Quantum gravity physics based on facts, giving checkable predictions

Friday, March 10, 2006


Nigel said...

The Standard Model is the best tested physical theory in history.

Forces are due to radiation exchange in spacetime.

The big bang has speed from 0 to c with spacetime of 0 toward 15 billion years, giving outward force of F = ma = mc/t.

This is about 7 x 10^43 Newtons. Newton’s 3rd law tells us there is an equal inward force, which according to the possibilities implied by the Standard Model, must be carried by gauge bosons, which predicts gravity constant G to within 2%.

Radiation pressure causes gravity, contraction in general relativity, and cosmic expansion, in addition to getting rid of the dark matter problem.

Obviously this is not a new theory, as the components are all well accepted quantum field theory, spacetime, etc. There is no speculation whatsoever.

The idea that gauge boson radiation physically causes forces is not of course discussed widely. Quantum field theory is based on forces being due to radiation exchange, but there has been little mainstream interest in physical mechanism since Richard P. Feynman's November 1964 lectures discussed the LeSage mechanism and found it wanting at that time.

If anyone is interested in the maths, please see:
http://electrogravity.blogspot.com/2006/03/edwin-budding-research-fellow-of.html and the link.


The major issue is of course that although people accept that recession velocity increases in spacetime, they are locked into breaking spacetime up into space and time, instead of looking at the recession velocity variation as being a variation in velocity with time => acceleration.

This is the major barrier people seem to have towards the facts above. It may help to remember the fine words of the originator of spacetime:

“The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.”

– Hermann Minkowski, 1908

Another way to see the problem with Hubble's velocity/distance relationship is that distance is ambiguous because the receding galaxies will automatically recede a further distance while the light travels to us. So we cannot possibly say what speeds and distances they have without reference to time past when the light was actually emitted.

It is a strange thing, but that is nature. The recession velocity we can observe varies as a function of time as well as distance, and it makes sense to express the variation as velocity/time because this is an acceleration which leads to the prediction of gravity strength accurately, while the alternative, velocity/distance, has created the current issues with dark matter and dark energy in cosmology.

Best wishes,
Nigel Cook
3/10/2006 03:09:58 PM

Why don't we just accept string theory?

You can’t make "scientifically correct" statements about UFOs, etc., except to ignore it. If you live in a society where unobserved gravitons and superpartners are believed to be "evidence" that string theory unifies standard model forces and "has the remarkable property of predicting gravity" {quoted from stringy M-theory originator Edward Witten, Physics Today, Apr 96}, then your tendency to ignore it is no help. You have to point out that it is simply vacuous.

String theory lacks a specific quantum field theory vacuum, yet as Lunsford says, that doesn’t stop string theory from making a lot of vacuous "predictions".

String theory allows 10^500 or so vacua, a whole "landscape" of them, and there is no realistic hope of determining which is the right one. So it is so vague it can’t say anything useful. The word "God" has about 10^6 different religious meanings, so string theory is (10^500)/(10^6) = 10^494 times more vague than religion.

Is this the sort of "scientific" dismissal of stringy speculation you need?

Alternatives to failed mainstream ideas are not automatically wrong. Those who are censored for being before their time or for contradicting mainstream non-tested speculation, are hardly crackpot.

As a case in point, see http://cdsweb.cern.ch/search.py?recid=688763&ln=en which was peer-reviewed and published but censored off arxiv according to the author (presumably for contradicting stringy speculation). It is convenient for Motl to dismiss this as crackpot.

It is curious that nobody remembers the problems that Einstein had when practically the entire physics establishment of Germany in the 1930s was coerced by fascists to call him a crackpot.
I think Pauli’s categories of "right", "wrong", and "not even wrong" are more objective than calling suggestions "crackpot".

The only way for a scientist to behave respectively towards new ideas struggling for attention is by constructive criticism. Ridicule and sycophantic, crowd-amusing sarcasm are OK if the theory is well accepted, because there's no other way to really attack an established theory without being ignored/censored. Half the problem for background independent approaches to quantum gravity is getting the ideas convincing and clear, and the other half is ridiculing mainstream string theory propaganda efficiently enough that people will give LQG a second glance.

