Confusion on just what fundamental means

[jason_one]

Confusion on just what "fundamental" means

I just read the Tao of Physics and I'm slightly confused. Are quarks and leptons fundamental units of matter or are they temporal manifestations of energy with E=mc^2? Is is that all matter is comprised of bundles of energy and that quarks and leptons are the most fundamental units created by this energy?

What is the difference between matter particles and force carrier particles? Aren't they all just temporal manifestations of energy?

And if so, why is Stephen Hawking so against books like the Tao of Physics that compare physics to Eastern mysticism?

Also, if photons are massless, why is light affected by gravity in General Relativity?

 

[arivero]

Particularly for the Tao of Physics, it is said to be just a defense of the Bootstrap Principle, a self-recursive way of defining elementary particles that was proposed in the sixties. It is problably obsolote physics development. As for the mystic content, it is also confusing, mixing Tao and Hinduism. It is regrettable also because Taoism by itself has a high scientific tradition, both in Chemistry (chinese alchemy) and in Geometry (volumes of polyhedra).

Note that the triumphant model, SU(3), also was denominated from Eastern mysticism: The Eighfold Way. Also some relevant teacher (Sakurai?) denominates some operators using god names from Hindu religion.

 

[dextercioby]

Light (the classical em field) has a nonvanishing energy momentum 4 tensor, therefore it affects spacetime and viceversa.


Daniel.

 

[jtbell]

I just read the Tao of Physics and I'm slightly confused. Are quarks and leptons fundamental units of matter or are they temporal manifestations of energy with E=mc^2?

What does "temporal manifestation of energy" mean, exactly? It must be some jargon from that book, because I've never seen that term before. Physicists consider quarks, leptons, and the gauge bosons to be fundamental particles because so far as we know for sure yet, they are not composed of more-fundamental particles, in the way that protons, neutrons etc. are composed of quarks.

I'm refraining from using the phrase "fundamental unit of matter" because some of the fundamental particles have no mass, as far as we know (photons, gluons).

 

[jason_one]

What Fritjof Capra, in the Tao of Physics, said when he stated that what we call fundamental particles are "temporal manifestations of energy", he was saying that the entire universe is made out of energy, and this energy comes together to form what we know as quarks, leptons, photons, gluons, etc. And because of the nature of the particles (their tendencies to annhilate each other into energy, or form out of energy) any particle that exists is a temporal grouping or bundle of the energy that makes up the entire universe.

Basically what he stated was that there is no "fundamental building block" that makes up the universe, except for the "cosmic energy" that manifests itself in the form of particles according to the equation E=mc^2, or m=E/c^2.

 

[ohwilleke]

The operational definition of "fundamental" in the standard model is "having no known composite nature". Fundamental particles can be, at least apparently, destroyed (for example in particle/anti-particle annillation) in the sense that they are transmuted into energy. They can also morph from one type of fundamental particle to one or more other particles.

Many, if not most physicists in the field, suspect that there is a layer of physics more fundamental than the standard model, that at least explains the relationships found in it, but there is no good theory that is universally accepted that does this (string theory and preon theory are examples of attempts to do this).

 

[ZapperZ]

What Fritjof Capra, in the Tao of Physics, said ...

I would not use Fritjof Capra, nor the Tao of Physics, as a source to either rebutt, or explain physics, if I were you. That book is one of the worst bastardization of physics.

Zz.

 

[Gokul43201]

At least Capra is a physicist.

At another forum someone recommended Gary Zukav's Dancing Wu Li Masters as a good book to learn QM from - this after the OP had stated that he was willing to learn the math needed !

Please let's talk about physics found in physics books. Methinks this discussion might be more appropriate in the M&E forum.

 

[Rade]

I think it possible (at least as a hypothesis to falsify) that "fundamental" in nuclear physics relates to what Linus Pauling in 1965 (Science, Proc. Nat. Acad. Sci) called "spherons"--which are 2-nucleon and 3-nucleon clusters. This view of the atomic nucleus thus rejects the more widely held view that (1) "single" (unbound) quarks are fundamental or that (2) "single" nucleons are fundamental. Thus at the macroscopic level, it is a cluster of nucleons such as [NP] that is fundamental to the structure of isotopes, which can also be viewed at the microscopic quark scale as [(ddu)(uud)]--a 6-bag quark entity, which is perhaps best viewed as [(ddduuu)]--a realistic entity that can interact with other such 6-bag quark entities, or 9-bag quark entities such as [PNP] = [(uud)(ddu)(uud)] = [(dddduuuuu)]. Thus, I offer the hypothesis (open here for discussion) that nucleons [P], [N], and quarks (u), and (d) are not "fundamental" to the structure of the atomic nucleus, only clusters of the above.

