[JP (OP)]

Yor_on, the photon picture doesn't have a classical wave model.  It's used because in certain cases, the classical wave theory breaks down.  The link between the two models is mathematically complex.  This is because they simply don't have a nice wave function that you can draw in space.  They have a very precise definition in terms of energy, but it turns out that you can't draw them in space.  A classical wave is a superposition of photons in a particular way, but that's incredibly hard to visualize without a grasp on the mathematics, simply because you can't write down what a photon's wave function looks like in space, whereas you can write a classical wave in space.  It can, however, be done.  (The link above to Mandel and Wolf is a good place to start, but you need to be ready for some heavy math and you want a working knowledge of quantum mechanics.) 

Photons are important because there are cases where knowing about energies is much more important than knowing about what it looks like in space, and there are cases where you can make approximations to get some idea of what they'd look like in space.  However, in most cases, you don't need the photon model.  Even though it should be right, treating most everyday problems in terms of photons is so incredibly complex that no one would want to do it.

[Soul Surfer]

when I say free space I mean a total vacuum with absolutely no other particles in it.  they only disturb the picture and are not required. a slight lack of perfection i.e. the odd particle does not have any significant effect.

As with an exponential decay the gaussian bell function goes off to infinity mathematically in both directions and is never zero.  physically it becomes to small to matter at a few standard deviations from the peak.   This is the big difference between mathematical things and physical things.

Some of your problems seem to be associated with mathematical absolutes.   in this sense every particle in the universe extends throughout the entire universe in all space and time

[Soul Surfer]

It suddenly struck me.  maybe you are thinking about what is sometimes called "the quantum mechanical vacuum"  which is a seething mass of virtual particles that only exist within the limits allowed by the uncertainty principle.  This is not what i am talking about because the details of that can never be known in any other way than the statistics of the uncertainty principle.  what I am talking about is the observable classical vacuum of standard physics.

[Farsight]

But Farsight, you will need to be able to explain the properties of an electron going through a Stern-Gerlach magnet too for your proposal to become a theory, don't you agree? Or maybe you already have?

It isn't my proposal, yor_on. Williamson and van der Mark used to be at CERN. The former is a senior lecturer at Glasgow University, the latter is chief scientist at Philips. Qiu-Hong Hu is a researcher at the University of Gothenburg. Don't let ad-hominems like "crank" deter you. This really is leading edge stuff, see this week's New Scientist and the article on page 15 http://www.newscientist.com/article/dn18526-atom-smasher-shows-vacuum-of-space-in-a-twist.html. Here's an excerpt - it's not done to repeat the whole thing:

Atom smasher shows vacuum of space in a twist

Ephemeral vortices that form in the vacuum of space may have been spotted for the first time. They could help to explain how matter gets much of its mass.

Most of the mass of ordinary matter comes from nucleons – protons and neutrons. Each nucleon, in turn, is made of three quarks. But the quarks themselves account for only about 1 per cent of the mass of a nucleon. The remainder of the mass comes from the force that holds the quarks together. This force is mediated by particles called gluons.

A theory called quantum chromodynamics is used to calculate how quarks and gluons combine to give mass to nucleons, but exactly how this phenomenon works is not fully understood.

One possibility is that the fields created by gluons can twist, forming vortex-like structures in the all-pervasive vacuum of space, and when quarks loop through these vortices, they gain energy, making them heavier.

Now the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) in Upton, New York, has seen signs of such vortices...

[Farsight]

Farsight: in addition to the properties you have discussed, the electron model that you propose which dimensions would have? Does the model also predict the wavelike properties of the electron?

It's three-dimensional, lightarrow, like a bagel with a twist only there's no actual surface to it. I wouldn't say the model predicts the wavelike properties of the electron, because that's what we observe. Rather it explains them because it describes the electron as a double-wrapped electromagnetic wave going round and round in a circle.

[yor_on]

JP you say that "A classical wave is a superposition of photons in a particular way" If I would guess then this math describing it is introducing some concept more than just 3D + time. It can't be enough with defining different vectors/tensors, can it?