British Library says I'm a co-author of Winston Churchill

I've just discovered that the British Library has listed me as being a co-author of Winston Churchill, for an article published in 1994. I do quote Churchill near the top of the article, so I suppose that's how he got his name as co-author on the British Library by-line:

"Author Churchill, W. Cook, N." - http://direct.bl.uk/bld/PlaceOrder.do?UIN=021081012&ETOC=EN&from=searchengine

Furthermore, Churchill has become the primary author, and my name is just added on. But I'm not complaining. It is very nice to be associated with someone whose views on the value of freedom are similar to mine! I'm trying to get Google Scholar to list all my articles without including other people's, but my name is too commonplace in electronics to get a complete list. Here is the list for publications in Electronics World (which is very incomplete, of course):

Scholar Results 1 - 5 of 5 for "N Cook" + "Electronics World". (0.13 seconds)
Tip: Try removing quotes from your search to get more results.
An electronic universe. Part 1: capacitors, inductors, and the electronic atom.
N Cook - Electronics World, 2002 - csa.com
An electronic universe. Part 1: capacitors, inductors, and the electronic
atom. N Cook Electronics World 108:17961796, 46-9, 2002. ...
Web Search http://www.csa.com/partners/viewrecord.php?requester=gs&collection=TRD&recid=AN138779AN

An electronic universe. Part 2: The Electronic Big Bang.
N Cook - Electronics World, 2003 - csa.com
An electronic universe. Part 2: The Electronic Big Bang. Nigel Cook Electronics
World 109:18041804, 47-52, 4/2003. This is another ...
Web Search

[CITATION] Weapon of Peace: The future of war. Four of these have become reality. And the fifth?
Web Search - BL Direct

Web Search - BL Direct

[CITATION] Electronic universe continues to question some established theories in this occasional series
Web Search - BL Direct

More about me:
Background info: http://nigelcook0.tripod.com/
Obsolete outline paper: http://cdsweb.cern.ch/search.py?recid=706468&ln=en
http://www.math.columbia.edu/~woit/wordpress/?p=353#comment-8728 http://www.math.columbia.edu/~woit/wordpress/?p=215#comment-4082


At 11:00 AM, Anonymous Anonymous said...

Christine prefers anonymous comments on her blog, so I made a couple here:


Anonymous said...
Dear Christine,

I respect your guidelines.

Presumably you are well aware of this from the lectures and the discussion of them you give.

You need to clarify "relativity" when you say that the correct unified theory must be identical to the existing form of special/general relativity.

For one thing, general relativity can be obtained in more than one way (of course the basic field equation was obtained by different routes by both Einstein and Hilbert), and a better understanding of how general relativity should be obtained theoretically using quantum field theory will probably result from quantum gravity.

Lee Smolin has lectured on how to go from a spin foam vacuum representation of path integrals in quantum field theory, to obtain the field equation of general relativity, without a metric.

This problem, to unify the quantum field theory with general relativity, is quantum gravity.

It is only likely to be interesting if it results in some prediction. To do so it may well alter the form of existing quantum field theory or of general relativity slightly.

What is important is that the right approach is consistent not with previous versions of theories, but is instead consistent with nature.

The debate in physics over modifications to the cosmological constant and other generally controversial aspects of "relativity" may be settled by the correct proof of the field equation from some kind of work along the lines Smolin suggests.

I do hope you will not call any correct derivation of the field equation of general relativity an "alternative" to be dismissed.

General relativity can be viewed in several ways, and what matters ideally is how much each predicts and whether it is based on empirical facts or speculations (fitting cosmological constant to observations, for instance).

If you read John Baez's crackpot list, it would dismiss string theory for being based on abject speculation, and for not making any useful or unique definite predictions.

Baez does not, however, automatically dismiss all new ideas. Because cosmology is based on the existing form of general relativity, if you say that existing general relativity is perfect and beyond improvement, then you are assuming that the unification of gravity and the standard model can only be achieved by some change in quantum field theory to accommodate existing general relativity.

There is no evidence that this is the case.

Best wishes

3/09/2006 06:44:51 AM

Christine said...
I do hope you will not call any correct derivation of the field equation of general relativity an "alternative" to be dismissed.

Not at all! And that was not what I had in mind when I stated those guidelines. As I have said previously, the fact that we still do not have a quantum theory of gravity means we must probably have to look for new ideas. Otherwise, this site would have no meaning. In fact I think it is quite logical and expected that quantum field theory and general relativity are effective theories that must be derived from a more fundamental theory, yet to be developed.

What I really do not like to be discussing here is things like "Einstein was wrong", etc. Special and General relativity are substantial and robust theories in their domain of validity. Of course this does not mean they are pristine theories that must remain untouched as long as humankind exists.

Thank you very much for bringing this discussion. I hope this clarifies the guidelines.

In any case, I am an open-minded person and of course we can continue this discussion if necessary.

Concerning string theory, I do think the landscape is a BIG problem to the "theory". However, I am still in the process of trying to learn whether there could be interesting mathematical elements in the "theory" worth pursuing. I also want to learn for string theorists their technical criticisms on LQG and other similar approaches.

