# Thread: A universal freeze frame

1. Originally Posted by KBstringer
Hello all,

I apologize if I am hijacking the thread, but I am not sure if I should start a new thread for a single question related to the OP's concept. Mods please assist if I am doing so.*

If the universe was frozen at any given time (noon in OP frame of reference), would it be true that as you approach a*
particular object from your point in spacetime, said object would not move backward in time, but forward until that object's*
local time was achieved? In a sense, appearing younger in age on approach as opposed to aging?*
Where moving further from said object would give the appearance of moving backward in time, thereby giving the*
appearance of aging.*
The idea is that you can observe any point in the freeze frame at any point in time from the big bang to the frozen point in time, i.e. noon my time. *You also have the tools to measure and quantify any aspect of the physical universe including energy density fluctuation at any or each point in space and compare the changes in energy density from one freeze frame to another across as many freeze points you deem necessary to carry out a thorough investigation of the cause and effect of every physical phenomenon.
OP, in your revised "idea experiment," I would be inclined to agree. Gravitation captures my imagination, and I'd be*
intensely interested in studying the mechanism from a frame by frame perspective.*

KBs
Welcome KB, you are obviously a very astute individual, . *Thank you for participating. *Maybe we can chat about the possibilities while I wait for answers to my questions.

The question right now is about the term I can use to describe the curvature of space caused by the presence of matter/energy density. *I think that it can legitimately be referred to as "gravitational energy" because the way I interpret the mainstream science there is only one gravity and there are two main views as to the nature of gravity. *One is general relativity where I get the idea that gravity equates to the curvature of space by the presence of matter/energy density, and the other is from the standard model of particle physics where the search is on for the graviton.

The mainstream effort to unify the theories is mainly focused on finding gravity waves predicted by GR and on developing a quantum gravity theory that includes the graviton.

One thing I think is sure is that there is energy involved. *Therefore, that energy can be referred to as "gravitational energy" without venturing into non-mainstream ideas. *I want to confirm that so that I can have a phrase to refer to the aspects of the physical nature of the*freeze frame as I start to quantify it.
*
Last edited by Bogie; 2012-Mar-19 at 12:42 PM.

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Bogie,

Thank you for the quick reply.

My intent was not to criticize the specific points of your idea, but to correct and solidify my understanding of relativity using your idea as an example.

Since quantum mechanics are currently beyond my grasp, I will bow out and watch to see how your idea and questions play out.

KBs

3. Originally Posted by KBstringer
Bogie,

Thank you for the quick reply.

My intent was not to criticize the specific points of your idea, but to correct and solidify my understanding of relativity using your idea as an example.

Since quantum mechanics are currently beyond my grasp, I will bow out and watch to see how your idea and questions play out.

KBs
OK, have it your way. But this is about getting a grasp, not having a grasp, lol.

Pending the unanswered question in post #31, if the term “gravitational energy” can be used, then I could say that we see that the "gravitational energy" of the earth warps the space through which the moon is moving and we see that the "gravitational energy" of the moon warps the space through which Earth is moving. That statement would be intended to recognize both of the current mainstream efforts to quantify gravity, i.e. to discover gravity waves predicted by GR and/or to discover and quantify the gravitations predicted by the standard particle model.

The investigation of the freeze frame then would be able to continue pending an answer to my question. If we discount the gravitational energy emanating from all other objects, the earth and the moon are observed to be falling directly toward each other, except for the fact that there is a time delay that results in them falling around each other.

I am saying that in our investigation of a sequence of freeze frames examining the motion of the earth and the moon we determine that the motion of each is directly toward where the other object was ~1.5 seconds ago. From that, it looks like the time delay of gravity, i.e. the "speed of gravity" is equal to the speed of light. I interpret that as being the mainstream view.

So it would be "mainstream" to say that objects follow curved paths relative to each other because the "gravitational energy" reaching out from an object isn't instantaneous, it occurs at the speed of light. Therefore any course change in the "emanating" object will require the same "speed of light" time delay before it is "felt" and reacted to by distant objects.

My question then becomes what is physically taking place, i.e. cause and effect. The math works almost perfectly to explain the motion but is it "mainstream" to accept that because the math isn't physical, that there are as yet unknown physical mechanics at work?

4. Originally Posted by Bogie
...

My question then becomes what is physically taking place, i.e. cause and effect? The math works almost perfectly to explain the motion but is it "mainstream" to accept that because the math isn't physical, that there are as yet unknown physical mechanics at work?
I’ll answer my own question by concluding that it is the mainstream view when I say that the scientific community is proceeding on the basis that there are as yet unknown natural mechanics that orchestrate gravity. Further, I expect the discovery work is being conducted through the dual paths of both GR in the search for the predicted gravity waves and particle physics to confirm the predicted graviton. Pending a response to the contrary I’ll go with that, though I hope someone will clarify the misconceptions about what is and is not the “mainstream view”.

Where that leaves me is that I am looking for evidence out in the freeze frame that will help determine the cause of gravity and help confirm the presence of gravity waves or gravitons or both. I say “or both” because EM displays particle/wave duality where light is referred to as photons or electromagnetic waves depending on the particular observation and model being invoked.

Out in the freeze frame my tools allow me to examine the energy density point by point. To show what that tool might detect, if the answer is “gravity waves”, there will be a gradual increase in energy density as I measure from the trough to the crest of a gravity wave. On the other hand, if the answer is the graviton, a particle, there will be a remarkable increase in energy density as my measurement crosses the particle boundary from outside to inside the graviton. If the graviton is a point particle then the differentiation between any point surrounding the graviton and the point occupied by the graviton will be remarkable.

My question is, if the results of my measurements were to show one or the other types of fluctuation in energy density as I examine point by point the space that should be affected by “gravitational energy”, then wouldn’t that answer the question as to whether gravity has a wave nature or a particle nature, i.e. if we had that special “energy density meter” that could detect energy density of space point by point as part of the “idea experiment” then we could determine the nature (particle or wave) of gravity transmission across space by examining the freeze frame with it?

5. I know, as Luckmeister points out, threads where the premise departs from the possibilities recognized by the fundamental concepts of physics, i.e. a freeze frame where you can move around at will, aren’t scientific. And I know that the activities and measurements of my alter ego out in the freeze frame are far from science. The thread and my freeze frame activities are meant to help determine for me what “mainstream thinking” is on various topics. That is what the questions all are aimed toward.

I asked if the curvature of space by the presence of matter/energy density could be referred to as “gravitational energy”. I would like to know, and hopefully not just a yes or no answer .