No SoulSurfer I was thinking straightly 'classically' when I asked you about it, and that's why went some way to define what I meant too. It's easy to see that light somehow can' make it' through space, some of the solutions I've seen suggested is just that "the quantum mechanical vacuum" you thought of. Then you have other solutions too that somehow seems to expect both a sink (eye) and a source (sun) present for any 'wave' to exist, meaning that they won't do it until our two prerequisites are fulfilled.

The interesting thing to me is that in a classical sense a vacuum is a 'nothing'. Let's say that you compress it, well, try to compress it It will be extremely easy to do so on earth. In fact the energy spent will be to create it, not compress it. So what exactly are those waves propagating through? Is a vacuum a 'medium'? And how, if so, should I understand that 'medium'?

Okay Farsight, keep forgetting that So did you find an description of how they explain the properties of an electron going through a Stern-Gerlach magnet?

[Farsight]

No, I didn't look for it. I know it anyway. That's easy.

[PhysBang]

This really is leading edge stuff, see this week's New Scientist and the article on page 15 http://www.newscientist.com/article/dn18526-atom-smasher-shows-vacuum-of-space-in-a-twist.html.

Why would you post this? This obviously has nothing to do with electrons?

It's three-dimensional, lightarrow, like a bagel with a twist only there's no actual surface to it. I wouldn't say the model predicts the wavelike properties of the electron, because that's what we observe. Rather it explains them because it describes the electron as a double-wrapped electromagnetic wave going round and round in a circle.

So how does this explain the wavelike properties?

No, I didn't look for it. I know it anyway. That's easy.

How can we take this answer seriously? If it's so easy, please demonstrate how your proposal produces the appropriate Stern-Gerlach magnet effects. It looks like you are merely trying to avoid answering the question, but surely that cannot be the case.

[yor_on]

I know we are getting of course now but I found this experiment when I was searching on experiments done with superimposing photons. Now, before someone tells me that this can't be done We have the idea and we use it to explain a lot of things, don't we? Which to me seems to imply that you can't used a 'flawed model' to build further proposals on, right?

The reason why it seems to be hard to do is HUP (Heisenberg's uncertainty principle) as I understands it. "You can't get photons that have perfectly defined position and trajectory. Photons with a perfectly defined trajectory must have an uncertainty in their wavevector direction of zero, which implies that the wavefunction of the photon is an infinite plane wave. Since the wavefunction is infinite in extent, the uncertainty in position is infinite. (by Claude Bile)" Remember that this answer is referring to when 'trying to superimpose photons', and not about superimposing waves.

In this experiment they say some, to me, remarkable things "The physicists allowed the photon to pass through the loop five times. They then found that one of the photons had fanned out into a chain of several wave packets which formed a superimposed state."

So they start with one photon, right? "They create this state by using a polarizer to first generate a photon oscillating in a horizontal or vertical direction. This is then moved to the superimposed state by means of a half-wave plate. The half-wave plate acts, to a certain extent, like the pin of a classical Galton board, except that it does not force the photon to adopt a specific direction but ensures that it figuratively continues to move in both directions." And here they seem to get a superimposition from only one photon. How is that done? Ah well it's the same principle as for creating a entanglement, right. But then we talk about waves, not 'photons'?

By the recirculating of those two 'new photons' superimposed, but going two different paths, one longer than the other, back to the half-wave plate (five times), they at last ends up with how many photons (wavepackets)? they must mean 32 like 2, 4, 8, 16, 32 or? Furthermore, after that first 'superimposition/split' they suddenly refer to them/it as wavepackets, why? Because they were treated as waves in the first 'split'? "They then found that one of the photons had fanned out into a chain of several wave packets which formed a superimposed state." 

'One of the photons'? Not wave packets suddenly but photons? And, one of what? They started with only one photon, superimposed it to ? wavepackets. Do they mean that one of those wavepackets now is treated as a singular photon, that in its turn make that chain they are referring too? Or are they still discussing our original photon, but now superimposed into several? And in the end they use a detector that only registers the photon as a particle, which then will give them, one photon again, right?

So it gives me a headache
They 'superimpose' a photon into several, which may be allowed according to HUP? From that they get several superimposed wavepackets but traveling different lengths in time, that then 'transforms' into a photon again, as I understands it?

Source.

