An excellent question, Cenap. Quantum theorists don't even bother reconciling the two conceptions, much less refuting GR. And it makes their aspiration, a Grand Unified Theory, infinitely more difficult -- I would say impossible.
But the enthusiasm of quantum theorists is such that they must bring everything under their jurisdiction, from particle physics to gravitation to consciousness. Maybe someday they will be burning critics at the stake.
I have an answer but not many will take it seriously since it is a spin off from my main first interest to show how quantum entangement is involved with the operation of mind and memory. Furthermore I work by observation without the benefit of mathematical ability, so be warned. If you look at my paper on this academia.edu website under my name Nick Greaves you wll find 'Mach's Principle, Gravtitation and matter distribution' (copy attached) amongst the rest which deal with memory and a few other allied effects. It is based on an assumption that the universe is bounded and finite, which is not currently fashionable. Having said that the latter assumption is also adopted by the remarkably neat Absorber theory (1945) of Wheeler and Feynman, two great Physicists, to show how electromagnetic field equations can be symmetrical in time reversal. Furthemore the expert cosmologists do not seem able to agree amongst themselevs on that much in any event, and are in a fearful muddle trying to explain dark matter, not to mention dark energy. Until this is resolved it seems to me the subbject of gravitation is open season for anybody to attempt an answer. My conclusions show that inertia and gravitation are directly linked but do not show how they might be reconcilable with quantum physics. However there is an indirect link there but for that you would have to read some of my other papers.
“Why are scientists trying to merge gravity and quantum physics even though gravity is just the curvature of space-time?”
for that there is quite natural answer: since the gravity cannot be fundamentally and so isn’t a “curvature of space-time”.
In the reality Gravity: (i) - is simply 4-th fundamental Nature force, which in many traits is similar to the fundamental Nature EM force; and (ii) - since gravitational interactions, as any other physical interactions, change states of material objects/systems, when, as that Zeno proved 2500 years ago, there cannot be continuous changes
[more commonly because of the absolutely fundamental logical self-inconsistence of the absolutely fundamental notion/phenomenon “Change”],
so to make some change is necessary to pay by two things: (a) - is necessary to spend some portion of absolutely fundamental also “Quantity”] “Energy”, and (b) – nonetheless the states of changing objects on some level fundamentally become be uncertain.
Both the (a) and (b) points are well described for Matter by using the quantum theory; and, of course, gravitational interactions are quantized also; however to develop corresponding QM formalism is necessary, as that is usual in the QM, before to develop “classical” theory of Gravity, where to solve such things, for example, as what is the corresponding Hamiltonian’s gravitational part.
After physicists will not study gravity by mostly senseless solving of the GR equations and develop corresponding theory of Gravity, corresponding QM section will be developed also.
Some version of the gravity theory for statics see https://www.researchgate.net/publication/265509276_The_informational_model_-_gravity
DOI: 10.13140/2.1.4332.9925
Where, including, it is shown what is the equivalence of the inertial and the gravitational masses.
The quantum nature of Gravity with rather large probability can be detected experimentally already now, see https://www.researchgate.net/publication/215526868_The_informational_model_-_possible_tests http://arxiv.org/abs/0706.3979 DOI 10.5281/zenodo.34963 ; at least the section 2.1.2. “Monochromatic photon beam distortion”.
The experiment was proposed yet in 2007…
Cheers
"gravity is just the curvature of space-time"
Yes, but quantum particles exchange energy and momentum with "just the curvature of space-time".
Well scientists are searching for quantization of space-time...
Yes, "scientists are searching for quantization of space-time..."
First they really should come to grips with the (literally) astronomical amount of energy it would take to keep the moon in an orbit around the earth. Where are all the gravitons? Why is it that astronauts in orbit around the earth experience no effects of energy? I know, the standard explanation is that such energy is "non-local." But how is that different from saying we can't see god because she is "non-local"?
ZN: " Geometry of space time is continuous entity only in Classical Physics. In Quantum world it is no longer such. ... So the merging is not possible. "
Hello Zbigniew!
Actually, continuous-space theories and discrete QM-style theories are mergable ... provided that the classical models being considered don't include special relativity.
Special relativity is the obstacle.
A classical theory can provide QM-style results via quantisation, and a quantum theory can generate a compatible classical theory via stochastic methods to produce an arbitrarily close representation of a classical model that agrees with the same basic outcomes. So if we have the right classical and quantum theories, they should merge successfully.
The problem with Einstein's general theory is that it's the wrong classical theory. Its inability to merge with QM is due to its bad structural design, and its bad predictions, when quantised, don't agree with what QM statistics insist ought to be proper behaviour.
If we delete the SR component from GR, and instead of having GR reduce to an inertial physics described by flat spacetime, have GR-style principles continue down to atom-scale effects (with every atom considered as having its own tiny gravity-well), QM and modified GR seem to work rather well together.
The reason we don't have a working theory of quantum gravity is not because of geometry, or because the problem is technically difficult. It's because of human nature: a lot of people in the GR community dislike the idea of disruptive change, and oppose the idea that anyone should be investigating non-SR-based alternatives.
