...So let's say it's more like a "brane theory" in your example but without the brane, superstring, supersymmetry and all the quantum stuff. Only general relativity. That's the main difference....
I can accept the (M) theory of strings as little as I can accept the existence of gravitons
{…}So keep an open mind as to whether gravitation will be quantizable, whether gravitons exist, and whether there are such things as compactified extra dimensions.
Reductionism breaks the world into elementary building blocks. Emergence finds the simple laws that arise out of complexity. These two complementary ways of viewing the universe come together in modern theories of quantum gravity.
Quote from: flux_capacitor on 09/15/2017 05:09 pm...So let's say it's more like a "brane theory" in your example but without the brane, superstring, supersymmetry and all the quantum stuff. Only general relativity. That's the main difference....OK, but this argument in this thread page started by a quotation about someone arguing against Quantum Gravity, the main objection being about whether gravity can be quantized (about whether gravitons are real). Because what string theory and other quantum gravity theories attempt to explain is the graviton. So, to me people railing against string (M) theory and the graviton is similar to Ernst Mach railing against Einstein's theory of relativity and against the existence of atoms, a statement which he made, amazingly, in the 20th century:Just substitute nowadays "string theory" for "relativity" and "gravitons" for "atoms" in Mach's statement, and it would read by a hypothetical 21st century of Mach:Quote from: a hypothetical 21st century MachI can accept the (M) theory of strings as little as I can accept the existence of gravitonsAnd the railing against unusual objects like strings and branes, compactified extra dimensions and the multiverse sounds like the railing against the concept of black holes and gravitational waves (both of which Einstein himself questioned at some points in his life).And hopefully everybody will agree that Mach's statements against relativity and against atoms was proven wrong.And similarly those that argued against the existence of black holes, the accelerated expansion of our Universe, and against the existence of gravitational waves were also proven wrong.So keep an open mind as to whether gravitation will be quantizable, whether gravitons exist, and whether there are such things as compactified extra dimensions.
...I don't think it's fair to compare Mach's dismissal of atoms with today's critics of supersymmetric string theory. It's my understanding that the Large Hadron Collider has placed enough limits on the mass-energies of potential supersymmetric pair particles that Supersymmetry is starting to create more problems than it solves.
I don't think it's fair to compare Mach's dismissal of atoms with today's critics of supersymmetric string theory. It's my understanding that the Large Hadron Collider has placed enough limits on the mass-energies of potential supersymmetric pair particles that Supersymmetry is starting to create more problems than it solves.
Quote from: RotoSequence on 09/15/2017 07:35 pm...I don't think it's fair to compare Mach's dismissal of atoms with today's critics of supersymmetric string theory. It's my understanding that the Large Hadron Collider has placed enough limits on the mass-energies of potential supersymmetric pair particles that Supersymmetry is starting to create more problems than it solves. 1) Supersymmetry does not necessarily equal (all possible versions of) string theory or M-theory2) Non-existence of supersymmetry does not necessarily equal non-existence of gravitonsMach's dismissal of atoms in the 20th century is indeed an embarrassing abomination that is indeed without comparison. It says more about Mach's mind than about the state of science at that time (early 20th century).
...BTW, we are way off topic.
Quote from: Rodal on 09/15/2017 04:54 pmQuote from: WarpTech on 09/15/2017 04:46 pmUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.This issue was also discussed in scalar-tensor theories starting with Brans-Dicke, but all tests up to now have rather confirmed the universality (in spacetime, to other epochs) of G, and very much narrowed the range in which G could be possible to varySince I was referring to the PV Model of GR, where we use a refractive index. The "coordinate" speed of light is given by c/K. Force is an invariant so;c4/G = (c/K)4/(G/K4)So G is a variable dependent on the refractive index. In the experiments, they use the "local" frame where "c" is a constant and K=1. Under those conditions, they will not measure a change in G either. This is based on dimensional analysis.
Quote from: WarpTech on 09/15/2017 04:46 pmUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.This issue was also discussed in scalar-tensor theories starting with Brans-Dicke, but all tests up to now have rather confirmed the universality (in spacetime, to other epochs) of G, and very much narrowed the range in which G could be possible to vary
Using dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.
