Challenging the Role of Photons in Explaining Light's Particle Behavior

[Faradave]

I don’t want to dismiss the obvious practical utility of photons as a model. But setting aside the wave nature of light (since it is complementary anyway), why do we need the intermediary, “photons” to explain the particle aspects of light?

SR says photons don’t age because they travel at c (the limit of time dilation). But in frame c, a photon sees its path length as zero (the limit of length contraction). Equating “zero path length” to “contact” would seem sufficient to explain all of light’s particle behavior (photoelectric effect, Compton effect, even virtual photon “exchanges”) without invoking massless energy bundles.

 

[bcrowell]

You don't need to invoke photons if all you want to talk about is classical relativity (i.e., not quantum gravity). You do need photons if you want to talk about the photoelectric effect or the Compton effect. The photoelectric effect is one of the classical empirical proofs that light is quantized.

 

[JesseM]

SR says photons don’t age because they travel at c (the limit of time dilation). But in frame c, a photon sees its path length as zero (the limit of length contraction).

SR doesn't allow inertial frames moving at c, so it doesn't give a definition of what a photon "sees", either in terms of time or distance. The issue of a photon not having its own frame has been discussed on a lot of previous threads, do a search and you'll probably find some.

 

[ZapperZ]

I don’t want to dismiss the obvious practical utility of photons as a model. But setting aside the wave nature of light (since it is complementary anyway), why do we need the intermediary, “photons” to explain the particle aspects of light?

SR says photons don’t age because they travel at c (the limit of time dilation). But in frame c, a photon sees its path length as zero (the limit of length contraction). Equating “zero path length” to “contact” would seem sufficient to explain all of light’s particle behavior (photoelectric effect, Compton effect, even virtual photon “exchanges”) without invoking massless energy bundles.

Please show exact references for these, especially when I mentioned earlier about the fact that no non-photon formulation has been done to explain a more detailed aspect of photoemission phenomenon (including angle-resolved photoemission, resonant photoemission, multiphoton photoemission, etc..), anti-bunding phenomenon, etc... etc...

Zz.

 

[Naty1]

I noticed this recently:

In the modern Standard Model of particle physics, photons are described as a necessary consequence of physical laws having a certain symmetry at every point in spacetime.

here: http://en.wikipedia.org/wiki/Photons

So it seems like the standard model requires photons? Is that correct??

and I did not recall ever reading that. I assume this means that as a consequence of quantum field theory certain symmetries leads to photons..

Can anyone explain that briefly...?

 

[Faradave]

bcrowell

The photoelectric effect is one of the classical empirical proofs that light is quantized.

I agree that light emitted and absorbed by atoms is quantized (as I also accept electron orbitals and transitions). It is the nature of the transmission which I question. Photons seem fantastical and superfluous, though useful as a conceptual crutch.

JesseM

SR doesn't allow inertial frames moving at c … a photon not having its own frame has been discussed…

I’m new and still finding my way around. I will search and read, thanks. However, I necessarily begin with the bias that not having an allowable frame is tantamount to saying that nothing in such a frame (including photons) exists. The disallowance also suggests a psychological aversion to the notion of remote contact for which the Lorentz equations appear indifferent.

ZapperZ

Please show exact references for these

The Lorentz transform equations clearly yield both agelessness and zero path length when v=c.
However, at the bottom of this Physics Forum page is a suggested thread “Photons” in which I found the following example on my first try, from Plover 7/3/4:

Part of the problem is that not only is there essentially no passage of time for a photon, but that mathematically, it would also appear that the photon would experience distances along its path of travel as contracted to zero. So one might say then that it takes the photon no time to travel because it finds that its starting point and its destination are the same place.

ZapperZ

no non-photon formulation has been done to explain a more detailed aspect of photoemission phenomenon (including angle-resolved photoemission, resonant photoemission, multiphoton photoemission, etc..), anti-bunding phenomenon, etc... etc...

That’s quite a list. I’m sure I will spend time exploring those (by the way, I recall no “earlier mention”). It’s the “etc.. etc…” part I worry about. The list could be endless. That’s not how science should work. I should discover one incontrovertible proof that remote contact occurs without the need of a photon, then everyone else goes back and adjusts their favorite theory accordingly (with some help on the mechanism by the discoverer).

Think about it. There we were, happily going along, confident in Newton’s Laws. Einstein came along, and after a look at Mercury’s orbit and the Eddington photos, its everyone back to adjust their model for relativity.

Meanwhile, lists are easy. So far, my list says photons are: massless, ageless, sizeless, spinless, chargeless (electric and color) and collisionless (with each other). Maybe photons are trying to tell us something, more or less!

What photons do appear to have is momentum and energy. But these are the very attributes most readily explained by remote contact (sans photon).

 

[ZapperZ]

ZapperZ
The Lorentz transform equations clearly yield both agelessness and zero path length when v=c.
However, at the bottom of this Physics Forum page is a suggested thread “Photons” in which I found the following example on my first try, from Plover 7/3/4:

Please make the exact citation as you would in a publication.

Secondly, this is a very strange thing to do, considering that the phenomena that we see light in are in OUR reference frame, i.e. not in light's reference frame. So why would you transform to light's reference frame (is this even valid in the first place?) to describe a phenomenon that we seen in another reference frame? You don't have such phenomena in light's frame, so how would you describe such a thing in the first place?

So yes, I'm still waiting for an exact reference here before I consider that you've violated the PF Rules on speculative, personal theory. Just because you know about Lorentz transformation, it doesn't mean that you've shown it's application in describing a particular phenomenon.

ZapperZ
That’s quite a list. I’m sure I will spend time exploring those (by the way, I recall no “earlier mention”). It’s the “etc.. etc…” part I worry about. The list could be endless. That’s not how science should work. I should discover one incontrovertible proof that remote contact occurs without the need of a photon, then everyone else goes back and adjusts their favorite theory accordingly (with some help on the mechanism by the discoverer).