If you have any understanding of how this is thought to be done, I'm very interested.
If you understands it that is. I know I don't.
==

And, can you really jump from calling it a photon to a wave, alternative wavepacket, like this?
==

Why I put a question mark after writing 'They 'superimpose' a photon into several, which may be allowed according to HUP?' Is because they call it a photon, not a wave.. to me those have different properties, and what you can observe and do with a wave you can't do with a 'photon', well, as I (still) see it

So yeah, I'm an old 'fogey', or 'stofil'  as we say in Swedish
==
One last question, how do they 'know' that 'they' take both paths experimentally?
Measuring it? Won't that collapse the 'photons' superposition/wavepackets?

[JP (OP)]

Yor_on, you don't need quantum optics to explain what they did.  A classical version of the experiment could be done by using a pules of light, and splitting it into two parts.  One part takes a longer path than the other and they recombine later on before they hit a detector.  What you'd see is that part of the pulse arrives first while the part that took the longer path arrives later.  It sounds like that's essentially what they did, except they had it working with only one photon at a time so that you could either detect it early or late, rather than seeing both pulses every time.

They don't give a lot of mathematical details on what they're doing and assuming in this problem, so its hard to comment on the wave packet terminology.  You can describe wave packets in terms of non-space variables, which is one way to describe photons, or you can make approximations to based on the fact that it's in a fiber in order to write a spatial wave packet in this case. 

By the way, this site should be useful as an introduction to photons.  If you can understand the basics on that site, you should be a long way to understanding photons and how they relate to classical waves.

[yor_on]

Yes JP, I agree, it may be due to me not seeing the concept here. The idea seems to be to illuminate 'many paths' in some quantum way. But when thinking of those experiments where they produce an entanglement I've never seen anyone calling the light 'photons', only waves? Or am I thinking wrong there? Awh, but I still don't understand how you can use use both concepts simultaneously in a experiment? I will look at your link and hope for enlightenment
==

Or maybe you can, after all it's the 'same' light )
Awwwhh, but the link is really nice JP.. Kudos for that one.

[Farsight]

Why would you post this? This obviously has nothing to do with electrons?

It has a lot to do with electrons. Read the article:

"Atom smasher shows vacuum of space in a twist
Ephemeral vortices that form in the vacuum of space may have been spotted for the first time. They could help to explain how matter gets much of its mass. Most of the mass of ordinary matter comes from nucleons – protons and neutrons. Each nucleon, in turn, is made of three quarks. But the quarks themselves account for only about 1 per cent of the mass of a nucleon. The remainder of the mass comes from the force that holds the quarks together..."

We don't talk of quarks in the context of an electron, but there is some kind of force that holds it together, and it does have mass. Light doesn't, and long wave radio tells us that light is "ephemeral" - a photon isn't a point particle. Setting gravity aside, it travels at c, in a straight line. After pair production this straight-line motion at c is no longer present, and instead we now see an electron and a positron. Let's imagine we're moving along with the electron to keep things simple. It has no discernible internal structure or surface, but it does have its wave/particle duality, and it does have some form of angular momentum or spin along with magnetic moment. And it also has mass.

The photon has no mass, but it does have energy / momentum, and delivers a "kick" as per Compton scattering. Now remember that motion is relative, so imagine that it was you moving instead of the photon. That momentum would now feel like inertia. There is a symmetry between these two measures - it's difficult to decelerate an object because of its momentum, and it's difficult to accelerate an object because of its inertia. At this juncture you might say that you can't make a photon not move at c. This is true. But after pair production, that straight-line motion at c has gone. The electron exhibits angular momentum and magnetic moment, so now the motion is circulatory, and there's no aggregate motion with respect to you, because in your reference frame the electron is at rest. So you have effectively "stopped" the photon, hence the momentum looks like inertia. Mass. Only we don't call it photon any more. We call it an electron.
 

So how does this explain the wavelike properties?

The electron is just a circulating photon. It's a soliton or "vorton". You could say it's an ephemeral vortex.

How can we take this answer seriously? If it's so easy, please demonstrate how your proposal produces the appropriate Stern-Gerlach magnet effects. It looks like you are merely trying to avoid answering the question, but surely that cannot be the case.

Take a look at my first post on this thread where I talked about two-dimensional spin. If something keeps changing its spin direction, you can only distinguish between two alternatives. It's all simple stuff, PhysBang, you should look into it properly.   

