When a charge accelerates, it feels B field resistance; Lenz's law.
Hence we see a form of inertia.

inertia = mass

Does this 'magnetic mass' act like rest mass, relativistically?
i.e. the way the 'relativistic mass' increases with velocity.

Then, does it contribute to gravity?

--
Rich

On Wednesday, July 14, 2021 at 2:25:11 PM UTC-7, RichD wrote:
> When a charge accelerates, it feels B field resistance; Lenz's law.
> Hence we see a form of inertia.
>
> inertia = mass
>
> Does this 'magnetic mass' act like rest mass, relativistically?
> i.e. the way the 'relativistic mass' increases with velocity.
>
> Then, does it contribute to gravity?
>
> --
> Rich

Google Bremsstrahlung: https://en.wikipedia.org/wiki/Bremsstrahlung

On Wednesday, July 14, 2021 at 2:25:11 PM UTC-7, RichD wrote:
> When a charge accelerates, it feels B field resistance; Lenz's law.
> Hence we see a form of inertia.

Right, that's what they called "electromagnetic mass" in the 19th century.

> inertia = mass

It's more accurate to say that all forms of energy, including electromagnetic energy, have inertia. In a discussion of this, you should clarify when you use the word "mass" if you are referring to rest mass or relativistic mass (i.e., energy) or the notions of longitudinal and transverse mass, etc. No good comes from being ambiguous.

> Does this 'magnetic mass' act like rest mass, relativistically?

No, it is called "electromagnetic mass" (not "magnetic mass"), and it doesn't act like rest mass in general, although you could have charged particles moving boundedly within a configuration and the electromagnetic field energy would contribute to the rest mass of the configuration, just like the kinetic energy.

> i.e. the way the 'relativistic mass' increases with velocity.

That is self-contradictory, since the previous sentence referred to rest mass and this clarification refers to relativistic mass. you're confusing different notions of "mass". To be clear, just note that the energy stored in the electromagnetic field of a moving charge is energy, and hence has inertia. Think of it like the kinetic energy of a moving neutral particle. (It was once speculated, around 1900, that all mass might be electromagnetic in origin, but we now know that is not true.)

> Then, does it contribute to gravity?

The electromagnetic energy of a moving charge is part of the energy-momentum tensor that is the source of gravitation, similar to the kinetic energy of an object. Don't confuse energy currents with rest mass.

On Wednesday, July 14, 2021 at 2:25:11 PM UTC-7, RichD wrote:
> When a charge accelerates, it feels B field resistance; Lenz's law.

Acceleration has opposite weight resisting more acceleration...

> Hence we see a form of inertia.
>
> inertia = mass

What curves inertia and how is it a constant?

>
> Does this 'magnetic mass' act like rest mass, relativistically?
> i.e. the way the 'relativistic mass' increases with velocity.

Motion mass does not have to be relative.
The atom can have its own motion like light.

>
> Then, does it contribute to gravity?
>
> --
> Rich

all energy contributes to gravity
magnets can move themselves
so they have kinetic time dilation
and movement energy order.

Mitchell Raemsch

On 7/14/21 4:25 PM, RichD wrote:
> When a charge accelerates, it feels B field resistance; Lenz's law.
> Hence we see a form of inertia.

This is not inertia, it is a force. They are Quite different. It is
RADIATION resistance, not whatever you mean by "B field resistance".
This is considerably more complicated than you seem to think.

A charged particle radiates when it is accelerated.
Radiation resistance is a force on the particle in a
direction opposite to its velocity, with a magnitude
such that the energy of the radiation equals the
decrease in the particle's kinetic energy (everything
referenced to an appropriate locally inertial frame).

Presumably you are thinking of a charged particle moving in an
externally-applied B field, as that is (loosely) what is described by
Lenz's law. In the inertial frame in which the applied field is pure B,
the force is perpendicular to the particle's 3-velocity, so it does no
work on the particle, and the particle's energy is unchanged, except for
the synchrotron radiation emitted.

Lenz's law involves a changing B field. A changing B field induces an E
field [#], which can do work on the particle. Also, in this case there
is no inertial frame in which the applied field is pure B.

[#] Described by Maxwell's equation
Del cross E = - dB/dt
Here d is partial derivative; Del, E, and B are 3-vectors.
Lenz's law implies the minus sign.

> does it contribute to gravity?

In GR, the "source" of the curvature of spacetime ("gravity") is the
energy-momentum tensor. The particle and the EM field both contribute;
their interaction does not except insofar as it changes the EM field
distribution, which includes the synchrotron radiation emitted by the
accelerated charged particle. All the fields involved, as well as the
particle's trajectory, are time dependent, including the curvature tensors.

Tom Roberts

Magnets can push/pull themselves setting
up their own "magnetic force" kinetic slow time
and energy of their motion...

