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north
2007-Jan-23, 04:08 AM
what stops it? inotherwords if protons come together, what stops them from just simply flowing through each other, continuously?

Tim Thompson
2007-Jan-23, 06:50 AM
... what stops them from just simply flowing through each other, continuously?
Electrostatic repulsion. They are both positively charged particles, and the repulsive power of the electric charge is enormous. Even at kinetic energies represented by the 15,000,000 Kelvin solar core temperature, only a small fraction of the protons available, in the high velocity wing of the distribution, are energetic enough to fuse together. And only a small fraction of those get close enough to each other anyway. That's how the sun (http://www.nineplanets.org/sol.html) manages to hang around the main sequence (http://en.wikipedia.org/wiki/Main_sequence) for 10,000,000,000 years or so.

Fusion only happens when the protons get so close to each other that the nuclear strong force (http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html#c2) can overpower the electromagnetic force, and pull them into fusion despite its resistence. That's also why large atomic nuclei have so many neutrons. The strong force from the neutrons keeps the positively charged protons from simply flying out of the nucleus by virtue of their mutual repulsion.


Solar Fusion & Neutrinos (http://www.tim-thompson.com/fusion.html)

north
2007-Jan-23, 07:50 AM
Electrostatic repulsion. They are both positively charged particles, and the repulsive power of the electric charge is enormous. Even at kinetic energies represented by the 15,000,000 Kelvin solar core temperature, only a small fraction of the protons available, in the high velocity wing of the distribution, are energetic enough to fuse together. And only a small fraction of those get close enough to each other anyway. That's how the sun (http://www.nineplanets.org/sol.html) manages to hang around the main sequence (http://en.wikipedia.org/wiki/Main_sequence) for 10,000,000,000 years or so.

Fusion only happens when the protons get so close to each other that the nuclear strong force (http://hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html#c2) can overpower the electromagnetic force, and pull them into fusion despite its resistence. That's also why large atomic nuclei have so many neutrons. The strong force from the neutrons keeps the positively charged protons from simply flying out of the nucleus by virtue of their mutual repulsion.


Solar Fusion & Neutrinos (http://www.tim-thompson.com/fusion.html)


Tim

the thing is though, and thanks for the site by the way, is that the explanation of proton-proton fusion does not seem to explain hydrogen proton-proton fusion. hence helium, which is the begining and the essence of all heavier elements.

so it seems the difficulty, is explaining the begining of the fusion process starting with hydrogen protons.

north
2007-Jan-23, 08:02 AM
Tim

further they talk of electrostatic forces( which are caused by friction) and electromagnetic forces( mechanical action)
I wonder what frictional forces, within the hydrogen atom are and what mechanical actions that are going on that would produce a electromagnetic forces.( or perhaps in this case is there a sort of permanent magnet within the proton? gluons perhaps)

Omicron Persei 8
2007-Jan-23, 08:15 AM
Tim

further they talk of electrostatic forces( which are caused by friction) and electromagnetic forces( mechanical action)
I wonder what frictional forces, within the hydrogen atom are and what mechanical actions that are going on that would produce a electromagnetic forces.( or perhaps in this case is there a sort of permanent magnet within the proton? gluons perhaps)

The electrostatic force discussion is only dealing with the fact that because protons are positively charged they naturally repel each other. Any pressure that can overcome the electrostatic repulsion (very high density of proton due to gravitation clumping..think of the sun) can cause protons to get close enough to each other for the strong nuclear force to attract them together, colliding and causing a fusion reaction.

north
2007-Jan-23, 08:45 AM
Originally Posted by north
Tim

further they talk of electrostatic forces( which are caused by friction) and electromagnetic forces( mechanical action)
I wonder what frictional forces, within the hydrogen atom are and what mechanical actions that are going on that would produce a electromagnetic forces.( or perhaps in this case is there a sort of permanent magnet within the proton? gluons perhaps)



The electrostatic force discussion is only dealing with the fact that because protons are positively charged they naturally repel each other.

but what is the essence of this electrostatic force? what physical actions does electrostatic force derive from?



