Interactions and intersections between force-fields

[lemur]

The Earth's gravity field, like its magnetic field, seems to be a conglomerate field consisting of numerous point-centered sources of force. In the case of magnetism, the polarization of individual atoms seem to unify into a single (macro) magnetic field and I assume the same is the case for gravity, i.e. the macro gravitational field is a unified field constituted from the many tiny gravitational fields of individual particles of matter.

 

Obviously two magnetic fields from two magnets can "pass through" each other and even intersect completely (at least relatively so to the extent that two magnets can be placed together with repellant poles facing each other. It also seems that the gravitational fields of the Earth, moon, and sun all more or less intersect to some extent. So this makes me wonder if there is any such thing as a fixed-boundary particle that does not intersect with other particles in any way - Or are all particles/fields capable of intersecting with each other to varying degrees?

 

This question becomes really interesting to me when I think of electrons, protons, or neutrons (sorry, I don't have much of a feel for leptons, quarks, muons, etc.) It seems that electrons avoid intersecting completely because of their repellant charge, and I assume protons do the same, but why wouldn't neutrons simply intersect to the point of merging with each other or other kinds of particles? A related but someone parallel question is what neutrons actually are except for a unit of gravitational field-force?

 

Am I exaggerating this idea that particles/fields don't have fixed boundaries because it is new to me? Is this a well-known and widely studied fact that fields and particles intersect to varying degrees in their interactions? Does it ultimately make any difference in the physics and if not, why not?

[swansont]

Fields follow the principle of superposition — they add, (as vectors for vector fields) leaving you with a unique field strength and direction at every point. How they start and end at certain points depends on the math involved. Electric fields, for example, start and end on charges. Magnetic fields loop back on themselves.

 

Neutrons do not have the right properties to be the force carrier for gravity.

[lemur]

Fields follow the principle of superposition — they add, (as vectors for vector fields) leaving you with a unique field strength and direction at every point. How they start and end at certain points depends on the math involved. Electric fields, for example, start and end on charges. Magnetic fields loop back on themselves.

My impression is that magnetism is the result of some asymmetry in the distribution of electron force around atoms, and I thought that this was related to how a moving electric field results in magnetism, i.e. because the waves of charge result in relative dense and less-dense regions of negative charge, which in turn allow the positive charge of the protons to express itself as the positive pole of the magnetic field. Is this misconstrued?

 

Neutrons do not have the right properties to be the force carrier for gravity.

 

I'm not sure what you mean by "force carrier for gravity." I assume you are talking about the possibility of gravitons as tiny particles that transmit gravitational force within a larger gravitational field. I don't really understand the logic of why it is necessary for a tiny particle to transmit gravity away from whatever its source may be. Is such a particle necessary for electrons to be surrounded by electrostatic force, or is an electrostatic field static?

 

Since I tend to think of a gravity field as static (although I have heard the Einstein said that gravity radiates at the speed of light from its source), I think of particles with mass (and probably photons as well) as having gravitational field-force surrounding them. Thus, while an electron and a proton seem to be special in that they display both electrostatic and gravitational force, the neutron doesn't have any electrostatic force, correct? It has only nuclear force and, I assume, gravitation. Could such a particle exist that exhibits only gravitation and no nuclear force? That would make no sense to me since all sub-atomic particles seem to be attracted to each other to form atoms, which requires nuclear and/or electrostatic force, correct? What would an exclusively gravitational particle do as it neared nuclear particles with gravity and nuclear force? Would it somehow interact with them gravitationally while being immune from nuclear attraction?

[swansont]

My impression is that magnetism is the result of some asymmetry in the distribution of electron force around atoms, and I thought that this was related to how a moving electric field results in magnetism, i.e. because the waves of charge result in relative dense and less-dense regions of negative charge, which in turn allow the positive charge of the protons to express itself as the positive pole of the magnetic field. Is this misconstrued?

It's the magnetic field of the unpaired electrons that are present in a ferromagnetic material, owing to the spin of the electrons and being present in a metallic lattice..