I would like to know if, in that sentence above would it be more appropriate to say, “I asked if the curvature of spacetime by the presence of matter/energy density could be referred to as “gravitational energy”. In other words, when the discussion is related to concepts of general relativity is it ever appropriate to refer to just space instead of spacetime in the normal context of mainstream discussion?

This thread has various questions that in themselves are trivial to most who are well versed in mainstream science but my layman self-teaching doesn’t have the benefit of an academic environment and the grace of actually discussing my learning with science instructors. Your answers to my questions might benefit other interested lay people as well as me.

Edit: The concept of gravitation energy I am trying to discuss might be thought of more as the gravitational field. As such, then the curvature of spacetime by the presence of matter/energy density would better be described as a gravitational field emanating from the matter/energy density of an object that influences the motion of distant objects. The moon in my earlier example would respond to the gravitational field of the earth similar to how the needle point of a compass responds to the earth’s magnetic field.

Therefore, like a magnet has potential magnetic energy, then the earth would have potential gravitational energy. Perhaps I should refer to the curvature of spacetime as potential gravitational energy?
Last edited by Bogie; 2012-Mar-20 at 03:27 PM.

6. Originally Posted by Bogie
...
Therefore, like a magnet has potential magnetic energy, then the Earth would have potential gravitational energy. Perhaps I should refer to the curvature of spacetime as potential gravitational energy?
If so, then the magnetic field affects a particle, the electron, and so would it be understood that the gravitational field might affect a particle, the graviton?

Also, the flow of electrons creates a magnetic field, so does the flow of gravitons create a gravitational field? I guess there is no reason to carry the analogy that far. However, the motion of gravitons would seem to be from matter/energy to matter/energy to cause gravity through some mechanics of emanation and capture, i.e. to translate the curvature of spacetime into actual mechanical steps. My question is, if the graviton exists, is it thought to emanate on the one hand and accumulate on the other, with both accumulation and emanation occurring simultaneously for any given object in space?

7. I know I am mixing concepts related to quantum mechanics and general relativity. Would I be right in thinking that gravity may well have elements of both, i.e. waves and particles?

If so, then isn’t it OK to consider it mainstream thinking that the emanation of gravitons profusely by matter at the speed of light could be involved in the mechanics of gravity?

Pending any comment from the community on my questions, I think I can safely draw another comparison between light and gravity. I have already mentioned that it seems to be within the range of mainstream thinking to consider the idea that both light and gravity travel at the same velocity (the speed of light), and that both light and gravity are potentially considered be both particles and waves.

Why not then, as an idea, compare the photon’s relationship to atoms and molecules with the graviton’s relationship to all particles with mass. All atoms and molecules are capable of emitting light radiation and so isn’t it comparable to think all particles with mass are capable of emitting gravity; gravity waves and/or gravitons?

That would mean that the search for a unifying theory of gravity would be looking for something in common about the presence of any and every particle with mass; something that would allow gravity waves and/or gravitons to be emitted and absorbed. Would that kind of thinking be in the mainstream as much as is the thinking that the mechanics of gravity might be a combination of GR’s gravity waves and the standard particle model’s gravitons?

Observing physical particles like electrons ejected from a metal surface confirms the particle mature of light, while observing interference patterns that demand a time exposure would confirm the wave nature of light, albeit that the exposure is build of individual particle impacts with the medium. Would anyone agree that it is the method of observing that determines the outcome as to whether light and potentially gravity would be displayed as particle or wave?

8. Originally Posted by Bogie
I know I am mixing concepts related to quantum mechanics and general relativity. Would I be right in thinking that gravity may well have elements of both, i.e. waves and particles?
I think reality works differently that either "wave" or "particle" as these are concepts placed on nature by man. Subatomic particles are just waves when you get right down to it, but put enough together, and you have a particle. Put a bunch of particles together, and they act like waves! Maybe they've always just been two sides of the same coin.

9. Originally Posted by Extrasolar
I think reality works differently that either "wave" or "particle" as these are concepts placed on nature by man. Subatomic particles are just waves when you get right down to it, but put enough together, and you have a particle. Put a bunch of particles together, and they act like waves! Maybe they've always just been two sides of the same coin.
That reminds me of inductive vs. deductive approaches to science. I do agree with you, and the reality we seek will have to find its way out to us through a maze of our own concepts and theories. If there is any “truth” to that statement, it supports the role of a deductive approach of working from an overall universal postulate like your “just waves” idea and then setting out to perceive the specific laws of nature that could be derived, perhaps like your view that, “Subatomic particles are just waves when you get right down to it, but put enough together, and you have a particle. Put a bunch of particles together, and they act like waves!”. Now all you have to do is test and verify, .

In the freeze frame idea we are saying that the waves and the particles freeze in place and that when we venture out and measure everything, reality will be revealed. Until then we will have to work with the scientific method, and be annoyed by what I perceive as incompatibilities between mainstream theories. Everyone knows there is one reality, and I am conducting this thread from the mainstream perspective. That means that though the deductive approach has lead to some of the greatest theories, it takes a back seat to the inductive approach because to put forth the “just waves” idea would not be tolerable in this question and answer forum; mainstream answers are called for here. But to differentiate between what the freeze frame would capture using “mainstream” views vs. what we would find out there using the “just waves” view should be allowable, so give it a try if you want to, lol.

10. Originally Posted by Bogie
That reminds me of inductive vs. deductive approaches to science. I do agree with you, and the reality we seek will have to find its way out to us through a maze of our own concepts and theories. If there is any “truth” to that statement, it supports the role of a deductive approach of working from an overall universal postulate like your “just waves” idea and then setting out to perceive the specific laws of nature that could be derived, perhaps like your view that, “Subatomic particles are just waves when you get right down to it, but put enough together, and you have a particle. Put a bunch of particles together, and they act like waves!”. Now all you have to do is test and verify, .

In the freeze frame idea we are saying that the waves and the particles freeze in place and that when we venture out and measure everything, reality will be revealed. Until then we will have to work with the scientific method, and be annoyed by what I perceive as incompatibilities between mainstream theories. Everyone knows there is one reality, and I am conducting this thread from the mainstream perspective. That means that though the deductive approach has lead to some of the greatest theories, it takes a back seat to the inductive approach because to put forth the “just waves” idea would not be tolerable in this question and answer forum; mainstream answers are called for here. But to differentiate between what the freeze frame would capture using “mainstream” views vs. what we would find out there using the “just waves” view should be allowable, so give it a try if you want to, lol.
I don't think Quantum Mechanics is exactly against the mainstream, is my interpretation of it? I've wondered about the Quantum effects of observing light as well. Is there only "one" reality past a point where no observations can take place, or is reality in a state of superposition? That is a question for another thread though.

