How do gluons work?

[vuquta]

Gluons are the mechanism. It doesn't answer the question of why the force exists. But if that's what you want, the proposed particle for gravitation is the graviton.

 

OK, how does the gluon work?

 

It is an exchange particle I know. But, do you have additional info?

[ajb]

In Electrodynamics you think of the electron charge as being the "reason" for the electromagnetic force. (Electrons act as sources) In a similar way, you can think of energy and momentum as being the "reason" for gravity. In QCD (or other Yang-Mills theories) the quarks act as sources because they have colour charge.

 

The important thing is that photons are electromagnetically neutral. Thus, electrodynamics is a linear theory. However in QCD the gluons carry colour charge and thus the theory is non-linear. This makes QCD much harder to deal with.

 

You may now ask what happens in general relativity? The theory is non-linear and gravitons carry energy. However, you cannot write down a localised energy-momentum tensor for the gravitational field. So, things are more subtle. For sure "morally" the theory resembles QCD.

[vuquta]

In Electrodynamics you think of the electron charge as being the "reason" for the electromagnetic force. (Electrons act as sources) In a similar way, you can think of energy and momentum as being the "reason" for gravity. In QCD (or other Yang-Mills theories) the quarks act as sources because they have colour charge.

 

The important thing is that photons are electromagnetically neutral. Thus, electrodynamics is a linear theory. However in QCD the gluons carry colour charge and thus the theory is non-linear. This makes QCD much harder to deal with.

 

You may now ask what happens in general relativity? The theory is non-linear and gravitons carry energy. However, you cannot write down a localised energy-momentum tensor for the gravitational field. So, things are more subtle. For sure "morally" the theory resembles QCD.

 

OK, if the gluons deal in this color charge, then how does the implementation of the strong nuclear force due to gravity (stars) emit so many photons?

[ajb]

OK, if the gluons deal in this color charge, then how does the implementation of the strong nuclear force due to gravity (stars) emit so many photons?

 

I don't follow what you are asking.

 

Gluons are electromagnetically neutral and so don't couple directly to the electromagnetic field.

 

Quarks do carry electric charge.

 

Anything with energy will couple to the gravitational force, this includes quarks, gluons, electrons, photons etc.

[Severian]

OK, if the gluons deal in this color charge, then how does the implementation of the strong nuclear force due to gravity (stars) emit so many photons?

 

This is due to confinement. Because the gluons carry a color charge, the strong force behaves differently from QED. In QED, as you move two charged particles apart, the force between them becomes weaker; but in QCD it becomes stronger. (The proof of this won the Nobel Prize a few years ago.)

 

This means that a gluon emitted by, say, the sun would not get very far before being pulled back by the strong force. Strongly interacting particles can be emitted but only in colorless combinations, which are then massive and don't get very far.

 

In other words, the photons escape because they are not charged.

[vuquta]

This is due to confinement. Because the gluons carry a color charge, the strong force behaves differently from QED. In QED, as you move two charged particles apart, the force between them becomes weaker; but in QCD it becomes stronger. (The proof of this won the Nobel Prize a few years ago.)

 

This means that a gluon emitted by, say, the sun would not get very far before being pulled back by the strong force. Strongly interacting particles can be emitted but only in colorless combinations, which are then massive and don't get very far.

 

In other words, the photons escape because they are not charged.

 

OK, normally, photons are exchange "particles" responsible for the electromagnetic force.

How are you gotting these mixed into the strong nuclear force. Oh, and you need so many also.

[Severian]

The photon has nothing to do with the strong interaction.

 

In stars, the first interaction in the fusion chain is a weak interaction that turns two protons into deuterium, a positron and a neutrino. The positron then annihilates with a nearby electron to form a photon. That is an electromagnetic interaction, and provides the photons we see (well, some of them anyway - there are other sources from interactions further down the chain).

[vuquta]

The photon has nothing to do with the strong interaction.

 

In stars, the first interaction in the fusion chain is a weak interaction that turns two protons into deuterium, a positron and a neutrino. The positron then annihilates with a nearby electron to form a photon. That is an electromagnetic interaction, and provides the photons we see (well, some of them anyway - there are other sources from interactions further down the chain).

 

Clearly in the sun we are not dealing with atoms. So, the problem of where the photon comes from is we need an electon nearby and then we can get a photon.

 

One photon per strong nuclear force implementation of one nucleus.

 

Does not sound like a lot. How do you explain that?

 

Further, are you suggesting if no electons are around for fusion, then no energy is created? Has this been experimentally verified?

[Severian]

Clearly in the sun we are not dealing with atoms. So, the problem of where the photon comes from is we need an electon nearby and then we can get a photon.

 

When you ionise a gas the electrons don't go anywhere - they are just not bound to the protons any more. There are still plenty of them.

 

One photon per strong nuclear force implementation of one nucleus.

 

Does not sound like a lot. How do you explain that?