Any pressure that can overcome the electrostatic repulsion (very high density of proton due to gravitation clumping..think of the sun) can cause protons to get close enough to each other for the strong nuclear force to attract them together, colliding and causing a fusion reaction.

the thing is though, is that the basis for the ability for protons to get close, is based on nucleons( protons with neutrons and the implied physics starts there ) of which hydrogen only has protons. hydrogen has no neutrons. here inlys the problem. how does proton-proton fusion take place in the hydrogen atom in absence of nucleons? it is not explained.

Sock puppet
2007-Jan-23, 12:21 PM
but what is the essence of this electrostatic force? what physical actions does electrostatic force derive from?

Physical actions? None. It simply is. Electric charge is a property which some particles possess, just like mass. Protons are positively charged, which causes them to repel each other.


the thing is though, is that the basis for the ability for protons to get close, is based on nucleons( protons with neutrons and the implied physics starts there ) of which hydrogen only has protons. hydrogen has no neutrons. here inlys the problem. how does proton-proton fusion take place in the hydrogen atom in absence of nucleons? it is not explained.

Neutrons and protons are both nucleons. Protons can fuse at the centre of the sun because at the massive temperatures present, very rarely a proton will have enough energy to overcome that repulsion.* Fortunately, with the mind boggling amounts of protons present there, even one pair fusing each second out of every 100,000,000,000,000,000 is good enough to produce lots of energy.

*And once they get close enough, the strong nuclear force [attractive] overwhelms the electrostatic force.

Squashed
2007-Jan-23, 03:12 PM
Physical actions? None. It simply is. Electric charge is a property which some particles possess, just like mass. Protons are positively charged, which causes them to repel each other.



Neutrons and protons are both nucleons. Protons can fuse at the centre of the sun because at the massive temperatures present, very rarely a proton will have enough energy to overcome that repulsion.* Fortunately, with the mind boggling amounts of protons present there, even one pair fusing each second out of every 100,000,000,000,000,000 is good enough to produce lots of energy.

*And once they get close enough, the strong nuclear force [attractive] overwhelms the electrostatic force.

I was reading somewhere that even though the overall charge of a neutron is zero that there are actual charge poles (+ - ) in the neutron due to the internal particle-structure of the neutron. I would imagine due to the particle-structure of protons that there would be poles of lesser positive charge on the proton also.

Tim Thompson
2007-Jan-23, 04:32 PM
... the thing is though, and thanks for the site by the way, is that the explanation of proton-proton fusion does not seem to explain hydrogen proton-proton fusion. hence helium, which is the begining and the essence of all heavier elements.
It does, and the explanation is given on the Solar Fusion & Neutrinos (http://www.tim-thompson.com/fusion.html) webpage. See the PPI chain (http://www.tim-thompson.com/fusion.html#ppI), the PPII chain (http://www.tim-thompson.com/fusion.html#ppII), and the PPIII chain (http://www.tim-thompson.com/fusion.html#ppIII) (the latter two are branches off the main PPI chain). When the 2 protons fuse, one changes to a neutron, forming a deuteron (neutron bound to proton). When a deuteron hits another proton, it forms a 3He nucleus. Finally, when two 3He nuclei hit each other, they form a 4He nucelus, with a couple of protons left over.


... further they talk of electrostatic forces (which are caused by friction) and electromagnetic forces (mechanical action)
Wrong on the first point. Electrostatic forces are not caused by friction. As Sock puppet already points out, electric charge is a fundamental property. All electrically charged particles repel each other if they have the same charge, and attract each other if they have opposite charges. All protons repel each other, simply because they have the same electric charge.

In general, electromagnetic forces come from putting charged particles in motion, so one might argue that mechanical action is responsible. But there is plenty of that; at 15,000,000 Kelvins, you can rest assured that the protons are moving very fast. But these electromagnetic forces are not a primary concern in this case. Fusion is all about getting things going fast enough to overcome electrostatic repulsion.


I was reading somewhere that even though the overall charge of a neutron is zero that there are actual charge poles (+ - ) in the neutron due to the internal particle-structure of the neutron. I would imagine due to the particle-structure of protons that there would be poles of lesser positive charge on the proton also.
The neutron does not have distinguishable charged poles in it, so far as I know. However, a free neutron will fall apart into a proton (+) and an electron (-), in about 10 minutes. When two protons fuse, one of them changes into a neutron, and in the process emits a positron (which amounts to a positively charged electron) to carry away the positive charge. It is also possible to have two protons meet coincidently with an electron. The resulting 3-body collision p+p+e- will also form a deuteron, but this is an extremely unlikely reaction (it's on the PPI table (http://www.tim-thompson.com/fusion.html#ppI)).