If I could see anything at anytime, I would see it all . Who wouldn't?

11. Originally Posted by Extrasolar
I don't think Quantum Mechanics is exactly against the mainstream, is my interpretation of it? I've wondered about the Quantum effects of observing light as well. Is there only "one" reality past a point where no observations can take place, or is reality in a state of superposition? That is a question for another thread though.

If I could see anything at anytime, I would see it all . Who wouldn't?
I agree, quantum mechanics is mainstream in my view. So is general relativity and so is Big Bang Theory. Each of the mainstream theories correlates well to specific phenomena and ranges of scale and observables. Certainly there is correspondence between the major theories where they agree on established facts, but also there are areas of incompatibility within mainstream views as well. There are areas where no existing theory fills the gap too; the duality of light, the cause of gravity ...

A few of the early posters didn't heed my suggestion that we not look where we weren't supposed too, lol, but I guess if we were allowed to wander around in the freeze frame there are interesting places that would normally be private that we might happen upon.

12. Originally Posted by Bogie
I agree, quantum mechanics is mainstream in my view. So is general relativity and so is Big Bang Theory. Each of the mainstream theories correlates well to specific phenomena and ranges of scale and observables. Certainly there is correspondence between the major theories where they agree on established facts, but also there are areas of incompatibility within mainstream views as well. There are areas where no existing theory fills the gap too; the duality of light, the cause of gravity ...

A few of the early posters didn't heed my suggestion that we not look where we weren't supposed too, lol, but I guess if we were allowed to wander around in the freeze frame there are interesting places that would normally be private that we might happen upon.
Have you ever read Stephen Hawkings "The Grand Design"? One of the major themes in that book is 'model dependent realism'. Really fascinating stuff!

13. Originally Posted by Extrasolar
Have you ever read Stephen Hawking's "The Grand Design"? One of the major themes in that book is 'model dependent realism'. Really fascinating stuff!
Thanks for mentioning it. I hadn't read it but since I was going to the library today I picked it up. So far I have skimmed through it and it looks like an quick and interesting read. The first four chapters cover a lot of familiar ground. I jumped to the last chapter which was different than I expected and now I'm going through chapters 5 and 6 in detail. I'll finish up tomorrow probably and will have some questions and comments, so check back if you are up to discussing them.

Your are exactly right about it relying on 'model dependent realism'. I'm a little uncomfortable about string theory - M-theory but the book is well done and food for thought. I look forward to finishing up and making my comments and posing my questions.

14. In the meantime, my wife and I are sitting in silence, each with our ear buds in tuned to different media. *She is listening to the Bill Gates biography on the Biography Channel on YouTube, and I have oldies on, lol. *But I have my I pad in my lap and so thought I would discuss an aspect of the freeze frame for fun.

Clearly if you are contemplating your first freeze frame trip between the Earth and the moon you will find that travel there in the freeze frame could involve a straight line instantaneous relocation from the point on Earth to the point on the moon that you want to go, or you could use anther option I would call the gravity trip, and also there is the third option, a straight line at the speed of light.

Let's take the gravity trip from Tampa to a favorite moon location .

In the instant before you leave you look out at the moon and you see it where it was ~1.5 seconds ago but we discussed that; the reason the trip takes ~1.5 seconds is due to the time delay of gravity.

So let's discuss the geodesics. *We know that if we are following the gravity path we would set out heading directly to where the moon appears to be because the light and the gravity have the same velocity. *Each tiny time increment of the trip can be a new freeze frame and gives us the ability to redirect our course. *We will notice that a course correction is necessary at each freeze frame because the moon has moved from the course heading we just set in the last instant. *

As we plot our path through space we notice that the path is curved and as we approach our destination we seem, at the end, to finally be heading in the right direction. *We touch down after the breath taking gravity trip exactly were we wanted to go, we took a curved path, and we measured and recorded the exact distance.

Now we get smart and say to ourselves, if we know all about the curved path and the motion of the moon after we set out, why not predict where the moon will be and where the point we want to go will be a second and a half after we leave, and just go straight there?

Let's call that the third option, a straight path at the speed of light.

After a few realizations we would get there following a straight line. *One realization is that the time it would take for the straight line trip at the speed of light would be slightly different, a hair shorter, and that would require recalculating the position of the destination, but if you are good enough to *use a little calculus you can work it out.

From this thought experiment the question arises, what exactly are the parameters needed to make the proper calculations. *If we assume as we did earlier that we are discounting any other heavenly bodies, then we might only need to know the relative motion of the moon as it revolves around the Earth and as it rotates on its axis.

*We would need to know the difference between the calculations of the gravity path and the light path to predict the time savings. *But wait, the light path must be curved too? *No, because I'm mathematically calculating a straight path that will not be a geodesic gravity path, but a calculated short cut. *

My calculations of the light path would not follow the same path as the gravity path. *It would be sort of like cheating nature, saving travel time at the expense of not maintaining the geodesic. *You would think it would be against the law but its not; or is it? *Think about it and tell me what you think. *Is there a straight path that would be shorter than the gravity path?

15. Originally Posted by Extrasolar
Have you ever read Stephen Hawkings "The Grand Design"? One of the major themes in that book is 'model dependent realism'. Really fascinating stuff!
The Grand Design, by Hawking and Mlodinow, is well worth reading. You will get a good overview of the history of physics and cosmology, and be able to see the evolution of theories, scientific discoveries and how they stimulated the advancement of science right up to date.

You may or may not take the bait offered by the authors to see the greater universe as M-theory see it with 10^500 different possible sets of physical laws going on in separate dimensional universes. But even if you don't go there with the authors, they take you through the theory and philosophy of the full range of alternatives.

To me, the departure point from the path laid out starts at the uncertainty principle. Not that there is certainty because there is no way to observe the details of the quantum world to give us certainty about particle location and momentum, but the Feynman view that a particle takes all possible paths to go from point A to point B, though it explains particle/wave duality, puts too great a burden on our efforts to describe reality, I think. If a particle takes all paths, it has infinite energy and that approaches the absurd. Then if you can then apply another absurd concept to "normalize" or re-normalize that infinite result to make it agree with observed particle energies, that seems to me to compound the absurd circumstance. But I guess that could be just my own shortsightedness as opposed to it being a valid criticism.