Thank you!


3/09/2006 08:05:14 AM

Christine said...
I also want to learn for string theorists

Please replace the typo above

"for" -> "from"


3/09/2006 08:07:47 AM

Anonymous said...
Dear Christine,

Thank you very much for this clarification:

"What I really do not like to be discussing here is things like "Einstein was wrong", etc. Special and General relativity are substantial and robust theories in their domain of validity."

The way to do this would be to keep all discussion constructive, and to emphasise that general relativity is more complete than special relativity. The special theory is a simplification of the more complex facts, and only gives the right answers for cases of uniform motion. (General relativity is not merely special relativity plus gravity, which string theorists falsely claim.)

Best wishes

3/09/2006 09:12:23 AM

Christine said...
General relativity is not merely special relativity plus gravity, which string theorists falsely claim.

Yes. ...

At 1:16 PM, Blogger nige said...

Copy of comment to Dr Christine Dantas' blog, in case it gets deleted for being too long:


Nigel said...
Dear Christine,

Item #1, arXiv:gr-qc/0603022, dealing with Doubly Special Relativity (DSR) is very enlightening.

Quantum field theory is in disagreement with SR because the virtual particles in the vacuum imply a Dirac sea which looks different to observers in different frames of reference; see hep-th/0510040, page 85:

'it is not possible anymore to define a state which would be recognised as the vacuum by all observers'.

- Luis Alvarez-Gaume and Miguel A. Vazquez-Mozo, Introductory Lectures on Quantum Field Theory, http://arxiv.org/abs/hep-th/0510040, 5 Oct 2005, p85.

So I was very interested to read how DSR was an improvement over SR, arXiv:gr-qc/0603022:

"Recall that Special Relativity is based on two postulates: Relativity Principle for inertial observers and the existence of a single observer independent scale
associated with velocity of light. In this DSR replaces the second postulate by assuming existence of two observer independent scales: the old one of
velocity plus the scale of mass (or of momentum, or of energy). That’s it. ...

"It can be easily understood, when contrasted with the notion of dimensionful coupling constant, like Planck constant ¯h or gravitational constant G. What is their status in relativity? Do they transform under Lorentz transformation? Well, naively, one would think that they should because they are given by dimensional quantities. But of course they do not. ...

"In the limit when the second scale is very large (or very small depending on how the theory is constructed) the new theory should reduce to the old one, for example when the second scale of DSR goes to infinity, DSR should reduce to Special Relativity. ...

"The idea of DSR arose from the desire to describe possible deviations from the standard Lorentz kinematics on the one hand and, contrary to the Lorentz
breaking schemes, to preserve the most sacred principle of physics - the relativity principle.

"Originally the view was that one may be forced by phenomenological
data to replace Special Relativity by DSR, and then, on the basis of the latter one should construct its curved space extension, “Doubly General Relativity”. Then it has been realized that, in fact, the situation is likely to be quite opposite: DSR might be the correct flat space limit of
gravity coupled to particles (see Amelino-Camelia et. al., 2004 and Freidel et. al., 2004).

"We are thus facing the fundamental theoretical question: is Special Relativity indeed, as it is believed, the correct limit of (quantum) gravity in the case when spacetime is flat? From the perspective of gravity flat Minkowski spacetime is some particular configuration of gravitational field, and us such
is to be described by theory of gravity. It corresponds to configurations of gravitational field in which this field vanishes."

Thank you very much, Christine, for this and the other references. They are very enlightening. I know string theory incorporates SR so if some form of DSR is correct, this will be very interesting. Dr Lubos Motl stated in a reply to me that SR must be correct simply because Dirac's equation is a relativistic version of Schroedinger's equation, but we know that the relativistic equations Dirac used also come from FitzGerald and Lorentz' electromagnetism, and Dirac's sea is incompatible with SR postulates.

The major difference between SR and GR is the spacetime fabric, so quantum field theory with the Dirac sea should naturally lead more easily to GR than to SR. This is exactly what you see when you look at Dr Lee Smolin's work. It leads from a QFT to GR.

I am sorry if this takes up too much space.

Best wishes,

3/10/2006 06:12:23 PM

At 2:53 PM, Blogger nige said...

new comment to motl blog


nigel said...
"1 x 2 x 3 x 4 x 5 x ... = sqrt(2.pi)
Whether you can combine different versions of loop quantum gravity in such a way that you obtain the correct entropy is up to your imagination. ;-)" - Lumos

Lumos, this may lead to the final theory! I'm thinking about the Dirac sea and the way different particles are associated with their neighbors, as modelled by the product of integers you give. Of course the product looks infinite, but isn't. It's just great how maths works :-)

sqrt(2.Pi) = 2.5066... = 1 + 1.5066...

