation of gravitational phenomena that objects are neither pulled nor pushed towards the source of gravity but they simply follow the law of inertia.

This being said, I would like to quote some of your phrases to base some of my forthcoming comments:

determining the true nature of gravitational phenomena is the experimental fact that particles falling towards the Earth's surface offer no resistance to their fall.

What also warrants such an examination is that an experimental (fact falling bodies do not resist their apparent acceleration) turns out to be crucial for determining the true nature of gravitational phenomena, but has been effectively neglected so far...

That gravity is not really a force has been considered several times during several moments in the history of physics. Descartes was one of the pioneers. In his treatise, the World, he considered that gravity was the result of the dynamics of the aether. He conceived a model in which space was filled with a continuous material medium and the motion of celestial and terrestrial bodies was based on the generation of vortices in the aether. For this reason his theory was known as the vortex theory. Unfortunately, the consummation of a mathematical model for vortices seemed an impossible task that Descartes' view was difficult to handle.

Years later, Newton firmly supported Descartes' view of gravity, in this sense, Newton was more Cartesian than Newtonian. He realized however that the Cartesian dynamics of gravity was impossible to model and decided not to consider it in the famous Principia. In his mathematical formulation he simply assumed that space was "EMPTY" (even though he knew it wasn't and that the aether existed) and apply the four laws along with Euclidean geometry. Due to the omission of the aether as the medium to transmit gravity among material bodies he was severely criticized by his contemporaries. In defense, he simply replied with the famous phrase: I do not feign hypothesis. After Newton's dead, most physicists believed that space was really empty and that gravity was an attractive force acting at a distance. The General Relativity got rid of instantaneous interactions, replaced empty space with space-time and reinterpreted (to a certain degree) the notion of gravity. Nonetheless, the conception of gravity as an attractive force still prevails nowadays.

You conclude:

that there is no gravitational interaction and therefore there is nothing to quantize.

Indeed, as Newton and Descartes held, gravity is not a force and thus there is nothing to quantize. In my essay, I explained the physical gap that the mathematical representation of gravity has overlooked since Newton and Descartes. I think that Descartes ideas should be reconsidered to explain physical phenomena. I would be glad if you take a look at my work and let me know your opinion.

Good luck in the contest

Israel

Vesselin,

There is something very pure and beautiful in the concept of inertia when one hears it expressed with such expert familiarity. Reading your essay, I think I almost understand now why Einstein said that he had experienced his theory "kinesthetically."

Great essay! Best wishes in the contest. (And I do hope you get a chance to visit my site, too -- thanks.)

Tom

it was me the spherical belgian, crazzy and parano.

ps hope there is not a competition between the Institute of Advanced Studied and the Minkowski institute.After all, the most important is the universal optimization.

Regards

Hi Vesselin

Thanks for your reply. Actually, I was aware of Newton's letter to Bentley, that's why I mentioned that Newton was in the philosophical matters of gravity Cartesian.

I would be expecting any comments you may have on my essay.

Best Regards

Israel