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On the Lighter Side => New Theories => Topic started by: flummoxed on 07/04/2019 12:38:06

Title: Can a photon be visualized ?
Post by: flummoxed on 07/04/2019 12:38:06
Can a photon be visualized?

We can describe a photon as having both wave and particle properties, and predict mathematically what it will do.
The double slit experiment shows clearly it has wave properties.

Quote from: chiralSPO on 05/04/2019 17:32:11
We can use different models to account for the different speeds of light in different materials--one model essentially views the photon as being absorbed and re-emitted repeatedly, and one model just looks at the effective permittivities (both electric and magnetic), and uses that to calculate the speed of light. Both models predict the same speeds (as far as I know), but sometimes it is better to use one model than the other.

This is a little like something I was mulling over a little while ago, and never found any conclusive answers on. Can space be viewed as a material? Ie can a photon passing through free space, be viewed as being absorbed and re-emitted by virtual particles? Thus maybe re-producing a wave effect via a jittery movement through space from virtual particle to virtual particle ?  .

Does anything come out of Feynman diagrams on this? I have not found any answers from my searches.
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 07/04/2019 14:43:51
The particle model doesn't predict the speed of light in vacuo because there is nothing there to absorb and re-emit particles.

Maxwell's equations show that you don't need any medium to transmit light, and imply that the speed of light in vacuo is independent of direction, with values of ε0 and μ0 chosen arbitrarily to rationalise the system of units in use - they don't refer to the properties of a medium but are the "fudge factors" that make electrostatics and electromagnetics mutually consistent.
Title: Re: Can a photon be visualized ?
Post by: jeffreyH on 07/04/2019 14:51:54
To describe observations the mathematics also has to be able to make predictions. These then can be tested and shown to agree with new observations or not. If a certain constant is required to produce those mathematics then it is used. There is no intention to explain why it is needed. It just works. How would you answer the why? How can anyone observe a vacuum?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 07/04/2019 21:40:28
Thanks for the replies. I understand the math and the predictions. But I don't think you answered my question :(

I know that the vacuum of space is not empty, it is full of virtual particles as predicted by the Heisenburg uncertainty principle, which are proven to exist via the Casimir effect. Virtual particles are also the basis for theoretical Hawking radiation around a black hole. ie the Vacuum of space is not empty, this is a known and accepted factoid in the standard models.

Maxwells equations are applicable at the classical level not the quantum level, I was trying to visualize the photon at the quantum level moving through space which is full of virtual particles.

Can a photon passing through free space full of virtual particles, be viewed as being absorbed and re-emitted by the virtual particles? Thus maybe re-producing a wave effect via a jittery movement through space from virtual particle to virtual particle ? A photon will collide or plough through all the quantum foam, so it seems reasonable that it may be being absorbed and reemitted by virtual particles as it whizzes along :) in some way  :-\

Non local effects observed in entangled photons can not explain the wave effects seen in the double slit experiment, yet if the double slit experiment is performed in multiple separate labs by firing a single photon through the slits, and the results brought together, the wave effect is still observed. Absorbtion and emission of said photon or deflection by virtual particles as it passes through space by virtual particles might produce the wave effect maybe  :-\



 
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 07/04/2019 23:34:47
Now you are trying to model a quantum phenomenon with a billiard ball! It is a waste of life. Fact is that we have two models for electromagnetic radiation, a wave model and a particle model, but a model is not the "real thing". We can count individual photon events, thus demonstrating the quantum photoelectric effect, and measure the speed of light, thus demonstrating the validity of Maxwell's continuum wave equations. The virtual particles that populate the vacuum are just that - virtual, not real, beasts that we invent to model the Casimir effect.  If there were indeed collisions between photons and virtual particles, light would be dispersed in a vacuum and not travel in straight lines or at a constant speed.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 08/04/2019 01:12:30
The virtual particles that populate the vacuum are just that - virtual, not real, beasts that we invent to model the Casimir effect.  If there were indeed collisions between photons and virtual particles, light would be dispersed in a vacuum and not travel in straight lines or at a constant speed.

Please correct where I am wrong.

Maxwells equations describe the classical view of electromagnetic waves.

A single photon can be viewed as a quantum particle. In quantum theory we can neither assign a precise position nor an exact direction to a particle. The probability to find a quantum object at position x with momentum p can be predicted from the absolute square of the quantum mechanical wave function. |ψ(x,p)|˛

At any given time this probability can assume non-zero values at several even widely separated positions. In that case we say that the object is delocalized and we cannot assign a single well-defined position in space. (just like in the double slit experiment)

In any position measurement on a photon we find a complete photon. Its properties, inertia, energy, polarizability are measurable – they are not diluted or smeared over larger areas of space (suggesting the photon is not a wave perhaps ?)

