Re: Is QCD (Quantum Chromodynamics) Infallible?
From: Bjoern Feuerbacher (feuerbac_at_thphys.uni-heidelberg.de)
Date: Tue, 25 Jan 2005 11:26:43 +0100
Arnold S. wrote:
> For those directly working with QCD.
Well, I did my PhD thesis in QCD, is that enough?
> Is there absolutely no chance
> it can based on a faulty theory?
For *no* physical theory, there can be *ever* no chance
that it can be based on a faulty theory.
However, like most current physical theories, QCD is quite
well-tested, and therefore it is fairly unlikely that it
is totally wrong.
> Or do you believe it is 100% true
> with no possibility of error.
I don't think that *any* physicists thinks that.
> I read the following and wondering about it.
Where did you read that? I can't find it with Google.
> "The principles of Quantum Chromodynamics (QCD), were developed
> approximately forty years ago to answer enduring questions that
> Quantum Mechanics and General Relativity could not.
GR had nothing to do with that!
> It was hoped
> that QCD could fill-in the blanks and answer the thousands of
> nuclear and cosmological questions.
It's news to me that QCD was proposed in order to address
any cosmological questions.
> QCD offered a number of
> inconclusive predictions, such as Color Force and Fractional
> Electric Charges,
Wrong. Fractional Electric Charges were not proposed by QCD,
but by the quark model, which came beforehand.
> that when tested, enthusiastic interpretation of
> the experimental results led to a few prominent supporters.
"enthusiastic interpretation"? If he can show me any
other possible explanation of the experimental evidence
(from inelastic electron-proton scattering, meson production
from electron-positron annihilation etc.), he is feel free to show
> This limited success
"limited"??? Hundreds of experiments were done on QCD.
AFAIK, all agree so far with the theoretical predictions.
> and the lack of a better Nuclear Model at the time
Err, QCD has little to nothing to do with nuclear models.
> eventually led to worldwide acceptance of QCD. And unfortunately,
> most physicists today consider this model to be factual rather than
It seems to me that here is someone who does not understand how the
words "fact" and "theory" are used in science.
> thus making the same mistakes as the previous
> generations of scientists have made.
> It is always a serious error
> to label flawed or unproven models as being factual.
Since *no* theory is *ever* really "proven" in science,
this complaint is rather moot.
> QCD proposes
> an explanation of nuclear interactions
Wrong. QCD says little to nothing about nuclear interactions.
> that take place within an
> atom and what is called the Strong Interaction and the associated
> phenomena of Charge Transformation
What on earth is "Charge Transformation" supposed to mean?
>..... The model must include a
> bonding system for the constituent particles of protons and
What is a "bonding system"?
> To address these events and data, QCD offers a series of
> hypothetical fractionally charged particles called Quarks
For which we have a lot of evidence.
> with a series of eight colorful bonding particles called Gluons
For which we also have a lot of evidence.
> which are presumed to compose protons and neutrons and other
> particles such as mesons. It is believed that gluons are exchanged
> between adjoining quarks to form bonds or the force that hold the
> particles within protons or neutrons together. A series of six
> Quarks of three colors each and six Antiquarks of three colors
> each, provide fractional electric charges of 1/3 + or - with some
> and 2/3 + or - with others (one whole charge is equal to 1.602 x
> 10-19 Coulombs).
Congratulations, he got something right here.
> Immediately, there are problems with the model, as
> these thirty-six quarks have been assigned unrealistic rest masses
> ranging from 2.0 MeV to 180.0 GeV.
What's so unrealistic here?
> For example, it is believed that
> the proton (mp = 927.28 MeV) is composed of UUD quarks, however,
> the mass of a U quark is mu = 5.00 MeV and a D quark is md = 10.00
> MeV, therefore, UUD has a total quark mass of mpq = 20.00 MeV,
> leaving a mass discrepancy of mp = 907.28 MeV.
Err, a small hint: there are also a lot of gluons and virtual
quark-antiquark pairs in the proton. Ever heard of E=mc^2?
And of the concept of "current mass"?
> One would think that
> just this mass inconsistency would raise some red flags?
Only someone who has no clue what he is talking about would
Hey, didn't this man *ever* consider that if there really
were such an *obvious* flaw in the model, people would never
have adopted it?
> On the
> other hand, the Top quark has been assigned an incredible mass of
> 180.00 GeV, which is equal to the mass of 194 protons existing as a
> single non-composite particle.
Yes, that's indeed quite large. So what? That's what the experiments
tell us. If he has another explanation for the experimental
evidence, he is free to show his work.
