The Strand Model of Christoph Schiller (MotionMountain.net) 'constructs' space-time from unobservable strands that create 'curvature' through strand crossings. The curvature and associated energy density is related to the density and rate of strand crossings. I'd be interested in knowing if this model approaches the concept you are exploring......

"Like constructing a “hidden medium” for curved space-time?"

It is necessary to induce a metric on the 4-manifold which is given by the velocity field of the particles of the medium in an 8-dimensional space, where 4 measurements are folded into a circle.

(not an answer but a comment:) Let's try to be more precise. Consider a solution approaching flat Minkowski space at its boundaries all around at infinity. Like Schwarzschild. Consider  a light ray traversing the solution. Now it is meaningful to ask wether the signal shows up at the other end before or after the time this ray would have arrived if we had flat Minkowski spacetime everywhere. I think this is a meaningful question, and I think the answer will always be: later! And then one can also ask how to embed the solution into flat space such that light goes slower than c everywhere; that's what I meant with choosing the right coordinates x\mu.

And yes, my complaint about many participants of pages such as these is that they don't feel constrained at all by their lack of understanding of what they're talking about. Same as @Jurg's complaint.

To answer another related question: yes, this has to do with my attempts to find a theory underlying QM. An ingredient I added to that theory at the very end - which is also the most speculative ingredient - is that local gauge equivalence classes may coincide with information-equivalence classes, that is, if there is information loss, it's the gauge dependent variables which get lost first. In a gravity theory this means: the "absolute" coordinates of a system do exist, but the information as to what they are gets lost. This would be gravity with a medium consisting of a Minkowski flat metric. Mind, I consider this very speculative myself, so you can just as well ignore this part.

One can create variable speed of light by adopting a hybrid coordinate system that uses the coordinate rate of time as the time standard and proper length as a length standard. This is an unconventional coordinate system that is a mixture between the (for example) Schwarzschild coordinate metric coordinate time and circumferential radius, and the standard coordinates that use proper time and proper length. This coordinate system can be used to analyze the covariance of the laws of physics when two locations have different gravitational potentials and different rates of time. It will produce a system where there is an effective variable velocity for the speed of light. I can provide a reference if you wish.

Why not dismiss 'Time Dilation' and accept that 'c is not a constant? Lorentz contraction (L.C.) explains the results of the MMx interferometry that decided 'c' to be a constant and was carried over from the postulates of SRT to GR and thus to QT. See 'Phase tuning in Michelson-Morley experiments performed in vacuum, assuming length contraction' arXiv:1010.2164v2 [physics.gen-ph] (J Levy).

If the active 'quantum' vacuum is a real medium, not merely for the passage of discrete particles but for the propagation of light waves, then L.C. is inevitable. A medium comprised of electrons and positrons in a bound state confirms Planck's postulate and explains gravitational field as the local binding energy density of that medium.

The Planck Quantum of Action has very real justification but I fear that Planck length, time and mass are meaningless mathematical constructs obtaining merely by juggling with units. No more meaningful than discussing a wavelength greater than the size of the universe. 'What' is the Planck length other than its formulaic expression?

This is a side kick to your question. My understanding is that in inflationary cosmology spacetime can inflate faster than the speed of light without violating Lorentz invariance. Could it also collapse, say into a BH-like-singularity, faster than c? thereby providing the mechanism for no escapism :) and beyond?

@Grantham:  the Planck length and time do seem to have a direct interpretation in quantum gravity when you look at the Bekenstein bounds. There is a direct consequence of  Hawking's radiation phenomenon:  from the fact that the derived temperature of a black hole is 1/8 pi M in Planck units one can derive directly that there is one bit of information per Planck-length^2 (up to a simple numerical constant) on a black hole horizon, which determines the quantum microstate a black hole can be in. According to Bekenstein this is an absolute maximum of information one can cram onto any surface. These are rather straightforward arguments. Although there is no super-solid proof of these things, since information is a delicate subject, they do suggest that there is a natural cot-off for information at the Planck scale, and that therefore, space and time are likely to be discrete. My conclusion is, if there's any limit on the information in nature, it's at the Planck scale.

Important note however: if there are extra dimensions, then also the horizon has extra dimensions and since also in that case the total amount of information should be the same per unit of area, the info will be much more dilutely spread over this multi-dimensional horizon ...

@ t Hooft: If we regard the nuclear and atomic states as different aggregation states of matter then we might choose to nominate the active vacuum for propagation of light as another aggregation state - of electrons and positrons with all the necessary attributes of 'photons'.  If light propagates as a vibrational wave of those leptons then it has a high freq cutoff with a wave of one e-&1e+. 