Mitchell Raemsch

> > does it contribute to gravity?
> In GR, the "source" of the curvature of spacetime ("gravity") is the
> energy-momentum tensor. The particle and the EM field both contribute;

Does not energy lead to weight?

> Tom Roberts

On Wednesday, July 14, 2021 at 2:25:11 PM UTC-7, RichD wrote:
> When a charge accelerates, it feels B field resistance; Lenz's law.
> Hence we see a form of inertia.

The atom's propulsion gives it weight resistance.

>
> inertia = mass

How then can the mass-less move?
Light's has inerta.. with no mass...

Mitchell Raemsch

>
> Does this 'magnetic mass' act like rest mass, relativistically?
> i.e. the way the 'relativistic mass' increases with velocity.
>
> Then, does it contribute to gravity?
>
> --
> Rich

On Thursday, July 15, 2021 at 10:36:04 AM UTC-7, tjrob137 wrote:
> This is not inertia, it is a force. They are Quite different. It is
> RADIATION resistance, not whatever you mean by "B field resistance".

He isn't referring to radiation resistance, he's talking about self-inductance and electromagnetic mass. This was fundamental to the early studies that led to special relativity and examined by Kaufmann's experiments, etc. It was known that a charged particle in motion is a current that induces an electromagnetic field of self-inductance, and it takes energy to establish this field, which implies that work must be done to accelerate the charge to that state of motion (even neglecting radiation), which accounts for some resistance to acceleration, and this behaves exactly like mechanical inertia, so early workers (including Lorentz and Poincare and others) speculated that perhaps all mass is electromagnetic in origin. This kind of "effective mass" increases with speed, so Kaufmann et al tried to find out how much of an electron's effective mass (resistance to acceleration) increases with speed, and they discovered that *all* the mass does, so their initial conclusion was that all mass is really just effective electromagnetic mass... but then Einstein's special relativity undermined that conclusion, because it showed that even mechanical "mass" (resistance to acceleration) has exactly the same velocity dependence, and it really just depends on the energy content. Hence the particle experiments tell us nothing about whether all mass is just effective mass produced by electromagnetic self-induction. It was later learned that only a very small fraction of the electron's mass is electromagnetic in origin.

On July 14, Arthur Adler wrote:
>>> When a charge accelerates, it feels B field resistance; Lenz's law.
>> Hence we see a form of inertia.
>
> Right, that's what they called "electromagnetic mass" in the 19th century..
>
> > inertia = mass
>
> It's more accurate to say that all forms of energy, including electromagnetic energy, have inertia. In a discussion of this, you should clarify when you use the word "mass" if you are referring to rest mass or relativistic mass (i.e., energy)

> or the notions of longitudinal and transverse mass, etc.

?
Don't know these.
Explicate, please.

> > Does this 'magnetic mass' act like rest mass, relativistically?
>
> No, it is called "electromagnetic mass" (not "magnetic mass"), and it doesn't act like rest mass
> in general, although you could have charged particles moving boundedly within a configuration
> and the electromagnetic field energy would contribute to the rest mass of the configuration, just like the kinetic energy.
>
>> i.e. the way the 'relativistic mass' increases with velocity.
>
> That is self-contradictory, since the previous sentence referred to rest mass and this clarification
> refers to relativistic mass. you're confusing different notions of "mass".. To be clear, just note
> that the energy stored in the electromagnetic field of a moving charge is energy, and hence has inertia.

Specifically, I have in mind a transient condition, an interval where a charge accelerates.
It generates a B field, which opposes its acceleration; the source of circuit inductance.
This is not velocity dependent (in Maxwell's model).

During that window, then, it has an additional electromagnetic mass Δm.. The question
is whether this Δm then increases with velocity, relativistically, the way rest mass
develops into 'relativistic mass' at high speeds.

Of course, this is all classical, I don't know how quantum field theory treats it.

> (It was once speculated, around 1900, that all mass might be electromagnetic in origin, but we now
> know that is not true.)

You mean, through the discovery of nuclear particles, or via some other method?

>> Then, does it contribute to gravity?
>
> The electromagnetic energy of a moving charge is part of the energy-momentum tensor that is
> the source of gravitation, similar to the kinetic energy of an object. Don't confuse energy currents with rest mass.

All right - does this transient Δm contribute to the energy-momentum tensor?
--
Rich

On July 17 RichD wrote:
>>> Then, does it contribute to gravity?
>
>> The electromagnetic energy of a moving charge is part of the energy-momentum tensor that is
>> the source of gravitation, similar to the kinetic energy of an object. Don't confuse energy currents with rest mass.
>
> All right - does this transient Δm contribute to the energy-momentum tensor?