 

[Norman]

I think it possible (at least as a hypothesis to falsify) that "fundamental" in nuclear physics relates to what Linus Pauling in 1965 (Science, Proc. Nat. Acad. Sci) called "spherons"--which are 2-nucleon and 3-nucleon clusters. This view of the atomic nucleus thus rejects the more widely held view that (1) "single" (unbound) quarks are fundamental or that (2) "single" nucleons are fundamental. Thus at the macroscopic level, it is a cluster of nucleons such as [NP] that is fundamental to the structure of isotopes, which can also be viewed at the microscopic quark scale as [(ddu)(uud)]--a 6-bag quark entity, which is perhaps best viewed as [(ddduuu)]--a realistic entity that can interact with other such 6-bag quark entities, or 9-bag quark entities such as [PNP] = [(uud)(ddu)(uud)] = [(dddduuuuu)]. Thus, I offer the hypothesis (open here for discussion) that nucleons [P], [N], and quarks (u), and (d) are not "fundamental" to the structure of the atomic nucleus, only clusters of the above.

up and down quarks are clusters of what? Experiments have not yielded any substructure of quarks yet- but there are models that address the quarks having an underlying structure- read the literature on it, there was a great thread on this board that gave a list of papers on this subject. The nucleons are clusters of quarks AND gluons. The "and" there is very important.

I assume you are taking this from the quark bag models derived from MIT's. These bag models are phenomenological descriptions of quarks being confined in hadrons. The quarks are treated as massless particles contained inside some bag of finite radius. (I believe they are then treated as very massive outside the bag... just checked, they are treated as infinitely massive outside the bag). It creates confinement by balancing the pressure on the bag wall- I don't remember what the outside pressure is taken as, but the kinetic energy of quarks inside provides that side of the pressure equilibrium.

 

[Rade]

To answer your question, I would offer that up and down quarks are clusters of what Pauling called "spherons", also known as nucleon clusters.

It is now well established by experiment that spherons are realistic entities in many different isotopes. John A. Wheeler in 1937 developed his resonating group method on this concept of interacting nucleon clusters as being fundamental to nuclei. One quick example, 3-lithium-6 is known to contain a 3 [NP] spheron structure, and a 1 [NPN] + 1 [PNP] spheron structure. At quark level we would then have 3[NP] = [(ddduuu)]+[(ddduuu)]+[(ddduuu)] = 3-lithium-6. For the case of [NPN]+[PNP] we get [(ddddduuuu)]+[(uuuuudddd)] = 3-lithium-6. Which internal spheron structure of 3-lithium-6 you observe via experimentation depends on how much energy you put into the system during the scattering event.

Thus (and this is the hypothesis I presented above) the "fundamental" structure of 3-lithium-6 (or any isotope) is not any single quark or any single nucleon, but the interacting bags of either six quarks or nine quarks shown above that each have their own good quantum numbers such as spin, magnetic moment, etc. The MIT "bag model" follows the line of thinking of Wheeler, Pauling and many others that study "nucleon clusters" as being fundamental to nuclear structure and dynamics--another would be the Interacting Boson-Fermion model.

 

[Norman]

To answer your question, I would offer that up and down quarks are clusters of what Pauling called "spherons", also known as nucleon clusters.

I really don't understand this notion of saying quarks are made up of "clusters of nucleons"- nucleons are made up of quarks. This is well understood.

It is now well established by experiment that spherons are realistic entities in many different isotopes.

If you are going to make a claim like this please give references from peer reviewed journals to support your argument. Claiming something is well known or well established does not make it so. So to avoid any confusion please document your references.

John A. Wheeler in 1937 developed his resonating group method on this concept of interacting nucleon clusters as being fundamental to nuclei. One quick example, 3-lithium-6 is known to contain a 3 [NP] spheron structure, and a 1 [NPN] + 1 [PNP] spheron structure. At quark level we would then have 3[NP] = [(ddduuu)]+[(ddduuu)]+[(ddduuu)] = 3-lithium-6. For the case of [NPN]+[PNP] we get [(ddddduuuu)]+[(uuuuudddd)] = 3-lithium-6. Which internal spheron structure of 3-lithium-6 you observe via experimentation depends on how much energy you put into the system during the scattering event.