And this is why we've been stuck on this problem for half a century: It's not because constructing a better QM-compatible replacement general theory is difficult, it's because the existence of an improved GR isn't obviously in the interests of people whose training and career status is based on SR and SR-based GR.
The problem is anthropological.
Eric, I agree that the problem is anthropological. GR is a highly useful and successful theory of gravity. QM can't even explain why the tremendous amount of energy that would be required to govern cosmological relationships can't be detected.The ocean tides would require a deluge of gravitons to media the energy. Where are they?
And why are quantum physicists ignoring the obvious?
Hi James!
GR1916 can't even properly predict the motion shift of a star coasting in a straight line at constant speed arbitrarily far from other disturbing masses. That's why it's so difficult to find any mention of that scenario in a textbook or a peer-reviewed paper. It's because nobody can get it to work.
The two components of the 1916 theory make unambiguously different predictions that aren't allowed to be wrong, but which nevertheless disagree:
According to the "gravitational" side of GR1916, a moving star has a gravitational field, the moving field has a distortion due to relative motion, the distortion creates a deviation from flat Minkowski spacetime, the gravitomagnetic shift has to be identical to the motion shift, and the question of the star's Doppler shift due to motion has to be described as a curved-spacetime problem. The shape of that region of spacetime then varies with the star's relative motion to other masses in the region (including the mass of the observer), we no longer have the predefined, fixed spacetime of Minkowski's geometry, and since the geometry is different, the frequency shift relationships can't change with velocity the way that they do under special relativity (Minkowski spacetime and the SR relationships are mutually-defining).
The star's Doppler shift cannot be the exact SR-predicted Doppler shift, due to these gravitational complications.
But if an isolated coasting atom's Doppler shift exactly agrees with SR, then if the atom lies on the line-of-sight to the star, and we change our own relative velocity to both the star and the atom, wave theory requires the star and the atom be seen to shift by precisely the same amount.
If gravitational theory is right about the star, then SR can't be right about the Doppler shift of the atom, and a general theory of relativity can't reduce exactly to SR physics, invalidating the 1916 theory and any other gravitational theory that depends on the EEP. OTOH, if SR is right about the atom's shift, then the star must show precisely the same shift, there can't be any complicating distortion of the star's field due to relative motion, and basic gravitational principles fail, leaving us with a cascading series of manual corrections, overrides, suspensions and patches to stop the whole thing falling apart.
So GR1916 has an inherent internal contradiction. The condition that it must be a workable gravitational theory requires that the star's Doppler shift can't be exactly that of SR, but the condition of reducing exactly to SR physics over small regions for weak-gravity bodies like atoms carries over to the result that the star's shift must be exactly that of SR.
Checkmate.
Eric, I believe the "contradiction" is solved by relating a body's gravitation field to its rest mass.
Hello James!
Yes, that seems to solve the problem, but with some caveats:
We can say that objects or particles with inertial rest mass should also have a matching gravitational field - this is pretty much a requirement for conforming with the Principle of Equivalence anyway. The strength of the gravitomagnetic effect then depends on the object's and/or particle's surface gravity.
- If the surface gravity is zero, we have no gravitomagnetic effect, no surface light-dragging effect, no distortion of the metric due to the relative motion of particles, and Minkowski spacetime and the equations of special relativity.
- If the surface gravity is maximal (if the "surface" is a gravitational horizon), we have the maximum gravitomagnetic effect, 100% light-dragging at the surface, maximum distortion of the metric due to relative motion of particles, and the maximal deviation from special relativity: an additional full Lorentz redshift.
If the surface gravity is somewhere in between these two extremes, we get a correspondingly weaker Lorentzlike deviation from SR, and correspondingly weaker gravitomagnetic effects.
OPTIONS
The natural first reaction to this is to say, okay, no problem, SR geometry holds when gravity is weak and doesn't hold when it's strong ... so what? Isn't that what we've always said? "SR applies where spacetime is (effectively) flat, otherwise we must use the full mathematical machinery of GR" ? Can't we then compartmentalise, and say that for weak-gravity situations we have SR, for strong-gravity we have GR, and say that GR necessarily reduces to SR over smallish regions?
Unfortunately this doesn't work. If we watch a distant star and a distant atom along the same line-of-sight, and we change our motion along that line, then both signals have to shift in frequency by precisely the same amount, otherwise we don't have a working metric theory of gravity. Light has no "memory", the signals cannot shift "here" by different amounts depending on the different distant physical systems that originally generated the light.
So we require a single set of "Universal" Doppler equations that applies the same way to moving atoms and moving neutron stars, and everything else in between.
Since the form of the equations depends on the surface gravity of the emitting bodies, this appears at first sight to be impossible, as we now require all bodies (and/or the particles that they are made from) to present the same surface gravity. There are only two ways to do this:
We then have three arguments that all give the same answer for how strong the effect and the deviation have to be:
- If our universe already contains horizon-bounded stellar objects, this universal "particle" sg can't be any less than the sg of a black hole, otherwise a baseball couldn't generate the same Doppler equations as horizon-bounded star.