Squashed
2007-Jan-23, 10:00 PM
...

The neutron does not have distinguishable charged poles in it, so far as I know. However, a free neutron will fall apart into a proton (+) and an electron (-), in about 10 minutes. When two protons fuse, one of them changes into a neutron, and in the process emits a positron (which amounts to a positively charged electron) to carry away the positive charge. It is also possible to have two protons meet coincidently with an electron. The resulting 3-body collision p+p+e- will also form a deuteron, but this is an extremely unlikely reaction (it's on the PPI table (http://www.tim-thompson.com/fusion.html#ppI)).

Thanks for the reply, Tim Thompson.

It does seem unusual to think a neutron could have magnetic/charge poles but then you state, and I've read elsewhere, that the neutron will decay into a proton and an electron within 10 minutes of being ejected/isolated from a nucleus this makes me wonder how those two charges mixed or interacted within the neutron.

If the two opposite charges were thoroughly homogenized within the neutron then it would make it all the harder for the two charges to assume their separate identities during the decay process.

If the two opposite charges are in a dynamic relationship that is constantly oscillating then:

a.) the two charges can separate easily upon decay and
b.) there would be localized charge poles in the neutron.

Jeff Root
2007-Jan-23, 11:42 PM
A proton consists of two up quarks and a down quark.
A neutron consists of an up quark and two down quarks.

An up quark has an electric charge of 2/3.
A down quark has an electric charge of -1/3.

Proton = 2/3 + 2/3 - 1/3 = 1.
Neutron = 2/3 - 1/3 - 1/3 = 0.

-- Jeff, in Minneapolis

Squashed
2007-Jan-24, 01:22 AM
A proton consists of two up quarks and a down quark.
A neutron consists of an up quark and two down quarks.

An up quark has an electric charge of 2/3.
A down quark has an electric charge of -1/3.

Proton = 2/3 + 2/3 - 1/3 = 1.
Neutron = 2/3 - 1/3 - 1/3 = 0.

-- Jeff, in Minneapolis

When the neutron decays it seems like, from the above formulas, that a down quark must convert to a up quark by expelling an electron so that the end result is:

two up quarks and a down quark (a proton) plus an electron.

Spaceman Spiff
2007-Jan-24, 01:38 AM
That would be a rather energetic electron. The electron's rest mass is 0.511 MeV, whereas the rest mass difference between protons and neutrons (which aren't relativistic at the temperatures found in stars) is something like 2.2 MeV. So the electron kinetic energy would be need to be substantially higher than its rest mass.

Also, without quantum "tunneling", even those relatively few nuclei in the high-velocity Maxwellian tail that Tim Thompson mentioned would fail to fuse with anywhere near the frequency required to produce the energies in stars. At the temperatures found in the Sun's center, the mean K.E. of nuclei is something like ~2 keV, whereas the electromagnetic (or Coulomb) barrier is something like an MeV for p-p collisions.

And note that in the very early hot universe, free neutrons (with half lives of 10.2 minutes) were found aplenty, so p + n --> D + gamma worked just fine, on the way to making primordial helium.

Tobin Dax
2007-Jan-24, 01:48 AM
That would be a rather energetic electron. The electron's rest mass is 0.511 MeV, whereas the rest mass difference between protons and neutrons (which aren't relativistic at the temperatures found in stars) is something like 2.2 MeV. So the electron kinetic energy would be need to be substantially higher than its rest mass.

Isn't there a neutrino involved in there somewhere? I'm pretty sure that's true (but I don't want to look it up).

01101001
2007-Jan-24, 02:00 AM
When the neutron decays it seems like, from the above formulas, that a down quark must convert to a up quark by expelling an electron so that the end result is:

two up quarks and a down quark (a proton) plus an electron.

You trying to count "entities" again?

I asked you before (http://www.bautforum.com/showthread.php?p=906638#post906638) how you count entities in a neutron decaying into a proton, electron and antineutrino. So, are you aiming toward thinking a neutron is to begin with a trinity of entities? How theological!

