It seems that the field theory is going in the right direction.

Because gravity is different to the other forces in nature.

Specifically

The first point means that the standard methods of quantum field theory only get us a little way. It is possible to treat quantum general relativity as an effective theory up to a couple of loops, but it cannot be considered a fundamental theory. It is however possible that the theory is okay, but not as a peturbative theory. There is some evidence that gravity has a UV fixed point. This means that gravity may not be a theory of gravitons. Working outside of perturbation theory is very difficult in general. You should look up asymptotic safety.

The second point means that the very arena of physics may have a very different nature to what we are used to. It may have some granular or fuzzy nature on the smallest scales. Space-time as we know it should be some emergent thing or a large scale limit of this exotic noncommutative geometry. We do not yet have a great understanding of noncommutative geometry, though the subject grows all the time. You should look up noncommutative geometry, there are various approaches here.

Another issue is that the scale of quantum gravity is outside of our experimental range. We have no real hints at what should replace general relativity. There is however, some chance of finding some clues in cosmology or extreme astrophysical events. Maybe gravitational wave astronomy could help here.

There is a lot more one could say. To recap, gravity does not submit to the standard methods of quantum field theory, a quantum theory of gravity means thinking of space-time in a very different way as compared to the classical picture, and nature is not giving us any clues.

All the science that we know is from universe, unfortunately we are trying to say how is universe should work by (GTR). First universe is not accidental event, second, it is not working mechanically as GTR explain it. As we know matter is stationary element, the only way that can move, it is by universe force. The reason that all the planets, suns and moons are weightless, it is because of universe's movement. to make long story short, we live in a quantum mechanics universe.

https://www.academia.edu/38373675/Creation_of_a_Quantum_Mechanic_Universe_and_its_Rotation.doc I am not genius, but my theory makes sense. It will be presented in France and Japan in next moth in Quantum Physics Summit.

Javad Fardaei at the risk of being a little off topic...

> First universe is not accidental event,

I suppose you mean the creation of the Universe, or really the triggering of the expansion of the Universe? If so, I do not think that many cosmologists see this as an accident. It may have some random or probabilistic nature, but right now no one knows. Though the answer may be rooted in quantum gravity, there are other reasons to seek a quantum theory of gravity.

> second, it is not working mechanically as GTR explain it.

But one must remember that general relativity is very well tested and agrees with observations to some huge degree of accuracy. For example see the following

Article The Confrontation Between General Relativity and Experiment

> As we know matter is stationary element, the only way that can move, it is by universe force.

Well, no. You have to consider stationary with respect to what? Moreover, Newton's first law says that in an inertial frame of reference, an object either remains at rest or continues to move at a constant velocity, unless acted upon by a force. So forces are related to acceleration not movement as such.

> The reason that all the planets, suns and moons are weightless, it is because of universe's movement

Weight is the force on an object due to the gravity of some larger object. It is not so useful when describing astrophysical bodies. And what do you mean by universe's movement?

> to make long story short, we live in a quantum mechanics universe.

This is true. Nature is fundamentally quantum.

Andrew James Bruce, 1st. First universe is not accidental event,

MY THEROY: We are duplicating universe, which it means universe did not created by explosion of the Big Bang. It mint to be created, and it had to go through pre-staging like us (in mother womb). The universe born small and now is getting big as its biological Time is ticking.

second: The GR pronounced when quantum mechanics was a theory, and all recent observation is not right as matter of fact, and interoperation is linked to GR. Like time is going slow in basement and going faster in attic is totally wrong.

Article Quantum Mechanics Gravity, Mechanical Gravity of Newton is Myth

3rd: Matter stationary.. The universe is made of duality, All the galaxies have rotation (spiral, somersault, and positioning) these movement must be coordinated by universe rotation, therefore, universe is hollow-sphere and it rotation must be opposite of galaxies' direction.

https://www.academia.edu/38373675/Creation_of_a_Quantum_Mechanic_Universe_and_its_Rotation.doc Last, you are right, the Mother Nature is quantum intelligent fundamentally.

Javad Fardaei we should try to keep this thread on topic, i.e., problems in finding a full quantum theory of gravity.

> Like time is going slow in basement and going faster in attic is totally wrong.

But this has been measured many times.General relativity predicts this and agrees well with what is seen.

> these movement must be coordinated by universe rotation,

This is really a question in cosmology. But why must this be?

The observational evidence so far does not support the idea of the Universe spinning. For example, the CMBR does not show any sign of such a rotation.

First, thank you to all who already have offered replies to this discussion. My question that opened the discussion is genuine and heartfelt; it is not merely a rhetorical question. It is a question that has truly and deeply puzzled me for all of my many years of watching a wide variety of other amazing advances in science. Why has this one crucial problem eluded solution by all of the best minds of science? Is the reason simply that it's a very, very difficult problem? Or is it possible that there is some other factor standing in the way of a satisfactory solution? I certainly do not know, but the world of science is eagerly awaiting the long-overdue answer.

I have hesitated to comment before myself, because I did not want to "prejudice" the nature or direction of the discussion with my own thinking. But perhaps it is time to do so in the hope of receiving your comments -- pro or con -- and your help to better inform my thinking.

I would like to begin by quoting theoretical physicist Lee Smolin from his book The Trouble With Physics, in which he writes: "More and more, I have the feeling that quantum theory and general relativity are both deeply wrong about the nature of time. It is not enough to combine them [quantum theory and general relativity (qt and gr)]. There is a deeper problem, perhaps going back to the beginning of physics."