Maybe you should have done a bit more "homework" first before making your earlier claim. To make such statements while being ignorant of a whole bunch of experiments and phenomena is just puzzling.

I've shown "incontrovertible proof" (as if there is such a thing in science) via several phenomena that have not been described using anything else other than the photon picture. It seems that the burden in on YOU to show that you can describe these otherwise. The "etc.. " part is because the list is quite long and the examples are quite in detail. The ARPES experiments, for example, is not simply something I talk about, but also something I DID (my avatar is a raw data from an ARPES measurment that I took)! And it is in the DETAILS that a non-photon picture failed! So it appears that it is you who need to do some adjusting.

Meanwhile, lists are easy. So far, my list says photons are: massless, ageless, sizeless, spinless, chargeless (electric and color) and collisionless (with each other). Maybe photons are trying to tell us something, more or less!

Photons are not spinless! And collisionless? You haven't heard about photon-photon collision in QED?

So you're right here, lists are easy to make. Sometime, it is without regards to accuracy, as in this case.

Zz.

 

[bapowell]

I noticed this recently:


here: http://en.wikipedia.org/wiki/Photons

So it seems like the standard model requires photons? Is that correct??

and I did not recall ever reading that. I assume this means that as a consequence of quantum field theory certain symmetries leads to photons..

Can anyone explain that briefly...?

Naty1,

The electromagnetic interaction is a direct result of the local invariance (also called gauge invariance) of the QED equations of motion. This local invariance is a symmetry (specifically, the laws of QED are invariant under U(1) transformations, which are phase rotations) that holds at each point in spacetime.

If one begins with the free Maxwell and Dirac Lagrangians and carries out a U(1) transformation on all the fields (photon and fermion fields), one finds that the free theory is not invariant. However, the Lagrangian can be made invariant if we add a specific term to the theory. This term is precisely the interaction term between matter and light -- the term involves a direct coupling of photon and fermion fields.

These U(1) transformations are the same gauge transformations of the vector potential that are discussed in introductory electromagnetism, but viewed from the standpoint of a gauge theory like QED, we see that such transformations are at the heart of why photons interact with matter in the first place!

 

[JesseM]

JesseM
I’m new and still finding my way around. I will search and read, thanks. However, I necessarily begin with the bias that not having an allowable frame is tantamount to saying that nothing in such a frame (including photons) exists. The disallowance also suggests a psychological aversion to the notion of remote contact for which the Lorentz equations appear indifferent.

What do you mean by "in" such a frame? Physical facts are not "in" one frame or another, different frames are nothing more than different coordinate systems used to label the space and time coordinates of different physical events. You can certainly come up with a coordinate system where different events on a photon's path are labeled with the same position coordinate but different time coordinates, in which case the photon is "at rest" in this coordinate system. But this would not be an inertial frame (one where the equations of SR apply), because the "inertial" frames are a special set of coordinate systems which satisfy both the first postulate of SR (which says the equations of the laws of physics obey the same equations in every inertial frame) and the second postulate (which says the speed of light is always c in every inertial frame--obviously a coordinate system where a photon was at rest wouldn't satisfy this postulate). The fact that it is possible to find a set of coordinate systems moving at constant velocity relative to one another and satisfying both postulates is basically the physical content of the theory of relativity, it's possible to imagine different laws of physics where it wouldn't be possible to find a set of coordinate systems satisfying these requirements.

 

[bcrowell]

I’m new and still finding my way around. I will search and read, thanks. However, I necessarily begin with the bias that not having an allowable frame is tantamount to saying that nothing in such a frame (including photons) exists.

Since you haven't invoked quantum mechanics in this argument, it isn't an argument against the existence of photons, it's an argument against the existence of classical electromagnetic waves.

Please take some time to think carefully about sorting out the relativistic issues you've been talking about from the quantum-mechanical ones. They are not related. (If they were related, we'd be talking about quantum gravity -- but we're not.) If you want to post about your doubts about photons, that belongs in the Quantum Physics forum. If you want to post about the question of frames moving at c, then that does belong in this forum, but you will find that people's patience is short, because this gets discussed here once or twice every month, and it gets tiresome to cover the same ground over and over.

Either way, I would encourage you to start fresh threads, because you've gotten this one off to a muddled start by mixing together unrelated issues.

On the topic of frames of reference moving at c, here is a FAQ I've written.

FAQ: What does the world look like in a frame of reference moving at the speed of light?

This question has a long and honorable history. As a young student, Einstein tried to imagine what an electromagnetic wave would look like from the point of view of a motorcyclist riding alongside it. But we now know, thanks to Einstein himself, that it really doesn't make sense to talk about such observers.

The most straightforward argument is based on the positivist idea that concepts only mean something if you can define how to measure them operationally. If we accept this philosophical stance (which is by no means compatible with every concept we ever discuss in physics), then we need to be able to physically realize this frame in terms of an observer and measuring devices. But we can't. It would take an infinite amount of energy to accelerate Einstein and his motorcycle to the speed of light.

Since arguments from positivism can often kill off perfectly interesting and reasonable concepts, we might ask whether there are other reasons not to allow such frames. There are. One of the most basic geometrical ideas is intersection. In relativity, we expect that even if different observers disagree about many things, they agree about intersections of world-lines. Either the particles collided or they didn't. The arrow either hit the bull's-eye or it didn't. So although general relativity is far more permissive than Newtonian mechanics about changes of coordinates, there is a restriction that they should be smooth, one-to-one functions. If there was something like a Lorentz transformation for v=c, it wouldn't be one-to-one, so it wouldn't be mathematically compatible with the structure of relativity. (An easy way to see that it can't be one-to-one is that the length contraction would reduce a finite distance to a point.)