Squashed
2007-Jan-24, 02:18 PM
You trying to count "entities" again?

I asked you before (http://www.bautforum.com/showthread.php?p=906638#post906638) how you count entities in a neutron decaying into a proton, electron and antineutrino. So, are you aiming toward thinking a neutron is to begin with a trinity of entities? How theological!

So when the neutron decays it becomes a proton, electron and anti-neutrino (I forgot about the antineutrino info in your post)?

I have no theological intent in my line of thought but if ya want to look at it that way then; yes, the neutron is theologically sound in its trinitarian existence (as Jeff Root points out): "A neutron consists of an up quark and two down quarks."

Mostly my numeralogical approach is a way of accounting. We can use entity count for preservation of mass-energy and/or we can use entity count for conservation of momentum and/or we can use entity count on the number of particles both before and after an event.

How a down quark converts into an up quark plus an electron and an anti-neutrino is a question that I would like to learn the answer to.

Maybe quarks have differing energy states and so the two down quarks in the neutron "slim down" and their shed mass-energy is used to create the electron and anti-neutrino - I don't know which is why I explore the process.

Thanks for the interesting viewpoint.

01101001
2007-Jan-24, 02:58 PM
I have no theological intent in my line of thought but if ya want to look at it that way then; yes, the neutron is theologically sound in its trinitarian existence (as Jeff Root points out): "A neutron consists of an up quark and two down quarks."

I'm still interested in what you consider an entity though, for if the pre-decay neutron is composed of three entities classified as quarks, then post decay we find ourselves with a proton also composed of three entities classified as quarks, plus the electron, plus the antineutrino. 3 becomes 5? What exactly do you consider to be an entity? Your books aren't balancing yet.

Squashed
2007-Jan-24, 03:08 PM
I'm still interested in what you consider an entity though, for if the pre-decay neutron is composed of three entities classified as quarks, then post decay we find ourselves with a proton also composed of three entities classified as quarks, plus the electron, plus the antineutrino. 3 becomes 5? What exactly do you consider to be an entity? Your books aren't balancing yet.

My use of the term: "entity"; is just a nondescriptive way of saying that the object in question is separate and distinct.

On the graphics system that I use any geometric object; such as a line, circle, point; is considered an "entity". Rather than being required to exactly specify what I want to delete I just enter the command: "Delete entity:"; and then pick the objects.

If you thought I was using the term "entity" to specify some god-like being then you are mistaken. I am using definition #2 NOT definition #1: http://www.miriamwebster.com/dictionary/entity

But now that you brought it up then if an electron is made up of 3 neutrinos then we have lots of 3s:

3 for the neutron,
3 for the proton,
3 for the electron and
3 for the atom.

Quite theologically sound!!!!!

tusenfem
2007-Jan-24, 03:28 PM
Sorry, Squashed, but an electron is made up of electronium, i.e. there is no division into neutrinos, that are neutral, so how would you get a minus charge anyway.

Squashed
2007-Jan-24, 03:52 PM
Sorry, Squashed, but an electron is made up of electronium, i.e. there is no division into neutrinos, that are neutral, so how would you get a minus charge anyway.

Well, so much for the theology lesson.

Anyways, using Jeff Root's quark accounting then couldn't an electron be made from 3 down quarks:

(-1/3) + (-1/3) + (-1/3) = -1

whether the mass-energy of these three quarks works out correctly for the electron mass-energy, I do not know.

If the mass-energy does not work out (and I suspect it does not) then it seems like there is a smaller entity of negative charge than the quark and whether this is a "unit" of electronium then that would be something I would like to learn.

Spaceman Spiff
2007-Jan-24, 03:57 PM
Isn't there a neutrino involved in there somewhere? I'm pretty sure that's true (but I don't want to look it up).

Yep. You need to conserve leptons (and charge and baryons and mass/energy):

p + e- --> n + electron neutrino.

But this requires a lot of kinetic energy on the part of the electron (it's gotta be relativistic).

01101001
2007-Jan-24, 04:21 PM
My use of the term: "entity"; is just a nondescriptive way of saying that the object in question is separate and distinct.
If you thought I was using the term "entity" to specify some god-like being then you are mistaken.

