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Author Topic: How can we reconcile electromagnetism and gravity?  (Read 15890 times)

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #25 on: 24/09/2014 08:38:55 »
Quote from: jeffreyH
It's all in the question.
I think I see what you were really trying to get at. What you might have had in mind was unification. That means that you're asking how to unify the gravitational field and the electromagnetic field into one field. That's the goal of a unified field theory - to unify all the fields into one. See
http://en.wikipedia.org/wiki/Unified_field_theory

Quote
In the years following the creation of the general theory, a large number of physicists and mathematicians enthusiastically participated in the attempt to unify the then-known fundamental interactions.[2] In view of later developments in this domain, of particular interest are the theories of Hermann Weyl of 1919, who introduced the concept of an (electromagnetic) gauge field in a classical field theory[3] and, two years later, that of Theodor Kaluza, who extended General Relativity to five dimensions.[4] Continuing in this latter direction, Oscar Klein proposed in 1926 that the fourth spatial dimension be curled up into a small, unobserved circle. In Kaluza–Klein theory, the gravitational curvature of the extra spatial direction behaves as an additional force similar to electromagnetism. These and other models of electromagnetism and gravity were pursued by Albert Einstein in his attempts at a classical unified field theory. By 1930 Einstein had already considered the Einstein–Maxwell–Dirac System [Dongen]. This system is (heuristically) the super-classical [Varadarajan] limit of (the not mathematically well-defined) Quantum Electrodynamics. One can easily extend this system to include the weak and strong nuclear forces to get the Einstein–Yang–Mills–Dirac System.
 

Offline JohnDuffield

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Re: How can we reconcile electromagnetism and gravity?
« Reply #26 on: 24/09/2014 08:51:41 »
The magnetic field produced by an electric current is independent of the mass of the charge carriers. A 1 amp proton, electron or ion beam has exactly the same magnetic field as a 1 amp current flowing in a copper (electron conductor) or aluminum (hole conductor) wire.
It isn't relevant. A photon is an electromagnetic field variation, and it has no mass or charge. However it's a concentration of energy, and it causes gravity. 

If you oscillate the current you will generate electromagnetic radiation, the frequency and intensity of which are dependent only on the frequency of oscillation and the rms current respectively, and have nothing to do with the mass of the charge carriers.
As above. In addition, that current is comprised of electrons. An electron has mass and charge, and because it's a concentration of energy, it causes gravity.     

Thus gravitation and electromagnetism are unrelated.
There's no logic to that.
 

Offline JohnDuffield

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Re: How can we reconcile electromagnetism and gravity?
« Reply #27 on: 24/09/2014 09:09:27 »
Let's think about the UV catastrophe and Planck's quantization of energy, angular momentum etc. If we think of spacetime itself as quantized
Don't. Light has it E=hf quantum nature, and spacetime is not what space is.

Quote from: jeffreyH
and the energy released from the electron to only fit neatly into this quatized spacetime it's only option is to move at one speed.
Waves move at a speed dictated by the properties of the thing they move through. In mechanics  v = √(G/ρ) where v is the speed, G is the shear modulus of elasticity, and ρ is density. In electromagnetism  c = √(1/ε0μ0) where c is the speed, ε0 is the electric permittivity of space and μ0 is the magnetic permeability.

Quote from: jeffreyH
If there is a compression of the quantization of spacetime, making it a smaller and denser medium this will ultimately affect light accordingly.
The quantization of spacetime is the wrong expression, but the "coordinate" speed of light does vary with gravitational potential. Hence the Shapiro quote:

"The proposed experiment was designed to verify the prediction that the speed of propagation of a light ray decreases as it passes through a region of decreasing gravitational potential."

Quote from: jeffreyH
Now mass is said to cause this effect. What is it about the mass that can cause such an effect.
Energy causes it. Mass is just a measure of energy-content. Energy causes it because it's intimately related to pressure, which is why the stress-energy-momentum tensor has an energy-pressure diagonal. Think of it as "energy presses outwards", affecting the surrounding space.


Public domain image by Maschen, based on image created by Bamse, see Wikipedia


Quote from: jeffreyH
We have charge which is independent of mass. The electron is smaller than the proton but both have the same charge. We have gravitation which is dependent on mass. Is it though? Can gravity itself be like charge and change in strength with the density of that mass. Like the observer getting the wrong speed from his gravitational constant when viewing a companion nearing a black hole are we missing this vital point? As the gravity changes with density this would increase the curvature of the spacetime around it. Also it could aid the compression of the mass until at a critical point it collapses in due to a dual system of compression. One compression of mass and another separate compression of spacetime. If these are proportional to each other we just have to find this proportionality. It may lie in the theory that the density of black holes lowers with mass increase. This could be counter balanced by an increasing spacetime density.
There's a lot of speculation in here Jeffrey. IMHO you need to rein back a bit and take it one step at a time.
 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #28 on: 24/09/2014 09:57:59 »
Jeff - I ignore JohnDuffield. Look for proof.
« Last Edit: 28/09/2014 22:54:39 by evan_au »
 

Offline alancalverd

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Re: How can we reconcile electromagnetism and gravity?
« Reply #29 on: 24/09/2014 19:07:46 »
Quote
They do carry kinetic energy when they move but I assume that you're referring to an electron at rest emitted photons. Is that correct?