Now: 1.5066 x 137.03597 x 0.510999 = 105.503 MeV

The muon mass is 105.658 MeV. 0.1% higher than the value above. However we know that the correction factor for the magnetic moment of an electron or muon to the first vacuum interaction correction is 1 + 1/(2 x Pi x 137.0397) ~ 1.001, so assuming this also factor for some reason applies here as well,

Mass of muon ~ [mass of electron],[sqrt(2.pi)].[1/alpha].[1 + (alpha)/(2.pi)] = 105.63 MeV

(Above, the value 137.03597 = 1/alpha is the well known Sommerfield dimensionless number, and 0.510999 MeV is the rest-mass energy of the electron.)

Quantoken's grand unified theory is something along these lines, which were also used in a grand unified theory of Sir Arthur Stanley Eddington ("gematria" is where you take Hebrew words which also have numerical meanings, and add up the value of the letters, getting 666 for the Hebrew version of "string theorist" for instance, but I suppose this stuff is just called "numerology").

It is fairly easy to work out that the 137 number can be interpreted as the ratio of electron core charge to the weaker strength beyond the veil of polarised vacuum around the core (see my page).

What is harder to work out is the correct heuristic justification for the 1.5 number, and of course the exact value. I don't recall what Quankoken uses.

A.O. Barut came up with an empirical formula for lepton masses in the Physical Review Letters, v42, p1251 (1979).

I've also seen a paper on arXiv by A. Rivero which studies some kind of relationship of this variety.

Of course to Lumos, it is all crackpot unless it instantly finds a place within string theory.

I also recall a remark on Peter Woit's blog by Carl Brennen which says that if you add up the individual square roots of the masses of the three leptons, and square that sum, then divide that number by the ordinary sum of the three lepton masses, you get the dimensionless number 1.5. In fact, I've just done that calculation and it only gives 1.4991, far too low for this problem.

It is easy to dismiss ideas this this as crackpot. But at least until 1979 the Physical Review Letters editor thought it might be wise to keep an eye on empirical relationships between coupling constants and elementary particle masses.

The problem is that whatever the truth is, whether string theory or LQG, some kind of connection with reality of these numbers is needed. You have three leptons and three families of quarks. The quark masses are not "real" in the sense that you can never in principle observe a free quark (the energy needed to break a couple or traid of quarks apart is enough to form new pairs of quarks).

So the real problem is explaining the observable facts relating to masses: the three lepton masses (electron, muon, tauon, respectively about 0.511, 105.66 and 1784.2 MeV, or 1, 1.5 and 25.5 respectively if you take the electron mass as the unit), and a large amount of hadron data on meson (2 quarks each) and baryon (3 quarks each) masses.

When you multiply the masses of the hadrons by alpha (1/137.0...) and divide by the electron mass, you get, at least for the long-lived hadrons (half lives above 10^-23 second) pretty quantized (near-integer) sized masses:

Charged pions = 1.99
Neutral Pions = 1.93
Charged kaons = 7.05
Neutral kaons = 7.11
Eta = 7.84

Lambda = 15.9
Sigma+ = 17.0
Sigma0 = 17.0
Sigma- = 17.1
Xi(0) = 18.8
Xi(-) = 18.9
Omega- = 23.9

Of course the exceptions are nucleons, neutrons and protons, which have both have masses on this scale of around 13.4.

I think it is a clue to why they are relatively stable compared to all the other hadrons, which all have half lives of a tiny fraction of a second (after the neutron, the next most stable hadron found in nature is the pion of course, which has a half life of 2.6 shakes (1 shake = 10^-8 second).

The general formula for at least hadron masses (excluding nucleons) is given on my home page:

This idea predicts that a particle core with n fundamental particles (n=1 for leptons, n = 2 for mesons, and obviously n=3 for baryons) coupling to N virtual vacuum particles (N is an integer) will have an associative inertial mass of Higgs bosons of:

(0.511 Mev).(137/2)n(N + 1) = 35n(N + 1) Mev,

where 0.511 Mev is the electron mass. Thus we get everything from this one mass plus integers 1,2,3 etc, with a mechanism. We test this below against data for mass of muon and all ‘long-lived’ hadrons.

The problem is that people are used to looking to abstruse theory due to the success of QFT in some areas, and looking at the data is out of fashion. If you look at history of chemistry there were particle masses of atoms and it took school teachers like Dalton and a Russian to work out periodicity, because the bigwigs were obsessed with vortex atom maths, the ‘string theory’ of that age. Eventually, the obscure school teachers won out over the mathematicians, because the vortex atom (or string theory equivalent) did nothing, but empirical analysis did stuff. It was eventually explained theoretically!