Using the mean Madelung constant of the ionic alkali halides and by analogy, one obtains a wavelength of 8.8e-15m and a single photon energy of 141MeV with Planck's Quantum of Action h at cutoff.  This is also the mass-energy of the pions ...where we enter the nuclear aggregation state, Presumably  the mesons provide the matrix inside nuclei. I see no reason to apply this nuclear state of matter to a giant BH (at the galactic scale) that would correspond to a 'hole' in the lepton lattice where no light (EM waves) can propagate nor nuclei hold onto their electrons. I suggest this electron positron lattice ('epola' - M Simhony, 1973) is Einstein's 'hidden variable' where gravitation results from energy density reductions induced by spin moments of 'guest' or 'dopant' atomic matter particles .

Electrons and  anti-matter positrons probably do add another dimension or dimensionality to the vacuum state (+/- T?)  and lead us to regard light waves comprised of spherical half-wave clusters of charge-excited epola corresponding fully to Planck's h at all freqs (

Sorry, Mr. @Grantham. I fail completely to understand any sentence in your comment, so I cannot answer it.

Verlinde has derived the GR Field Equations from his 'entropic Gravity' approach - which is essentially the assumption that information is coded at Planck-scale on the Cosmological Horizon. Gibbons-Hawking Radiation also implies this is the case, just as Beckenstein-Hawking Radiation similarly implies such coding for black holes. Schiller has similarly derived the same field equations equations using the Principle of Maximum Force/Power advanced by him and Garry Gibbons. Further, one can show that the two approaches are equivalent, and even go further in either approach to show that the average energy/mass density of the Universe is equal to the Critical Density (as current observational data suggest). I don't believe that the same results can be obtained using either approach if one assumes that space is other than 3 dimensions......

@ Prof. Gerard 't Hoofd: "the local speed of light is always slower than the coordinate speed of light". The bending of light gives an apparent slowing down compared with the straight line (by coordinates).

Gravitational lensing is just an observation of the bending of light, and so, it is not intrinsically linked to the GR, since it is just an observation.

"This would be gravity with a medium". A wise idea, which led Oliver Heaviside to his gravitomagnetism, in 1893. (By the way, Prof. Oleg Jefimenko worked on this, and found that the value of the time dilatation depends on the type of clock that one uses. So, time dilatation is not universally the same, but depends on the used clock.)

The so-called linearized GR, but in reality the fully independent theory of gravitomagnetism, deduced the bending of light as an application only. Amazingly, disc galaxy and cluster formation are explained by it as well, without the need to introduce "dark matter" nor "dark energy". So, I think that what you now consider a bit speculative has instead a great value.

Moreover, the rotation of the sun will slightly bend the light beam a little more or less, depending on the side (East-West, North-South) that the beam uses. It is not a negative mass, but spinning matter that can act as if it were negative mass.

I add a short presentation. The bending of light equation is shown at page 27.

I hope this helps you in your quest.

Dear Prof. Gerard t Hooft

Thank you for this important question.

I think the best way to get the unification between QM and GR is rewriting the space time metric in a form that can conserve the constancy of speed of light. I started to do that by assuming a general metric that applies for all objects massive and zero rest mass particles at the same time. The new metric conserves speed of light and at the same time can predict the delay in light waves, but this time due to longer paths that light needs to pass before reaching the observer. The work is still in progress. Glad for any collaboration.

With best regards

Sadeem

@Mohamed El Naschie: this remark is totally  logical in terms of degrees of freedom. It also is a typical Hawking way of thinking. However, I am shocked about the ease with which nowadays' scientists add dimensions to theories, add new theories to explain failing theories while maintaining them, and so on.

@Amrit & Remi: In understood it more like Prof 't Hoofd wrote it in his question. Shapiro time delay is not the slowing down of the speed of light but the time difference between the coordinate distance and the path distance. This means that one should see the universe as a system that must be described in an  Cartesian 

...described in an Euclid space with Cartesian (or polar) coordinates.

@Amrit Sorli could you please explain why at a stronger gravitational field the vacuum thins out? for slowing light wouldn't you expect the dielectric constant to grow? shouldn't the strain-tensor depend on the vacuum and thereby affect the field? Consider the Unruh effect, since acceleration is equivalent to gravitational field for  larger acceleration you'd expect higher temperature ergo denser vacuua...  

The Shapiro effect is consistent with constant c but larger traveled distance as per GR

Dear Remi

Thank you for your interesting Article: Superluminal Signalling by Path Entanglement.