 

There are plenty more steps in the pp-chain. Take a look at the Wiki page if you like.

 

Further, are you suggesting if no electons are around for fusion, then no energy is created? Has this been experimentally verified?

 

There is certainly no energy 'created' at any stage in the fusion process. However there is energy released already in the initial pp interaction, in the form of kinetic energy of the positron and neutrino.

Edited September 6, 2010 by Severian

[vuquta]

When you ionise a gas the electrons don't go anywhere - they are just not bound to the protons any more. There are still plenty of them.

Yea, any experiments to validate this claim?

 

 

 

There are plenty more steps in the pp-chain. Take a look at the Wiki page if you like.

 

Energy release

Comparing the mass of the final helium-4 atom with the masses of the four protons reveals that 0.007 or 0.7% of the mass of the original protons has been lost. This mass has been converted into energy, in the form of gamma rays and neutrinos released during each of the individual reactions. The total energy yield of one whole chain is 26.73 MeV.

 

OK I am not seeing the photons. In the real world, we see lots of these with the sun.

 

 

 

There is certainly no energy 'created' at any stage in the fusion process. However there is energy released already in the initial pp interaction, in the form of kinetic energy of the positron and neutrino.

 

One could make this same statement about the destructions of the covalent bond but certainly, it does not compare to the implementation of the strong nuclear force.

 

How does this reconcile with Einsteins's mass energy equivalence equation?

It does not mention all this stuff, but we used this as a justificatiuon to create the "bomb".

 

It seems you are missing something.

[swansont]

 

 

Comparing the mass of the final helium-4 atom with the masses of the four protons reveals that 0.007 or 0.7% of the mass of the original protons has been lost. This mass has been converted into energy, in the form of gamma rays and neutrinos released during each of the individual reactions. The total energy yield of one whole chain is 26.73 MeV.

 

OK I am not seeing the photons. In the real world, we see lots of these with the sun.

 

 

Proton + Deuteron gives He-3 plus a gamma

 

There's also blackbody radiation. It's not part of the fusion process.

 

One could make this same statement about the destructions of the covalent bond but certainly, it does not compare to the implementation of the strong nuclear force.

 

How does this reconcile with Einsteins's mass energy equivalence equation?

It does not mention all this stuff, but we used this as a justificatiuon to create the "bomb".

 

It seems you are missing something.

 

No, Severian is not missing something. Mass is a form of energy. Reactions resulting in a change in mass are not "creating" energy, they are converting it to other forms.

[Severian]

Yea, any experiments to validate this claim?

 

Of course. It is also pretty self evident, since the sun has no net charge.

 

Comparing the mass of the final helium-4 atom with the masses of the four protons reveals that 0.007 or 0.7% of the mass of the original protons has been lost. This mass has been converted into energy, in the form of gamma rays and neutrinos released during each of the individual reactions. The total energy yield of one whole chain is 26.73 MeV.

 

OK I am not seeing the photons. In the real world, we see lots of these with the sun.

 

Look back at the text you copied: "...in the form of gamma rays..." Gamma rays are photons.

 

 

How does this reconcile with Einsteins's mass energy equivalence equation?

 

If you measure the mass of the starting particles and then measure the mass of the final particles, you will see there is a mismatch. The mass of the final particles is less. If the difference in mass is say [math]\Delta m[/math] then the energy released is [math]\Delta mc^2[/math], exactly as per Einstein's mass-energy equivalence.

[vuquta]

Of course. It is also pretty self evident, since the sun has no net charge.

 

How is this verified?

 

Further, even if it is, how do we have the fusion greater in energy than say the covalent bond?

 

Your logic does not explain it.

 

 

If you measure the mass of the starting particles and then measure the mass of the final particles, you will see there is a mismatch. The mass of the final particles is less. If the difference in mass is say [math]\Delta m[/math] then the energy released is [math]\Delta mc^2[/math], exactly as per Einstein's mass-energy equivalence.

 

I thought photons had zero mass.

 

So, how does this work out under the Einstein mass-energy equivalence?

[swansont]

 

I thought photons had zero mass.

 

So, how does this work out under the Einstein mass-energy equivalence?

 

They do. Mass is not conserved. When a system releases a photon, the system's mass decreases, in accordance with E=mc^2

[Severian]

How is this verified?

 

If the sun was made up of protons and no electrons, it would fly apart. The electromagnetic force is much stronger than gravity.

 

Further, even if it is, how do we have the fusion greater in energy than say the covalent bond?

 

Your logic does not explain it.

 

Which covalent bond are you talking about? These objects are ions - just the nucleus. There is no covalent bonding going on here.

 

I thought photons had zero mass.

 

So, how does this work out under the Einstein mass-energy equivalence?

 

The original pp fusion contains no photon. The mass difference is that between 2 protons and a dueterium nucleus (+ positron). The photon only comes about when the positron annihilated with an electron.