The HUP predicts virtual particles do exist in space, they do have inertia, and they are proven to exist via the Casimir effect, to suggest otherwise is to deny experimental proof of their existence. It would also be discrediting Hawking Radiation as nonsense which is based on virtual particles around a BH event horizon.

Electrons absorb and emit photons and transmit forces via theoretical virtual particles which MIGHT NOT exist, electrons them selves can borrow energy from the vacuum and repay it. This type of virtual particle helps to balance the math, and maybe the one you are claiming doesnt exist. Conceptually it does.

I accept virtual particles may not present any resistance to a photon, to slow it down or cause it to be deflected. I was asking a question to which I am not sure your analogy of a billiard ball is correct, its more like a bowling ball bashing through ping pong balls, or the Ping Pong ball momentarily absorbing the photon and re-emitting it.

Would I be correct in thinking that the quantum explanation and wave particle explanation, give the same answers?
 
Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 08/04/2019 01:13:52
The particle model doesn't predict the speed of light in vacuo because there is nothing there to absorb and re-emit particles.
Let a source emit a photon at A and it arrive at B where a detector registers it. The particle model states that the photon is emitted at and absorbed at B. No need to re-emit. And this holds for distances from 1 nm to any number of light years.
Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 08/04/2019 01:16:34
Please correct where I am wrong.

Maxwells equations describe the classical view of electromagnetic waves.

A single photon can be viewed as a quantum particle.
Its not possible to state whether a photon is a particle or a wave unless you state how its observed. That's the essence of the wave-particle duality.

Note that the Schrodinger equation only holds for non-relativistic particles and photons are relativistic particles.
Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 08/04/2019 02:14:34
0 spin connotes zero angular momentum
Not true. Angular momentum is the sum of angular momentum associated with angular speed + spin.

sub elementary particles in the space/time fabric are in a ground state
What is a "sub elementary particle"? There's no such thing that I'm aware of. In any case there's no basis to assert that they're in the ground state. That's only possible when a particle is in a potential. And spacetime has little to do with explaining this.
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 08/04/2019 08:17:37
The particle model doesn't predict the speed of light in vacuo because there is nothing there to absorb and re-emit particles.
Let a source emit a photon at A and it arrive at B where a detector registers it. The particle model states that the photon is emitted at and absorbed at B. No need to re-emit. And this holds for distances from 1 nm to any number of light years.
Unlike Maxwell, the particle model doesn't predict the speed of light, nor that it is constant for all photons, unless you accept the conclusion of general relativity, i.e. that massless particles must all travel at c. Problem there is that this is an experimental result that is axiomatic to the GR model, not a prediction of the model. Nor is it terribly good at propagating radio waves. Admittedly it all hangs together in the end, but  I don't think GR requires quantisation, nor vice versa.
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 08/04/2019 08:35:59

Its not possible to state whether a photon is a particle or a wave unless you state how its observed. That's the essence of the wave-particle duality.


Here's where I get picky about language.

Consider the double slit experiment, with just one particle at a time. If whatever-it-is passes through both slits simultaneously (i.e. a wave), then its energy, mass and charge must be distributed simultaneously across the detector according to the observed diffraction pattern. But nobody has observed a particle with a fractional charge, mass, or increased photon wavelength at any point. What actually happens is that single photons, electrons or entire buckyballs ping into the detector at various positions and the integral of their distribution over umpteen particles looks like a classical interference pattern.

At the time of reaching the slit, our projectile has no way of knowing how or even whether it is going to be detected, so the implications of "duality"  don't make sense.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 08/04/2019 10:50:34
Please correct where I am wrong.

Maxwells equations describe the classical view of electromagnetic waves.

A single photon can be viewed as a quantum particle.
Its not possible to state whether a photon is a particle or a wave unless you state how its observed. That's the essence of the wave-particle duality.

Note that the Schrodinger equation only holds for non-relativistic particles and photons are relativistic particles.

Understood, I was trying to visualize or get a mental picture that covered both scenarios of a photon, from a quantum perspective. Wave Particle duality sounds like Schrodingers cat, which might be dead or alive, unless maybe you don't feed it :( .

Relativistic versions of the Schrodinger equation exist, ie the Klein Gordon equation. https://en.wikipedia.org/wiki/Klein–Gordon_equation and there is relativistic quantum mechanics https://en.wikipedia.org/wiki/Relativistic_quantum_mechanics neither of which give any support to what I was trying to visualize as far as I can see. :(


Thanks for the reply
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 08/04/2019 10:55:08


At the time of reaching the slit, our projectile has no way of knowing how or even whether it is going to be detected, so the implications of "duality"  don't make sense.