Quote from: WarpTech on 09/15/2017 05:17 pmQuote from: Rodal on 09/15/2017 04:54 pmQuote from: WarpTech on 09/15/2017 04:46 pmUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.This issue was also discussed in scalar-tensor theories starting with Brans-Dicke, but all tests up to now have rather confirmed the universality (in spacetime, to other epochs) of G, and very much narrowed the range in which G could be possible to varySince I was referring to the PV Model of GR, where we use a refractive index. The "coordinate" speed of light is given by c/K. Force is an invariant so;c4/G = (c/K)4/(G/K4)So G is a variable dependent on the refractive index. In the experiments, they use the "local" frame where "c" is a constant and K=1. Under those conditions, they will not measure a change in G either. This is based on dimensional analysis.Since you are stating that the coordinate speed of light is c/K, then you still need the universal constant c, which is equal to the proper speed of light (that thing you referenced as measured in the local frame), but also has fundamental meaning that extends beyond electromagnetic waves. The value c can't be a function of K because otherwise you get into a recursive c = c/K.Since this value c is a constant, if you say that G/c^4 is constant, then G is a constant.There are theories that examine what if constants such as G are not constant across spacetime, but as Rodal said, experiments (mostly astronomical observations I think) currently don't support this. (These theories have the constants themselves change as if some property of the vacuum, not just adjustments to the coordinate speed of light due to general relativistic effects that are calculated based on the constants.)
Quote from: meberbs on 09/15/2017 08:46 pmQuote from: WarpTech on 09/15/2017 05:17 pmQuote from: Rodal on 09/15/2017 04:54 pmQuote from: WarpTech on 09/15/2017 04:46 pmUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.This issue was also discussed in scalar-tensor theories starting with Brans-Dicke, but all tests up to now have rather confirmed the universality (in spacetime, to other epochs) of G, and very much narrowed the range in which G could be possible to varySince I was referring to the PV Model of GR, where we use a refractive index. The "coordinate" speed of light is given by c/K. Force is an invariant so;c4/G = (c/K)4/(G/K4)So G is a variable dependent on the refractive index. In the experiments, they use the "local" frame where "c" is a constant and K=1. Under those conditions, they will not measure a change in G either. This is based on dimensional analysis.Since you are stating that the coordinate speed of light is c/K, then you still need the universal constant c, which is equal to the proper speed of light (that thing you referenced as measured in the local frame), but also has fundamental meaning that extends beyond electromagnetic waves. The value c can't be a function of K because otherwise you get into a recursive c = c/K.Since this value c is a constant, if you say that G/c^4 is constant, then G is a constant.There are theories that examine what if constants such as G are not constant across spacetime, but as Rodal said, experiments (mostly astronomical observations I think) currently don't support this. (These theories have the constants themselves change as if some property of the vacuum, not just adjustments to the coordinate speed of light due to general relativistic effects that are calculated based on the constants.)Until you at least read and understand Puthoff's papers on the PV Model of GR, not to mention Joe Depp's revisions and my extensions, don't confuse people here with your assumptions. You don't know or care to understand the model, and it shows.
Quote from: Mulletron on 09/15/2017 02:22 pmMy thinking about G isn't unmotivated. This appears to be happening, and in a predictable way. The question is, why? This is worth time and effort. Such a small deviation. Perhaps it's possible to have large deviations? Are we already and just don't understand it? Definitely worth exploring. Interesting comments in the phys.org article about planetary orbital resonances. https://www.richarddawkins.net/2015/04/why-do-measurements-of-the-gravitational-constant-vary-so-much/https://m.phys.org/news/2015-04-gravitational-constant-vary.htmlUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.