[swansont]

Further, even if it is, how do we have the fusion greater in energy than say the covalent bond?

 

 

Nuclear interactions are stronger than electrostatic ones (as evidenced by the fact that nuclei exist despite electrostatic repulsion). So nuclear interactions will generally involve higher energies than chemical ones.

[vuquta]

If the sun was made up of protons and no electrons, it would fly apart. The electromagnetic force is much stronger than gravity.

What? The strong nuclear force keeps the nuclii together..

 

Also, to date in the natural universe, only gravity has the ability to force nuclii together to implement the strong nuclear force.

 

 

 

Which covalent bond are you talking about? These objects are ions - just the nucleus. There is no covalent bonding going on here.

No, this is not what I was talking about. You claimed the implementation of fusion created one photon. Then, the breakdown of the covalent bond produces one photon. Yet fusion > chemical operations.

 

 

The original pp fusion contains no photon. The mass difference is that between 2 protons and a dueterium nucleus (+ positron). The photon only comes about when the positron annihilated with an electron.

 

Still does not work. You do not have enough photons to explain the sun.

[Severian]

What? The strong nuclear force keeps the nuclii together..

 

The strong force binds the protons and neutrons together to form nuclei, but these nuclei are then positively charged and will repel one another.

 

No, this is not what I was talking about. You claimed the implementation of fusion created one photon. Then, the breakdown of the covalent bond produces one photon. Yet fusion > chemical operations.

 

The energy released in a chemical reaction is much much smaller than that released in a nuclear one. The number of photons has nothing to do with it.

 

Still does not work. You do not have enough photons to explain the sun.

 

Rather than just disagreeing with no explanation, wouldn't it be more constructive to say why you think there would not be enough "photons to explain the sun"?

[swansont]

 

Still does not work. You do not have enough photons to explain the sun.

 

You can make as many of them as you want; photon number is not conserved. As I mentioned before, there is blackbody radiation to consider.

[vuquta]

The strong force binds the protons and neutrons together to form nuclei, but these nuclei are then positively charged and will repel one another.

 

 

 

The energy released in a chemical reaction is much much smaller than that released in a nuclear one. The number of photons has nothing to do with it.

 

 

 

Rather than just disagreeing with no explanation, wouldn't it be more constructive to say why you think there would not be enough "photons to explain the sun"?

 

Yea, I have all this figured out.

 

I have been working to explain where the photons come from in fusion vs chemical reactions.

Your first answer for fusion produced a photon for each fused nucleus which is wrong. I showed why.

 

So, I am trying to figures the soyrce of all the photons for a fused nucleus. It is that simple.

 

You can make as many of them as you want; photon number is not conserved. As I mentioned before, there is blackbody radiation to consider.

 

This sounds very silly.

 

You cannot make all you want, because they are particles. You must functionally create them somehow.

 

I am looking for that function.

[swansont]

 

This sounds very silly.

 

You cannot make all you want, because they are particles. You must functionally create them somehow.

 

I am looking for that function.

 

I don't care if it sounds silly to you. Photon number is not a conserved quantity. A laser is simple proof that you can create photons. And I've already mentioned the way they are created: it's blackbody radiation.

[vuquta]

I don't care if it sounds silly to you. Photon number is not a conserved quantity. A laser is simple proof that you can create photons. And I've already mentioned the way they are created: it's blackbody radiation.

 

OK, I am getting somewhere.

 

Show me how to invent/create Photons.

 

The context is nuclear fusion for photon creation since that is really the problem, but I will take anything.

[granpa]

any accelerating charge will emit electromagnetic radiation.

This is very basic stuff. If you dont understand even this then maybe you shouldnt be trying to figure out nuclear fusion.

You would probably be better of studying the basics first.

I very much doubt that anyone here is going to take the time to try to explain fusion to you when you dont even understand something as simple as charges emitting electromagnetic radiation.

[swansont]

OK, I am getting somewhere.

 

Show me how to invent/create Photons.

 

The context is nuclear fusion for photon creation since that is really the problem, but I will take anything.

 

As granpa has said, you accelerate a free charge. Or, you can have some sort of transition: atomic, molecular or nuclear de-excitation. Or you can annihilate matter and antimatter.

 

The sun, being a plasma, has lots of charges bouncing around, undergoing accelerations when they scatter.

[vuquta]

any accelerating charge will emit electromagnetic radiation.

This is very basic stuff. If you dont understand even this then maybe you shouldnt be trying to figure out nuclear fusion.

You would probably be better of studying the basics first.

I very much doubt that anyone here is going to take the time to try to explain fusion to you when you dont even understand something as simple as charges emitting electromagnetic radiation.

 

Thank you grandpa, but I know accelerating electrons will emit photons as well as chemical reactions.

 

These are very minor sources don't you agree? It they were not, then our energy troubles would have been over a long time ago.

 

So, where is this tremendous source of photons for nuclear fusion come from?