That seems to underlie a consistent misconception in this thread.

You can add kinetic or binding energy to an electron, or mess with its spin, but the electron itself doesn't absorb or emit anything - they appear to be indefinitely stable.

A lot of misunderstanding arises from inaccurate paraphrasing. You learn at school that "a photon is emitted when an electron moves to a lower orbital" Sometimes paraphrased as "....changes state" which is a bit ambiguous - it's the quantum state (or better, status) of the electron that changes, not the structure of the beast itself. 
« Last Edit: 24/09/2014 19:10:59 by alancalverd »
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #30 on: 24/09/2014 19:20:36 »
Quote
They do carry kinetic energy when they move but I assume that you're referring to an electron at rest emitted photons. Is that correct?

That seems to underlie a consistent misconception in this thread.

You can add kinetic or binding energy to an electron, or mess with its spin, but the electron itself doesn't absorb or emit anything - they appear to be indefinitely stable.

A lot of misunderstanding arises from inaccurate paraphrasing. You learn at school that "a photon is emitted when an electron moves to a lower orbital" Sometimes paraphrased as "....changes state" which is a bit ambiguous - it's the quantum state (or better, status) of the electron that changes, not the structure of the beast itself.

Now that is a very interesting point. How do you see the photon interacting with the electron? It is considered massless but obviously has energy.
 

Offline alancalverd

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Re: How can we reconcile electromagnetism and gravity?
« Reply #31 on: 24/09/2014 22:22:34 »
Not merely "considered" but actually massless.

How do you add energy to a water molecule? No mass transfer is involved in a microwave cooker. The molecules are stretched and bent by the oscillating electric field. 

But just to add to the confusion, a photon has momentum even though it has no mass. As for any other particle, momentum = energy/velocity, hence p= hν/c = h/λ
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #32 on: 25/09/2014 01:23:48 »
The photon loses the angular momentum of its waveform as it moves from an area of higher to lower spacetime curvature and time dilation.Its energy therefore decreases and it red shifts. This action on a massless particle and the relationship between angular momentum and energy divorces both from a direct connection with mass. This MAY mean that it does not require infinite energy to reach light speed. However this does not imply that it is possible to reach light speed.
 

Offline acsinuk

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    • electricmagnofluxuniverse.blogspot.com
Re: How can we reconcile electromagnetism and gravity?
« Reply #33 on: 25/09/2014 09:29:18 »
You seem to have proved that a photon of energy is not a particle or a wave nor some sort of entangled quantum. I think that it is a pyramid shaped volume of vibrating magnoflux energy which helixes or rather tumbles forward through magnetised space.
If it encounters matter it can be absorbed by vibrating the molecules inner magnet which increases its temperature. CliveS at acsinuk
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #34 on: 25/09/2014 18:42:53 »
You seem to have proved that a photon of energy is not a particle or a wave nor some sort of entangled quantum. I think that it is a pyramid shaped volume of vibrating magnoflux energy which helixes or rather tumbles forward through magnetised space.
If it encounters matter it can be absorbed by vibrating the molecules inner magnet which increases its temperature. CliveS at acsinuk

I disagree. I don't think I have proved anything of the sort. I have proposed an idea that is all. I find it very interesting that the idea of interaction rather than absorption has come up. It is an important distinction to consider. Especially if we are considering interacting waves with a built-in uncertainty.
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #35 on: 25/09/2014 21:30:25 »
If we think of partial separation of momentum and energy from mass then the discrepancy between charge and mass size between the proton and electron disappears. It is simply that a greater amount of free field energy exists around the electron whilst confinement binds most of the energy in the proton and neutron. This is what would then account for the equivalent charge. Then this equivalence of charge marries the electron to the nucleus. What if we are thinking the wrong way about the positively charged proton. If only a weak field energy surrounds it, enough to sustain the electron orbitals then it could be an attractive force which is hidden behing the electron cloud. It may have the potential to attract any mass whether it has charge or not but is itself confined behind the cloud of electrons. In noble gases this confinement is strong because of the complete electrons shells. Valent elements may allow energy to escape in the form of gravitational energy from the weak field of the nucleus. This would relate to colour charge in some way and have a confining energy by virtue of its source. This could be released due to phonon vibrations. I have no idea if this is possible. It may also be due to the interaction of the photon with an electron field in combination with the phonon vibrations. What would a Feynman diagram of that look like?
« Last Edit: 25/09/2014 21:35:41 by jeffreyH »
 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #36 on: 25/09/2014 23:17:01 »
Quote from: alancalverd
That seems to underlie a consistent misconception in this thread.
I asked because if that's what you meant I'd have to object to it. However we had some discussion on this recently and I spoke to some colleagues of mine who know particle physics and field theory. They explained to me that it's not as simple as this. There are instances when an electron can, in a sense, emit photons. However its not as simple as that since it's the electron combined with a system that is doing the emitting. After I learn those fields, perhaps in a year or two, I'll come back to this subject and be better able to address this. Meanwhile I met a new colleague so I'll ask him about this.
 