- Gravitomagnetic effects change the apparent gravitational field of a body or particle as a function of relative velocity, destroying the viability of the "intermediate" solutions. The only non-zero solution that always presents the same apparent sg is the maximal solution: in that case, instead of the apparent sg varying with relative velocity, the apparent horizon associated with the gravitational source simply extends or retracts. A horizon regulates a particle's apparent surface gravity (if the horizon is identified as the surface that the particle presents to the outside world).
- A full gravitomagnetic theory requires the gravitomagnetic shift to be equal to (and dual with) the conventional motion shift. If light aimed at a particle receding at v crosses a gravitomagnetic differential also equal to v, then the light can be emitted at cEMITTER, but be travelling at cTARGET once it reaches the target. This is equivalent to saying that the target seems to show 100% light-dragging, which means that we're once again talking about the surface having the properties of a horizon.
In each case, once we accept that wave theory requires a single Doppler equation to apply everywhere, and allow that our universe supports gravity and gravitational horizons, the only workable physics seems to involve all light-matter interfaces being horizon-bounded, and the Doppler equations for motion being exactly one Lorentz factor redder than the SR predictions. This seems to be compulsory.
CONSEQUENCES:
- Gravitational physics no longer reduces to flat-spacetime physics. There's no longer any such thing as flat-spacetime physics, it's "gravitational" all the way down.
- The EEP is wrong. We have to revert to the original principle of equivalence.
- Invoking a gravitational differential of v for a body receding at v means that gravitational shifts and velocity-shifts become fully interchangeable. As well as describing a gravitational shift as a velocity-shift, we can now also describe a velocity-shift as a gravitational (more properly a "gravitomagnetic") shift.
- Full shift equivalence means that we automatically have local lightspeed constancy regulated by curvature. With c-constancy explained, special relativity becomes redundant.
- SR gets downgraded from being foundation theory to being a flat-spacetime approxiomation of an inherently curved physics. It's still useful for engineering purposes, but it's no longer fundamental theory.
- The "redder" equations just happen to agree with those of Newtonian optics ("NO"). So for astronomy, where we're using a "Newtonian approximation" of GR for modelling rather than the full equations, we're already using the replacement non-Einstein equations, we're just giving GR1916 the credit when they work!
- Our redder "NO" equations also just happen to be the same set that we already use for cosmological shifts, where the SR set don't work properly (cosmological horizon physics requires a leaky observer-specific horizon and the NO Doppler set, the SR set gives wrong behaviour).
- The "new" equations don't just unify velocity and gravitational effects, they also unify both of these with cosmological effects. We now have the choice of describing Hubble shift as a curvature effect without distinguishing between gravitational and cosmological curvature, or we can describe it as a simple recession effect, using the same Doppler formula in each exercise. It unifies three previously-different classes of physical behaviour.
- Merging gravity with cosmology means that gravitational horizons now act more like cosmological horizons, and fluctuate and radiate in response to events on both sides of the horizon. The causal structure is different, horizons become "apparent" or "effective" horizons, and the Minkowski metric is replaced by a more advanced relativistic acoustic metric. By switching to the NO equations, 1960s GR "black holes" turn into something more similar to C19th horizon-bounded but indirectly-radiating "dark stars".
- Classical indirect radiation through an acoustic horizon is a class of Hawking radiation, so changing the equations solves the black hole information paradox. Note that the NO solution is the only classical relativistic solution that allows these indirect-radiation effects, so starting with QM would give us a fourth way of deriving the same non-SR relationships.
CONCLUSIONS
Einstein's general theory didn't just disagree with QM, it disagreed with itself. Solving GR's internal structural conflicts without making any reference to QM doesn't just introduce an additional simplifying three-way equivalence principle between velocity, gravitation and cosmological curvature, it also accidentally gives us possibly the first workable theory of quantum gravity.
So not just a "win-win" scenario, but "win-win-win-win-win".
This is the next iteration of general relativity, and since eliminating SR also solves the 1916 theory's incompatibility with the GPoR, it's arguably our first real general theory of relativity. Einstein's theory was a partial prototype, this one is the real thing.
General Relativity violates the usual conservation of energy and momentum for a closed system. It is therefore in conflict with a vast array of experiments at a fundamental level. It is therefore false.
Crothers, S.J., A Critical Analysis of LIGO's Recent Detection of Gravitational Waves Caused by Merging Black Holes, Hadronic Journal, n.3, Vol. 39, 2016, pp.271-302, http://vixra.org/pdf/1603.0127v5.pdf
Huau Stephen!
I see that you have strong scientific arguments against GR! Based on: "I do not believe! Dot! Just all.
Why don't you try to submit your "dot" article to a serious scientific journal?