If you don't accept that particles take all possible paths from point to point, then you aren't burdened with the concept of 10^500 possible universes and that alone is ample motivation to me to keep M-theory at arms length, lol. But we then must reject Feynman's explanation for the interference patterns in the two slit experiments. His explanation allows a particle to go through both slits or circle around and interfere with itself.

But regardless of my views, the books asks you to forget your current views of cosmological history and consider the sum of all histories that lead to our current state which represents the highest probability. This is model dependent realism. If you don't agree with that model, what model do you agree with?

Extrasolar, this brings me back to your post where you said ...
Originally Posted by Extrasolar
I think reality works differently than either "wave" or "particle" as these are concepts placed on nature by man. Subatomic particles are just waves when you get right down to it, but put enough together, and you have a particle. Put a bunch of particles together, and they act like waves! Maybe they've always just been two sides of the same coin.
That is sounding better every time I read it .

16. Originally Posted by Bogie
The Grand Design, by Hawking and Mlodinow, is well worth reading. You will get a good overview of the history of physics and cosmology, and be able to see the evolution of theories, scientific discoveries and how they stimulated the advancement of science right up to date.

You may or may not take the bait offered by the authors to see the greater universe as M-theory see it with 10^500 different possible sets of physical laws going on in separate dimensional universes. But even if you don't go there with the authors, they take you through the theory and philosophy of the full range of alternatives.

To me, the departure point from the path laid out starts at the uncertainty principle. Not that there is certainty because there is no way to observe the details of the quantum world to give us certainty about particle location and momentum, but the Feynman view that a particle takes all possible paths to go from point A to point B, though it explains particle/wave duality, puts too great a burden on our efforts to describe reality, I think. If a particle takes all paths, it has infinite energy and that approaches the absurd. Then if you can then apply another absurd concept to "normalize" or re-normalize that infinite result to make it agree with observed particle energies, that seems to me to compound the absurd circumstance. But I guess that could be just my own shortsightedness as opposed to it being a valid criticism.

If you don't accept that particles take all possible paths from point to point, then you aren't burdened with the concept of 10^500 possible universes and that alone is ample motivation to me to keep M-theory at arms length, lol. But we then must reject Feynman's explanation for the interference patterns in the two slit experiments. His explanation allows a particle to go through both slits or circle around and interfere with itself.

But regardless of my views, the books asks you to forget your current views of cosmological history and consider the sum of all histories that lead to our current state which represents the highest probability. This is model dependent realism. If you don't agree with that model, what model do you agree with?

Extrasolar, this brings me back to your post where you said ...
That is sounding better every time I read it .
My bold. One has to accept that particles take all possible paths if one accepts the evidence of QM. I don't think that has to be stretched to the entire universe though. That particular theory is Feynman's (I think). OF course, if you consider that the universe has been measured to be flat (+/- 0.05%), and that means the universe is infinite, then if there is a possibility of something happening, it would have to happen somewhere in an infinite universe. (Though I'm not sure infinite matter is part of the equation).

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Originally Posted by Bogie
Is there a straight path that would be shorter than the gravity path?
No, by definition. Also gravity corrects up to and including acceleration, so the "gravity path" wouldn't take you to where you see the moon, but where it actually is (provided it didn't change acceleration in the meantime).

But the more important thing is that timelike geodesics are not available (and meaningless) in your freeze frame, it is a spacelike surface.

18. Originally Posted by Extrasolar
My bold. One has to accept that particles take all possible paths if one accepts the evidence of QM. I don't think that has to be stretched to the entire universe though. That particular theory is Feynman's (I think). OF course, if you consider that the universe has been measured to be flat (+/- 0.05%), and that means the universe is infinite, then if there is a possibility of something happening, it would have to happen somewhere in an infinite universe. (Though I'm not sure infinite matter is part of the equation).
I am aware of some evidence that marked the separation between classical physics and modern physics around 1900, and quantum theory as expressed in quantum mechanics may be the most notable.

I worked out this list form my battle worn copy of Isaac Asimov's Biographical Encyclopedia of Science and Technology that I have used as a quick reference for years. From my layman perspective, I'm OK with the following evidence and scientific theory up until quantum electrodynamics:

Planck's constant 'h' that explains black body radiation and Wien's earlier contribution of discovering the black body curve, Lenard's work on the photoelectric effect, Einstein's use of energy quanta to explain the photoelectric effect, Stark's "Stark effect" which applied quantum theory to explain why strong electric fields multiplied the spectral lines, Heisenberg's principle of "indeterminacy" of both the position and momentum of any body known as the uncertainty principle, De Broglie showing that an electron was a wave and Schrödinger working out the theory of the electron as a "standing wave" around the nucleus and the release of radiation only when there was a shift in the electron wave and not perpetual radiation as had been predicted by Lorentz, Bohr applying quantum theory to the structure of the atom and electron orbital energies, the work of James Franck and Gustav Hertz called the Franck-Hertz experiments that connect electron energy to absorption by gases in quantum increments, Stern and Rabi's work on the magnetic nature and the wave nature of molecules, Born, Schrödinger and Dirac's work on the mathematical basis of quantum mechanics, Dirac's theorizing anti-particles confirmed by Anderson who discovered the anti-electron, Mulliken's work on quantum interactions between molecules, Pauling's work identifying chemical bonds between electrons and rationalization of observed effects in organic chemistry, Heisenberg's uncertainty principle and matrix mechanics which supported Schrödinger's wave mechanics as shown by Neumann, and of course that takes us up to Feynman, Schwinger, and Tomonaga who brought us quantum electrodynamics which is where it gets over my head.

What I am having trouble with is the evidence that particles take all possible paths as Feynman describes.

19. Originally Posted by Bogie
I am aware of some evidence that marked the separation between classical physics and modern physics around 1900, and quantum theory as expressed in quantum mechanics may be the most notable.