What if a system of interacting, massless particles was conscious, and could make observations? The argument given in the preceding paragraph proves that this isn't possible, but let's be more explicit. There are two possibilities. The velocity V of the system's center of mass either moves at c, or it doesn't. If V=c, then all the particles are moving along parallel lines, and therefore they aren't interacting, can't perform computations, and can't be conscious. (This is also consistent with the fact that the proper time s of a particle moving at c is constant, ds=0.) If V is less than c, then the observer's frame of reference isn't moving at c. Either way, we don't get an observer moving at c.

 

[TCS]

I don’t want to dismiss the obvious practical utility of photons as a model. But setting aside the wave nature of light (since it is complementary anyway), why do we need the intermediary, “photons” to explain the particle aspects of light?

SR says photons don’t age because they travel at c (the limit of time dilation). But in frame c, a photon sees its path length as zero (the limit of length contraction). Equating “zero path length” to “contact” would seem sufficient to explain all of light’s particle behavior (photoelectric effect, Compton effect, even virtual photon “exchanges”) without invoking massless energy bundles.

It's just a matter of interpretation. You don't really need massive particles either.

 

[Phrak]

Faradave. You've presented an idea of that I entertain quit often, though make no progress with: "can action at a distance mediated by photons be equally explained by direct interaction?"

 

[bapowell]

Faradave. You've presented an idea of that I entertain quit often, though make no progress with: "can action at a distance mediated by photons be equally explained by direct interaction?"

What does that even mean?

 

[GRDixon]

I don’t want to dismiss the obvious practical utility of photons as a model. But setting aside the wave nature of light (since it is complementary anyway), why do we need the intermediary, “photons” to explain the particle aspects of light?

I've often wondered the same thing. Since we can't "see" or locate photons in flight (without obliterating them, it seems to me that the interaction of matter with light, at points in space and time, says it all. The concept of a photon particle, flying through space from souce to sink, seems as whimsical to me as the concept of an ether.

 

[ZapperZ]

I've often wondered the same thing. Since we can't "see" or locate photons in flight (without obliterating them, it seems to me that the interaction of matter with light, at points in space and time, says it all. The concept of a photon particle, flying through space from souce to sink, seems as whimsical to me as the concept of an ether.

You can't "see" electron either!

The concept of photon having clumps of energy AND can be "located" is plainly obvious upon interaction (i.e. a single photon doesn't spread itself all over a detector) and in any which-way experiments. I don't know why this is so "whimsical" considering that these are very good experiments that are in good agreement with such picture. When was the last time you had such experiments for the ether for you to put them in the same category?

Zz.

 

[Faradave]

Zz

Please make the exact citation as you would in a publication…I'm still waiting for an exact reference here before I consider that you've violated the PF Rules on speculative, personal theory…

The citation I gave came from Physics Forums' own recommendation (https://www.physicsforums.com/showthread.php?t=33583). It stated my interpretation of photonic path length zero and time stopping exactly. So, I learned it here, doing “homework”. It’s been there since 2004! Where were the censors then? The citation is plausible, since it agrees with the transform equations when v=c. And as is oft repeated, light has no speed other than c (in a vacuum). If the equations can’t be trusted, they might come with an asterisk. But no, I don’t publish anymore and never did in a physics journal if that’s what you want me to admit.

So why would you transform to light's reference frame (is this even valid in the first place?)

To explain remote contact. What a “photon” appears to do, is transfer momentum and energy from an emitting particle to an absorbing particle. If the photon has a trajectory from one particle to another (future) particle and that trajectory has zero length, the photon is telling us that it represents an actual collision in frame c ( projecting as a remote collision in frames <c).
I’m suggesting that the kinetic theory of heat can finally be extended to explain radiation in addition to conduction, convection and the gas laws. All in terms of collisions and migrations of real (massive) particles. It would be... beauty!

Maybe you should have done a bit more "homework" first before making your earlier claim. To make such statements while being ignorant of a whole bunch of experiments and phenomena is just puzzling.

If I wasn’t ignorant, I wouldn’t be here! I can’t understand what claims and statements are so offensive to you. In view of the fact that photons are seen as “force carriers”, I am simply asking, is the carrier really necessary?

Photons are not spinless!

I’m embarrassed! You are indeed correct that photons are reported to have spin=1. I had read this before but considered the notion of a massless and sizeless “particle” having spin angular momentum so absurd that it just didn’t register. My apologies. I don’t think spin =1 really helps the photon case though. It seems all too coincidental that the emitting and absorbing electrons each have spin =1/2 and the intermediary has spin=1 as if it were connecting and summing the two!

In any case so that my list doesn’t have a gap, let's replace "spinless" with "frameless" and "observerless". It’s still a lot of things for something real not to be.

And collisionless? You haven't heard about photon-photon collision in QED?

No. And I don’t think I want to. For example, at http://en.wikipedia.org/wiki/Two-photon_physics I found, “Two photons cannot ever collide. In fact light is quantized only when interacting with matter.”

…several phenomena that have not been described using anything else other than the photon picture. It seems that the burden in on YOU to show that you can describe these otherwise.

Let’s consider the photoelectric effect. You have incident light and if you increase intensity you get more electrons ejected but with identical energies. If you increase the energy (frequency) you get the same number of electrons but at higher velocities coming off the metal plate.

Don’t you agree that the same effect could be achieved with an incident electron beam? More electrons in means more get ejected but faster (more energetic) electrons in mean faster electrons ejected. Photons are like electron collisions. So maybe that is what they ultimately are. But “maybe” isn’t much in the way of proof. I agree, the burden is on me. Thus, I offer the following:

The spectroscopic character of antihydrogen is expected to be identical to that of normal hydrogen when it is ascertained soon at CERN (http://en.wikipedia.org/wiki/Antihydrogen):

“According to the CPT theorem of particle physics, antihydrogen atoms should have many of the characteristics regular hydrogen atoms have, i.e. they should have the same mass, magnetic moment, and transition frequencies (see Atomic spectroscopy) between its atomic quantum states.”