You have wrirren: "it is noteworthy that at the instant of transmission between the two stations that there is no transfer of mass-energy to instigate communication but the transmission of a quantum state - pure information only."

What does carry Superluminal Signalling? What path is made up of?

G. ‘t Hooft said: “the Planck length and time do seem to have a direct interpretation in quantum gravity when you look at the Bekenstein bounds. There is a direct consequence of Hawking's radiation phenomenon: from the fact that the derived temperature of a black hole is 1/8 pi M in Planck units one can derive directly that there is one bit of information per Planck-length^2 (up to a simple numerical constant) on a black hole horizon, which determines the quantum microstate a black hole can be in. According to Bekenstein this is an absolute maximum of information one can cram onto any surface. …My conclusion is, if there's any limit on the information in nature, it's at the Planck scale. ”

However, Planck’s ‘natural units’ are fallacious. All proponents of Planck’s ‘natural units’ are invited to defend or admit the falsity of Planck’s false proof of Kirchhoff’s false law:

Robitaille, P.-M., Crothers, S. J., “The Theory of Heat Radiation” Revisited: A Commentary on the Validity of Kirchhoff’s Law of Thermal Emission and Max Planck’s Claim of Universality, Progress in Physics, v. 11, p.120-132, (2015),

http://www.ptep-online.com/index_files/2015/PP-41-04.PDF

http://vixra.org/pdf/1502.0007v1.pdf

Dear Prof. Mohamed

I agree with you that G'Hooft, Susskind and Hawking are great physicists, with so dynamics mind. G'Hooft found patterns in the renormalization counter terms, which led to the discovery of supergravity. Leonard Susskind combined G'Hooft's ideas (the holographic principle) with previous ones of 't Hooft and Charles Thorn.

These so hard efforts were not able to solve the quantum gravity problem.

Why Is Quantum Gravity So Hard?

Today’s physics is outspread between macro and micro world. General Theory of Relativity very well describes Macro world, while Quantum Mechanics very well describes probability in micro world. But problem occurs when we want to unify these two theories into the one that would be able to describe each phenomenon in the Universe.

I don’t claim that my model is a unified theory of general theory of relativity and quantum mechanics. But I claim that this is a great step for explaining gravity better than formal quantum theory.

A new definition of graviton

To define graviton, let’s consider to a photon that is falling in the gravitational field, and revert back to the behavior of a photon in the gravitational field. When a photon is falling in the gravitational field, it goes from a low layer to a higher layer density of gravitons. We should assume that the graviton is not a solid sphere without any considerable effect. Graviton carries gravity force, so it is absorbable by other gravitons; in general; gravitons absorb each other and combine. When some gravitons are around a photon (or other particles) they convert to color charges and enter into the structure of photon. Color charges around particles/objects interact with each other. There exists so much graviton around any particle. There are many layers of gravitons around a photon. The first layer is closed with photon, so that its gravitons interact with charge and magnetic fields in the structure of photon. The second layer interacts with the first layer and third layer and so on. Therefore; when a stone is falling in the gravitational field of the Earth, two layers of gravitons are applied to it, first layer up (at high h) and second down (at high h-dh). In down layer, the density of graviton is greater than up, so the stone falls and its kinetic energy increases.

In this model, an attempt has been made according to the concept of gravitational blue shift, to take the Mössbauer effect, Pound-Rebka experiments and the interaction between gravity and the photon into consideration from a Higgs field point of view. Blue shift and the Mössbauer effect indicate clearly that three different Higgs bosons cause increasing photon mass when they have electromagnetic specifications. This generalizes color charge from the nuclear regime to the photon. This new view of color charge means that we can redefine the graviton and electromagnetic energy.

Gravitons behave like charged particles and in the interaction between gravity and the photon, gravitons convert to negative and positive color charges and magnetic color. These color charges and magnetic color form electromagnetic energy and then

electromagnetic energy converts to matter and anti-matter such as charged particles.

https://www.researchgate.net/publication/260982893_A_new_Definition_of_Graviton?ev=prf_pub

Data A new Definition of Graviton

General Relativity: In Acknowledgement Of Professor Gerardus ‘t Hooft, Nobel Laureate, 4 August, 2014,

http://vixra.org/pdf/1409.0072v7.pdf

Mr. @Crothers: funny and wrong as always ...