Heaven forfend I should think that. I was thinking you were using it in a vague and undefined way. That's why I ask you to clarify. I've come to believe you'll call anything an entity in order to make your hypothesized Conservation of Entity Count (my naming) behave. Help me understand your speculation. But, maybe do it in ATM. It is pure speculation, right?


But now that you brought it up then if an electron is made up of 3 neutrinos then we have lots of 3s:

3 for the neutron,
3 for the proton,
3 for the electron and
3 for the atom.

Quite theologically sound!!!!!

Yes. It is a miracle. 3 Squashed-entities become 9. How do you balance the books?

Squashed
2007-Jan-24, 04:44 PM
Heaven forfend I should think that. I was thinking you were using it in a vague and undefined way. That's why I ask you to clarify. I've come to believe you'll call anything an entity in order to make your hypothesized Conservation of Entity Count (my naming) behave. Help me understand your speculation. But, maybe do it in ATM. It is pure speculation, right?

Yes. It is a miracle. 3 Squashed-entities become 9. How do you balance the books?

I liked your post and I also like your "Conservation of Entity Count".

I suppose I could just ask direct questions but as I have said before I am not a particle physicist and so I do not always know what questions to ask or what terminology to use.

I speculate hoping for correction if the item of speculation is already known but if it is unknown then speculation is all we have.

I would balance the books, first, by mass-energy conservation; second by momentum conservation; third by charge conservation and fourth by entity count.

By looking at the entity count from decay events and annihilation events one, supposedly, should be able to derive a base integer/fraction in which all assemblies (whether atomic, or subatomic like quarks) have in common.

Once this is identified then identifying the specifics that the base entity(ies) have would be next: maybe all have the same mass-energy but one is positively charged and one is negatively charged; which would mean the universe is built from only two components.

The big bang either started as pure electromagnetic radiation (light), or pure particles, or a mixture of electromagnetic radiation and particles.

If it started from pure electromagnetic radiation then the base particle is the photon and how charges were created from photons becomes a major question.

If the big bang started from pure particles then what is the "sub-particle" that makes photons?

If the big bang started from a mixture then we can only hope to find the basic particle and the light is just a continuum of energy flow.

korjik
2007-Jan-24, 04:59 PM
Well, so much for the theology lesson.

Anyways, using Jeff Root's quark accounting then couldn't an electron be made from 3 down quarks:

(-1/3) + (-1/3) + (-1/3) = -1

whether the mass-energy of these three quarks works out correctly for the electron mass-energy, I do not know.

If the mass-energy does not work out (and I suspect it does not) then it seems like there is a smaller entity of negative charge than the quark and whether this is a "unit" of electronium then that would be something I would like to learn.

Dosent work that way. An electron isnt made up of quarks, but is a completely different kind of particle all together. That is about the first thing looked for after someone realized that a proton has structure. An electron is still a point like object (namely we dont have the resolution to get a radius) that has no internal structure.

Squashed
2007-Jan-24, 05:13 PM
Dosent work that way. An electron isnt made up of quarks, but is a completely different kind of particle all together. That is about the first thing looked for after someone realized that a proton has structure. An electron is still a point like object (namely we dont have the resolution to get a radius) that has no internal structure.

Is the cummulative charge of the 3 down quarks equivalent to the charge of an electron?

Particle physicists use -1/3 as the charge of the down quarks, does the 1/3 fraction have any significance to the amount of charge or is the 1/3 a kind of shorthand notation?

If the 1/3 fraction is directly proportional to the total charge of the electron then it would seem like either there are two "substances" that display the negative charge characteristic (one for the electron and one for the quark) or the electron charge is sub-divideable.

korjik
2007-Jan-24, 05:27 PM
Is the cummulative charge of the 3 down quarks equivalent to the charge of an electron?

Particle physicists use -1/3 as the charge of the down quarks, does the 1/3 fraction have any significance to the amount of charge or is the 1/3 a kind of shorthand notation?

If the 1/3 fraction is directly proportional to the total charge of the electron then it would seem like either there are two "substances" that display the negative charge characteristic (one for the electron and one for the quark) or the electron charge is sub-divideable.

Three anti-up and an anti-down quark also have a charge of -1. That would be an antiproton. I think 2 strange and an anti-down also are charge -1 also. There are alot of ways to get a charge of -1. The fact that 3 down are also charge -1 isnt really relevant. Any lepton is a completely different type of particle from any hadron. Leptons are not made up of quarks.