Offline JohnDuffield

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Re: How can we reconcile electromagnetism and gravity?
« Reply #37 on: 26/09/2014 08:39:02 »
...You can add kinetic or binding energy to an electron, or mess with its spin, but the electron itself doesn't absorb or emit anything - they appear to be indefinitely stable.
I'm afraid this isn't quite true, Alan. In Compton scattering the electron absorbs part of a photon, and there is such a thing as an "Inverse Compton".

 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #38 on: 26/09/2014 09:59:08 »
Quote from: JohnDuffield
In Compton scattering the electron absorbs part of a photon, and there is such a thing as an "Inverse Compton".
I disagree.

It's called Compton Scattering for a very good reason, i.e. because a photon is never absorbed but is scattered off the electron just like one electron would scatter off another. Had the electron absorbed the photon it would violate conservation of energy  and if the law of conservation of energy and is true then it's impossible.

To be specific JD is claiming that the following two processes occur in sequence

e- +ae539dfcc999c28e25a0f3ae65c1de79.gif -> e-

e- -> e- +ae539dfcc999c28e25a0f3ae65c1de79.gif

Which both violate conservation of energy. JD's assertion implicitly assumes that once the electron absorbs the photon it's proper mass, and hence proper energy, increases. However that's impossible because when an electron exists it has a unique proper mass which is well defined and cannot change.
« Last Edit: 28/09/2014 22:57:33 by evan_au »
 

Offline JohnDuffield

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Re: How can we reconcile electromagnetism and gravity?
« Reply #39 on: 26/09/2014 10:09:40 »
It's called Compton Scattering for a very good reason, i.e. because a photon is never absorbed but is scattered off the electron just like one electron would scatter off another. Had the electron absorbed the photon it would violate conservation of energy  and if the law of conservation of energy and is true then it's impossible.

To be specific JD is claiming that the following two processes occur in sequence

e- +ae539dfcc999c28e25a0f3ae65c1de79.gif -> e-

e- -> e- +ae539dfcc999c28e25a0f3ae65c1de79.gif

Which both violate conservation of energy. JD's assertion implicitly assumes that once the electron absorbs the photon it's proper mass, and hence proper energy, increases. However that's impossible because when an electron exists it has a unique proper mass which is well defined and cannot change.
The electron absorbs part of a photon. The photon's E=hf wave energy is reduced.



See hyperphysics. Conservation of energy applies. The photon loses energy, the electron gains it. The reverse occurs in Inverse Compton scattering.

« Last Edit: 28/09/2014 23:02:02 by evan_au »
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #40 on: 26/09/2014 20:15:35 »
The following caught my eye,

http://hyperphysics.phy-astr.gsu.edu/hbase/particles/hadron.html#c2

"The negative pion decays into a muon and a muon antineutrino as illustrated below. This decay is puzzling upon first examination because the decay into an electron plus an electron antineutrino yields much more energy. Usually the pathway with the greatest energy yield is the preferred pathway. This suggests that some symmetry is acting to inhibit the electron decay pathway."

Whenever something is described as puzzling it gets my attention. What symmetry is acting to inhibit the electron decay pathway?
 

Offline alancalverd

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Re: How can we reconcile electromagnetism and gravity?
« Reply #41 on: 26/09/2014 20:29:02 »
The electron absorbs part of a photon. The photon's E=hf wave energy is reduced.
drivel



Quote
Conservation of energy applies.
true. The electron gains kinetic energy. A scatter photon is emitted such that the energy of the Compton  photon plus the kinetic energy gain of the electron equals the energy of the incident photon.

The Compton photon isn't "the original photon with a bit less energy", and the electron is no different from any other electron. If it had mysteriously "absorbed part of the incident photon" we would find a second scatter photon emitted as the "electron plus a bit of photon" decays, which it doesn't.   
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #42 on: 26/09/2014 23:11:56 »
Following the trail from the pion another interesting detail came up concerning the glueball.

http://en.wikipedia.org/wiki/Glueball
"Total angular momentum[edit]

Two gluon glueballs can have total angular momentum (J) of 0 (which are scalar or pseudo-scalar) or 2 (tensor). Three gluon glueballs can have total angular momentum (J) of 1 (vector boson) or 3. All glueballs have integer total angular momentum which implies that they are bosons rather than fermions.