“Today, no conclusive spectral signature for the presence of antihydrogen could be reported, since measuring the spectrum of antihydrogen, especially the 1S-2S interval, is exactly the goal of these CERN collaborations.”

If that is the case, I’m wrong! About contact, zero path length, pinholes (photo-induced wormholes), remote collisions, the whole shebang! End of story. That’s because I predict unexpected instability of antihydrogen upon absorption of light from normal atoms. Specifically, there will be signature gamma emissions indicating the remote annihilations of the emitting electrons and absorbing positrons from their respective locations. All we really have to do is wait (vigilantly)!

In the meantime, I note that Mills and Cassidy who are leading investigators of Positronium (Ps, arguably the closest thing to antihydrogen currently available for investigation) report http://focus.aps.org/story/v16/st16:

"Mills and his colleagues found a higher decay rate with the denser pulses - clear evidence, they say, of frequent positronium collisions, an important step toward making molecules. They were surprised, however, that the decay rate was four times as high as expected based on the simplest understanding of the collisions." I enquired about the possibility of light contamination but received no reply.

The ARPES experiments, for example, is not simply something I talk about, but also something I DID (my avatar is a raw data from an ARPES measurment that I took)!

You avatar is wonderful! From what little I could gather on Wikipedia, ARPES (Angle-resolved photoemission spectroscopy) seems like a very sophisticated and sensitive photoelectric effect measurement (I got completely lost on "reciprocal lattice" though). Congratulations on your accomplishments there and thank you for your very considerable efforts here (Disagreements aside, I mean that.)

 

[Faradave]

What do you mean by "in" such a frame?...The fact that it is possible to find a set of coordinate systems moving at constant velocity relative to one another and satisfying both postulates is basically the physical content of the theory of relativity...

Good point! I'm thinking about this. By "in" I mean whatever frame in which "photons" exist . If relativity excludes the very frame in which its photons exist, shouldn't we be all the more careful in guessing what a photon might be?

Could they be conduits (for energy, but not mass)? That is, buy being merely a "hole" big enough only for tangential contact by fundamental particles (I call them pinholes), photons could represent yet another support (and mechanism) for the notion that no massive particle can achieve c.

 

[espen180]

Good point! I'm thinking about this. By "in" I mean whatever frame in which "photons" exist . If relativity excludes the very frame in which its photons exist, shouldn't we be all the more careful in guessing what a photon might be?

Could they be conduits (for energy, but not mass)? That is, buy being merely a "hole" big enough only for tangential contact by fundamental particles (I call them pinholes), photons could represent yet another support (and mechanism) for the notion that no massive particle can achieve c.

Photons exist in every frame. What relativity says is that there is no intertial frame where a photon is at rest(more spesifically, photons move at c in every intertial frame). You make make a frame where it is at reast, but it would be non-inertial.

 

[JesseM]

Good point! I'm thinking about this. By "in" I mean whatever frame in which "photons" exist . If relativity excludes the very frame in which its photons exist, shouldn't we be all the more careful in guessing what a photon might be?

Again, a frame is just a coordinate system for assigning events position and time coordinates, and you are free to construct one where a photon's position coordinate remains the same at different time coordinates, relativity just says this won't qualify as an inertial frame (you are certainly free to use non-inertial frames in relativity but the equations for various laws of physics may look different in these frames than they do in their standard inertial form). Why should this suggest anything especially mysterious about "what a photon might be"?

 

[ZapperZ]

Good point! I'm thinking about this. By "in" I mean whatever frame in which "photons" exist . If relativity excludes the very frame in which its photons exist, shouldn't we be all the more careful in guessing what a photon might be?

Could they be conduits (for energy, but not mass)? That is, buy being merely a "hole" big enough only for tangential contact by fundamental particles (I call them pinholes), photons could represent yet another support (and mechanism) for the notion that no massive particle can achieve c.

There is a severe misunderstanding of SR here, and in your reply to me, so much so I have no idea where to begin. I believe you've received several replies already on why this is a rather faulty concept to begin with. Take note that while you may have understood Lorentz transformation, your application of it to the photon frame is faulty. That, in itself, is the crux of your original argument in your first post. You need to first and foremost, understand why this is wrong, because it makes the rest of your argument in this thread rather moot.

Zz.

 

[Faradave]

Since you haven't invoked quantum mechanics in this argument, it isn't an argument against the existence of photons, it's an argument against the existence of classical electromagnetic waves.

...If you want to post about your doubts about photons, that belongs in the Quantum Physics forum. If you want to post about the question of frames moving at c, then that does belong in this forum, but ...it gets tiresome to cover the same ground over and over.

Either way, I would encourage you to start fresh threads...

On the topic of frames of reference moving at c, here is a FAQ I've written...

we need to be able to physically realize this frame in terms of an observer and measuring devices. But we can't. It would take an infinite amount of energy...

other reasons not to allow such frames...there is a restriction that they should be smooth, one-to-one functions...for v=c, it wouldn't be one-to-one, so it wouldn't be mathematically compatible with the structure of relativity. (An easy way to see that it can't be one-to-one is that the length contraction would reduce a finite distance to a point.)

...the observer's frame of reference isn't moving at c. Either way, we don't get an observer moving at c.

All good points! Thanks for digging up your FAQ for me, I had run across it before in my wanderings so I've had some time to think.

I am certainly willing to move to other forums. As you can see, path contraction (to zero) is central to my reinterpretation of "photon" and that's why I started here. But having stated that (in my earlier replies today), I may be finished here because the question of its impact on the wave aspects of light, implications at low frequency and for static charge (0 Hz) forces can be can be anticipated and would be more appropriately addressed elsewhere.

Regarding the requirement for smooth one-to-one functions:
I had not been aware of the requirement (but that is true for a great deal).
You may be completely correct.
But I wonder, does a point really know it's just one? I think we may be able to specify a single location (at least mathematically) but I don't think we can require it to contain only a single point.