Physicists use -1/3 as the charge of a down quark because the amount of charge is 1/3 that of an electron. The electron became the standard for charge between its discovery and the discovery of quarks.

As far as I know electrons, anti-muons, anti-tauons, down quarks, anti-up quarks, strange quarks, anti-charm quarks, bottom quarks and anti-top quarks all have negative charge, just like all their anti particles are positive charge.

Charge is a basic property of the universe. There isnt some magical substance that is 'charge' but alot of things that have charge as a property, just like spin is a basic property of the universe.

Squashed
2007-Jan-24, 05:39 PM
Three anti-up and an anti-down quark also have a charge of -1. That would be an antiproton. I think 2 strange and an anti-down also are charge -1 also. There are alot of ways to get a charge of -1. The fact that 3 down are also charge -1 isnt really relevant. Any lepton is a completely different type of particle from any hadron. Leptons are not made up of quarks.

Physicists use -1/3 as the charge of a down quark because the amount of charge is 1/3 that of an electron. The electron became the standard for charge between its discovery and the discovery of quarks.

As far as I know electrons, anti-muons, anti-tauons, down quarks, anti-up quarks, strange quarks, anti-charm quarks, bottom quarks and anti-top quarks all have negative charge, just like all their anti particles are positive charge.

Charge is a basic property of the universe. There isnt some magical substance that is 'charge' but alot of things that have charge as a property, just like spin is a basic property of the universe.

I know I need to look into this further on my own (unless lots of other viewers want to go through my painfully slow learning process) but there is one question that I would like answered, for now: Is there a particle with a fractional electron charge that is less than 1/3 (like 1/6 or 1/12)?

korjik
2007-Jan-24, 07:27 PM
nope

crosscountry
2007-Jan-24, 08:20 PM
what stops it? inotherwords if protons come together, what stops them from just simply flowing through each other, continuously?


Fermi says no. And there is of course the Pauli Exlusion Principle (http://hyperphysics.phy-astr.gsu.edu/hbase/pauli.html)

Sorry if I'm late

Squashed
2007-Jan-24, 09:22 PM
nope

Thanks for the answer.

So would it be reasonable to state that the smallest negative charge-size is 1/3 of the electron's charge?

And is this also a reasonable statement for the smallest positive charge (except for the opposite sign)?

In other words we can not divide charges into smaller units than the 1/3 electron charge?

Sock puppet
2007-Jan-25, 02:37 PM
Thanks for the answer.

So would it be reasonable to state that the smallest negative charge-size is 1/3 of the electron's charge?

And is this also a reasonable statement for the smallest positive charge (except for the opposite sign)?

In other words we can not divide charges into smaller units than the 1/3 electron charge?

Currently, yes. We know of no particles which have charge in smaller units than this.

korjik
2007-Jan-25, 07:19 PM
Thanks for the answer.

So would it be reasonable to state that the smallest negative charge-size is 1/3 of the electron's charge?

And is this also a reasonable statement for the smallest positive charge (except for the opposite sign)?

In other words we can not divide charges into smaller units than the 1/3 electron charge?

As far as I know thirds is the smallest fraction. Any real free particle must have an integer charge tho. Quarks are virtually impossible to free, so you wont find fractional charges in particles. I think, but dont know, that a quark-gluon plasma is the only place that a quark may be free, but I would also bet that any direct measurment of a free quark is impossible, and that all you could see is decay products.

Squashed
2007-Jan-25, 07:26 PM
As far as I know thirds is the smallest fraction. Any real free particle must have an integer charge tho. Quarks are virtually impossible to free, so you wont find fractional charges in particles. I think, but dont know, that a quark-gluon plasma is the only place that a quark may be free, but I would also bet that any direct measurment of a free quark is impossible, and that all you could see is decay products.

I was reading about quarks over in Wikipedia and I believe that you are correct that a quark can never exist in a free state (half-life of zero???).

It was after reading about the Standard Model (http://en.wikipedia.org/wiki/Proton_decay) at Wiki that my mind turned to the question: "What is a true entity?" and hence this thread came to be: The Law of Conservation of Entity Count (http://www.bautforum.com/showthread.php?t=52908)