> Keep in mind that theory dictates a
> union of several of these that will combine to form a single
> composite elementary particle.
Err, "composite" and "elementary" is contradictory. Leave
the second out.
> This is incredible because no
> stable particle larger than a neutron has ever been detected
> nor have we observed unstable particles with masses greater than 2% of
> a T-quark.
All the heavy quarks decay quite quickly - so why on earth
*should* there be any stable heavy particles???
> Amazingly, from the mid 1970's to the mid 1980's, claims
> of discovery of various fractionally charged quarks came in rapid
> Many other serious problems exist with QCD. For example,
> regrettably, few physicists realize, and others that know are
> reluctant to acknowledge, that fractional electric charges have
> never been isolated or even observed.
Since it is a *predicition* by the theory that this should not
be possible, why should this be a problem for it?
> The smallest electric charge
> known is the whole number charge of the electron or positron,
> proton or any other charged particle, which is equal to 1.602 x
> 10-19 Coulombs. All larger charges are multiples (integers) of this
> fundamental charge and lesser charges do not exist.
Do not exist *in isolation*.
> applying the system only to nucleons (baryons)
Err, "nucleons" is not the same as "baryons". And it was
also applied to mesons.
> solved nothing
It solved a lot.
> (a very big mistake), as some scientists finally realized that the QCD
> mechanism must also apply to leptons (positron '+', electron '-',
> neutrino '0')
What on earth is this supposed to mean? What scientists were
> because of the identical electric charge values or
> states that exist between the two classes of particles.
Err, what on earth has that to do with QCD?
> gigantic proton (m = 927.28 MeV), a baryon and the tiny positron or
> electron (m = .511 MeV), which are leptons, for example, all have
> the identical value (magnitude) of the electric charge.
Indeed. Hint: that has to do with the vanishing of the Adler
> Compounding the situation is that QCD is completely out of
> character when attempts are made to solve for the charge of
> electrons and other leptons or other properties related to
Since QCD has nothing to do with the charges of leptons, and
was never built to address this, it is not surprising that
it fails there, don't you think?
> Be advised that to preserve any future utility, QCD must
> be able to explain and predict the specifics of leptons,
> however this dream appears desperate.
> Naturally, there are legitimate reasons why so many believe in the
> existence of quarks. Experiments in the 1960's,
And ongoing in all the 40 years since then.
> at SLAC and other
> labs, involving the collision of accelerated electrons into fixed
> target protons or other nuclei (electron scattering) suggested that
> the electric charge may be divided among three different areas of a
Nonsense. No one ever said that the electric charge in a proton
is "dividing among different areas".
> Based upon the total of the data existing at the time, this
> was just one possible conclusion!
If he has another explanation which is consistent with the
data, he is free to show his work.
> Actually, there were many, more
> reasonable conclusions that could have been developed from the
> data. The possibility of charges spread over three areas of a
> proton or neutron seemed like a reasonable bases to consider the
> existence of particles with fractional charges, then.
He has no clue of the actual evidence (read up e.g. on
Bjorken scaling, on nucleon-neutrino scattering, and on
the production cross section for mesons, compared to muons),
and misrepresents the actual conclusions drawn.
> But, by the
> mid 1980's, we should have realized that the model was wrong
Only his straw men are wrong.
> and that it did not describe the nature of the electric charge within a
> proton or neutron,
QCD was never built to explain "the nature of electric charge".
> other baryon or meson, or any other charged
> particle. Obviously, the data of the 1960's was misinterpreted and
> this error was perpetuated.
If he has another explanation for the data, he is free to
show his work.
> Few consider that the QCD is unable to explain common nuclear
> events of charge transformation or account for mass deficiencies or
> losses that occur during most nuclear events and interactions.
1) QCD is not about nuclear reactions.
2) What is "charge transformation"?
> Few scientists will acknowledge that QCD is unable to conserve Mass,
> Rest Mass,
Mass is not conserved generally in physics, so why is this a problem?
> Charge, Energy, or Momentum.
QCD does not violate the conservation of charge, energy or
> And many scientists fail to
> consider that there is absolutely no attractive force associated
> with or between different colors
I get the faint suspicion that he did not understand that
"color" is merely a fancy name given to the charges of the
> or through the exchange of particles.
It is shown in most books on QFT and even in the sci.physics
FAQ how the exchange of virtual particles can indeed result
in an attractive force.
> Some may argue that colors are only representive of
> nuclear forces, but if this is how it works, then we still do not
> have a clue about the nuclear forces."
Replace "we" with "I" (the author of this pile of horse
dung), then the last part of the sentence is indeed right.