Mr. 't Hoof invokes Planck's 'natural units'. However, Planck's natural units are a fantasy. Mr. 't Hooft, and any other proponent of Planck's 'natural units', is invited to adduce on this forum the means by which they uphold Planck's false proof of Kirchhoff's false law:

Robitaille, P.-M., Crothers, S. J., “The Theory of Heat Radiation” Revisited: A Commentary on the Validity of Kirchhoff’s Law of Thermal Emission and Max Planck’s Claim of Universality, Progress in Physics, v. 11, p.120-132, (2015),

http://www.ptep-online.com/index_files/2015/PP-41-04.PDF

Dear Professor Gerard 't Hooft,

For all the above reasons I'd like from you to solve the attached problem.

Thank you

With my regards 

@Demetris, 1)  I don’t see what this  problem has to do with my question; I suspect you should solve it yourself; I would need more motivation ...       2) Are you sure that not both u and v should be in the entire interval  [0, 2 pi ] ? Your surface is now a doughnut cut in half ... you’ve got the top half.

G. ’t H

Dear Gerard,

(1)The fact that you cannot understand the relationship to GR and your question really scares me...

(2)That's irrelevant. The 'point' is that you wrote [0,2*Pi]. Don't you know that for an atlas it is necessary to have an open interval? ([0,2*Pi) open end is crucial...)

Regards.

@Mohamed : Fortunately, neither Mahler's nor Beethoven's music are wrapped by space-time...

@Demetris, Athens, (1) I do understand that this is mathematically related to GR, but not what it has to do with my question. I would be quite happy if my question would have to be restricted to simply connected spaces.

(2) You wrote closed intervals in the question yourself; so I had reasons to think that the edges of the surface were irrelevant to your questions, which actually look more like an undergraduate or graduate exercise than a scientific contribution.

Dear Gerard, thanks for the notification for [0,2*Pi), I had misstyped it and now I have corrected it.

Your question is about a GR related issue.

But, GR is mathematically ill-defined.

The only way to find the reasons for that is by keeping Differential Geometry requirements as a 'holy writing'. Otherwise, you will not find the causes.

I want to believe that you have studied deeper the whole mathematical pre-requirements. But, if you had done that, then you'd had found all the ill-defined concepts. Except if you have done it, but you prefer to downrate the value of your personal findings...

I have not neither the time nor the willing to work further on it. I suggest you to collaborate with somebody that has studied the field equations in detail.

But, since you speak to all of us (the so called "average bloggers") "ex cathedra", then you have to prove your abilities and your superiority.

So, please solve it!

PS The exercise is a typical one for students following a course named 'Differential Geometry of Curves and Surfaces" and  I randomly found it in my files. Actually I have developed a simple procedure in order to solve all kind of similar X(u,v) problems without any manual computation...

@Demetris, Sorry, I have no time to calculate your doughnut, but I see no difficulty with it at all. All curvature tensors and Christoffel symbols can be calculated. And you still have only half the doughnut; your intervals should be [0, 2pi) x [0, 2pi). Your doughnut happens to be embedded in a higher dimensional space. That’s irrelevant for GR. As a physicist, I know that GR is mathematically accurately defined in the sense that you can do physics with it: given the initial conditions you can calculate how everything evolves. When horizons show up, they have consequences for the topology of space-time, which, in spite of Crothers’s noises, present no problems whatsoever. But you can encounter real curvature singularities. In practice these are always hidden behind horizons and for that reason harmless, but I know that this is difficult to prove in all its mathematical generality. Weaker, physically observable  singularities would be interesting as such, but do not show up in reasonable physical models such as black holes.   When people such as Crothers hit upon difficulties it is because they don’t know how to choose coordinates. In particle theory we’re used to that: we fix a gauge condition, which immediately gives all terms in a perturbation expansion, for starters. Only in rare cases, such as a global description of black holes, one needs more than that. One then has to divide space-time into smaller regions, each of which are fine. The really tough one is black hole mergers. Numerical calculation algorithms are nowadays closing in on that problem. What else do you want ...

I am afraid that General Relativity doesn't explain anything but the bending of light, which is an observation by itself. It appears that the Schwarzschild metric, which consists of not one, but two useless singularities, is an incomplete solution of GR. This metric falsely “proves” Mercury's perihelion advance (see Anatoli Vankov's work) because the approximations hide another part that cancels the perihelion advance.

The “deduced” Kerr metric is just a fabrication, an extension of the Schwarzschild metric without being a direct solution of the GR equations. It was just invented to try getting an answer for rotation.

The so-called Thirring-Lense precession (with alleged Coriolis and centrifugal effects for spinning objects) was only confirmed by the Gravity B Probe to 20%. Instead, the Lunar Laser Ranging (LLR) confirms the gravitomagnetic term of Gravitomagnetism to 0.1% and the Gravity Probe B confirms the gravitomagnetic term with a different method to only 1%

The Equivalence Principle (Eötvös experiment) is naive. It was instead by the definition of the gravitational constant that the link between inertial and gravitational mass has been defined, not by any other consideration or thought experiment.