 

[Faradave]

Zz

There is a severe misunderstanding of SR here, ... you've received several replies already on why this is a rather faulty ...Lorentz transformation, your application of it to the photon frame is faulty. That, in itself, is the crux of your original argument in your first post. You need to first and foremost, understand why this is wrong...

I have made note of this and the other replies. I will take time and give careful consideration to your diagnosis. I was indeed attempting to refer to "frame c" as the frame in which a photon is theoretically rest and apparently the one which Einstein wrestled with. Even though frame c is constant (uniform, non-accelerating), I am to consider it not inertial (confused).

If a frame c is allowed but non-inertial, what is the impact on length? Perhaps some of the threads referring to gravity and length? I'd been avoiding them.

 

[espen180]

I was indeed attempting to refer to "frame c" as the frame in which a photon is theoretically rest and apparently the one which Einstein wrestled with. Even though it is constant (uniform, non-accelerating), I am to consider it not inertial (confused).

You have to accept that a frame such that you are descriping does not exist. It violates the second postulate of SR. You don't even need relativity to see it. An oscillating electric and magnetic field at rest (zero propagation velocity) doesn't satisfy Maxwell's equations.

If a frame c is allowed but non-inertial, what is the impact on length. Perhaps some of the threads referring to gravity and length? I'd been avoiding them.

You are free to choose your time and length scale in your non-inertial photon "rest frame", but there is no way to corelate that to any inertial frame not moving at c.

I.e. choosing "one second" to be one period of one million periods of the photon oscillation or choosing "one meter" as one or a million wavelengths won't make a difference to an inertial observer.

 

[Phrak]

You have to accept that a frame such that you are descriping does not exist. It violates the second postulate of SR. You don't even need relativity to see it. An oscillating electric and magnetic field at rest (zero propagation velocity) doesn't satisfy Maxwell's equations.

Actually, all electric and magnetic fields are at rest, by definition. Electric and magnetic fields do not propagate.

 

[espen180]

Actually, all electric and magnetic fields are at rest, by definition. Electric and magnetic fields do not propagate.

Ah, my bad. I was referring to electromagnetic waves.

 

[Faradave]

Zz:

…while you may have understood Lorentz transformation, your application of it to the photon frame is faulty. That, in itself, is the crux of your original argument in your first post. You need to first and foremost, understand why this is wrong…

This is valuable advice to me (and future, error prone individuals).

Espen 180:

You have to accept that a frame such that you are [describing] does not exist. It violates the second postulate of SR. You don't even need relativity to see it. An oscillating [EM wave] at rest (zero propagation velocity) doesn't satisfy Maxwell's equations.

This is representative of the issue referred to by Zz, others above and in other forums. Thank you all for your efforts to clarify this. It is incredibly easy for outsiders, such as myself, to make this mistake! I had been applying the concept of Newtonian inertial reference frames which according to Wikipedia (http://en.wikipedia.org/wiki/Inertial_frame_of_reference#Newton.27s_inertial_frame_of_reference) are non-accelerating (i.e. no change in speed or direction) compared to other such frames. Once I started using concepts like absolute speed c, length contraction, time dilation or simultaneity, I had an a priori requirement to adopt relativistic inertial reference frames (RIRFs). Since the rest of you clearly know this, I quote for my own benefit (and future visitors making the same mistake):

Einstein's theory of special relativity, like Newtonian mechanics, assumes the equivalence of all inertial reference frames, but makes an additional assumption, foreign to Newtonian mechanics, namely, that in free space light always is propagated with the speed of light c₀, a defined value independent of its direction of propagation and its frequency, and also independent of the state of motion of the emitting body. This second assumption has been verified experimentally…

So, my eyes are open. I now understand why there was so much pushback to my concept of pinholes (photo-induced wormholes) as a replacement for photons. That was based on a mechanism of length contraction in each photon’s own frame c. But if those frames are disqualified as RIRFs, I’m not justified in invoking path contraction to zero.

But help me out please. Suppose two photons A & B pass at right angles. I pick Frame A on photon A (so photon A is “at rest” in Frame A). What is the behavior of photon B in Frame A?

I’m guessing photon B does what it always does in an RIRF. Doesn’t it just zip away at speed c? If that’s the case, are we really saying that Frame A is disqualified as an RIRF just because one photon (photon A) is not traveling at speed c? The whole point of my inquiry is that instead of disqualifying Frame A as an RIRF, we should instead be disqualifying photon A as a photon!

I suggest that in Frame A, photon A is not a photon, it's a collision. With the emitting and absorbing electrons in contact, there is no room for a photon. The frequency of that light goes to zero while the wavelength becomes infinite, as with a static charge. So, as was pointed out, there’s no EM wave, no propagation, just transfer of energy and momentum. But with all the other photons behaving as if Frame A is an RIRF I think the weight of evidence shows it is.

 

[JesseM]

But help me out please. Suppose two photons A & B pass at right angles. I pick Frame A on photon A (so photon A is “at rest” in Frame A). What is the behavior of photon B in Frame A?

There is no relativistic inertial reference frame where this is true. You just quoted something that said "Einstein's theory of special relativity, like Newtonian mechanics, assumes the equivalence of all inertial reference frames, but makes an additional assumption, foreign to Newtonian mechanics, namely, that in free space light always is propagated with the speed of light c₀"--this assumption would be violated if we allowed a coordinate system where photon A is at rest to qualify as an "inertial" frame in relativity. Such a coordinate system can be defined, but it is a non-inertial frame, by definition.

 

[Faradave]

...in free space light always is propagated with the speed of light c₀"--this assumption would be violated if we allowed a coordinate system where photon A is at rest to qualify as an "inertial" frame in relativity. Such a coordinate system can be defined, but it is a non-inertial frame, by definition.

