Nuclear Strong Force is a Fiction

[dafydd]

Considering you did not understand the critique or ignored it, the irony is astounding. See if you can address the actual argument.

"By that standard, you could say anything decays to anything whatsoever with the same net quantum numbers. "

You failed to actually discuss this.

Stop blubbing!!!

 

[ben m]

No, what I do is correct people whose physics knowledge is scant. Look above. I've corrected Dancing David on the residual strong force, I've corrected RC on energy causing gravity, and I've corrected ben on low-energy proton-antiproton annihilation and his specious buckyballs.

Keep it up, you're doing great.

 

[dafydd]

Keep it up, you're doing great.

I'm learning from this thread, but not via a certain person's posts.

 

[Farsight]

Thanks ben. OK, I just had a quick look back, see post #327 where RC starts by saying "Wow that is a lot of ignorance!". Then a bit lower down he says "a proton is 1824 times heavier than an electron". The irony is rather splendid don't you think?

 

[dafydd]

Thanks ben. OK, I just had a quick look back, see post #327 where RC starts by saying "Wow that is a lot of ignorance!". Then a bit lower down he says "a proton is 1824 times heavier than an electron". The irony is rather splendid don't you think?

A typo. RC was probably thinking about G.R. Kirchhoff's and William Thomson's birth year.

 

[ben m]

Thanks ben. OK, I just had a quick look back, see post #327 where RC starts by saying "Wow that is a lot of ignorance!". Then a bit lower down he says "a proton is 1824 times heavier than an electron". The irony is rather splendid don't you think?

It's truly Alanis-Morissette-grade irony.

 

[Farsight]

Considering you did not understand the critique or ignored it, the irony is astounding. See if you can address the actual argument.

"By that standard, you could say anything decays to anything whatsoever with the same net quantum numbers. "

You failed to actually discuss this.

Because it's trash. Things decay into what they decay into. For example a neutral pion usually decays into two gamma photons in about 8.4 times ten to the minus seventeen seconds. It sometimes decays into one gamma photon and and an electron and a positron, but that's fairly rare, see wikipedia. You could arrange things so thet the electron and positron annihilate into two (or more) gamma photons. However two (or more) gamma photons will happily zip through space for a million years without magically "decaying" into a pion. A buckyball doesn't magically "decay" into a Higgs boson either. Hence saying anything decays to anything whatsoever with the same net quantum numbers is just pseudoscience twaddle. Any more trash you want me to waste my time on?

 

[Farsight]

A typo. RC was probably thinking about G.R. Kirchhoff's and William Thomson's birth year.

Yeah yeah. Just like his typo about mass and DD's typo about the strong force and ben's typo about buckyballs. And there's not one who will put his hands up and say Sorry, you're right Farsight, my mistake.

 

[ben m]

Because it's trash. Things decay into what they decay into. For example a neutral pion usually decays into two gamma photons in about 8.4 times ten to the minus seventeen seconds. It sometimes decays into one gamma photon and and an electron and a positron, but that's fairly rare, see wikipedia. You could arrange things so thet the electron and positron annihilate into two (or more) gamma photons. However two (or more) gamma photons will happily zip through space for a million years without magically "decaying" into a pion.

Farsight, the point is:

a) You seem to think that "p-pbar annihilates to photons" is:
a') true, and
b') an important statement about the nature of the strong force.

a'') You argue it's "true" by pretending that neutral pions might as well be photons, because that's what the neutral ones decay to, and the charged ones decay to stuff that you could re-collide later to get photons. Including, um, the neutrinos---well, technically yes, but good lord.

Whatever. More importantly.

b'') Your rearrangement cannot possibly contain any information about the strong, weak, or electromagnetic forces. Because it's a tautology. It's true for any particle whatsoever, known or hypothetical---muons, buckyballs, W-bosons, Higgs bosons, axions, charginos, technimesons, Z' bosons, the "video quark"---for any X, it is true that X-Xbar annihilation leads to (a) photons, (b) things that can decay to photons, and (c) pairs of things that could be made to annihilate to photons. It's just a conservation law.