Also the need for Dark Matter and Dark Energy are nothing more than expressions of the uselessness of GR. The pretended GR successes of binary stars at millions of light years are naive too, since several parameters are unknown and a curve fit is easy to make.

But the motions of asteroids, the structure formation of supernovae, planetary systems, galaxies and clusters are in no way explained by GR. Instead, Gravitomagnetism perfectly describes these phenomena.

So, please don't tell me that there is anything valuable that Einstein's GR has ever performed!

@Thierry De Mees: A.A. Vankov agrees with all the calculations of GR including the perihelion precession. Only that he calculates them by introducing a "Minkowski force" - Kµ.  He writes: "The bending of light is due to the “gravitational refraction”. We conducted different calculations of the bending effect: using a refraction model,

and using the angular momentum conservation; in both cases, the result was

the same and similar to that in GR."

https://www.researchgate.net/post/Why_do_physicists_ignore_fact_that_Plancks_proof_of_Kirchhoffs_false_Law_of_Thermal_Emission_is_false

https://www.researchgate.net/post/Why_do_scientists_ignore_the_observational_evidence_that_attests_that_the_Sun_is_condensed_matter_not_a_hot_ball_of_gas

Thierry De Mees, surely Gravitomagnetism is only the GR Field Equations in the weak-field, low-velocity limit......?

@Mohamed, I would welcome a “hidden medium” (with which I mean to say: a flat background metric) for my theories underlying quantum mechanics. I should immediately add that this medium must be very well-hidden. It must become truly invisible under most circumstances. But most likely I’m just day dreaming.

The Bekenstein bounds can be interpreted as follows: it is the maximal number of states (or max nr of combinations) that one can get with a given quantity of units (this may be particles and so on). A nice example is that a crystal can be built up in numerous ways out of atoms. In spite of the production of a structured entity, the entropy nevertheless increases. However, the question arizes if a black hole will ever stop recombining its particles or its energy, and so, stop in increasing its entropy.

However, the question arizes if non-spinning black holes would possibly exist. When a nebula contracts, it will have the tendency to group the like-moving particles and slightly repell the opposite-like particles (this is a gravitomagnetic effect, details upon request). This will generate a rotation of the cloud. When it further contracts, the spin will even increase until the velocity near the equator will act as if the star were very heavy there.

Spinning black holes will always allow an energy exchange nearby the poles, where the velocity is low. So, it isn't a closed system. It seems very unlikely that black holes would have the chance to merge and become so heavy that even at the poles nothing would escape.

So, I even wonder how one could take any time in studying such a totally hypothetical case.

So, dear Gerard, if I have understood well:

• after your success in renormalization at quantum field theory you decided to try your fortune in quantum gravity

But, I simply copy from the attached link the Feynmann's quote (mine word format):

"The shell game that we play ... is technically called 'renormalization'. But no matter how clever the word, it is still what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate."

While I also copy:

"The Standard Model of particle physics contains only renormalizable operators, but the interactions of general relativity become nonrenormalizable operators if one attempts to construct a field theory of quantum gravity in the most straightforward manner (treating the metric in the Einstein-Hilbert Lagrangian as a perturbation about the Minkowski metric), suggesting that perturbation theory is useless in application to quantum gravity."

Of course you are free to use your time as you want.

But, mine prediction, at the end of the day you will not create something.

That's all.

PS Finally I didn't answer my question about your expert knowledge of Differential Geometry ... Were you going to perform the computations by hand?

https://en.wikipedia.org/wiki/Renormalization

Demetris Christopoulos: Indeed, I too have awaited in vain for Mr. ‘t Hooft to “do something interesting”. Here is yet another Nobel Laureate for physics in action, on television:

A Nobel Laureate Talking Nonsense: Brian Schmidt, a Case Study,

16 July, 2015, http://vixra.org/pdf/1507.0130v1.pdf

It seems that Nobel Laureates for physics all go to the same silly school.

The last e-mails stink at jealousy.

If Prof. Gerardus 't Hoofd has managed to convince a few privileged endorsers to nominate himself to the Nobel Prize Commitee for the studies he made, that's fine for him of course, because he earned nearly half a million as a Laureate.

Indeed, one can wonder if these studies brings us closer to the truth or instead farther away, but that question can be posed since long time. Maybe it just brings us nowhere, again.