Not knowing exactly which slit might make it probable 50 50 which slit. However the interference pattern suggests if it is a particle it didn't go in a straight line. Which is where I got stuck in a loop, with absorption and emission :)

Thanks for the responses.


Title: Re: Can a photon be visualized ?
Post by: flummoxed on 08/04/2019 12:12:44
Perhaps a better explanation lies in QED
"
How is the double-slit experiment interpreted via quantum field?
Photons are localized lumps of energy, wave packets with a reasonably well-defined position and momentum, with an uncertainty consistent with atandard quantum mechanics. Like waves, photons can be very delocalized. Each photon in a laser beam has the same shape as the classical field by which this beam is described.
In a double-slit experiment with visible light the distance between two slits can be macroscopic, e.g. 0.1 millimeter, or something like that. In order to get an interference pattern, the photon lump should be no smaller than this size. The corresponding volume is filled with a time-changing electromagnetic field, the light beam. This macroscopically large (but in a weak beam possibly very faint) lump of electromagnetic energy falls on the double slit and interferes with itself according to Maxwell equations - its shape becomes that of a superposition of two spherical waves and becomes even more delocalized over a quickly growing region. Then this big but distributed lump of energy reaches the photographic plate and blackens a single silver grain. The photon energy that was previously spread up in a macroscopic region now gets released within a group of few atoms.
"https://www.mat.univie.ac.at/~neum/physfaq/topics/doubleSlit.html
https://en.wikipedia.org/wiki/Quantum_electrodynamics
If the field around photons is reacting with the double slits as it approaches would this negate the need for wave particle duality?

Title: Re: Can a photon be visualized ?
Post by: alancalverd on 08/04/2019 22:46:43
You might get away with that for a photon, but not a buckyball.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 09/04/2019 10:52:26
You might get away with that for a photon, but not a buckyball.

Why would you think a buckyball double slit experiment would be any different?

Wouldn't it also be represented as a field which interacts with the slits before going through one of them?

I expect the same experiment can equally be performed by firing a single buckey ball in multiple separate locations, and when the results are brought together the wave pattern still exists. Clearly the buckey balls or photons in separate labs will have had no wave interference from the other labs.

The wave interaction is theorized to exist after multiple particles go through one or the other slit producing the waves

With QED the interaction is before the particle goes through the slits and doesnt require wave particle duality, which is hard to visualize, and not very appealing when there is a simpler way of viewing photons and particles.

Title: Re: Can a photon be visualized ?
Post by: flummoxed on 09/04/2019 21:56:16
Please correct where I am wrong.

Maxwells equations describe the classical view of electromagnetic waves.

A single photon can be viewed as a quantum particle.
Its not possible to state whether a photon is a particle or a wave unless you state how its observed. That's the essence of the wave-particle duality.

Note that the Schrodinger equation only holds for non-relativistic particles and photons are relativistic particles.

Does De Broglie Bohm / Bohemian mechanics give a valid explanation of a photon in your opinion ? A field surrounded by a pilot wave. It is deterministic, and relativistic versions exist. 

A wiki link for them as don't know what I am waffling about to save time googling.
https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 09/04/2019 22:54:45
Why would you think a buckyball double slit experiment would be any different?
Because a buckyball is not a "distributed lump of energy" but a projectile with mass and a very definite structure.
 
Quote
The wave interaction is theorized to exist after multiple particles go through one or the other slit producing the waves
So an interaction B which occurs after event A determines the outcome of A? I think not. Or does B hang around the slits waiting to direct the second particle, whenever it turns up, based on the message left behind by the first one?

Quote
With QED the interaction is before the particle goes through the slits and doesnt require wave particle duality, which is hard to visualize, and not very appealing when there is a simpler way of viewing photons and particles.
So now you want a wave W that travels ahead of a photon p. This can only happen if W travels faster than c, which itself demands some explanation. It also implies that after a sufficiently long distance (say 1000 lightyears) W and p will have become substantially separated. Now suppose p bumps into some interstellar gas. You have a pilot wave entirely independent of its photon, and thus capable of determining the performance of  some other photon. Has this ever been detected? 

Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 10/04/2019 00:30:28
Unlike Maxwell, the particle model doesn't predict the speed of light, nor that it is constant for all photons, unless you accept the conclusion of general relativity, i.e. that massless particles must all travel at c.
I said that not to argue that the standard model predicts c but that your argument was fallacious.