I worked out this list form my battle worn copy of Isaac Asimov's Biographical Encyclopedia of Science and Technology that I have used as a quick reference for years. From my layman perspective, I'm OK with the following evidence and scientific theory up until quantum electrodynamics:

Planck's constant 'h' that explains black body radiation and Wien's earlier contribution of discovering the black body curve, Lenard's work on the photoelectric effect, Einstein's use of energy quanta to explain the photoelectric effect, Stark's "Stark effect" which applied quantum theory to explain why strong electric fields multiplied the spectral lines, Heisenberg's principle of "indeterminacy" of both the position and momentum of any body known as the uncertainty principle, De Broglie showing that an electron was a wave and Schrödinger working out the theory of the electron as a "standing wave" around the nucleus and the release of radiation only when there was a shift in the electron wave and not perpetual radiation as had been predicted by Lorentz, Bohr applying quantum theory to the structure of the atom and electron orbital energies, the work of James Franck and Gustav Hertz called the Franck-Hertz experiments that connect electron energy to absorption by gases in quantum increments, Stern and Rabi's work on the magnetic nature and the wave nature of molecules, Born, Schrödinger and Dirac's work on the mathematical basis of quantum mechanics, Dirac's theorizing anti-particles confirmed by Anderson who discovered the anti-electron, Mulliken's work on quantum interactions between molecules, Pauling's work identifying chemical bonds between electrons and rationalization of observed effects in organic chemistry, Heisenberg's uncertainty principle and matrix mechanics which supported Schrödinger's wave mechanics as shown by Neumann, and of course that takes us up to Feynman, Schwinger, and Tomonaga who brought us quantum electrodynamics which is where it gets over my head.

What I am having trouble with is the evidence that particles take all possible paths as Feynman describes.
That's more than my knowledge on the subject. I was thinking of the double slit experiment(s) .

20. Originally Posted by Extrasolar
That's more than my knowledge on the subject. I was thinking of the double slit experiment(s) .
You have read Hawking’s, The Grand Design, and much of the science that I mention in my list is mentioned even if they don’t name names and dates; certainly they play into the justification for the title.

For example Planck’s constant is mentioned when they discuss Heisenberg’s uncertainty principle where they explain that “when you multiply the uncertainty of the position of a particle by the uncertainty in its momentum”, the result must be equal or greater than Planck’s constant. Lenard’s work on the photoelectric effect isn’t mentioned specifically but Einstein’s work on it is stated, “… early in the twentieth century Einstein showed that the photoelectric effect could be explained by a particle or quantum of light striking an atom and knocking out an electron”. The whole book is at least an introduction to the history of quantum physics.

Your point and reference to the double-slit experiments though is a key to understanding the concepts of Feynman when it comes to presenting a case for string theory and M-theory. It was the first time I had heard of using buckyballs to conduct the experiment, and they even go further and illustrate the effect using a soccer player kicking soccer balls through the slit, lol.

The book was fun to read and very well illustrated.

21. Originally Posted by caveman1917
No, by definition. Also gravity corrects up to and including acceleration, so the "gravity path" wouldn't take you to where you see the moon, but where it actually is (provided it didn't change acceleration in the meantime).

But the more important thing is that timelike geodesics are not available (and meaningless) in your freeze frame, it is a spacelike surface.

In the thread some of my questions are meant to draw attention to the efforts to unite the mainstream theories that apply to the quantum realm and to the macro realm including the search for a quantum theory of gravity and to get answers from the mainstream perspective. Our mainstream consensus on gravity is general relativity and in that context I think of geodesics as the shortest path between objects in spacetime.

I’m not sure if that is true in QM and so the post you responded to had a scenario using the freeze frame to distinguish between the geodesic which I was saying was the gravity path, and a scenario using light traveling in a straight line so ... I pointed out by use of that thought experiment that the path following the geodesic of spacetime (assuming gravity following the curvature of spacetime is the GR path) was not the shortest physical path that I could take to get from point A to point B. That example acknowledged the geodesic path curving because of the time delay of gravity meaning that to get to point B where the gravity path leads, then from where you set out, i.e. at point A, you would have to make continual course corrections as the moon moves in its orbit. This is because your course information is time-delayed.

Note that I mentioned invoking a new freeze frame every time I made a course correction, so I have left the original freeze frame Cauchy surface and have jumped from one Cauchy surface to another periodically as I headed for the moon, and made a course correction every time I "jumped".

I then used a different system for the second journey that did not include hyperbolic geometry, but simply took my starting position in space and a calculated destination in space (point B which is on the moon), and did the calculations necessary to get me to the moon destination following a straight path and the predicted time delay of gravity, which I called "a straight path at the speed for light".

I appreciate your answering the question. You said no, there was not a shorter path than the gravity path and I take that to be in the context of the general theory of relativity and curved spacetime.

Could a quantum theory of gravity turn out to work with a non-hyperbolic geometry?
Last edited by Bogie; 2012-Mar-27 at 12:09 AM.

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Originally Posted by Bogie
I’m not sure if that is true in QM and so the post you responded to had a scenario using the freeze frame to distinguish between the geodesic which I was saying was the gravity path, and a scenario using light traveling in a straight line so ... I pointed out by use of that thought experiment that the path following the geodesic of spacetime (assuming gravity following the curvature of spacetime is the GR path) was not the shortest physical path that I could take to get from point A to point B. That example acknowledged the geodesic path curving because of the time delay of gravity meaning that to get to point B where the gravity path leads, then from where you set out, i.e. at point A, you would have to make continual course corrections as the moon moves in its orbit. This is because your course information is time-delayed.
Since you're on a spacelike surface, any path along it is strictly spacelike. The paths you are describing are not physical, all physical paths will appear as single points on your surface (notice the definition in the wiki page you link to: "that intersects every causal curve exactly once", your link doesn't work btw). There is no path following "the geodesic of spacetime" (which i assume to mean a timelike or null geodesic) on your surface, all those paths are single points.

Note that I mentioned invoking a new freeze frame every time I made a course correction, so I have left the original freeze frame Cauchy surface and have jumped from one Cauchy surface to another periodically as I headed for the moon, and made a course correction every time I "jumped".

I then used a different system for the second journey that did not include hyperbolic geometry, but simply took my starting position in space and a calculated destination in space (point B which is on the moon), and did the calculations necessary to get me to the moon destination following a straight path and the predicted time delay of gravity, which I called "a straight path at the speed for light".
It's not a straight path at the speed of light, every path at the speed of light is null, which again are merely single points on your surface. I have no idea what you mean by "including hyperbolic geometry", you didn't include any anywhere.

I appreciate your answering the question. You said no, there was not a shorter path than the gravity path and I take that to be in the context of the general theory of relativity and curved spacetime.

Could a quantum theory of gravity turn out to work with a non-hyperbolic geometry?
You will not be able to get any physical insight by this. Physics is expressly the study of the dynamical behaviour of systems. What you are doing is looking only at the initial conditions, which will, by its very nature, not reveal anything about the dynamics of the system.