The Nobel Prize Commitee members need to rely upon their scientific entourage, and the fashion nowadays is the actual GR, QM and cosmology, the farther from reality the better.

Scientists can embellish the findings in order that there exists a slight hope for a clue if the studies are pursued.

That's why many of them study black holes and even the whole universe, but nevertheless need to implement miracle words like “dark matter” and “dark energy” to make the show getting on.

And yet, since the 'average blogger' has the honor to debate in a forum with the great man, the courtiers are kowtowing and praising him to receive his sympathy.

That's how it goes... If someone wins the Lottery, everybody becomes his friend. Here however, instead of being an independent Lottery reward, there is a enormous consequence related to a large community of scientists over generations, and an enormous budget all over the world involved. It is not just a fashion, but a dynasty, an era, a religion.

A few weeks after CERN announced to stop searching after the Higgs boson with a deadline of a few months, a miracle arrived, and they found it!

The theories and many of the findings cannot be checked (or maybe very, very indirectly and mostly theoretically, or they must be accepted in good faith) nor falsified (because you don't need just to falsify it, you also need a wide support from the same scientific community). And like a French songs says: "Celui qui a dit la vérité,... il doit être exécuté!".

Stephen Hawking once admitted in a private e-mail: “.../... You will face a lot of opposition now as you have challenged all existing scientific theories, which will make a lot of physicists lose jobs. Now all physics has to be rewritten, and almost all work done on relativity has to be discarded.”

Thierry De Mees: You are absolutely right. The lesson learned from the LHC crew at CERN is that when the physicists have some obscenely expensive contraption, they have to justify its existence and their jobs in operating it, and so they manage to ‘discover’ what they wish for; as the LHC crew did with their ‘discovery’ of their Higgs boson. Incidentally, the particle physicists claim that their Higgs is composite – made of higgsinos (i.e. little Higgses!) The cosmologists did the same thing with their CMB and CMB anisotropies, using obscenely expensive satellites. Now they have obscenely expensive contraptions dedicated to finding black holes, since they have already decided that they exist and claim that they have found many of them. They still await their Einstein gravitational waves, in the meantime fiddling with obscenely expensive contraptions they say will detect them. Soon they will of course claim they have discovered the waves – after all their black holes generate them and their holes they claim they have taken photographs of. Now they are earnestly looking for aliens, with a pot of at least $100,000,000.00

http://www.independent.co.uk/news/world/australasia/scientist-warns-world-to-think-twice-before-replying-to-alien-signals-from-outer-space-10408201.html

Perhaps they will soon report ‘discovery’ of their aliens too; since they even have a journal for them, in which they publish ‘scholarly peer-reviewed papers’. Surely the aliens must be out there, because the journal for them exists.

International Journal of Astrobiology

http://journals.cambridge.org/action/displayJournal?jid=IJA

They have successfully turned physics and astronomy into circus freak shows.

@Crothers & De Mees: you are on the wrong platform!

@Demetris, I'm sure you can find more citations by Feynman or anyone else. Feynman was well-known to mistrust renormalization theory. Yes, he too missed some important developments in science. Renormalization is only mathematically legitimate as long as you understand what you are doing. What Feynman said later about quantum gravity, according to the citation you found, is basically correct and accepted by everybody, except that perturbation expansion, even in quantum gravity, can be useful, as long as you understand what you are doing. What I referred to in my earlier statements in this blog, was a perturbative approach to the unquantised theory, but even there, you have to understand what you are doing; I mentioned that in many cases perturbation expansions are legitimate. In GR, you always have to keep in mind your choice of coordinates, but I won't repeat myself (unlike some others here).

You are free to make predictions, I'll ignore them. As for the curvature along the doughnut, it is easy to see that it's positive at the outer part and negative at the inner part  (its integral over the entire doughnut vanishes), I still don't see your problem.

@Thierry, don't you think that Stephen Hawking was joking?

@Gerardus: Of course Hawking was joking! I will not copy the totality of the text that he wrote to that person who advanced his theory, but the point is that Hawking nevertheless indicated the doomsday scenario if indeed a theory is found that would bring radically different and successful ideas. And this is not on the wishlist of the living mainstream scientists. I am convinced that they would rather drop dead than to fundamentally question the standard theories.

Because when I advance that the "dark matter" invention is due to a misunderstanding of gravitational properties, you are of course laughing!

However, spinning masses generate an anisotropic gravity field. Out of the spinning center of a spherical galaxy, this field forces the stars' orbits towards the equatorial plane, and make their velocities prograde and complying with the velocites' observation in the so-formed disc galaxy. This is something what GR can't show.