" I see that you have strong scientific arguments against GR! Based on: "I do not believe! Dot! Just all.Why don't you try to submit your "dot" article to a serious scientific journal?" Cesar Zen Vasconcellos
Your comments are unscientific, as usual. My paper is published in a scientific journal. That my proofs are published in a journal that you don't like is irrelevant. Try studying my paper instead. It's obvious you have not done so. General Relativity violates the usual conservation of energy and momentum for a closed system and so it is thereby in conflict with a vast array of experiments. Speed of propagation of the alleged gravitational waves is not the speed of light at all because the speed is coordinate dependent. The mathematical theory of black holes violates the rules of pure mathematics - analytically speaking it requires that the absolute value of a real number take on negative values, which is impossible. Geometrically speaking it requires a sphere, initially centred at the origin of coordinates, when translated from the origin, to leave its centre behind! This is also impossible, yet is precisely how the mathematical theory of black holes obtains two singularities, one allegedly removable ('event horizon') the other 'physical', where the finite mass of the black hole is concentrated in zero volume, infinite density, and infinite gravity. But no finite mass has zero volume, infinite density, and infinite gravity, anywhere. Consequently, the black hole does not exist. Therefore all talk of black hole thermodynamics is nonsense. Professor Robitaille is correct: Hawking's black hole temperature and the Bekenstein-Hawking black hole entropy violate the laws of thermodynamics. It's no wonder. Cosmologists do not get to alter the laws of thermodynamics in order to advance theories that violate the established laws of thermodynamics so that they can bring into thermodynamics entities that do not exist. It is also no wonder that cosmologists, led by Hawking, are trying to contact aliens, using radio telescopes all around the world, funded with $100,000,000.00 of Milner's thoughtless money [4]; the very same aliens that fly saucers and UFO's, and who kidnap people for experiments and vivisection, because they all come from outer space!
Black hole thermodynamics and the Zeroth Law [1,2].
(a) Hawking's black hole temperature: TH = hc3/16π2GkM
The LHS is intensive but the RHS is extensive; therefore a violation of thermodynamics [1,2].
(b) Bekenstein-Hawking black hole entropy: S = πkc3A/2hG
The LHS is extensive but the RHS is neither intensive nor extensive; therefore a violation of thermodynamics [1,2].
(c) Black holes do not exist [1-3].
REFERENCES
[1] Robitaille, P.-M., Hawking Radiation: A Violation of the Zeroth Law of Thermodynamics, American Physical Society (ABSTRACT), March, 2018,http://meetings.aps.org/Meeting/NES18/Session/D01.3
[2] Robitaille, P.-M., Hawking Radiation: A Violation of the Zeroth Law of Thermodynamics, American Physical Society (SLIDE PRESENTATION), March, 2018, http://vixra.org/pdf/1803.0264v1.pdf
[3] Crothers, S.J., A Critical Analysis of LIGO's Recent Detection of Gravitational Waves Caused by Merging Black Holes, Hadronic Journal, n.3, Vol. 39, 2016, pp.271-302, http://vixra.org/pdf/1603.0127v5.pdf
[4] Scientist warns the world to 'think twice before replying to alien signals from outer space',
http://www.independent.co.uk/news/world/australasia/scientist-warns-world-to-think-twice-before-replying-to-alien-signals-from-outer-space-10408201.html
Hello Stephen!
Re: thermodynamics, I think that traditional thermodynamics might need a bit of an update as well as general relativity.
Special relativity's Doppler equations are unique amongst the spectrum of potential relativistic Doppler equations in that they predict that if we aim a light-signal through a simple moving system, it emerges with exactly the same energy it started with. This is typically regarded as A Good Thing. Any equations less red than SR predict an energy-gain (which is terrible, because it allows infinite-energy machines), and anything more red than SR (including Newtonian optics) gives an energy-loss. So Newtonian theory applied to light violated traditional energy conservation (something they don't teach in school).
The relativistic energy-loss wasn't necessarily a bad thing: the resulting physics wasn't symmetrical with respect to time, it created a bias towards exothermic reactions over endothermic ones, and created a universal arrow of time. Also, it predicted an energy-loss for light travelling into and out of a gravity-well, so solutions "redder" than SR (applied to gravitation) gave an average long-range redshift as a function of distance, which (with the earlier gravitomagnetic arguments) is then also exactly equivalent to a recession redshift, so the "lossy" NO Doppler equations gave us Hubble shift and an expanding universe.
About the only scientifically-legitimate reason for Einstein's general theory to incorporate SR's Doppler law was the (perfectly reasonable-sounding) specification that energy values shouldn't change over the course of an experiment.
Unfortunately we then discovered Hubble redshift, which violated that rule, and we then also had to use a non-SR equation for cosmological shifts to support the behaviour of cosmological horizons.
So we ended up using the Newtonian optics Doppler equations for cosmology anyway, with their attendant Hubble redshift ... but couldn't make all the pieces fit together as above because the same 1916 theory also had to accommodate SR. Which is how we ended up with the current mess.
----
There might also be experimental evidence of "traditional" energy-conservation being broken on smaller scales, by the thermal redshift effect ("SOD effect"). This was the complicating (and apparently previously unpredicted) temperature-dependent redshift that appeared in the famous ~1959 Harvard gravity-shift experiments. Since their hardware used the Mossbauer effect, it shouldn't have generated recoil redshifts, so the residual redshift apparently caught everyone by surprise.
Although these thermal redshifts appear with Doppler equations redder than SR's they aren't supposed to appear under SR-based physics. Last time I checked the citation indexes, nobody seemed to have produced an explanation of how these effects could appear in an SR-conforming universe, in a manner sufficiently convincing to pass peer review. So it would currently seem that the well-respected Harvard experiments experimentally disproved the SR shift equations and therefore also disproved Einstein's attempt at a general theory (which uses those SR equations).