It's a cool idea to imagine moving around a spacelike surface, but it is not physics, and will not answer any physical questions (other than some very technical aspects of GR which are most easily done by looking at the types of cauchy surfaces available in a spacetime).

Run with the idea and have fun with it, just don't expect it to lead you to physical insight, that's a dead end.

23. Originally Posted by caveman1917
Since you're on a spacelike surface, any path along it is strictly spacelike. The paths you are describing are not physical, all physical paths will appear as single points on your surface (notice the definition in the wiki page you link to: "that intersects every causal curve exactly once", your link doesn't work btw). There is no path following "the geodesic of spacetime" (which i assume to mean a timelike or null geodesic) on your surface, all those paths are single points.
I corrected the link btw, thanks.

I did realize that the freeze frame is a spacelike surface representing every causal curve and I think of each point on the Cauchy surface as a point that has its individual causal history as I mentioned before. Each freeze frame is a new Cauchy surface and each point in each freeze frame has a corresponding point on the next freeze frame, then the next, etc. The time separating two frozen frames is defined by the change in all of the points from one surface to the next.

The gravity path of an object, for example someone starting on Earth and going to the moon, is described in my thought experiment by incremental freeze frames. The difference in the position of the points from one frame to the next represents motion from one frame to the next.
It's not a straight path at the speed of light, every path at the speed of light is null, which again are merely single points on your surface. I have no idea what you mean by "including hyperbolic geometry", you didn't include any anywhere.
OK, forget hyperbolic geometry for now if what I mean by that in relation to general relativity doesn't make sense. The sequential freeze frames are used in my example of the "gravity trip" to represent motion.

The course change is required because my motion is based on the position of the moon on a ~1.5 second time delay.
You will not be able to get any physical insight by this. Physics is expressly the study of the dynamical behaviour of systems. What you are doing is looking only at the initial conditions, which will, by its very nature, not reveal anything about the dynamics of the system.

It's a cool idea to imagine moving around a spacelike surface, but it is not physics, and will not answer any physical questions (other than some very technical aspects of GR which are most easily done by looking at the types of Cauchy surfaces available in a spacetime).

Run with the idea and have fun with it, just don't expect it to lead you to physical insight, that's a dead end.
There is physical insight to be gotten from this. One, there is a time delay for gravity to occur between two points. If gravitational motion has a physical cause, and if the gravitation force causes motion that works on the time delay, then the object under the influence of gravity will follow a curved path. Is this a misconception on my part?

The freeze frame may be just a cool idea but I do expect it to lead to some discussion of physical phenomena. In the case of the current thought experiment the phenomenon is gravity and this part is about understanding the efforts of the scientific community to discover a physical cause of gravity.

That would help unit the forces at the micro and macro realms and reconcile the theories of QM and GR. This discussion is aimed at trying to get a grasp of where we stand, of what words and phrases are being used in the scientific discussions, and what can be called mainstream thinking on the topic of the ongoing efforts to reconcile the theories. Am I correct to think that there is such an effort going on within the scientific community, because if not then there are two camps working independently and not speaking with each other, lol.

I can agree with the definition that physics is the study of the dynamical behavior of systems. If in my example I am looking at initial conditions, and if incremental changes to those conditions lead to new initial conditions, then that is the dynamics of the idea of the gravity path from the Earth to the moon that I tried to convey. Each freeze frame represents a spacelike slice, a starting point from which motion of each point on one surface becomes a point on the next surface. The delta or change between surfaces is time dependant, and though the perception of time is not going to be the same for each point from surface to surface, the variable between each point is time, and the change in position of each point (as each time increment take place) is motion.

Call it fun if you want because I do, but I think of it as a means of learning what the current thinking is by testing ideas in the context of the "freeze frame". I know my conceptions are full of misconceptions and that is why I am asking these questions.

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Originally Posted by Bogie
I did realize that the freeze frame is a spacelike surface representing every causal curve and I think of each point on the Cauchy surface as a point that has its individual causal history as I mentioned before. Each freeze frame is a new Cauchy surface and each point in each freeze frame has a corresponding point on the next freeze frame, then the next, etc. The time separating two frozen frames is defined by the change in all of the points from one surface to the next.

The gravity path of an object, for example someone starting on Earth and going to the moon, is described in my thought experiment by incremental freeze frames. The difference in the position of the points from one frame to the next represents motion from one frame to the next.
OK, forget hyperbolic geometry for now if what I mean by that in relation to general relativity doesn't make sense. The sequential freeze frames are used in my example of the "gravity trip" to represent motion.
A continuous time-sequence of cauchy surfaces is simply the spacetime itself. If your goal is to study the paths of objects then you might as well just work directly on the entire spacetime. Consider this: you have a cauchy surface at some time , then you take another at some time later . However because of the time interval objects will appear to have "jumped" from one position to another (and there are several issues in even making this work but let's ignore that). So because of that jump, if you want to be more correct, you have to decrease the time interval between your cauchy surfaces. This argument applies all the way to making the time increment infinitesimal. But then you have just added the time dimension back in and are back to working on the spacetime itself.

Think of it like a movie consisting of a time-sequence of still frames. You can look at one still frame, but it of course won't tell what happens in the movie. So you take one still frame, then another one from a couple of seconds later, and so on. So now you get a better look at what's happening in the movie. However this is still far from perfect because the time interval is large. Actors will appear to have jumped from one position to another. So you decrease the time interval to get a better view of the dynamic situation. But this is still pretty crude, so in the end you put all the frames in their proper sequence and time interval, and you simply end up with the movie you started with. So what is the point, when given a movie, to do all this to just end back up with the movie you started with? If this is what you want to do (see the dynamics of the movie), just watch the movie and don't bother with the still frames.

The course change is required because my motion is based on the position of the moon on a ~1.5 second time delay.
There is physical insight to be gotten from this. One, there is a time delay for gravity to occur between two points. If gravitational motion has a physical cause, and if the gravitation force causes motion that works on the time delay, then the object under the influence of gravity will follow a curved path. Is this a misconception on my part?
That is a misconception on your part. Newtonian gravity worked instantaneous, and it has to, otherwise the solar system wouldn't be stable. GR replicates this behaviour by correcting up until acceleration terms. The thing that is time-delayed is gravitational waves, not gravity itself.

The freeze frame may be just a cool idea but I do expect it to lead to some discussion of physical phenomena. In the case of the current thought experiment the phenomenon is gravity and this part is about understanding the efforts of the scientific community to discover a physical cause of gravity.
If what you want to discuss is physical phenomena then discuss the entire system including its dynamics in the proper way. Just like when you ask friends over to watch a movie they don't expect you to slowly show them one still frame after another adding commentary to each frame.