 

I'm not sure what you mean by "force carrier for gravity." I assume you are talking about the possibility of gravitons as tiny particles that transmit gravitational force within a larger gravitational field. I don't really understand the logic of why it is necessary for a tiny particle to transmit gravity away from whatever its source may be. Is such a particle necessary for electrons to be surrounded by electrostatic force, or is an electrostatic field static?

 

Since I tend to think of a gravity field as static (although I have heard the Einstein said that gravity radiates at the speed of light from its source), I think of particles with mass (and probably photons as well) as having gravitational field-force surrounding them. Thus, while an electron and a proton seem to be special in that they display both electrostatic and gravitational force, the neutron doesn't have any electrostatic force, correct? It has only nuclear force and, I assume, gravitation. Could such a particle exist that exhibits only gravitation and no nuclear force? That would make no sense to me since all sub-atomic particles seem to be attracted to each other to form atoms, which requires nuclear and/or electrostatic force, correct? What would an exclusively gravitational particle do as it neared nuclear particles with gravity and nuclear force? Would it somehow interact with them gravitationally while being immune from nuclear attraction?

 

Changes in the gravitational field propagate at the speed of light.

 

A neutron has no charge but it does have a magnetic moment, so it does interact via the electromagnetic force.

 

Dark matter is hypothesized to interact only gravitationally. It would not interact via the means.

[lemur]

It's the magnetic field of the unpaired electrons that are present in a ferromagnetic material, owing to the spin of the electrons and being present in a metallic lattice..

So the electrons basically pair-up and neutralize the direction of each other's charge, and when they don't spin symmetrically, the charge becomes denser in one direction leaving the positive charge of the protons dominant in the other direction? I don't really know what is meant by the word, "lattice," although I read it fairly often. Does it just refer to the layout of the electrons within the atomic/molecular configuration of a particular material? Does this mean that the configuration of the atoms in the metal influence its magnetism? I know, for example, that heat or jarring affects magnetism, and I assumed that it was because the individual particles got knocked-out of alignment or something like that.

 

Changes in the gravitational field propagate at the speed of light.

So it is the force-density changes that propagate at C, not the force itself? I had the impression that people were saying that the only reason the moon stays in orbit around the Earth, for example, is because the Earth is radiating some kind of undetectable particles called "gravitons" that cause the moon to be attracted toward the Earth when they reach it. That sounds implausible to me. I'm more inclined to believe that a gravitational field is a static envelope of force surrounding matter and that such envelopes interact with each other directly instead of needing to reach the EM/nuclear part of the matter.

 

A neutron has no charge but it does have a magnetic moment, so it does interact via the electromagnetic force.

Thanks, I didn't know that. How can EM force exist without polarity/charge?

 

Dark matter is hypothesized to interact only gravitationally. It would not interact via the means.

So it would be pure gravitational force? Would it have inertia? What would cause it to move except gravitational attraction to other gravity fields? If nothing, how would it ever move away from any gravity field it was near?

 

 

[swansont]

So the electrons basically pair-up and neutralize the direction of each other's charge, and when they don't spin symmetrically, the charge becomes denser in one direction leaving the positive charge of the protons dominant in the other direction? I don't really know what is meant by the word, "lattice," although I read it fairly often. Does it just refer to the layout of the electrons within the atomic/molecular configuration of a particular material? Does this mean that the configuration of the atoms in the metal influence its magnetism? I know, for example, that heat or jarring affects magnetism, and I assumed that it was because the individual particles got knocked-out of alignment or something like that.

 

The spin directions of the electrons line up, so the fields add. A lattice is a regular pattern/grid/framework of the atoms. Without that framework, the spins would orient randomly, and this happens when the temperature is high enough; that's known as the Curie temperature

http://en.wikipedia.org/wiki/Curie_temperature

 

So it is the force-density changes that propagate at C, not the force itself? I had the impression that people were saying that the only reason the moon stays in orbit around the Earth, for example, is because the Earth is radiating some kind of undetectable particles called "gravitons" that cause the moon to be attracted toward the Earth when they reach it. That sounds implausible to me. I'm more inclined to believe that a gravitational field is a static envelope of force surrounding matter and that such envelopes interact with each other directly instead of needing to reach the EM/nuclear part of the matter.