Imagine someone saying "I understand the number 16 better than anyone else. Here's a hint: divide sixteen by all of its factors (2,2,2, and 2), and what do you get? One."

 

[Farsight]

Farsight, the point is:

a) You seem to think that "p-pbar annihilates to photons" is:
a') true, and
b') an important statement about the nature of the strong force.

I do actually. It's to do with unification.

a'') You argue it's "true" by pretending that neutral pions might as well be photons, because that's what the neutral ones decay to, and the charged ones decay to stuff that you could re-collide later to get photons. Including, um, the neutrinos---well, technically yes, but good lord.

It is true. Neutral pions have got nothing to do with it. I only referred to them whilst talking about decay in general. In proton-antiproton annihilation at rest there's various channels, one of them is gamma-gamma.

Whatever. More importantly.

b'') Your rearrangement cannot possibly contain any information about the strong, weak, or electromagnetic forces.

Don't be too sure about that.

Because it's a tautology. It's true for any particle whatsoever, known or hypothetical---muons, buckyballs, W-bosons, Higgs bosons, axions, charginos, technimesons, Z' bosons, the "video quark"---for any X, it is true that X-Xbar annihilation leads to (a) photons, (b) things that can decay to photons, and (c) pairs of things that could be made to annihilate to photons. It's just a conservation law.

And that fundamental strong force appears to have totally disappeared, doesn't it? But look carefully. You started out with a proton and an antiproton sitting there, at rest. They don't stay like that for long. After a little while you've got "protonium", which is akin to positronium. That doesn't last long either, but whilst it does, your strong force is alive and kicking. The proton and antiproton circle one another plughole-style, whilst overall the protonium "atom" is at rest. Then BANG, annihilation. (Yes pions predominate, but they don't last long and they cloud the issue, so let's focus on the gamma-gamma channel). What you've now got is two gamma photons. We think of the photon as being something that is purely electromagnetic in nature. But what's distinctive about it? You might point to charge, mass, spin, parity, but let's say you don't know anything about the photon's properties. There's something very obvious that distinguishes it from the proton. What is it?

Imagine someone saying "I understand the number 16 better than anyone else. Here's a hint: divide sixteen by all of its factors (2,2,2, and 2), and what do you get? One."

That's just another rubbish analogy ben. Do you want to talk about where does the strong force go or not? I think it's interesting myself. But I guess too many people here don't like talking physics, they like pulling the wings off flies instead.

 

[dafydd]

And there's not one who will put his hands up and say Sorry, you're right Farsight, my mistake.

You'll have a long wait for that.

 

[ben m]

In proton-antiproton annihilation at rest there's various channels, one of them is gamma-gamma.

No, there's really not. Annihilation goes to various combinations of pions, kaons, and other light mesons. Those mesons later decay; some of them decay to photons. If all the mesons happen to be neutral, the final state is may be indeed all photons, but the minimum number of photons is 4, not 2, from p pbar --> pi0 pi0.

p + pbar --> gamma gamma (i.e., 2 gammas and nothing else, like in e+e- annihilation) has never been observed. It probably occurs, but we expect extremely rarely due to a double dose of the OZI rule.

 

[Reality Check]

I've corrected RC on energy causing gravity.

You pointed out what was obvious and I already knew (and have mentioned elsewhere) - mass and energy in GR cause gravity.
Are you going to start to correct my speling missstakes also ?

 

[Reality Check]

"a proton is 1824 times heavier than an electron". The irony is rather splendid don't you think?

The typo is obvous don't you think?
The actual ratio is 1836.15267247:1

 

[Tubbythin]

p + pbar --> gamma gamma (i.e., 2 gammas and nothing else, like in e+e- annihilation) has never been observed. It probably occurs, but we expect extremely rarely due to a double dose of the OZI rule.

I'd always assumed it was because the proton and the anti-proton saw each other as 3 quarks (and all the sea quark stuff) each and so you have multiple interactions going on at once.