That would help unit the forces at the micro and macro realms and reconcile the theories of QM and GR. This discussion is aimed at trying to get a grasp of where we stand, of what words and phrases are being used in the scientific discussions, and what can be called mainstream thinking on the topic of the ongoing efforts to reconcile the theories. Am I correct to think that there is such an effort going on within the scientific community, because if not then there are two camps working independently and not speaking with each other, lol.
There is certainly effort towards that.

I can agree with the definition that physics is the study of the dynamical behavior of systems. If in my example I am looking at initial conditions, and if incremental changes to those conditions lead to new initial conditions, then that is the dynamics of the idea of the gravity path from the Earth to the moon that I tried to convey. Each freeze frame represents a spacelike slice, a starting point from which motion of each point on one surface becomes a point on the next surface. The delta or change between surfaces is time dependant, and though the perception of time is not going to be the same for each point from surface to surface, the variable between each point is time, and the change in position of each point (as each time increment take place) is motion.
Yes but the change between frames is continuous, not incremental. Now there are certainly some ideas that try to discretize things, but those are not expressible in the language of GR (and cauchy surfaces), which is a continuous theory.

Call it fun if you want because I do, but I think of it as a means of learning what the current thinking is by testing ideas in the context of the "freeze frame". I know my conceptions are full of misconceptions and that is why I am asking these questions.
It would seem more fruitful to do it the other way around. First learn about the dynamics of a system's behaviour and then look at the state of the system at some instants of time. Or more in line with the analogy, first actually watch the movie before you look at each still frame seperately so that you can provide yourself the necessary context to those frames. If you start of with looking at each frame seperately before having watched the movie they won't make much sense.

25. Originally Posted by caveman1917
A continuous time-sequence of cauchy surfaces is simply the spacetime itself. If your goal is to study the paths of objects then you might as well just work directly on the entire spacetime. Consider this: you have a cauchy surface at some time , then you take another at some time later . However because of the time interval objects will appear to have "jumped" from one position to another (and there are several issues in even making this work but let's ignore that). So because of that jump, if you want to be more correct, you have to decrease the time interval between your cauchy surfaces. This argument applies all the way to making the time increment infinitesimal. But then you have just added the time dimension back in and are back to working on the spacetime itself.
You are being a little too practical . Try to consider time passing between freeze frames as periods of motion that still happen and anyone living through all the freeze frames will not be aware that freeze frames even occur.
Think of it like a movie consisting of a time-sequence of still frames. You can look at one still frame, but it of course won't tell what happens in the movie. So you take one still frame, then another one from a couple of seconds later, and so on. So now you get a better look at what's happening in the movie.
OK, you do get that idea.
However this is still far from perfect because the time interval is large. Actors will appear to have jumped from one position to another. So you decrease the time interval to get a better view of the dynamic situation. But this is still pretty crude, so in the end you put all the frames in their proper sequence and time interval, and you simply end up with the movie you started with. So what is the point, when given a movie, to do all this to just end back up with the movie you started with? If this is what you want to do (see the dynamics of the movie), just watch the movie and don't bother with the still frames.
OK, you are saying you don't get why I'm using the freeze frame. It is simply a way to establish a foundation for discussion of changes from one selected frame to the next without having to mention each tiny incremental “Zeno instant”. You see, this "idea experiment" then allows anyone who wants to discuss any physical aspect of science to set the start point as a freeze frame, explain the next point they want to use, and discuss the physical nature and natural causes of the motion between frames to determine the mainstream view.

I would say that there is no movie out yet that corresponds precisely to reality and so it is a question of "which movie" we are watching.

Throughout the thread I have been acknowledging that there are different theories for the micro and macro realms and so we could take the movie analogy and say that there are movies based on each. There are unsolved differences between each. Therefore the freeze frame allows you to set up a situation that is theory dependent and allows you to describe the setting of the particular movie. The theory that is being examined determines the setting and the script and allows you to analyze the changes under that theory as time increments are added.
That is a misconception on your part. Newtonian gravity worked instantaneous, and it has to, otherwise the solar system wouldn't be stable. GR replicates this behaviour by correcting up until acceleration terms. The thing that is time-delayed is gravitational waves, not gravity itself.
I can live with that if what you are saying is that an object acting as a gravitational source is instantaneously emanating gravity, either by warping spacetime or gravitons and/or gravity waves. The waves and or the gravitons which are being emitted instantaneously take time to reach out to other objects and that time is often discussed as being the same as the speed of light. Or does the circumstance that I mentioned in regard to "which moving are we watching" apply here? Are you are saying that there is only one movie that you would consider worth watching to depict reality? Which one?
If what you want to discuss is physical phenomena then discuss the entire system including its dynamics in the proper way. Just like when you ask friends over to watch a movie they don't expect you to slowly show them one still frame after another adding commentary to each frame.
It is about which movie we watch. The thread employs the freeze frame to help discuss different theoretical versions of reality and to get input about the mainstream views, given each particular version, by asking questions.
There is certainly effort towards that.
Exactly. There are different theories within mainstream thinking; different movies that can be examined and compared. Each allows different questions to be brought up.
Yes but the change between frames is continuous, not incremental. Now there are certainly some ideas that try to discretize things, but those are not expressible in the language of GR (and cauchy surfaces), which is a continuous theory.
Well that is a good point. Like you say, some people may believe in a discrete universe and some a continuous universe. A continuous universe will have discrete increments at the quantum level. The “movie” might be discrete to them while someone else might see the buildup of those discrete increments occurring as a continuous process.

General relativity is a macro theory and is thought to work when the size of the universe is greater than Planck length but I take that to mean that GR does not apply to the quantum realm. There is another "movie" for that realm, and the final epoch version uniting both is not in theaters yet.
It would seem more fruitful to do it the other way around. First learn about the dynamics of a system's behaviour and then look at the state of the system at some instants of time. Or more in line with the analogy, first actually watch the movie before you look at each still frame seperately so that you can provide yourself the necessary context to those frames. If you start of with looking at each frame seperately before having watched the movie they won't make much sense.
I don't see why you don’t think I could be doing both, having started the learning a long time ago. It is just that I still am not able to understand reality and so I have resorted to this, :shrug:.
Last edited by Bogie; 2012-Mar-27 at 04:06 PM.