And, does it participate in the famous energy-mass formula?
--
Rich

On Saturday, July 17, 2021 at 4:51:27 PM UTC-7, RichD wrote:
> > All forms of energy, including electromagnetic energy, have inertia... you should
> > clarify when you use the word "mass" if you are referring to rest mass or relativistic
> > mass (i.e., energy) or the notions of longitudinal and transverse mass, etc.
>
> Don't know these. Explicate, please.

One way of defining "mass" by analogy with the Newtonian relation F=ma is as the proportionality between force and acceleration. By that definition, the "mass" of a moving object is different in the direction of motion versus in the transverse direction. The so-called longitudinal mass is m0/(1-v^2/c^2)^(3/2), whereas the transverse mass is m0/(1-v^2/c^2)^(1/2). Naturally the effective electromagnetic mass exhibits this same proportionality. Once relativistic mechanics was clarified, it was more advantageous to define the relativistic mass by analogy with the Newtonian relation F=dp/dt where p=mv, and this yields the isotropic m0/sqrt(1-v^2/c^2), which of course is proportional to the total energy.

> > It is called "electromagnetic mass" (not "magnetic mass"), and it doesn't act like rest mass
> > in general, although you could have charged particles moving boundedly within a configuration
> > and the electromagnetic field energy would contribute to the rest mass of the configuration,
> > just like the kinetic energy.
>
> I have in mind a transient condition, an interval where a charge accelerates.
> It generates a B field, which opposes its acceleration; the source of circuit inductance.
> This is not velocity dependent (in Maxwell's model).

You're confused. The magnetic field of a charged particle in terms of a given frame depends on the particle's velocity in terms of that frame. As a result, there is energy in the field, depending on the velocity, just like the kinetic energy, in terms of a given frame, and this energy contributes to the inertia of the particle. This is the effective "electromagnetic mass" associated with the self-induction producing a magnetic field. This is not to be confused with radiation reaction effects. You need to decide if you are talking about the effective electromagnetic mass associated with the magnetic field of a moving charge, or if you are talking about radiation reaction. The latter does not represent the effective electromagnetic mass..

> During that window, then, it has an additional electromagnetic mass Δm.

Radiation reaction is not the same as electromagnetic mass. Conceptually the particle/field configuration is emitting radiation while accelerating, with the energy provided by whatever is doing the work to carry out the acceleration. It doesn't make sense to regard this as a contribution to the mass of the particle because the energy (and momentum) is radiated away, so it is not a conservative process -- unlike the electromagnetic mass associated with velocity.

> The question is whether this Δm then increases with velocity...

Again, it doesn't make sense to imagine a delta m associated with the work done to produce the radiation, because the radiation is, well, radiated away. That energy is no longer localized with the particle/field configuration of the charge. Don't confuse electromagnetic mass with radiation reaction.

> > (It was once speculated, around 1900, that all mass might be electromagnetic in origin, but we now
> > know that is not true.)
>
> You mean, through the discovery of nuclear particles, or via some other method?

Through an understanding of elementary particles and the strong and weak nuclear forces we now know that only a small fraction of the effective masses of objects is due to electromagnetic mass. In a primitive sense, Poincare was already aware of this by 1905 with his explanation of what was later called "Poincare pressure", which he envisaged as the Lorentz invariant pressure needed to maintain the structure of the electron. This isn't exactly consistent with the modern understanding of elementary particles, but it was the first explicit discussion of the necessity of some non-electromagnetic force(s) to account for the existence of charged particles.

> All right - does this transient Δm contribute to the energy-momentum tensor?

Again, there is no "transient delta m", since that doesn't make sense, because the work to produce radiation is radiated away, so it is not part of the particle. Radiation is a non-conservative process.

> And, does it participate in the famous energy-mass formula?

Well, the radiated energy gravitates, like all energy, but is it no longer associated with the particle, it is radiating away into space.

On July 17, Arthur Adler wrote:
>> I have in mind a transient condition, an interval where a charge accelerates.
>> It generates a B field, which opposes its acceleration; the source of circuit inductance.
>> This is not velocity dependent (in Maxwell's model).
>
> You're confused. The magnetic field of a charged particle in terms of a given frame
> depends on the particle's velocity in terms of that frame. As a result, there is energy
> in the field, depending on the velocity, just like the kinetic energy, in terms of a given
> frame, and this energy contributes to the inertia of the particle. This is the effective
> "electromagnetic mass" associated with the self-induction producing a magnetic field.

Inductance acts like inertia, in that it opposes acceleration. Thus a battery
has to work to overcome inductance. Classically, the energy goes into
the particle's velocity, increasing the current, and energy is stored in the
increased B field.

The modern explanation is relativistic:
higher velocity --> higher kinetic energy --> higher (relativistic) mass

Thus relativity explains inductance, is that correct?

> This is not to be confused with radiation reaction effects. You need to decide if you are
> talking about the effective electromagnetic mass associated with the magnetic field of
> a moving charge, or if you are talking about radiation reaction. The latter does not represent
> the effective electromagnetic mass.