Do you understand this? I mean: are you familiar with this?

It's about time to formulate an interesting rule to recognise crackpot physics: it often comes with a warning that all those "mainstream" scientists who defend the standard theories do this to "defend their interests". The very notion that the standard theories come with tons of experimental and theoretical evidence supporting them is of course rejected and supplanted by wild and amateurish reasonings for fancy and hopelessly flawed hobbyhorses. I would love to overthrow the Standard Model, renormalization theory, GR, quantum mechanics, and so on, but only if I could replace them by something better, and in contrast to our blog partners, I find this extremely difficult.

@Gerardus: U wordt geprikkeld, nerveus en persoonlijk, en toch zó zeker van de superioriteit van uw geliefkoosde theorie!

"only if I could replace them by something better" : It's because you never tried.

If you call Gravitomagnetism crackpot physics, you indeed don't know what you are talking about. But also there, none of you, people, tried to understand it.

You decided to ignore that the Lunar Laser Ranging (LLR) confirms the gravitomagnetic term of Gravitomagnetism to 0.1% and that the Gravity Probe B confirms the gravitomagnetic term with a different method to only 1%. However, the GR results are only accurate with 20%.

You can't explain why fast spinning stars don't explode, can you? And you can't explain the actual shape and the explosion conditions of SN1987A, can you? Well, Gravitomagnetism can.

GR proved nothing but the observation that the bending of light is twice the Newtonian value. GR didn't even prove Mercury's perihelion advance, since the Schwarzschild solution is an incomplete solution due to successive, but non-negligible approximations that were made.The other part cancels it out.

I don't know if you will have the guts the check the annexed paper that claims it. It's GR calculus, your speciality. All the eyes are now on you.

Mr. ‘t Hooft said: ‘It's about time to formulate an interesting rule to recognise crackpot physics: it often comes with a warning that all those "mainstream" scientists who defend the standard theories do this to "defend their interests". The very notion that the standard theories come with tons of experimental and theoretical evidence supporting them is of course rejected and supplanted by wild and amateurish reasonings for fancy and hopelessly flawed hobbyhorses. I would love to overthrow the Standard Model, renormalization theory, GR, quantum mechanics, and so on, but only if I could replace them by something better, and in contrast to our blog partners, I find this extremely difficult.’

Mr. ‘t Hoof is being disingenuous, haughty and evasive – as is his long demonstrated modus operandi. His “interesting rule to recognise crackpot physics” is itself unscientific. First, here again are examples of unscientific drivel from cosmologists, for which they receive a lot of money:

(1) Hawking and other cosmologists spending $100,000,000.00 or more on looking for aliens (previously Hawking got a separate $3,000,000.00 from Milner):

http://www.independent.co.uk/news/world/australasia/scientist-warns-world-to-think-twice-before-replying-to-alien-signals-from-outer-space-10408201.html

(2) A journal for scholarly peer-review papers about aliens:

International Journal of Astrobiology

http://journals.cambridge.org/action/displayJournal?jid=IJA

(3) Another Nobel Laureate talking unbridled rubbish on national television:

A Nobel Laureate Talking Nonsense: Brian Schmidt, a Case Study,

16 July, 2015, http://vixra.org/pdf/1507.0130v1.pdf

And Schmidt was recently awarded a new job with a salary of $1,000,000.00, plus significant fringe benefits:

http://www.canberratimes.com.au/act-news/anus-nobel-prize-winning-vicechancellor-to-take-home-1-million-20150812-gixd39.html

Second, it is legitimate science to expose falsehoods in the dogmas professed by scientists and in doing so nobody is obliged to produce a new theory simply because he has proven the current cherished theory is false.

Third, scientists routinely cling to their cherished dogmas and idols despite the evidence that proves their dogmas and idols patently false. Here are some examples:

(a) Planck’s proof of Kirchhoff’s false law is patently false:

Robitaille, P.-M., Crothers, S. J., “The Theory of Heat Radiation” Revisited: A Commentary on the Validity of Kirchhoff’s Law of Thermal Emission and Max Planck’s Claim of Universality, Progress in Physics, v. 11, p.120-132, (2015),

http://www.ptep-online.com/index_files/2015/PP-41-04.PDF

http://vixra.org/pdf/1502.0007v1.pdf

Without universality of Planck’s equation for thermal spectra the cosmologists lose their big bang creationism and black hole phantasmagoria in one stroke.

I once again extend invitation to Mr. ‘t Hooft, and all other proponents of Planck’s ‘natural units’, to explain to us all why Planck’s false proof of Kirchhoff’s false law is not false.