Thus (and this is the hypothesis I presented above) the "fundamental" structure of 3-lithium-6 (or any isotope) is not any single quark or any single nucleon, but the interacting bags of either six quarks or nine quarks shown above that each have their own good quantum numbers such as spin, magnetic moment, etc. The MIT "bag model" follows the line of thinking of Wheeler, Pauling and many others that study "nucleon clusters" as being fundamental to nuclear structure and dynamics--another would be the Interacting Boson-Fermion model.

I am getting confused here. Are you claiming instead of the nuclei having nucleons (which are composed of gluons and quarks) as the fundamental constituents, that instead we use the MIT bag model to create the spherons. Spherons have not been observed (again if I am wrong please document proof) but nucleons have and are observed- so why would we use spherons instead of nucleons? Is there an issue with the experimental data described by nucleon models?

One of the big failures of the bag models is the description of what causes confinement. Let me be clear here. The MIT bag model was used to describe the confinement of quarks in hadrons. It has not been used to describe nuclei. If I am wrong please provide documentation- again peer reviewed journal papers.

 

[Rade]

OK, as requested, below are a few citations of nucleon clusters (e.g., the spherons of Pauling) documented as realistic structures in isotopes--this forum does not allow for large downloads, so I limited the abstracts to essential details. I believe that the MIT bag model fits the hypothesis I suggest--although that may not be its original motivation.
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Cluster Nature of Li7 and Be7 Tombrello, T. A.; Phillips, G. C. ; Physical Review, vol. 122, Issue 1, pp. 224-228, 1961

Abstract

Measurements of the capture gamma-radiation processes, mass 3+alpha-->mass 7+gamma and nucleon+Li6-->mass 7+gamma, give information about the cluster structure of the mirror nuclei Li7 and Be7. The cluster model predicts that the ground state and low excited states of these nuclei should have large reduced widths...Scattering experiments provide accurate initial, capturing, wave functions, and an assumption of the cluster nature of the final, bound, states...reduced widths deduced show that theta3+42 is large, theta1+62 is small, and that the ground states and first excited states of Li7 and Be7 are primarily of the two-body cluster form mass 3 + alpha particle.
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The "two-body cluster mass 3" that is referenced for Li7 would be the [NPN] spheron and [PNP] for Be7. Thus the "fundamental structure" of Li7 is two spherons [NPN]+ alpha which is the spheron {[NP]+[NP]}. For Be7 we get [PNP]+ {[NP]+[NP]}. Now, if we apply MIT bag model formalism we see that the dynamics of Li7 at quark level would be a 9-quark bag for [NPN] forming resonance with alpha, which is itself a structure with two 6-quark bags interacting. I realize this is not how the Standard Model views Li7--that is why I offer a new hypothesis as discussed above, which is supported by experiment such as cited above and below.
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Supermultiplet Symmetry and Near-Threshold Levels in Systems Featuring Two or Three Extremely Light Clusters

Physics of the Atomic Nuclei, Vol. 63, 2000, pp. 195-203

Lebedev, V. M.a; Neudatchin, V. G.a; Sakharuk, A. A.b

a. Institute of Nuclear Physics, Moscow State University, Vorob’evy gory, Moscow, 119899 Russia b. Brest State University, Brest, Belarus

Abstract

On the basis of the supermultiplet potential model for the interaction of extremely light clusters (formalism of Young diagrams), it is explained why the d + t system does not feature a (1/2)+ (L = 0) level allied to (3/2)+ (L = 0) thermonuclear resonance. By using known data on the quasielastic knockout of nucleons from the inner 1s shell of light nuclei, a systematics of near-threshold states in the t + d + d, t + t + d, and t + t + t systems is constructed in terms of excited Young diagrams like \{f\} = \{322\}. The emergence of similar states in going over from the d + d and t + t systems (which feature no such states) to the alpha + d + d, alpha + t + d, and alpha + t + t systems (where they appear owing to the binding effect of the alpha particle) is discussed. The three-cluster states being considered may be important not only for nuclear physics proper but also for nuclear astrophysics. © 2000 MAIK “Nauka / Interperiodica”.

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The "three cluster states" cited above are the spherons of Pauling, today more commonly called "nucleon clusters".
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Finally, lots of good information on the cluster aspects of isotopes at these two links:
http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.ns.45.120195.000513?journalCode=nucl&cookieSet=1

http://www.worldscibooks.com/physics/4354.html