 

You are mixing models. Under relativity, the curvature of space is static. The interaction propagates at c, but without the source accelerating, the space is already curved where you are going, so you would not notice the propagation speed. Under a quantum theory, the effect would be due to gravitons.

 

The effect is not due to the EM or nuclear interaction.

 

Thanks, I didn't know that. How can EM force exist without polarity/charge?

 

Neutrons have an internal charge distribution, since they are made of charged quarks. That gives rise to the magnetic moment.

 

So it would be pure gravitational force? Would it have inertia? What would cause it to move except gravitational attraction to other gravity fields? If nothing, how would it ever move away from any gravity field it was near?

 

It would have mass. D H has already pointed out that inertia is an ambiguous term and isn't used anymore (by itself at least).

 

Motion does not require a force, acceleration does. And it would be accelerated due to gravitational force.

[lemur]

The spin directions of the electrons line up, so the fields add. A lattice is a regular pattern/grid/framework of the atoms. Without that framework, the spins would orient randomly, and this happens when the temperature is high enough; that's known as the Curie temperature

http://en.wikipedia....rie_temperature

So it is the alignment of the directions the electrons themselves spin in that cause the magnetism and it has nothing to do with their revolutions around the nuclei? I don't understand the concept of electrons spinning. Does this cause their fields to have angular momentum which results in a form of charge-motion, which in turn results in a magnetic field similar to that caused by electric charge moving through a conductor? Only in the case of the spinning electrons, the charge is moving in a circle instead of linearly between electrodes?

 

You are mixing models. Under relativity, the curvature of space is static. The interaction propagates at c, but without the source accelerating, the space is already curved where you are going, so you would not notice the propagation speed. Under a quantum theory, the effect would be due to gravitons.

Well, I guess I am just comparing the models in terms of intuitive plausibility. It doesn't make sense to me that a gravity field would consist of lots of smaller particles transmitting the gravitational force. If that was the case, then wouldn't there have to be little electromagnetic force carrier particles emanating from electrons too? It is more logical, imo, to view point-particles as force-field "anchors" and the fields themselves as cohesive units. An electron, imo, is a EM field surrounding a volume-less point. I think gravitation may be the same, as well as nuclear particle force-fields. I don't think these fields need any container called "space" to exist within. I think gravitational field-force itself is the container of other force-fields, unless there is some other force that extends beyond gravitational fields that allows them to have mobility as well.

 

Neutrons have an internal charge distribution, since they are made of charged quarks. That gives rise to the magnetic moment.

I see. So they're like atoms whose charge is internally neutralized? Do the quarks have spin like electrons that makes it possible to magnetize neutrons? Could you make super-magnets out of neutron-lumps?

 

It would have mass. D H has already pointed out that inertia is an ambiguous term and isn't used anymore (by itself at least).

Yes, I've been struggling with that. What better than inertia describes the ability of a particle or object to slow down as a result of force imparted in the direction opposite its line of motion? To me, you can't slow a photon down by applying force against its line of motion. At best, you can reflect it in another direction but then it doesn't slow down. Matter seem special to me in that it can accelerate and decelerate through a range of speeds. Is this a fantasy of everyday perception or something?

 

Motion does not require a force, acceleration does. And it would be accelerated due to gravitational force.

Right, but how would it ever do anything besides fall into the nearest gravity well if it didn't have any means of receiving force and thereby accelerating away from the center of the gravity well?

 

 

[swansont]

So it is the alignment of the directions the electrons themselves spin in that cause the magnetism and it has nothing to do with their revolutions around the nuclei? I don't understand the concept of electrons spinning. Does this cause their fields to have angular momentum which results in a form of charge-motion, which in turn results in a magnetic field similar to that caused by electric charge moving through a conductor? Only in the case of the spinning electrons, the charge is moving in a circle instead of linearly between electrodes?

 

Electron spin is intrinsic angular momentum, not physical spinning. It causes the electron to have a magnetic moment.