Perhaps someone can somehow come up with an SR-preserving explanation of the Harvard data ... but the community have had half a century to think of one, and apparently still haven't managed it.
I think the simplest explanation of all of this is that the Doppler equations are simply redder than SR says, that the 1916 theory is wrong, and that traditional energy conservation has to be updated to include some sort of apparent energy-loss.
@ Cenap Özel
my dear Cenap Özel ....
As i am Physics student.... As we are scientists it is our primary duty to merge gravity and quantum physics even though gravity is just the curvature of space-time....
i think gravity is just the curvature of space-time is not a big hurdle to unite GR with QM until we found a proper way....
Dear Cenap Özel
Since general relativity (GR) is a classical theory, GR and quantum mechanics, or more precisely, quantum field theory (QFT) and GR are incompatible.
QFT is understood by the scientific community as the formal/conceptual/structural motivation for the development of a theory of quantum gravity. The conception that predominates in this process of construction of a quantum theory for the gravitational field is that, since the gravitational interaction corresponds to a fundamental interaction, and quantum field theory is a fundamental theory in physics to describe, at the smallest physical scales, atoms and subatomic particles, then the gravitational field must be quantized.
The challenge in the elaboration of a theory of quantum gravity would be the identification of the quantum intrinsic properties and the quantum dynamics of the gravitational field.
This implies then to reconcile, in the quantum level, the geometric nature of the gravitational field and the metrics of space-time.
According to Albert Einstein's general theory of relativity, the phenomenon of gravity is the manifestations of the (continuous) curvature of the space-time manifold. John Weller's synthesis "Mass-energy tells space-time how to curve, curved space-time tells mass-energy how to move", establishes in a very precise and concise way that in GR, the geometry of space-time and the movement and dyamics of massive bodies are intrinsically related.
But the question that remains is: the quantization of the gravitational field implies the discretization of space-time? And since the answer seems to be positive, the next question would be: how to define the quanta of the discretized space-time? The idea that the Planck length is the smallest unit of length, and the Planck time the smallest unit of time, seems to be natural, and has been suggested many times.
Here is an interesting example of a possible answer to this question.
Gerard 't Hooft (J.Phys.Conf.Ser. 701 (2016) no.1, 012014) has recently rigorously derived this important idea, which has been suggested many times previously, that the Planck length is the smallest unit of length, and the Planck time is the smallest unit of time. By combining Hawking's black hole theory for the emission of gravitationally interacting particles and black hole thermodynamics, the formation of micro quantum states bouncing against the horizon, the predictions about the dynamics of these microstates using a partial wave expansion, and by establishing a cut-off in the transverse momentum of the particles, in the form of a Brillouin zone, he concluded that these particles live on a lattice, i.e. that the quantization of gravity leads to a discretization of space-time.
Quantum gravity would have to involve the mutual exchange of gravitons. Please explain how this could occur in the relationship between the earth and moon, presumably with an enormous quantity of particles (has anyone tried to calculate the energy involved?), and yet be undetectable.
“….Quantum gravity would have to involve the mutual exchange of gravitons. Please explain how this could occur in the relationship between the earth and moon, presumably with an enormous quantity of particles (has anyone tried to calculate the energy involved?), and yet be undetectable….”
That is indeed so; just because of the numbers of gravitons that are radiated by particles in Earth and Moon, which interact with particles in Earth and Moon, including with particles in some possible gravitons’ detector on Earth, are rather big. Correspondingly attempts to detect single gravitons interactions with even very cold particles in special traps, seems are now practically outside existent technical possibilities.
However the existence of gravitons isn’t a principal problem, they exist quite naturally for sure, since Gravity is nothing else then the 4-th fundamental Nature force and isn’t, of course some mystic action of some mystic “curvature” [of some strange for Nature 4D pseudo Riemannian space, which has (mathematically) imaginary either space or time], which [curvature] is caused by some magic forces of masses, as that the GR postulates.
In the reality Matter’s spacetime is the absolute [if we don’t take attention some peculiar QM effects] [5]4D Euclidian empty container and has all dimensions be [mathematically] real; when the emptiness evidently cannot be impacted/ curved by anything inside the container, and the emptiness cannot impact on anything inside the container.
Correspondingly as any other [EM, strong, weak] Nature force Gravity acts for sure as exchange by mediators, i.e. gravitons, and rather reasonable model of Gravity is suggested in 2007
http://arxiv.org/abs/physics/0703043 .
From the model follows, including, that if gravitons interact with very small masses, the interactions can be singled in time; and, since the lightest particles are photons, corresponding experiments are realizable already now, see
https://www.researchgate.net/publication/245583444_On_the_photon_spectrums_of_some_monochromatic_beams_in_Earth_gravitation_field arXiv:0707.4657v2 2007 ,
https://www.researchgate.net/publication/215526868_The_informational_model_-_possible_tests ; http://arxiv.org/abs/0706.3979 ; at least the section 2.1.2. “Monochromatic photon beam distortion”.
All what is necessary in this case is to make in any existent interferometer that are built aimed at detection of the gravitational waves [which, of course, can exist, Gravity is rather similar to the EM force, where EM waves aren’t something exotic; but if they exist, they aren’t of course, some GR’s “ripples in spacetime”] additional vertical arm in a borehole having length 300-400 m,
and to measure gravitational distortion of the vertical photons beam relatively non-distorted horizontal beam.