(b) There is no CMB. It is a scientific fact that the monopole signal has never been detected beyond ~900km of Earth. Without a monopole signal beyond Earth influence, at say L2, all talk of a CMB and its alleged anisotropies is wishful thinking:

Robitaille P.-M.

WMAP: A Radiological Analysis, Progress in Physics, v.1, pp.3-18, (2007),

http://www.ptep-online.com/index_files/2007/PP-08-01.PDF

Robitaille P.-M.

COBE: A Radiological Analysis, Progress in Physics, v.4, pp.17-42, (2009),

http://www.ptep-online.com/index_files/2009/PP-19-03.PDF

(c) The observational evidence attests overwhelmingly that the Sun is condensed matter, not a hot ball of gas:

Robitaille P.-M.

Forty Lines of Evidence for Condensed Matter — The Sun on Trial: Liquid Metallic Hydrogen as a Solar Building Block, Progress in Physics, v.4, pp.90-142, 2013

http://www.ptep-online.com/index_files/2013/PP-35-16.PDF

The continuous emission spectrum of the Sun and the circular transverse waves in the photosphere produced by the eruption of a solar flare cannot be produced by a gas.

(d) Contrary to the claims of Einstein and his followers, material sources cannot be both present and absent by means of the very same mathematical constraint for material sources in Einstein’s field equations:

To Have and Not to Have - the Paradox of Black Hole Mass, 12 August, 2015, http://vixra.org/pdf/1508.0106v1.pdf

(e) Contrary to the claims of the cosmologists their black holes cannot have and not have an escape speed simultaneously at their 'event horizon':

Black Hole Escape Velocity - a Case Study in the Decay of Physics and Astronomy, 7 August, 2015, http://vixra.org/pdf/1508.0066v1.pdf

(f) Contrary to the claims of the cosmologists, Droste's metric cannot be extended to Hilbert's metric to produce a black hole (because the square of a real number cannot ever take values less than zero):

A Few Things You Need to Know to Tell if a Mathematical Physicist is Talking Nonsense: the Black Hole - a Case Study, 29 July, 2015

http://vixra.org/pdf/1508.0007v1.pdf

@ Mohamed: I agree that I should use more general standards in the word choice of my communications.

I further agree that it is a boon that Gerard (being a Laureate) is willing to communicate with some of the bloggers. Many scientists are willing to progress, but nevertheless, they bear the burden of their own scientific history.

@Gerard 't Hoofd: there is nothing meant personal in my communications to you, but as you know: "hoge bomen vangen veel wind"...

All the best!

Every time I find a discussion that indicates the so many 'gray points' of a theory I remember an old question of mine, see link.

Then we had agreed that Science is not less corrupted than other disciplines of our social life.

Provided that we live in not so ethical eras, I think that problems of keeping a theory even if so many controversial points have been found, is a sign of a general moral decline of our world.

It was supposed that a theory drops down when one only inconsistent points is found, but we have lost the count here...

Of course I refer to relativity theories, just for not be misunderstood...

https://www.researchgate.net/post/How_percent_dirty_job_is_doing_science_today

Dear all;

I think we just need to ask ourselves; are we interested to find the real laws that can describe the dynamics of universe or we just looking for the theories that get better

attension and bring higher citation?

Sometimes the reality is hard to be accepted but its better than keep repeating the same mistakes.

There is a problem in GR and it needs to be solved so the road of unifing the four forces is paved well.

Dear Prof. Mohammmed

Thank you for your sympathy and kind words. I only intended to say that there is more than one way to derive the equations of GR which leads to the same experimental results. As they said "There are more ways than one to skin a cat". The form of different procedures are based on different assumptions of the curvature of space time, the current procedure that is followed by GR equations is not the best to achieve unification with quantum mechanics, in spite of its perfectness in classical limit.

With best regards

Sadeem

Hm, since I see more interest, what would you say if we try to define gravity?

Are we all satisfied from the current definition?

Are you?

For his 'proof' of Kirchhoff's Law of Thermal Emission, Max Planck claimed that all materials have the same reflectivity.

Robitaille, P.-M., Crothers, S. J., “The Theory of Heat Radiation” Revisited: A Commentary on the Validity of Kirchhoff’s Law of Thermal Emission and Max Planck’s Claim of Universality, Progress in Physics, v. 11, p.120-132, (2015),

http://www.ptep-online.com/index_files/2015/PP-41-04.PDF

http://vixra.org/pdf/1502.0007v1.pdf

Without Kirchhoff and Planck, Big Bang creationism and its black holes are dead.