Smolin is one among an eclectic band of well-regarded contemporary scientists who have given much thought to this topic. Among this group, however, Smolin is the only one of whom I'm aware who has seriously suggested looking back to the beginning of physics for clues about the nature of our current, seemingly intractable impasse regarding a reconciliation of qt and gr. And I happen to believe Smolin is prescient and exactly on the right track in doing so. (In the spirit of truth in advertising, I've long been a general admirer of Smolin's thinking and writing.)

Moreover, in this particular instance, Smolin's thinking happens precisely to dovetail with my own, so how could I possibly imagine it as being anything other than totally brilliant? In fact, however, I do agree with Smolin wholeheartedly, and I have speculated in some of my own musings on the topic that a problem of the sort to which Smolin alludes easily could have arisen in a seemingly innocent and innocuous -- but ultimately insidious -- manner, having origins that well predate the birth of physics as a science.

The potential deeply underlying problem that concerns me in this regard comes down in the end to the paradigm for the nature of time that currently is being used in physics. It is the same paradigm that was used by Galileo and it is the same paradigm that has been used by every other physicist -- including Einstein -- since the inception of physics as a science. It is the operational definition of time: time is that which is measured by clocks. It is this powerful definition -- or paradigm -- that has made it possible for physicists to convert their empirical, experimental observations into the language of mathematics, and thus ultimately to convert their observations into theories such as general relativity and quantum mechanics, among others.

But what would be the consequences if there were some sort of fundamental, hidden, underlying flaw with this paradigm? An analogy that comes to mind is that of the Ptolemaic and Copernican paradigms of cosmology. Imagine, for example, that today's scientists and engineers were attempting to plan and execute missions of interplanetary space exploration while still wedded firmly to the Ptolemaic paradigm of cosmology. Could it be done? Perhaps, but a what cost in terms of needless complexity and difficulty?

Is it possible that the contemporary scientists who are attempting to reconcile qt and gr are laboring under a similar hidden constraint and burden?

I sincerely welcome and invite your thoughts and comments on all of this.

JCN

Andrew James Bruce.

> problems in finding a full quantum theory of gravity.

Article Quantum Mechanics Gravity, Mechanical Gravity of Newton is Myth

>But this has been measured many times.General relativity predicts this and agrees well with what is seen.

You right, the reason that atomic clock is going slow by sea level, and going faster on higher level is because of atmosphere pressure, (pressure makes electron goes slower) it is nothing to do with GR. the interpretation and connect it to GR is absolutely wrong, because whole Einstein's theory is wrong.

>This is really a question in cosmology. But why must this be?

The Universe is made of duality, and opposite direction is a science.

https://www.academia.edu/38373675/Creation_of_a_Quantum_Mechanic_Universe_and_its_Rotation.doc

The Universe is a Quantum Mechanics Universe. All of my theory is making a sense, and it will be reveal in Quantum Physics Seminar France and Japan in next months.

Smolin may well be right with the idea that our notion of time needs to be amended. This is the famous "problem of time in quantum gravity". It comes down to the fact that the idea of time in quantum mechanics is a different notion in general relativity. The differences appear in several contexts, but one well-known one is the Wheeler–DeWitt equation. Applying canonical quantisation to general relativity (and similar theories) does not lead to a time-dependent wave equation. Applying quantum mechanics to the Universe in this way suggests that noting happens!

There has been much effort to explain this or find sole way around. One could start here and chase up the references

Article The Problem of Time in Quantum Gravity

Andrew James Bruce,

Thank you for this reference.

I believe that the Wheeler-DeWitt equation's lack of a time-dependent wave equation is one extremely important clue toward a resolution of this conundrum.

A second clue can be found, I believe, in explorations of relativity by Kurt Gödel during his collaboration with Einstein at the Institute for Advanced Study. Gödel's analysis called into question whether time, rather than merely being relative, could be said to exist at all. Einstein's equations, he figured, could describe a universe that was rotating rather than (or in addition to) expanding. In such a case, the relationship between space and time could become, mathematically, mixed up [1].

A third clue may be found in a technique Richard Feynman used to simplify his equations. In his popular book Six Not-So-Easy Pieces [2], Feynman wrote, ". . . nature is telling us that time and space are equivalent; time becomes space; they should be measured in the same units." [Feynman's emphasis]

A unifying explanation for these clues -- all three of which point in the same direction -- may be found in a conjecture of my own which strongly suggests that time is an emergent rather than a fundamental aspect of the universe. As Feynman said, time and space should, indeed, be measured in the same units.

The "Cliff's Notes" version of my conjecture runs as follows:

1. A particular time is identically equivalent to and is completely defined by, and only by, a particular configuration of the universe. (An explanation and justification for this key underlying assertion will be found in my essay 'Time: Illusion and Reality,' at my ResearchGate homepage).

2. Time changes from one particular time to another if, and only if, the configuration of the universe changes from one particular configuration to another.

3. But the configuration of the universe changes if, and only if, some portion of the universe is displaced relative to some other portion.

4. Therefore, if we wish to observe and measure a change from one particular time to another we must observe and measure a displacement of some portion of the universe relative to some other portion.

5. But displacements are measured -- not surprisingly -- in units of displacement, i.e., length.

This strongly suggests, I believe, that our traditional units of time are emergent rather than fundamental units. Hence, Feynman's conclusion as stated above.

The assertion spelled out in Point 1. above leads to a number of other interesting conclusions that are addressed elsewhere in my various essays.

JCN

___________________

[1] Walter Isaacson, Einstein: His Life and Universe, Simon & Schuster Paperbacks, New York, NY, 2007.

[2] Richard P. Feynman, Six Not-So-Easy Pieces: Lectures on Symmetry, Relativity, and Space-Time, Allen Lane, New Edition 1998.