Since the interferometers’ upgrade is rather small, this experiment, where with rather non-zero probability evidently fundamental result can be obtained, would cost a few tens of $millions, what is negligible comparing with experiments that “confirm GR”.
Cheers
"Gravity acts for sure as exchange by mediators" but "attempts to detect single gravitons interactions ... seems are now practically outside existent technical possibilities."
Well, if it's "for sure", I suppose it is for sure. But never mind the difficulty of detecting a single graviton, how about detecting the literally astronomical quantity of gravitons needed to force the moon to move around the earth? It seems to me for sure that it should be difficult to avoid detecting the torrential shower of such little bitsies needed to move the moon.
And how do all those lunar gravitons avoid collisions with the terrestrial gravitons? Shouldn't we be seeing lots of bright flashes as we look around at night?
And please explain why it takes the same number of gravitons to move a hollow coconut shell from the top of a tower to the pavement as it does to move a cannon ball.
I'm perplexed, and that's for sure.
Dear James Arnold,
it seems you read the SS post above non-attentively enough, when the post is rather clear. Including:
“…But never mind the difficulty of detecting a single graviton, how about detecting the literally astronomical quantity of gravitons needed to force the moon to move around the earth?…”
here is no problem, the quantities of [“circular”] gravitons that are radiated by Earth’s and Moon’s particles are indeed practically infinite, and the quantities of particles in Earth and Moon are practically infinite also, thus, in spite of every particle obtains at every interaction with a graviton practically infinitesimal momentum, both, Earth and Moon obtain such the resulting momentums, that they rotate around their common mass center in accordance with the Newton laws.
“… It seems to me for sure that it should be difficult to avoid detecting the torrential shower of such little bitsies needed to move the moon…”
about that see the SS post above again. Indeed, the number of interactions per second of a single rest mass particles [that really can be used at detecting of single gravitons’ interactions, in fact only protons] with the torrential showers of Earth’s and Moon’s gravitons is too large at real attempts to detect these interactions even in very cold traps. However that is possible for photons, since visible light photons have gravitational masses
[the GR postulate that they don’t have such masses is rather evidently incorrect, there is nothing mystic in photons, they are rather banal particles and as every other particle have both - inertial and gravitational masses. This fact can be very easily confirmed now experimentally – see https://www.researchgate.net/publication/277710038_The_informational_model_-_gravity_a_next_experiment ; to make the experiment is enough to have a pair of clocks with uncertainty better then 10-14; what isn’t problem now; and to make one day experiment in any building having height more 400 m; so all would cost no more the 1 $million. The experiment was suggested 3 years ago, however isn’t made till now, when its result would be fundamental in physics since from the result a next essential evidence about non-adequacy of the GR to the objective reality follows; besides any possible ways are applied to prevent sharing of any, including in this case, information about the informational conception/model. The reasons are the same – the result shows the non-adequacy of the GR, when this theory is claimed as something that is unbelievably fundamental, and since so it is too fundamental for some unknown authors that don’t belong to some community; when such results can be obtained only by members of the community; and seems the experiment will not be made till the real authors are alive;
that relates to other fundamental experiments that follow from the informational conception/model and to the conception/model themselves, though ]
near billion times lesser then protons. Thus the probability of gravity interaction of photons in short time intervals becomes be essentially lesser then unity, and, for example, in the suggested in 2007 experiment [again see the SS post above] only a part of the vertical beam will be [till experiment isn’t made, will be rather probably, of course; that is just the essence of the graviton’s problem which is studied in the experiment] randomly distorted because of the interactions with Earth gravitons, when the rest of photons in the beam will have the initial energy/frequency.
If gravity acts continuously, then the frequencies of all photons in the vertical beam will be the same [if the fringe is on Earth surface], as that is for a pair of horizontal interferometer’s arms; in the GR there is no difference of the beams also.
“…And please explain why it takes the same number of gravitons to move a hollow coconut shell from the top of a tower to the pavement as it does to move a cannon ball…”
that again follows from the gravity model in the informational model in physics, see again the SS post above and linked in the post papers; and proceeds because of at gravity interactions every particle in any/every body is radiator of gravitons, and every particle in any/every body interact with the [“alien”] gravitons. At that every particle, since it is a 4D gyroscope, resists to attempts to change its 4D vector rotation rate, i.e. have the inertial mass.
Thus the gravitational and inertial masses of all/every particles and so of all/every bodies, at least at the statics, are equivalent and so every particle, a hollow coconut shell, a cannon ball, etc. moves from the top of a tower to the pavement with equal acceleration. With the exclusion of photons, though; see above: if the tower isn’t too high, then falling from the top photons partially will be bluer and partially will be the same as at the top when hit on the pavement.
Cheers
How 'general' is GR really? SR has constant velocity, GR has constant acceleration. What happens if acceleration is not constant?'
Hi Leslie
In this case GR is not invariant and non covariant anymore due to the "presence" of fictitious forces.
Hi Sidney
As I said before, the way you pose your question, refers to a kind of topic intrinsic to us humans.