 

Well, I guess I am just comparing the models in terms of intuitive plausibility. It doesn't make sense to me that a gravity field would consist of lots of smaller particles transmitting the gravitational force. If that was the case, then wouldn't there have to be little electromagnetic force carrier particles emanating from electrons too? It is more logical, imo, to view point-particles as force-field "anchors" and the fields themselves as cohesive units. An electron, imo, is a EM field surrounding a volume-less point. I think gravitation may be the same, as well as nuclear particle force-fields. I don't think these fields need any container called "space" to exist within. I think gravitational field-force itself is the container of other force-fields, unless there is some other force that extends beyond gravitational fields that allows them to have mobility as well.

 

The EM force has a force carrier; it's the photon.

 

I see. So they're like atoms whose charge is internally neutralized? Do the quarks have spin like electrons that makes it possible to magnetize neutrons? Could you make super-magnets out of neutron-lumps?

 

Yes, quarks have spin 1/2.

http://en.wikipedia.org/wiki/Quark#Properties

 

Yes, I've been struggling with that. What better than inertia describes the ability of a particle or object to slow down as a result of force imparted in the direction opposite its line of motion? To me, you can't slow a photon down by applying force against its line of motion. At best, you can reflect it in another direction but then it doesn't slow down. Matter seem special to me in that it can accelerate and decelerate through a range of speeds. Is this a fantasy of everyday perception or something?

 

If you mean momentum, use momentum. If you mean mass, use mass. A particle that can slow down has mass.

 

Right, but how would it ever do anything besides fall into the nearest gravity well if it didn't have any means of receiving force and thereby accelerating away from the center of the gravity well?

 

If it has a velocity relative to the source, it won't necessarily fall in, or stay in.

[lemur]

Electron spin is intrinsic angular momentum, not physical spinning. It causes the electron to have a magnetic moment.

If I am picturing an electron as a tiny ball of negative charge field-force, what does "intrinsic angular momentum" mean if the field itself is not spinning? Does it refer to the vectors of force within the field curving in some non-linear radial direction?

 

The EM force has a force carrier; it's the photon.

So the only reason electrons repel each other is because they are emitting photons that push against each other? I didn't think light could push against light.

 

Yes, quarks have spin 1/2.

http://en.wikipedia....uark#Properties

I believe that all these attributes work when plugging them into equations/formulas. I'm just trying to get a logic to the modeling.

 

If you mean momentum, use momentum. If you mean mass, use mass. A particle that can slow down has mass.

To me, momentum refers to the speed of an object combined with its mass/inertia. A bowling ball has more mass/inertia than a balloon, so it carries more momentum at a slower speed and when it collides with the balloon, the balloon will translate the momentum it receives into a faster speed. A stationary object can have mass and force due to gravity without having momentum. Still, its inertia prevents it from leaping into motion in the direction of imparted force. Plus, I see mass as an attribute/quality whereas inertia is a functional tendency to resist force. Theoretically, it would be possible for an object to have a different amount of inertia as it does mass; e.g. a gyroscope resists motion is certain directions although its mass is the same as when it is not moving.

 

If it has a velocity relative to the source, it won't necessarily fall in, or stay in.

Right, but how would it gain speed/momentum except by gravitational attraction, if it can't interact with EM or nuclear force? Something would have to push it away from the direction of gravity, no?

 

 

[swansont]

If I am picturing an electron as a tiny ball of negative charge field-force, what does "intrinsic angular momentum" mean if the field itself is not spinning? Does it refer to the vectors of force within the field curving in some non-linear radial direction?

 

Electrons are, as far as we can tell, point charges. But they behave like they are spinning, and the electron looks like a small magnet.

 

So the only reason electrons repel each other is because they are emitting photons that push against each other? I didn't think light could push against light.

 

The particle emits virtual photons, which interact with the other charged particle.