Clearly what's physically happening is that the true force is 137.036 times Coulomb's law, so the real charge is 137.036. This is reduced by the correction factor 1/137.036 because most of the charge is screened out by polarised charges in the vacuum around the electron core:

"... we find that the electromagnetic coupling grows with energy. This can be explained heuristically by remembering that the effect of the polarization of the vacuum ... amounts to the creation of a plethora of electron-positron pairs around the location of the charge. These virtual pairs behave as dipoles that, as in a dielectric medium, tend to screen this charge, decreasing its value at long distances (i.e. lower energies)." - arxiv hep-th/0510040, p 71.

‘All charges are surrounded by clouds of virtual photons, which spend part of their existence dissociated into fermion-antifermion pairs. The virtual fermions with charges opposite to the bare charge will be, on average, closer to the bare charge than those virtual particles of like sign. Thus, at large distances, we observe a reduced bare charge due to this screening effect.’ – I. Levine, D. Koltick, et al., Physical Review Letters, v.78, 1997, no.3, p.424.

Koltick found a 7% increase in the strength of Coulomb's/Gauss' force field law when hitting colliding electrons at an energy of 80 GeV or so. The coupling constant for electromagnetism is 1/137 at low energies but was found to be 1/128.5 at 80 GeV or so. This rise is due to the polarised vacuum being broken through. We have to understand Maxwell's equations in terms of the gauge boson exchange process for causing forces and the polarised vacuum shielding process for unifying forces into a unified force at very high energy.

The minimal SUSY Standard Model shows electromagnetic force coupling increasing from alpha of 1/137 to alpha of 1/25 at 10^16 GeV, and the strong force falling from 1 to 1/25 at the same energy, hence unification.

The reason why the unification superforce strength is not 137 times electromagnetism but only 137/25 or about 5.5 times electromagnetism, is heuristically explicable in terms of potential energy for the various force gauge bosons.

If you have one force (electromagnetism) increase, more energy is carried by virtual photons at the expense of something else, say gluons. So the strong nuclear force will lose strength as the electromagnetic force gains strength. Thus simple conservation of energy will explain and allow predictions to be made on the correct variation of force strengths mediated by different gauge bosons. When you do this properly, you may learn that SUSY just isn't needed or is plain wrong, or else you will get a better grip on what is real and make some testable predictions as a result.

Heisenberg's uncertainty says

pd = h/(2.Pi)

where p is uncertainty in momentum, d is uncertainty in distance.
This comes from his imaginary gamma ray microscope, and is usually written as a minimum (instead of with "=" as above), since there will be other sources of uncertainty in the measurement process.

For light wave momentum p = mc,
pd = (mc)(ct) = Et where E is uncertainty in energy (E=mc2), and t is uncertainty in time.

Hence, Et = h/(2.Pi)

t = h/(2.Pi.E)

d/c = h/(2.Pi.E)

d = hc/(2.Pi.E)

This result is used to show that a 80 GeV energy W or Z gauge boson will have a range of 10^-17 m. So it's OK.

Now, E = Fd implies

d = hc/(2.Pi.E) = hc/(2.Pi.Fd)


F = hc/(2.Pi.d^2)

This force is 137.036 times higher than Coulomb's law for unit fundamental charges.
Notice that in the last sentence I've suddenly gone from thinking of d as an uncertainty in distance, to thinking of it as actual distance between two charges; but the gauge boson has to go that distance to cause the force anyway.

Clearly what's physically happening is that the true force is 137.036 times Coulomb's law, so the real charge is 137.036e.

5:51 PM
Saturday, March 11, 2006

At 2:58 AM, Blogger nige said...

“If a man reads or hears a criticism of anything in which he has an interest, watch whether his first question is as to its fairness … If he reacts to any such criticism with strong emotion; if he bases his complaint on the ground that is not “in good taste” or that it will have a bad effect … he thereby reveals that his own attitude is unscientific.

“Likewise if in his turn he judges an idea not on its merits but with reference to the author of it; if he criticizes it as “heresy”; if he argues that authority must be right because it is authority; if he takes a particular criticism as a general depreciation; if he confuses opinion with facts; if he claims that any expression of opinion is “unquestionable”; if he declares that something will “never” come about or is “certain” that any view is right. The path of truth is paved with critical doubt and lighted by the spirit of objective inquiry.”

- B. H. Liddell Hart, “Why Don’t We Learn From History?”, http://infohost.nmt.edu/~shipman/reading/liddell/c01.html


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