We are beings who, in contact with the outside world to our mind, we behave with as materialistic beings. Our senses reflect this sensation. We like to touch things, to reveal their "identity". We like to hear, to have contact with other people, our fellow human beings. We like to see, to taste.
It happens that theoretical science is a mental construction. It is not a mirroring of reality. It does not pretend to reproduce, as a logical clone, reality.
Theoretical physics represents a conceptual vision, embedded in logic, expressed through mathematics, but it is not reality. It is a theoretical and mental description of alleged elements of reality. Reality cares little about our view of it, about our conceptual, metaphorical, modelistic description of it. The concept of space-time and curvature of space-time is inserted in this conceptual context. It is an abstraction.
Fields, when related to particles, they are local concepts. There is no meaning to relate curvature to local fields.
Our description of reality is based in mental models, which represent our internal pictures of how the world works. Mental models are the conceptual and operational representations that humans develop while interacting with complex systems.
Cesar, you are expressing a philosophy called "nominalism", based in a belief that thought and nature are fundamentally alien to each other. People like Galileo, Newton, and Einstein rejected that philosophy, they believed in a fundamental identity of human thought and nature, and had considerable success in achieving an operational affinity with the natural world. You might consider a philosophical reorientation -- it could make you more useful and happy.
“…our universe as a whole creates reality from moment to moment, inclusive our thoughts…”
this proposition is uncertain, since the notion/phenomenon “universe” is undefined. In the reality the informational system “our Universe” is sub-set of the absolutely fundamental and absolutely infinite “Information” Set; and consists of at least two informational sub-systems “Matter” [the system of material objects] and “Consciousness” [the system of at least humans’ consciousnesses]. These sub-systems are fundamentally different, that are fundamentally different "stuffs"; so any material object cannot create any thoughts, they are products only of consciousness, except, of course, indirectly, the thoughts that relate to the object when a consciousness, say, observes the object. But, again, that is purely consciousness’s product; besides consciousness produces many other thoughts that have no relations to Matter at all.
“…when we try to discover the structure of the underlying quantum fields the “nominalism” point of view comes into sight…. Thus at the lowest scale reality is a mathematical construction…”
that isn’t so, at the lowest scale reality indeed can be a mathematical construction; however it is at that without any relation to any human’s [in the reality human’s consciousness’s] “point of view”, including “nominalism”. Simply, as that is rigorously proven in the Shevchenko and Tokarevsky “The Information as Absolute” conception, all/everything is/are some informational patterns/systems, Matter is an informational system, at that from experiments follows, that this system (i) - is based on a set of logical rules and links, and (ii) - at informational exchange between informational patterns [particles, bodies, etc.] , i.e. at their interactions, exclusively true information is used. These two main facts determinate, that the consciousness’s product “mathematics” is very useful tool at describing/analyzing of material objects and processes.
However a “mathematical construction” isn’t a “physical construction”, in mathematics there is no of many physical phenomena/parameters, for example “action”, “energy”, “charge”, etc. And, say , Coulomb electricity or Newton gravity laws by any means don’t follow from mathematics.
That doesn’t mean, of course, that eventually the phenomena aren’t some mathematical constructions, however the lowest level, where all fundamental Nature forces are observable, is, seems principally, the Planck scale – see the Shevchenko and Tokarevsky informational physical model https://www.researchgate.net/publication/273777630_The_Informational_Conception_and_Basic_Physics DOI 10.5281/zenodo.16494 ,
where elementary particles are close-loop algorithms, which are always and constantly run and which use as “hardware” some fundamental logical elements (FLE), that have sizes at [sequential] “flipping” in the 3 space and in the coordinate time [so in the true time also] dimensions of Matter’s absolute [5]4D Euclidian spacetime be equal to Plank length [if both temporal dimensions metrics are “cτ” and “ct” correspondingly].
And, for example, the experiment that is pointed in the last SS post above [comment to James Arnold], not only, if will be successful, will detect the quantum nature of Gravity, it also will confirm at that that the Planck scale is indeed the base of physics, since the gravity model, from which this experiment follows, postulates that elementary “circular gravitons” are radiated by single FLE .
Again, eventually FLEs, which are rather complex structures, can be some “only mathematical” structures. However these structures seems are principally unobservable/unknown by/for humans. And it isn’t impossible, that if some human by some way will decode this structure, some asteroid having sizes a few hundreds of kilometers accidentally will change its orbit…
Cheers
The idea that "at the lowest scale reality is a mathematical construction" leaves out what is most fundamental to existence. Mathematics only provides a description of external relations. What is it that is involved in relationships? In what sort of universe can there be a thought? a perception? a creative act?
Mathematics can describe spontaneous interactions, as between quanta and people, in terms of probabilities. Math can describe the interactions of bound or constricted populations, as with the quanta that comprise a ball or rolling wheel (see "Sperry's wheel"), in terms of determinism. But math cannot describe the creative intuition of a mathematician, not even a mathematician who forgets herself in her calculations.
Mathematics is barren. Life, and thought, are lush beyond all calculation.