I hear you. The recurrence of this important message is starting to get through even my thick skull. I’d like to consider photon A a bit further though. Just thinking out loud.

Photon A travels from emitting to absorbing electron with a trajectory. That trajectory can be thought to have a slope, covering a certain span of distance in a certain time. In all relativistic inertial reference frames (RIRFs), the slope MUST be c. (You see, I did hear you, and the others!)

As we sample different RIRFs, though time dilates and length contracts, the ratio for the trajectory of photon A is always c. Well, in calculus we used to calculate slopes of curves quite successfully as the span under consideration shrinks to zero. In the case of photon A, I assert that its speed remains c, as path length shrinks, right down to a single point, of “contact”. That photon A becomes undetectable to us in frame A is of no consequence because its energy and momentum are never lost from our view. Nothing is ever lost to us, including the status of Frame A as an RIRF. Photon A never stops traveling at speed c, its path simply gets too short to matter, but the ratio stands. Zero path length occurs in a relativistic inertial reference frame.

That was just me. Here is a similar line of thought I found wandering around PF.

…you can consider what happens if we give progressively lighter particles a fixed amount of kinetic energy before they are to transit from point A to B (which are at rest relative to you). As the the particles become lighter (i.e. having less rest mass) they will have to move faster relative to you (but still less than c) to have the same fixed amount of kinetic energy. From the perspective of each of these particles (ie. from a reference frame at rest relative to each particle) the distance A B has been shortened due to length contraction. In the limit where the mass go to zero, the distance each particle travel also goes to zero, meaning they would travel any finite distance however big in zero time. Now change the particles with ones that are born at A and absorbed at B and you have, more or less, "the life of a photon".

Nonetheless, I’m not really expecting to win any converts here. Your opinions are qualified, mine are not. But aren’t you just a little more interested in the pending spectral analysis of ultracold antihydrogen now than you were before? Why else would Gerald Gabrielse and others spend decades working toward this experiment unless there was some possibility that antiatoms will show us something new? Surprises happen!

 

[nismaratwork]

I hear you. The recurrence of this important message is starting to get through even my thick skull. I’d like to consider photon A a bit further though. Just thinking out loud.

Photon A travels from emitting to absorbing electron with a trajectory. That trajectory can be thought to have a slope, covering a certain span of distance in a certain time. In all relativistic inertial reference frames (RIRFs), the slope MUST be c. (You see, I did hear you, and the others!)

As we sample different RIRFs, though time dilates and length contracts, the ratio for the trajectory of photon A is always c. Well, in calculus we used to calculate slopes of curves quite successfully as the span under consideration shrinks to zero. In the case of photon A, I assert that its speed remains c, as path length shrinks, right down to a single point, of “contact”. That photon A becomes undetectable to us in frame A is of no consequence because its energy and momentum are never lost from our view. Nothing is ever lost to us, including the status of Frame A as an RIRF. Photon A never stops traveling at speed c, its path simply gets too short to matter, but the ratio stands. Zero path length occurs in a relativistic inertial reference frame.

That was just me. Here is a similar line of thought I found wandering around PF.

Nonetheless, I’m not really expecting to win any converts here. Your opinions are qualified, mine are not. But aren’t you just a little more interested in the pending spectral analysis of ultracold antihydrogen now than you were before? Why else would Gerald Gabrielse and others spend decades working toward this experiment unless there was some possibility that antiatoms will show us something new? Surprises happen!

Yes, but this doesn't change some of your fundamental confusion here, and using the personal motivation of some researchers doesn't change the possible reality. I also do not believe that the researchers are making the same error in their assumptions that you have been regarding SR.

 

[Faradave]

Yes, but this doesn't change some of your fundamental confusion here, ...error in...assumptions that you have...regarding SR.

I agree there is confusion, understandably so, but is it mine? The model for light, like model for the atom, has been undergoing extensive revision since mankind first had one. Do you imagine we’re finished? Pinholes are not awfully different than photons. They offer collisions. What could be more particle-like than that?

As far as reference frames go, I was quick to recognize and concede to the need for relativistic inertial reference frames (RIRFs), as pinholes rely on path contractions. But as I believe I have shown, the error lies with current theory. A frame in which a photon “would be” at rest is not at all the same as a photon “being” at rest! The instantaneous velocity of a photon, determined as path length shrinks to zero, remains c. Thus, the frame is an RIRF. In such a frame, the photon energy and momentum still exist, no longer between emitting and absorbing electrons but in them (same as billiard balls).

 

[DrGreg]

In such a frame, the photon energy and momentum still exist, no longer between emitting and absorbing electrons but in them (same as billiard balls).

No, if such a "frame" were valid, both the "energy" and "momentum" would be red-shifted to zero.

Your "frame" has some peculiar properties

1. photons are at rest
2. photons travel at speed c
3. all distances are zero
4. all times are zero
5. photons have zero energy and momentum

None of this makes sense, which is what everyone has been telling you.

 

[nismaratwork]

No, if such a "frame" were valid, both the "energy" and "momentum" would be red-shifted to zero.

Your "frame" has some peculiar properties

1. photons are at rest
2. photons travel at speed c
3. all distances are zero
4. all times are zero
5. photons have zero energy and momentum

None of this makes sense, which is what everyone has been telling you.

Thank you, I was pondering how to respond to that one.

 

[TCS]

I agree there is confusion, understandably so, but is it mine? The model for light, like model for the atom, has been undergoing extensive revision since mankind first had one. Do you imagine we’re finished? Pinholes are not awfully different than photons. They offer collisions. What could be more particle-like than that?

As far as reference frames go, I was quick to recognize and concede to the need for relativistic inertial reference frames (RIRFs), as pinholes rely on path contractions. But as I believe I have shown, the error lies with current theory. A frame in which a photon “would be” at rest is not at all the same as a photon “being” at rest! The instantaneous velocity of a photon, determined as path length shrinks to zero, remains c. Thus, the frame is an RIRF. In such a frame, the photon energy and momentum still exist, no longer between emitting and absorbing electrons but in them (same as billiard balls).