Glueballs are the only particles predicted by the Standard Model with total angular momentum (J) (sometimes called "intrinsic spin") that could be either 2 or 3 in their ground states, although mesons made of two quarks with J=0 and J=1 with similar masses have been observed and excited states of other mesons can have these values of total angular momentum.

Fundamental particles with ground states having J=0 or J=2 are easily distinguished from glueballs. The hypothetical graviton, while having a total angular momentum J=2 would be massless and lack color charge, and so would be easily distinguished from glueballs. The Standard Model Higgs boson for which an experimentally measured mass of about 125-126 GeV/c^2 has been determined (although the status of the measured particle as a true Standard Model Higgs boson has not been definitively established), is the only fundamental particle with J=0 in the Standard Model, also lacks color charge and hence does not engage in strong force interactions. The Higgs boson is about 25-80 times as heavy as the mass of the various glueball states predicted by the Standard Model."

A glueball cannot be a graviton because the graviton has no color charge. It is interesting that other types of particles with the same values for J can be easily distinguished from glueballs. Since for glueballs J can equal 2 but is not a graviton then could the graviton unlike the glueball be confused with some other field or particle which is why we seem not to have detected gravitational waves? I doubt it personally.
 

Offline JohnDuffield

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Re: How can we reconcile electromagnetism and gravity?
« Reply #43 on: 27/09/2014 13:36:44 »
A scatter photon is emitted such that the energy of the Compton  photon plus the kinetic energy gain of the electron equals the energy of the incident photon.
There is no emitted photon. The incident photon is deflected and its energy is reduced.   

The Compton photon isn't "the original photon with a bit less energy"
It is. Go look it up. The electron doesn't absorb one photon and emit another.

and the electron is no different from any other electron. If it had mysteriously "absorbed part of the incident photon" we would find a second scatter photon emitted as the "electron plus a bit of photon" decays, which it doesn't.
There is no emitted photon.
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #44 on: 28/09/2014 02:16:19 »
A while back I asked a question that most people would have thought crazy. It was what amount of matter would fit into a Planck cube. If we are discussing increasing density of energy then this becomes a very important question when viewed against both length contraction and time dilation. The other question is does the Planck scale vary with a change of reference frame. Do we need a Lorentz transform at this scale. To complete a theory of quantum gravity we need some sort of answer to questions like this.
 

Offline jeffreyH

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Re: How can we reconcile electromagnetism and gravity?
« Reply #45 on: 28/09/2014 02:22:19 »
The other important consideration relating to the above post is that we are always trapped within our own current light cone and see only histories. These histories are less critical locally but we cannot determine how critical they are when viewing over vast distances.
 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #46 on: 28/09/2014 02:27:16 »
Quote from: JohnDuffield
The electron absorbs part of a photon. The photon's E=hf wave energy is reduced.
There's no such thing as an electron absorbing part of a photon.


« Last Edit: 28/09/2014 23:01:31 by evan_au »
 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #47 on: 28/09/2014 02:29:23 »
Quote from: alancalverd
The Compton photon isn't "the original photon with a bit less energy", and the electron is no different from any other electron. If it had mysteriously "absorbed part of the incident photon" we would find a second scatter photon emitted as the "electron plus a bit of photon" decays, which it doesn't.   
Please tell me that you don't believe that the electron absorbs a photon at any time during this process?
 

Offline Ethos_

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Re: How can we reconcile electromagnetism and gravity?
« Reply #48 on: 28/09/2014 17:44:05 »
The only correction that needs to be applied here is this:

The photon is not absorbed by the electron, however, some of the energy that the photon possesses can be transferred to the electron.

The mistake the layman makes here is to assume that the photon is energy when in fact, the photon only carries varying amounts of energy. The photon is a wave/particle, it is not energy.
« Last Edit: 28/09/2014 23:03:24 by evan_au »
 

Offline PmbPhy

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Re: How can we reconcile electromagnetism and gravity?
« Reply #49 on: 29/09/2014 03:17:34 »
Quote from: Ethos_
The only correction that needs to be applied here is this:

The photon is not absorbed by the electron, however, some of the energy that the photon possesses can be transferred to the electron.

The mistake the layman makes here is to assume that the photon is energy when in fact, the photon only carries varying amounts of energy. The photon is a wave/particle, it is not energy.
Beautiful my good man. You make my heart proud! :)
 

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Re: How can we reconcile electromagnetism and gravity?
« Reply #49 on: 29/09/2014 03:17:34 »

 

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