 

To me, momentum refers to the speed of an object combined with its mass/inertia. A bowling ball has more mass/inertia than a balloon, so it carries more momentum at a slower speed and when it collides with the balloon, the balloon will translate the momentum it receives into a faster speed. A stationary object can have mass and force due to gravity without having momentum. Still, its inertia prevents it from leaping into motion in the direction of imparted force. Plus, I see mass as an attribute/quality whereas inertia is a functional tendency to resist force. Theoretically, it would be possible for an object to have a different amount of inertia as it does mass; e.g. a gyroscope resists motion is certain directions although its mass is the same as when it is not moving.

 

If you want to discuss physics, you need to use the same language as the rest of us. When something means something to you, it's not enough. Your concept of momentum is very classical, and that's a problem if you want to discuss physics that includes quantum mechanics. A photon, for example, exerts a force when it is absorbed by an atom or molecule — they will recoil. A photon has momentum.

 

A gyroscope resisting rotation does so because it has angular momentum.

 

Right, but how would it gain speed/momentum except by gravitational attraction, if it can't interact with EM or nuclear force? Something would have to push it away from the direction of gravity, no?

 

Or pull it, such as another mass. You can't just model everything as starting at rest.

[lemur]

Electrons are, as far as we can tell, point charges. But they behave like they are spinning, and the electron looks like a small magnet.

In what sense does their behavior resemble the effects of spinning?

 

The particle emits virtual photons, which interact with the other charged particle.

I've heard of virtual photons but I can't understand what can be virtual about a physical thing. It either exists or it doesn't, no?

 

If you want to discuss physics, you need to use the same language as the rest of us. When something means something to you, it's not enough. Your concept of momentum is very classical, and that's a problem if you want to discuss physics that includes quantum mechanics. A photon, for example, exerts a force when it is absorbed by an atom or molecule — they will recoil. A photon has momentum.

Well, what I call critical rigor some people might call stubborness. Until a concept makes sense to me, I don't just accept it because others with strong reputations accept it as well. I could, but I would not really be learning in the way that I want to learn. My concept of momentum may be "classical" but I'm not going to base my preference for how to think about something on the popularity of one school of thought over another. That's academic politics and it's the worst part of academia, imo. I'm aware that photons exert force, which is why lasers can push (I think they can anyway). Still, they don't have inertia in the sense that they can move at different speeds and accept partial momentum transfer the way a balloon can when struck by a bowling ball.

 

A gyroscope resisting rotation does so because it has angular momentum.

Could inertia be caused by angular momentum then?

 

Or pull it, such as another mass. You can't just model everything as starting at rest.

So you're saying that these could be particles that are expanding with the universe that have been basically moving with the energy of the big bang since their inception? They can "fall" along geodesic paths according to their inertia/mass but nothing can ever impart any energy into them by pushing? What happens once they fall irretrievably into a gravity well? Do they pass through other fields seamlessly, falling back and forth within the gravity well frictionlessly for eternity?

 

 

[swansont]

In what sense does their behavior resemble the effects of spinning?

 

It has angular momentum.

 

I've heard of virtual photons but I can't understand what can be virtual about a physical thing. It either exists or it doesn't, no?

 

That's philosophy more than physics. What is real? What is a physical thing?

 

Well, what I call critical rigor some people might call stubborness. Until a concept makes sense to me, I don't just accept it because others with strong reputations accept it as well. I could, but I would not really be learning in the way that I want to learn. My concept of momentum may be "classical" but I'm not going to base my preference for how to think about something on the popularity of one school of thought over another. That's academic politics and it's the worst part of academia, imo. I'm aware that photons exert force, which is why lasers can push (I think they can anyway). Still, they don't have inertia in the sense that they can move at different speeds and accept partial momentum transfer the way a balloon can when struck by a bowling ball.

 

Ideas are not accepted because they are popular, they are accepted because of the weight if the evidence that both supports the idea and makes alternatives unacceptable. What you call critical rigor some might call being unscientific.

 

Could inertia be caused by angular momentum then?

 

I can't attempt to answer the question until you provide a definition of inertia.

[lemur]

It has angular momentum.

Meaning that when it collides with another electron, they don't repel each other at some product of their trajectory vectors?