BTW - its SR that c is invariant, nor GR. In GR the speed of light varies with the gravitational potential. Einstein showed this in 1907 and 1911.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 10/04/2019 10:04:19
Quote from: flummoxed on Yesterday at 10:52:26Why would you think a buckyball double slit experiment would be any different?Because a buckyball is not a "distributed lump of energy" but a projectile with mass and a very definite structure.

If a pilot wave precedes the bucky ball like a photon or electron, then what is the difference. 
Quote from: alancalverd

link=topic=76713.msg572494#msg572494 date=1554846885
The wave interaction is theorized to exist after multiple particles go through one or the other slit producing the waves  So an interaction B which occurs after event A determines the outcome of A? I think not. Or does B hang around the slits waiting to direct the second particle, whenever it turns up, based on the message left behind by the first one?

The double slit experiment can be performed in multiple separate locations on separate days by firing only a single photon or electron or buckey ball at the slits. When the results from all the locations are brought together the double slit result of firing multiple photons is reproduced. Particle A from location A does not affect the results of Particle B from location B, C D E F etc. There is no wave function interactions from Particle A to Particle B in the double slit experiment, especially when the test is performed in separate locations with single photons. 
So now you want a wave W that travels ahead of a photon p. This can only happen if W travels faster than c, which itself demands some explanation. It also implies that after a sufficiently long distance (say 1000 lightyears) W and p will have become substantially separated. Now suppose p bumps into some interstellar gas. You have a pilot wave entirely independent of its photon, and thus capable of determining the performance of  some other photon. Has this ever been detected? 

I did not say the pilot wave was completely independent of the photon, according to what I have read it surrounds it.
Photons, electrons buckey balls etc are all affected by gravity, gravitational waves for instance have been shown to travel at light speed via Ligo results. The gravitational field will surround any particle/packet of energy and arrive at the detectors before said particles.
I am still reading up on Pilot waves, and was hoping for a little guidance BUT
I am pretty damn sure gravity has been detected, this might not be what is meant by a pilot wave but then gravity might be based on entanglement of space, and the pilot wave is explained in Bohemian mechanics as producing a non local effect, which is I think is wordology for entanglement, spooky action.
Unlike Maxwell, the particle model doesn't predict the speed of light, nor that it is constant for all photons, unless you accept the conclusion of general relativity, i.e. that massless particles must all travel at c.
I said that not to argue that the standard model predicts c but that your argument was fallacious.

BTW - its SR that c is invariant, nor GR. In GR the speed of light varies with the gravitational potential. Einstein showed this in 1907 and 1911.

I noted this but decided not to mention it, as I wasn't sure I could back it up. I did not know that Einstein showed that GR predicts the speed of light to be variable in a gravitational field, do you happen to have a reference.

I am pretty convinced that c is constant in free space. If c isn't constant in free space my whole house of cards might collapse. Can you confirm c is the same for everyone under GR and SR relatively speaking. I am not aware of any experiments indicating c is variable in a gravitational field. Are you perhaps referring to the trajectory of light in curved space. Or length of rulers appearing shorter when aligned with a gravitational field in flat space.   
Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 10/04/2019 12:39:19
Can you confirm c is the same for everyone under GR and SR relatively speaking. I am not aware of any experiments indicating c is variable in a gravitational field.
Experiments in the 1960's by Irwin Shapiro confirmed what Einstein predicted, i.e. that c is variable in a non-inertial frame, i.e. a gravitational field.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 10/04/2019 17:05:15
Can you confirm c is the same for everyone under GR and SR relatively speaking. I am not aware of any experiments indicating c is variable in a gravitational field.
Experiments in the 1960's by Irwin Shapiro confirmed what Einstein predicted, i.e. that c is variable in a non-inertial frame, i.e. a gravitational field.

Thanks I never thought of it this way.

http://physicsdetective.com/the-speed-of-light/   :o  Rulers are shrunk by gravity, clocks are slowed by gravity, c= 2.98x10^8 m/s  measured by rulers and clocks that have shrunk and slowed.


Would I be correct in thinking c is still measured as constant, wherever it is measured, because the ruler has shrunk and time as slowed? light is actually slower as it moves away from a gravitational source. Does this also mean light is faster than c as it moves towards a gravitational source, if this is so what happens at event horizons of BH's, do things suddenly disapear as they enter a BH or does time slow, and rulers shrink meaning they are stuck in the horizon??