My thinking about G isn't unmotivated. This appears to be happening, and in a predictable way. The question is, why? This is worth time and effort. Such a small deviation. Perhaps it's possible to have large deviations? Are we already and just don't understand it? Definitely worth exploring. Interesting comments in the phys.org article about planetary orbital resonances. https://www.richarddawkins.net/2015/04/why-do-measurements-of-the-gravitational-constant-vary-so-much/https://m.phys.org/news/2015-04-gravitational-constant-vary.html
Quote from: flux_capacitor on 09/15/2017 04:35 pmQuote from: Rodal on 09/15/2017 04:25 pmThe problem with the view that Quotethe black hole is under this view a bridge of limited spatial extension with no central singularity, linking two Minkowski spaces is 1) proving the stability of such a bridge, which appears unstable unless it contains negative mass-energy2) the existence of another space is reminiscent of bridges in M-theory's multiverse, there is no experimental proof to decide between different theories (because black holes are...black)Sure, it all boils down to allow either:- an imaginary time and pure imaginary lengths inside the black hole, "beyond the event horizon" (as usually done)- or consider that the interior of such a solution is physically (an mathematically) real.PS : You're right this is unstable, and such solution represents a transient, very short, ephemeral bridge in time.where is the bridge going into? if it comes back into our own Universe, shouldn't it display the other end of the bridge as a white hole? If so why is there no experimental evidence of such white holes (which should be easier to detect than black holes).If the bridge goes into another brane, then I don't understand why people would be so much against M-theory and its multiverse of different branes and prefer this theory instead, since both seem to agree on bridges to other branes .
Quote from: Rodal on 09/15/2017 04:25 pmThe problem with the view that Quotethe black hole is under this view a bridge of limited spatial extension with no central singularity, linking two Minkowski spaces is 1) proving the stability of such a bridge, which appears unstable unless it contains negative mass-energy2) the existence of another space is reminiscent of bridges in M-theory's multiverse, there is no experimental proof to decide between different theories (because black holes are...black)Sure, it all boils down to allow either:- an imaginary time and pure imaginary lengths inside the black hole, "beyond the event horizon" (as usually done)- or consider that the interior of such a solution is physically (an mathematically) real.PS : You're right this is unstable, and such solution represents a transient, very short, ephemeral bridge in time.
The problem with the view that Quotethe black hole is under this view a bridge of limited spatial extension with no central singularity, linking two Minkowski spaces is 1) proving the stability of such a bridge, which appears unstable unless it contains negative mass-energy2) the existence of another space is reminiscent of bridges in M-theory's multiverse, there is no experimental proof to decide between different theories (because black holes are...black)
the black hole is under this view a bridge of limited spatial extension with no central singularity, linking two Minkowski spaces
The value c can't be a function of K because otherwise you get into a recursive c = c/K.Since this value c is a constant, if you say that G/c^4 is constant, then G is a constant.
Quote from: WarpTech on 09/15/2017 04:46 pmQuote from: Mulletron on 09/15/2017 02:22 pmMy thinking about G isn't unmotivated. This appears to be happening, and in a predictable way. The question is, why? This is worth time and effort. Such a small deviation. Perhaps it's possible to have large deviations? Are we already and just don't understand it? Definitely worth exploring. Interesting comments in the phys.org article about planetary orbital resonances. https://www.richarddawkins.net/2015/04/why-do-measurements-of-the-gravitational-constant-vary-so-much/https://m.phys.org/news/2015-04-gravitational-constant-vary.htmlUsing dimensional analysis along with how gravity affects M,L,T. The value of G is not a universal constant. In the PV Model of GR, it is G/c4 that is a universal constant.So what you are saying above is that in the PV Model c is not universally constant. I don't personally have an issue with that, but it seems even the suggestion would require some supporting argument.
Quote from: meberbs on 09/15/2017 08:46 pmThe value c can't be a function of K because otherwise you get into a recursive c = c/K.Since this value c is a constant, if you say that G/c^4 is constant, then G is a constant.This is not true in the PV Model of GR.
We use the frame of a distant observer, far from gravitational fields to determine what K is. In this reference frame, c/K is what is measured non-locally, it's not constant and neither is G, ε0 or μ0. Read the papers, you will learn something.
This was the original work where all of the tests of GR are reproduced by the PV representation, published by Springer:https://www.researchgate.net/publication/1978393_Polarizable-Vacuum_PV_representation_of_general_relativity
The theory predicts a radiation power from a binary system that is 2/3 that predicted by GR, and so incompatible with observed orbital decay rate of PSR 1913 + 16.