 

[ben m]

I'd always assumed it was because the proton and the anti-proton saw each other as 3 quarks (and all the sea quark stuff) each and so you have multiple interactions going on at once.

That's right. p-pbar annihilation looks quite a lot like the superposition of three separate "quark-antiquark" annihilations---if you can picture such a thing---plus some final state interactions. However, you *can* draw a diagram---try it!---in which two of the quark pairs annihilate to gluons, then those gluons get absorbed by the remaining pair, which annihilates to photons.

The OZI rule is a statement of the especial unlikelihood of this sort of diagram; it involves giving lots and lots of energy to a small number of gluons, which is disfavored by the structure of the QCD coupling.

 

[Tubbythin]

That's right. p-pbar annihilation looks quite a lot like the superposition of three separate "quark-antiquark" annihilations---if you can picture such a thing---plus some final state interactions. However, you *can* draw a diagram---try it!---in which two of the quark pairs annihilate to gluons, then those gluons get absorbed by the remaining pair, which annihilates to photons.

The OZI rule is a statement of the especial unlikelihood of this sort of diagram; it involves giving lots and lots of energy to a small number of gluons, which is disfavored by the structure of the QCD coupling.

I see (I think). After reading your previous post I checked out the OZI rule on Wikipedia. It didn't seem to agree with what I said above but I can kind of see the connection now. My assumption was roughly accurate but a bit simplistic... I think.

 

[Farsight]

Can I point out that gluons are virtual particles. Check it out. They aren't real particles like photons, neutrinos, electrons, and protons. We've never actually seen a gluon. We've seen pions, and muons, and other short-lived real particles, but not gluons.

Come on ben, don't fight shy of this. It's important. When we start with a proton and an antiproton at rest we don't actually see any gluons. When we end up with gamma photons we still don't actually see any gluons. Now what's particularly distinctive about a photon as opposed to a proton? Anybody?

 

[bjschaeffer]

So what? There is no massive body at the center of a positronium atom either, but an e+ and and e- will orbit each other just fine. There's no massive body at the center of a globular cluster. There's no massive body at the center of asteroid system 90 Antiope. Things that attract each other may form a bound state. There is nothing special about states where one of the things is massive and stays near the center.

OK that is a good objection but the difference between an atom and a nucleus remains.

The hypothesis of orbiting nucleons and the correlative strong force is only a word, nobody knows its fundamental laws and constants. The only solution able to predict the binding energy of a nucleus is the Coulomb's laws (or more generally Maxwell equations), without orbiting nucleons.

Indeed, for a simple nucleus like the deuteron, the nuclear potential has two parts, an electric attraction between the proton and the neutron like an electrized pen attracts small pieces of paper. The electric force is equilibrated by the magnetic repulsion between the proton and the neutron. A simple calculation by derivation of the corresponding potential gives a value of the binding energy of the deuteron 1.6 MeV for an experimental value of 2.2 MeV. A more precise numerical calculation taking into account the induced neutron dipole gives 2.1 MeV. I have calculated the hydrogen and helium isotopes. Of course, it becomes more complicated for heavier nuclides…

Here is the potentials and graph for ²H with and without the neutron dipole :
(α is the fine structure constant, m_p is the proton mass, c the light velocity R_P the proton Compton radius, g_n, g_p the Lande factors and r_np the separation distance between the centers of the proton and the neutron.

 

[bjschaeffer]

If you use a really simplistic (and wrong!) picture of nucleon's "orbiting" then what they "orbit" are the other nucleons! For example, Deuterium has 1 proton and 1 neutron. So in your anaolgy there are nucleons "orbiting" each other like two planets orbiting each other.

I never said that the deuteron is like two planets orbiting each other but exactly the contrary. The figure below shows the electromagnetic structure of the deuteron. The electrostatic attraction between the proton induced neutron dipole is equilibrated by the magnetic repulsion between the nucleons (opposite magnetic moments).