“…The idea that "at the lowest scale reality is a mathematical construction" leaves out what is most fundamental to existence. Mathematics only provides a description of external relations. What is it that is involved in relationships?..”
that is indeed, in a lot of cases, so; however mostly [fundamentally] relates to such cases as
“…In what sort of universe can there be a thought? a perception? a creative act?… math cannot describe the creative intuition of a mathematician, not even a mathematician who forgets herself in her calculations…”
i.e. to the operating/products .of seems unique known non-material informational system “human’s consciousness”, what indeed cannot be formalized by recent mathematics. Though even in this case there is a formal possibility to define known objects and links at the consciousness’s operating as some new mathematical objects and operations, and claim that “all is mathematics” again.
However, it seems evident that such “mathematical approaches” don’t add something new, though formally are legitimate, and so are senseless. So there is seems no necessity to discuss them in general sense, though in any case often it is rather useful, if some relations in particular systems can be formalized, and an analysis with using mathematics is useful and informative.
However that above doesn’t relate to the informational system “Matter”, where all objects and links between objects are rigorously defined and interactions are exchanges by exclusively true information, in this case mathematics is quite effective.
At that, again, in the “The Information as Absolute” conception [see links in the SS posts above] it is rigorously proven, that all is/are some informational patterns/systems of the patterns, including all material objects and links, when mathematics is nothing else then a branch of the absolutely fundamental system/phenomenon “Information”.
For humans it is inessential, on what language some information is given, thus humans can indeed use mathematical language “directly”, and consider material objects and links as some mathematical objects.
Nonetheless here is two, rather fundamental nuances: (i) – material objects aren’t conscious, and understand, when interact, only one known for them language, and don’t know anything else, including mathematics; and (ii) – [see again SS posts above] the “completely mathematical” nature/structures of material objects and the system “Matter” as a whole can [but not obligatorily!] appear only on ultimately fundamental for this system level; and since this level isn’t accessible, humans are forced inevitably to introduce and to use non-mathematical “physical” notions [“charges” , “energy”, etc.] and further to use mathematics at studying of material objects and phenomena above this level, seems principally above the Planck scale.
It would be useful to read https://www.researchgate.net/post/Is_gravity_a_dark_energy_effect
also.
Cheers
Dear Cenap Özel ~
Maxwell’s classical electromagnetic (EM) theory, expressed in terms of continuous fields, looks very different from Feynman’s QED, the quantum theory of interacting photons and electrons. Yet no-one talks of a the problem of “merging” those two very different descriptions. They refer to the same physical phenomena, described at “macroscopic” or at “microscopic” scales. Indeed, the starting point for the development of QED is Maxwell’s field theory, along with Dirac’s field equation for the electron and the coupling between them. That is then expressed in “momentum space” and “quantized”. Conversely, Maxwell’s classical theory arises from QED at the macroscopic scale where the probabilistic aspects are “averaged out.”
So why (in over a century!) has no corresponding reconciliation of Einstein’s classical gravitational theory (GR) and quantum theory been achieved? There are several reasons: the field equations are formidably complicated and aggressively non-linear; also, “gravity is just the curvature of spacetime”. That latter stumbling block perhaps requires a little more careful analysis: the mathematics of GR makes use of the concept of “curved spacetime”, but perhaps the characteristics of a successful conceptual model of a physical phenomenon shouldn’t be too readily accepted as characteristics of “objective physical reality”.
The electromagnetic field is the simplest example of a gauge field (Yang-Mills field) so there is no obstacle in principle to treating more general gauge theories the way Feynman treated electromagnetism to arrive at QED. Complications arise because the field equations (of “intermediate bosons”) unlike those of electromagnetism, are non-linear - there are self-coupling terms, which means that the gauge particles are self-interacting.
Now, although classical GR in its usual form isn’t a gauge theory, there exist extensions of it that are – the “Poincaré gauge theories”. In these theories the sources of gravity are the Noether energy-momentum density and the spin current density (analogous to the way the charge current density is the source of EM).
The little-known work of S N Gupta seems to me to indicate a promising starting-point for the development of a true quantum theory of gravity: S N Gupta, Proc. Phys. Soc. London 1952, A65, 608 (see also S Deser, Gen. Rel. Grav. 1971, 1, 9 or E A Lord, Pramana 1987, 29, 359).
I first came across Gupta’s work in his contribution to Infeld Festschrift: Recent Developments in General Relativity (1962).
This is Gupta’s idea and its conclusion, briefly summarized:
Electromagnetism is the Lorentz-invariant theory of a massless spin-1 field. Its source is charge current density. If you take the standard Lorentz-invariant linear equations for a massless spin-2 field and insert the energy-momentum tensor density as source term, the energy-momentum tensor of the spin-2 field itself has then to be included in the source. That is, there is self-coupling. The equations become non-linear. By a process of iteration the equations converge to become, in the limit, Einstein’s gravitational equations!
I find that astonishing! It leads me to wonder if a quantized GR could be obtained by combining the iterative steps with quantization techniques. Energies and momenta of “gravitons” would be the “observables”, just as QED deals with the energies and momenta of “photons”.
The prospect of working all this out would be truly horrific. But then, I wouldn’t expect the solution to a problem that has haunted theoretical physics for more than a century to be simple (-:
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