'radiation reaction' is the load of a transmitting antenna, as seen by the source.
Unless I'm mistaken -

>>> (It was once speculated, around 1900, that all mass might be electromagnetic in origin, but we now
>>> know that is not true.)
>
> > You mean, through the discovery of nuclear particles, or via some other method?
>
> Through an understanding of elementary particles and the strong and weak nuclear
> forces we now know that only a small fraction of the effective masses of objects is
> due to electromagnetic mass.

So some of the mass associates with EM, other bits with strong
or weak force.

This raises the question of whether all mass is associated with a
particle/field. Going back to Newton, mass is a generic lump of
stuff which causes inertia. In modern physics, is any of the rest
mass such a simple neutral lump, unassociated with any field?

> In a primitive sense, Poincare was already aware of
> this by 1905 with his explanation of what was later called "Poincare pressure", which
> he envisaged as the Lorentz invariant pressure needed to maintain the structure of
> the electron.

Maintain the structure? Let me guess - because the moving E-field
is deformed by motion, which pressurizes the electron?

--
Rich

On Tuesday, July 20, 2021 at 7:40:31 PM UTC-7, RichD wrote:
> Inductance acts like inertia, in that it opposes acceleration.

"Opposing acceleration" is not sufficient to imply "acting like inertia". For example, if you try to run in a pool of water, the drag of the water opposes your acceleration, but it does not act like inertia. Drag is a lossy phenomena (although mechanical drag depends on velocity). Analogously an electric charge with second and third derivatives is subject to radiation reaction which is a kind of drag, but that does not act like inertia. What acts like inertia is self-inductance, whereby a moving charge entails energy stored in its electromagnetic field, so it takes energy to impart motion to a charge, and this energy can be recovered when the charge slows back down, so it is conservative.

> Classically, the energy goes into the particle's velocity, increasing the current,
> and energy is stored in the increased B field.

Right, the fact of self-inductance was known from Maxwell's equations.

> The modern explanation is relativistic:
> higher velocity --> higher kinetic energy --> higher (relativistic) mass

The electromagnetic energy of the field is not the same as the kinetic energy of non-electromagnetic rest masses. But they all represent energy, and hence they all have inertia that transforms in the same way.

> Thus relativity explains inductance, is that correct?

It's a little strange to say "relativity explains inductance", since inductance is already entailed by Maxwell's classical equations (although those equations are, of course, Lorentz invariant), but one could make some true statements that somewhat resemble that statement. For example, it's sometimes said that special relativity combined with the existence of static electric fields implies the existence of magnetic fields, in the sense that the electromagnetic field of a moving charge is just the transformed version of the purely electrostatic field of the charge in terms of its own rest frame, etc. And relativity gives arguably a more symmetrical *interpretation* of unipolar induction, etc. dispensing with the semantic asymmetry of the ether-based interpretation.

> > This is not to be confused with radiation reaction effects. You need to decide if you are
> > talking about the effective electromagnetic mass associated with the magnetic field of
> > a moving charge, or if you are talking about radiation reaction. The latter does not represent
> > the effective electromagnetic mass.
>
> 'radiation reaction' is the load of a transmitting antenna, as seen by the source.
> Unless I'm mistaken -

Well, an antenna has oscillatory motion and currents, so it isn't a good clean illustration of "electromagnetic mass", although it is certainly involved transiently, but the energy to maintain the oscillations is radiated away both as electromagnetic radiation in the signal frequency and also as heat in the thermal range, etc. Again, you have to decide what you are talking about. Radiation reaction does not act like inertia, so you're jumping back and forth between different subjects.

> > Through an understanding of elementary particles and the strong and weak nuclear
> > forces we now know that only a small fraction of the effective masses of objects is
> > due to electromagnetic mass.
>
> So some of the mass associates with EM, other bits with strong or weak force.

Yes, some of the rest mass is due to the binding energies, and much is due to the kinetic energies of the bound quarks in a proton (for example), and when you get down to the level of individual leptons and quarks the inertial mass arises from the Higgs field interaction, which you can see in the interactions between the different components of the Dirac equation of an electron (for example).

> In modern physics, is any of the rest mass such a simple neutral lump, unassociated with any field?

No, all rest mass is composed of Higgs field interactions, binding energy, and kinetic energy. That's why you just have to ignore lab technicians who sophomorically insist that "rest mass" is fundamental. It would be more accurate to say that all rest mass is, on some level, actually relativistic mass, but of course that it really another term of energy.

> Maintain the structure? Let me guess - because the moving E-field
> is deformed by motion, which pressurizes the electron?

No, the "Poincare pressure" was a universal Lorentz invariant external pressure that was hypothesized to hold the parts of a charged particle together..

Magnets can push each other giving them
motion time dilation and kinetic energy.

Mitchell Raemsch