 

That's philosophy more than physics. What is real? What is a physical thing?

Physical things interact with other physical things physically.

 

Ideas are not accepted because they are popular, they are accepted because of the weight if the evidence that both supports the idea and makes alternatives unacceptable. What you call critical rigor some might call being unscientific.

You may not be aware that you're assuming discourse creates imperative knowledge, but that's what you're doing when you say "ideas are accepted" in the passive tense without a subject. Truth may be independent of subjective whim, but there is a difference between accepting an idea because you "get it" or accepting it because someone in position of authority told you so. I don't want to learn by memorizing things that people in positions of authority tell me "because they say so." I want the lightbulb in my mind to go on when I "get" something.

 

I can't attempt to answer the question until you provide a definition of inertia.

This wasn't a clear enough explanation?: "I'm aware that photons exert force, which is why lasers can push (I think they can anyway). Still, they don't have inertia in the sense that they can move at different speeds and accept partial momentum transfer the way a balloon can when struck by a bowling ball."

How about this?: "inertia is the ability to resist accelerating to the speed of light when force is applied."

Edited December 25, 2010 by lemur

[swansont]

Meaning that when it collides with another electron, they don't repel each other at some product of their trajectory vectors?

 

No, meaning that an electron possesses angular momentum regardless of its motion.

 

Physical things interact with other physical things physically.

 

That's more of a tautology than an explanation.

 

You may not be aware that you're assuming discourse creates imperative knowledge, but that's what you're doing when you say "ideas are accepted" in the passive tense without a subject. Truth may be independent of subjective whim, but there is a difference between accepting an idea because you "get it" or accepting it because someone in position of authority told you so. I don't want to learn by memorizing things that people in positions of authority tell me "because they say so." I want the lightbulb in my mind to go on when I "get" something.

 

Whether some science is valid is independent of whether you personally "get it."

 

This wasn't a clear enough explanation?: "I'm aware that photons exert force, which is why lasers can push (I think they can anyway). Still, they don't have inertia in the sense that they can move at different speeds and accept partial momentum transfer the way a balloon can when struck by a bowling ball."

How about this?: "inertia is the ability to resist accelerating to the speed of light when force is applied."

 

That sounds like you mean mass. Why not just use mass?

[lemur]

No, meaning that an electron possesses angular momentum regardless of its motion.

Yes, I get that there's angular momentum. I just don't understand how the angular momentum manifests itself in interactions with other electrons/things.

 

That's more of a tautology than an explanation.

Why, because I used the word "physical" three times in the same sentence?

 

Whether some science is valid is independent of whether you personally "get it."

How could I attempt to assess validity if I can't "get it?"

 

That sounds like you mean mass. Why not just use mass?

I told you, because "mass" is a passive property to me whereas inertia refers to an active function. Mass refers to how much force an object will impart at a given rate of acceleration. Inertia refers to the object's ability to resist push-force when acted upon by an external impulse. I know that an object's inertia is directly related to its mass, but the meanings just don't converge as I understand them. Maybe I'm just dense, or should I say that my concept of inertia has too much inertia?

Edited December 25, 2010 by lemur

[mississippichem]

Yes, I get that there's angular momentum. I just don't understand how the angular momentum manifests itself in interactions with other electrons/things.

 

Electron orbitals in atoms and molecules are affected by spin-orbit coupling. The electrons' spin can couple to the magnetic field from the nucleus and cause further splitting of orbitals. The coupling is expressed as the sum of all the angular momentum numbers of all the electrons, the sum of all the spin numbers of all the electrons, and the sum of those two sums.

[lemur]

Electron orbitals in atoms and molecules are affected by spin-orbit coupling. The electrons' spin can couple to the magnetic field from the nucleus and cause further splitting of orbitals. The coupling is expressed as the sum of all the angular momentum numbers of all the electrons, the sum of all the spin numbers of all the electrons, and the sum of those two sums.

So it is basically just a way of explaining variations in the magnetic field of atoms and molecules? Or by "orbitals" are you talking about the pattern/shape of the electron cloud buffering the nucleus?