I don't believe that electrons are like pinholes. They are more like diffraction patterns created by pinholes. As long as the electron is at a constant velocity, it exists as a perfect diffraction pattern/standing wave. If you distort that distribution, you accelerate the particle.

Accelerating an electron, is like moving the central portion of a spherically diffracted wave. That motion is then translated through the diffraction pattern at the speed of light. A photon is the embodiment of that dispersion of the interaction through the electron's diffraction pattern, since that dispersion will alter the way that the elecron interacts with all the other waves.

Accordingly, you can't have a photon reference frame because photons are just the redistribution of energy through a particle's wave pattern.

 

[Faradave]

No,...

DrGreg, thank you for taking the time to respond. I love your accent! When you say, “No” it has a convincing tone which I couldn’t hope to achieve. I’ll give it a try though. Ahem, “Touch the stars! Pinholes are ours!”

Aw, shucks. Even rhyming and color don’t seem to help.

…if such a "frame" were valid,…

For the benefit of latecomers, the “frame” referred to is a reference frame moving at speed c and parallel to any particular “photon”. Let’s refer to this as "Frame c" in this post and for simplicity, let’s assume the emitting and absorbing particles are both electrons occupying a different frame we’ll name "Frame<c", a relativistic inertial reference frame (RIRF). I put the term “photon” in quotes because I believe they are actually pinholes (photo-induced wormholes) but I will refer to photons normally now.

I’m afraid I see the question of validity settled. It was one of your fellow Brits, who showed us the way to instantaneous velocity, and I do say, it’s worked out quite well! The instantaneous velocity of a photon, determined as its path length shrinks to zero (as frame velocity goes to c), remains c. Frame c is an RIRF.

… both the "energy" and "momentum" would be red-shifted to zero.

If the momentum and energy were locked in a photon perhaps, but not when they are in objects. The emitting and absorbing electrons are massive and therefore can’t be at rest in Frame c. So they must be moving and not just capable of, but obligated to, have energy and momentum in that frame. The difference in their energy is one quantum, as verified in the disposition of their orbitals before and after the collision. With an instantaneous velocity of c giving a path length reduced to a point of contact, it is conceptually much easier to envision a hole than a particle. The pinhole projects as the trajectory of a light ray in Frame<c.

Your "frame" has some peculiar properties

Quantum tunneling, virtual particles, point particles, dark energy, renormalization… Nah! Ain’t nothin peculiar ‘bout physics!

But seriously, consider the pairing behavior of electrons. There are orbital filling, covalent bonds, ionic bonds even the Cooper pairs in metallic superconductors to illustrate the tendency that electrons pair in space for various lengths of time. To the extent that Einstein attributed dimensionality to time, there may also be a tendency that electrons pair in time over various distances in space. While I explain light as pinholes with slope c. The “quantum non-local connection” of the EPR paradox seems to offer us a spinhole (spatial interconnecting wormhole), with slope zero to explain entanglement. So, it’s not just outsiders who envision the utility of a "tiny wormholes" model. As I recall, John Wheeler’s quantum foam is also filled with them.

1. photons are at rest

Photons always travel at speed c in RIRFs, even Frame c. But there is no obligatory distance which must be traveled.

2. photons travel at speed c

Yes they do! They all do. That’s why Frame c is an RIRF.

3. all distances are zero

By "all distances", I assume you refer to those components of distance parallel to Frame c. The perpendicular components are unaltered. Now for the parallel components. While the Lorentz transformations do not explicitly contain this restriction, it is intuitive and consistent with observation that its effects, while independent of path length, do not extend beyond the emitting and absorbing particles. A solution might be to adjust the definition of “opacity” to restrict the transforms externally. In addition, pinholes, unlike photons are very narrow. The transform need only be considered within it. It is the unrestricted nature of current electric and magnetic field descriptions which have lead us to think otherwise.

4. all times are zero

Nothing ages in Frame c. And there is nothing to say transfer of energy between to colliding electrons takes any time at all. This is equivalent to the question, “Does a photon accelerate from an emitting electron or is it “born” at speed c? My impression is distinctly the latter for the photon model.

5. photons have zero energy and momentum

Photons have E= hf, as always but only as far as they travel (see reply to 1.)

None of this makes sense,…

You are obviously in very good company. I hope it makes more sense now.

…what everyone has been telling you.

“What do you care what other people think?”, R. Feynman, in a book title no less! Do you think he meant it?

Please excuse my sometimes, “playful” wording on a subject you obviously take seriously. I take it from your PF name, that you have an advanced degree in physics. I respect your accomplishment and value your opinion. I don’t think you should change that opinion based upon anything I’ve written. Demand proof! I believe Dr. Gabrielse and colleagues will be as pivotal to pinhole theory as Sir Arthur Eddington was to Relativity (description above, diagram attached).

Can you imagine the blunder though, if without testing, we continue in the assumption that light (from normal matter) is exactly the same as antilight (from antimatter). There could be entire distant galaxies of antimatter out there and their dim rays would be entirely invisible to us unless we adapt telescopes to detect the characteristic secondary gamma emissions resulting from remote annihilations. Here's to not keeping ourselves in the dark. Good day.

 

[Faradave]

A question was posed to me from outside PF. I will volunteer and respond to it here since, in my view, it represents the last, logically independent argument from Relativity against pinholes (photo-induced wormholes) as an alternative to photons. That is, I believe all arguments would challenge based upon validity of reference frame (as relativistic), length contraction (path = 0), time dilation (to infinity) or simultaneity. The following question is based upon the last of these and has not yet been raised here.

Suppose you’re right that “Frame c” (moving at light speed) actually is relativistic. It seems that you have still painted yourself into a corner regarding simultaneity. Many times you stressed that the electrons make “contact”, “collision” or have “zero path length” through a pinhole. But when there is an event such as contact, occurring in one place at one time, it must be that all observers agree on the event. But when a picture is taken of the night sky, no one agrees that any star is touching the camera!