[JP (OP)]

How can we take this answer seriously? If it's so easy, please demonstrate how your proposal produces the appropriate Stern-Gerlach magnet effects. It looks like you are merely trying to avoid answering the question, but surely that cannot be the case.

Take a look at my first post on this thread where I talked about two-dimensional spin. If something keeps changing its spin direction, you can only distinguish between two alternatives. It's all simple stuff, PhysBang, you should look into it properly.  

Farsight, just because a proposed system has two different options it can choose from, doesn't mean that it actually has physical properties that match experiments.  Can you show any calculations that demonstrate how it gives rise to the various properties of the electron that are known from experiments?

[Farsight]

Yes, but they aren't mine, see http://www.cybsoc.org/electremdense2008v4.pdf

[PhysBang]

Yes, but they aren't mine, see http://www.cybsoc.org/electremdense2008v4.pdf

OK, but that paper has absolutely nothing to so with the earlier paper you linked to, a paper that has nothing to do with electrons. Just because two papers use the same word does not mean that they are using that word in even a remotely similar manner. What quarks do is central to the first paper and the construction of quarks is briefly mentioned in the second paper but never actually addressed. Nothing about what quarks do and how their mass is produced is discussed in the second paper. And this second paper does not give us any calculations relevant to the discussion here about the Stern-Gerlach magnets.

[PhysBang]

Take a look at my first post on this thread where I talked about two-dimensional spin. If something keeps changing its spin direction, you can only distinguish between two alternatives. It's all simple stuff, PhysBang, you should look into it properly.   

Since it is so simple, please give us the calculation.

[Farsight]

I don't know how offhand, Physbang. I'd have to spend a lot of time on it, and that would mean I wouldn't be able to chat with you. Maybe I'll put out the word with guys like David Hestenes, or maybe you should have a crack at two-dimensional spin yourself? Here, check out my first post on this thread then look at the Stern-Gerlach experiment on say wiki, and spot the non-sequitur:

"If this value arises as a result of the particles rotating the way a planet rotates, then the individual particles would have to be spinning impossibly fast. Even if the electron radius were as large as 14 nm (classical electron radius) then it would have to be rotating at 2.3×10¹¹ m/s. The speed of rotation would be in excess of the speed of light, 2.998×10⁸ m/s, and is thus impossible. Thus, the spin angular momentum has nothing to do with rotation and is a purely quantum mechanical phenomenon. That is why it is sometimes known as the "intrinsic angular momentum."

It's a trivial logical flaw, especially when you know about pair production and annihilation. The electron clearly isn't a tiny charged cannonball spinning like a planet. But to then say that its angular momentum and magnetic moment is nothing to do with rotation just doesn't follow. Ditto for scattering experiments that find no cannonballs down to 10^-18 m and then consider this to be an upper size limit.

[PhysBang]

If your proposal cannot account for the operation of the Stern-Gerlach devices, then it does not explain the electron, end of story.

[Farsight]

It does. Two dimensional rotation offers only two alternatives.

Which way does a clock hand rotate? Clockwise? But go round the back, and it's anticlockwise. Keep going round, and it's clockwise then anticlockwise then clockwise then anticlockwise. You can't say which way it's going. But you can tell the difference if the hand is going backwards. 

[JP (OP)]

In their second paper, it's not two dimensional spin.  It's a higher dimensional spin of abstract quantities, but they do claim it only offers two alternatives.  I'm still not convinced the paper actually offers any predictions, since they're not very detailed in their mathematics.  Also, the paper describes the confinement of these photons by means of some extra energy term that they put in by hand so that it gets the right spin.  I'm still not convinced that actually describes the Stern Gerlach effect, again, because they're not very detailed in deriving electron properties in this paper, but at least they claim they get the right spin.

The big problem I have after browsing the paper is that the extra energy term is troublesome, because none of the current models or experiments have detected it.  It seems like it would essentially be giving a gravitation-like force that only applies to light (it attracts two waves together).  Proposing an extra force is going to cause problems because this force has never been observed, and I imagine it should show up in other processes involving either multiple photons or single electrons (beta decay, for example).  Maybe in future papers, the authors will come up with a more detailed analysis of this force and explain why it hasn't been seen before, but until then it isn't a very physically convincing model.