26. Hi Bogie
Take a look at the Initial Value Formulation by Dirac and the related work by ADM. GR can be rewritten as a dynamical evolution of 3-spaces but it is not without its problems. The attraction is that it can be used to write a Hamiltonian which can then be used to create various types of quantum gravity models. See Anderson for a good background.

27. Originally Posted by loglo
Hi Bogie
Take a look at the Initial Value Formulation by Dirac and the related work by ADM. GR can be rewritten as a dynamical evolution of 3-spaces but it is not without its problems. The attraction is that it can be used to write a Hamiltonian which can then be used to create various types of quantum gravity models. See Anderson for a good background.
I appreciate the links and I don’t interpret your gracious gesture as supposing you would even consider from my comments that I would be up to anything more than looking at those pages and the Anderson paper. I have looked, I have considered what I could get from trying to understand even the language, and I feel like I should clarify my interest in gravity as being that of an interested layman.

As a layman I keep informed on the popular science material and am continually digging into physics and chemistry but am far from being trained to take part in any science that goes on or even to technically grasp important science like the EFEs, let alone the initial value formulation, Dirac equations, or ADM. Is there an ADM for Dummies?

I see that the idea of a freeze frame could be construed to be similar in some respect to the ways that GR is analyzed and discussed, but in my hands, the freeze frame is a simple vehicle for asking questions in hopes of sorting out what I broadly call “mainstream views”. I probably should stop calling it a Cauchy surface to avoid sounding like I know something I don't.

My view of general relativity is that it describes how matter curves spacetime and how curved spacetime determines where matter will go, lol. I guess that makes me almost 100 years behind. My concern is not that the EFEs or their reformalizations that you encourage me to look at accurately depict the force of gravity, it is that I want the scientific community to find out how, and to tell us in layman's terms what the mechanics are. Until then I'm left with my own misconceptions and many questions, most of which don't lend themselves to simple answers that one could expect to get in a "science questions and answers" forum.

So let me ask a follow up question to the links you provided. How much of a role does quantum mechanics play in the kind of work people like Anderson are doing?

28. I was wandering around out in the freeze frame last night and I noticed that the ~2.7 K background temperature appeared in all directions while I was standing still in deep space, but as I moved quickly in any direction it heated up in that direction.

Then I noticed that there as a very strong correlation between the observation of red shifted galaxies and the background temperature. While standing still there was a consistency of temperature in every direction and most galaxies were red shifted (with few exceptions of blue shifting within some galaxy groups scattered around).

Rapid motion caused a corresponding change in both observations. The temperature heated up and more blue shifted galaxies were observed in the direction of motion. This held true in all directions.

I think these two observations can be interpreted to mean that the background radiation is coming and going in all directions at the speed of light and has been doing so for 13 or 14 billion years, and that the galaxies and galaxy groups are all moving away from each other and have been doing so for all of that time too.

If that is the case, doesn't that correlation between the observations of the background radiation and the light from distant galaxies mean that there is a preferred rest frame and the preferred frame can be determined by the background temperature and redshift measurements? Wouldn’t any other frame of reference be an inertial frame of reference relative to that preferred rest frame? Do those observations indicate that the physics are different in the inertial frames vs. the rest frame?

29. Originally Posted by Bogie
I appreciate the links and I don’t interpret your gracious gesture as supposing you would even consider from my comments that I would be up to anything more than looking at those pages and the Anderson paper. I have looked, I have considered what I could get from trying to understand even the language, and I feel like I should clarify my interest in gravity as being that of an interested layman.

As a layman I keep informed on the popular science material and am continually digging into physics and chemistry but am far from being trained to take part in any science that goes on or even to technically grasp important science like the EFEs, let alone the initial value formulation, Dirac equations, or ADM. Is there an ADM for Dummies?

I see that the idea of a freeze frame could be construed to be similar in some respect to the ways that GR is analyzed and discussed, but in my hands, the freeze frame is a simple vehicle for asking questions in hopes of sorting out what I broadly call “mainstream views”. I probably should stop calling it a Cauchy surface to avoid sounding like I know something I don't.

My view of general relativity is that it describes how matter curves spacetime and how curved spacetime determines where matter will go, lol. I guess that makes me almost 100 years behind. My concern is not that the EFEs or their reformalizations that you encourage me to look at accurately depict the force of gravity, it is that I want the scientific community to find out how, and to tell us in layman's terms what the mechanics are. Until then I'm left with my own misconceptions and many questions, most of which don't lend themselves to simple answers that one could expect to get in a "science questions and answers" forum.

So let me ask a follow up question to the links you provided. How much of a role does quantum mechanics play in the kind of work people like Anderson are doing?
The purpose of Quantum Gravity research is to integrate Quantum Mechanics into General Relativity. The Hamiltonian was created as a reformulation of classical mechanics that didn't really have a use until it was discovered to play a major role in QM. Hamiltonians describe the time evolution of a system so are very useful for modelling particles moving about and colliding.

General Relativity as set out by Einstein does not admit Hamiltonians as GR's field equations give solutions that "encompass the whole history of a universe" as Wiki puts it. So to make GR look more like QM, Dirac split spacetime back into space + time and derived a Hamiltonian describing the time evolution of the spatial slices then tried to use the Hamiltonian to bring QM into it. He ran into trouble with that approach and ever since researchers like ADM, Wheeler (who created the quote you used above "Space tells matter how to move, matter tells space how to curve"), Ashketar and the rest of a small group of Quantum Gravity researchers have been trying different approaches to get around it.

30. Originally Posted by loglo
The purpose of Quantum Gravity research is to integrate Quantum Mechanics into General Relativity. The Hamiltonian was created as a reformulation of classical mechanics that didn't really have a use until it was discovered to play a major role in QM. Hamiltonians describe the time evolution of a system so are very useful for modelling particles moving about and colliding.

General Relativity as set out by Einstein does not admit Hamiltonians as GR's field equations give solutions that "encompass the whole history of a universe" as Wiki puts it. So to make GR look more like QM, Dirac split spacetime back into space + time and derived a Hamiltonian describing the time evolution of the spatial slices then tried to use the Hamiltonian to bring QM into it. He ran into trouble with that approach and ever since researchers like ADM, Wheeler (who created the quote you used above "Space tells matter how to move, matter tells space how to curve"), Ashketar and the rest of a small group of Quantum Gravity researchers have been trying different approaches to get around it.
Thank you for that interesting and well informed recap. Why do you know all that?

Did you by any chance think about the question in my last post (#58) about the preferred rest frame?

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