This is a good point. I could give a wimpy answer like, “There aren’t really enough star electrons touching the camera for anyone to witness.” But that wouldn’t get to the heart of this issue. To be sure, Wikipedia in the first paragraph in, “Relativity of Simultaneity” says:

Where an event occurs in a single place-for example, a car crash-all observers will agree that both cars arrived at the point of impact at the same time.

I assert that a speed of light reference frame (Frame c) is a relativistic inertial reference frame because its motion is uniform and all photons have speed c (even those traveling zero distance). However, it remains true that no massive particle can achieve speed c. Thus, as has been stated here (#10) and in other forums, no observer can enter Frame c. Frame c is, in fact, the only place that we can be sure all observers will agree they did not see the collision! If you roll it about in your mind a bit, I think you’ll find that this is really quite consistent with what the questioner and Wikipedia have said.

 

[starthaus]

I assert that a speed of light reference frame (Frame c) is a relativistic inertial reference frame because its motion is uniform and all photons have speed .

Ok,

Can you derive the transformations between your "Frame c" and the other inertial frames?
All the other inertial frames are connected by the Lorentz transforms, derive the transform that connects your "Frame c" with the rest.

 

[Faradave]

Can you derive the transformations between your "Frame c" and the other inertial frames?

I use the limiting case where velocity of the frame approaches c. Time stops (goes to infinity), path length goes to zero and contact between emitting and absorbing particle occurs. I believe the particle aspects of light are not an accident or mysterious but a simple collision.

Controversy arises when people mistakenly presume a photon is “at rest” in Frame c. That is resolved two ways. First, a “photon’s” instantaneous velocity remains c as path length shrinks to zero. Zero path length is not itself problematic as there is no obligatory distance required for any photon in relativistic inertial reference frames (RIRFs). But with path length zero a photon is obviously superfluous. So second, photons were never more than a very useful accounting tool in any frame (in my view). I replace photons with pinholes (photo-induced wormholes).

There is room for debate about the meaning of “contact” as the position and velocity of electrons is uncertain and their diameters (let alone surfaces) are indeterminate for what are often referred to as “point particles”. But a functional definition is still available to us. For this discussion, “contact” is: sufficient proximity for transfer of kinetic energy (and momentum). In the test case illustrated in #34 asserting a remote collision between electron and positron (via light transmission) contact is: sufficient proximity to result in annihilation. I offer this as both necessary and sufficient to the confirmation of pinholes. Except for this discussion, such an occurrence is, to my knowledge, completely unanticipated. To the extent that contact may "work" at distances greater than zero (Planck length?), the discussion only shifts toward more established RIRFs and pinholes.

 

[starthaus]

I use the limiting case where velocity of the frame approaches c.

So, where are your formulas for the transformation I asked you? Can you show them?

 

[Faradave]

l=ct, l'=c't', c=c' {...goose bumps}

 

[starthaus]

l=ct, l'=c't', c=c' {...goose bumps}

There are not transforms, these are nothing.

 

[reilly]

Faradave -- There's a good reason why the concept of photon has survived for over a century -- the concept is immensely useful, spanning many branches of physics, and it passed many tests with flying colours. Simply stated, there is no reason to challenge the idea of a photon -- there's no evidence at all that the concept is wrong.

To gain any legitimacy, you must show 1. that your ideas agree with experiment, and 2. the specifics of where current theory is not correct and your theory is.
You have yet to do this.

Lot's of luck.
Regards,
Reilly Atkinson

 

[Fysiks Phan]

Light from the sun is slowed when entering water. What is its speed after emerging from the water?

 

[starthaus]

Light from the sun is slowed when entering water. What is its speed after emerging from the water?

c.

BTW, light is not slowed down in water, its path is lengthened. This is a complex phaenomenon.

 

[Fysiks Phan]

We know that light is slowed when passing through water. Is this slowing cumulative? What is the speed of the same light upon emerging from the water?

 

[Fysiks Phan]

Btw: I disagree. But let me put it another way. When I see objects that are under water, like a tasty tuna, I know that this light has passed through a given distance, let's say 100 feet. 100 feet is the same distance whether in air or water. Is the light from the tuna faster after leaving the water?

 

[starthaus]

We know that light is slowed when passing through water. Is this slowing cumulative?

No.

What is the speed of the same light upon emerging from the water?

I have already answered that, c.

 

[starthaus]

Btw: I disagree.

That's your problem. Taking a physics class might help.

But let me put it another way. When I see objects that are under water, like a tasty tuna, I know that this light has passed through a given distance, let's say 100 feet.

Actually light in the water has taken a complex, zig-zag path, not a straigh one like in vacuum.

100 feet is the same distance whether in air or water.

No, see above.

Is the light from the tuna faster after leaving the water?

No. It is still c.

 

[nismaratwork]

We know that light is slowed when passing through water. Is this slowing cumulative? What is the speed of the same light upon emerging from the water?

This shows that you have literally no idea what Relativity in its special or general formulation is. None at all, which is alright, but not if you're trying to debunk photons, instead of learning basic physics.

 

[Faradave]

...these are nothing.

They were quite something to Dr. Einstein, especially the last one, c=c'.

 

[DrGreg]

l=ct, l'=c't', c=c' {...goose bumps}

There are not transforms, these are nothing.

Faradave, what is being asked for here are equations that express l' and t' in terms of l and t (although I'd prefer to use the symbol x instead of l), not just for the motion of photons but for any arbitrary events.

Hint: the Lorentz transform between two inertial frames is conventionally given by the equations

t&#039; = \gamma(t -vx/c^2)
x&#039; = \gamma(x - vt)​

where \gamma = 1/\sqrt{(1-v^2/c^2)}.