Title: Re: Can a photon be visualized ?
Post by: PmbPhy on 10/04/2019 18:31:02
Thanks I never thought of it this way.
The derivation is on my website at http://www.newenglandphysics.org/physics_world/gr/c_in_gfield.htm
The paper I mentioned is Fourth Test of General Relativity[/b] by Irwin S, Physical Review Letters, Vol. 13, No. 26, Dec 28, 1964

The author writes
Quote
Because , according to the general theory, the speed of a light wave depends on the strength of the gravitational along its path, ...
You might be able to find that paper online at https://booksc.xyz/

Would I be correct in thinking c is still measured as constant, wherever it is measured, because the ruler has shrunk and time as slowed?
No. That's only the why it happens.

Does this also mean light is faster than c as it moves towards a gravitational source, ..
No.

if this is so what happens at event horizons of BH's, do things suddenly disapear as they enter a BH or does time slow, and rulers shrink meaning they are stuck in the horizon??
Those are the reasons behind why light never reaches event horizon.

I urge you to get a GR book and study this phenomena. My website will give you a place to  start. I'm  always here of course.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 13/04/2019 20:03:35
I understand bosons have spin 0,1,2 whilst fermions have spin 1/2,3/2 etc

Numerous models of photons exist, are there any preferred models?

Photons have spin 1, am I correct in thinking the spin of a photon is related to its angular momentum, and wave shape? ie polarization. Can the photon be modelled as a flat disc, if not why not ?
When a photon is generated by an atom changing energy levels an electron moves to a different energy level, by either absorbing or emitting energy in the form of a photon. Is it possible a photon consists of 2 virtual particles with opposite charges, spinning around each other?  :-\

In the absence of answers is the following plausible?
 
Similarities between virtual particles/photons and photons exist, both have momentum neither have mass, both are excitations of the field that fills space. Both can carry forces. If they are travelling at c neither will experience time. According to the HUP this EM field can suddenly convert part of itself into a particle - antiparticle pair with up or down spin( something in the z direction up or down). We can have electrons with both up and down spin, and positrons with both up and down spin etc

The creation of a pair ensures the conservation of physical quantities such as momentum, charge, and also angular momentum, etc. In quantum mechanics, angular momentum comes from the spin of particles. So if one virtual particle has a certain spin, its antiparticle pair will have the opposite spin. Does this mean in terms of charge, this would be a positron with up spin and electron with down spin and vice versa??

For a boson to have spin 0 it might be a simple case of a virtual particle pairs with up and down spin. To achieve spin 1 for a photon could this be achieved from virtual particle pairs both with up spin? ie If they are up and down the result is 0 and if they are up-up or down-down the result is 1. If they are both up and down the result is 0 and if they are up-up or down-down the result is 1.

My photon picture at the moment is a virtual particle pair inside a pilot wave from bohemian theory. Is this plausible ?
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 14/04/2019 17:14:12
No. You have said that virtual particles are massless, but the e-p pair derived from a photon has mass of 2me., so all you have done is make your model more complicated than reality. That is the job of religion and philosophy, not science!
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 14/04/2019 19:26:15
No. You have said that virtual particles are massless, but the e-p pair derived from a photon has mass of 2me., so all you have done is make your model more complicated than reality. That is the job of religion and philosophy, not science!

My initial response to this post involved 2 syllables involving the letters BS, however being an open minded person I would be amused to know how you think religion is involved in the very basic question what is a photon.

Religion "In the beginning there was light", does not include virtual particles. Could everything in the universe be based on virtual particles which appear real ????

HUP "in the beginning there was virtual particles" does not include gravity.

Entanglement " in the beginning all things were connected(singularity) and still are today" Lacks how many dimensions are required, with various string theories having up to 26 dimensions, it is a hard instrument to understand :)

Virtual particles/photons have inertia and no mass, would you agree photons have inertia and no mass also??

Electrons lose inertia as they change orbitals, would you agree that inertia/energy is conserved ?
What have a photon and virtual particle in common? could it be inertia?

The big difference between a virtual photons and real photons is life time. When travelling at c time does not exist. IE Muon life time is increased drammaticaly when in free fall, not experiencing gravity as a force creating weight.  .   

The BIG difference appears to be a virtual photon/particle is not on shell, ie has random values(not stable), whereas a photon originates from the shell of an  atom (or mollusc :) ? ) has velocity c and inertia. A virtual photon appears local with little or no velocity.

How is this complicated? :)

Title: Re: Can a photon be visualized ?
Post by: alancalverd on 15/04/2019 00:11:20
I would be amused to know how you think religion is involved in the very basic question what is a photon.
It isn't. Religion is the business of making the obvious obscure and the simple, complicated. Usually by introducing binary or triune mysteries.

A photon is what we use to model some of the phenomena  associated with electromagnetic radiation. Its properties are all, only and exactly those we have observed that can be modelled by a massless particle travelling at the observed speed of light in vacuo.
Title: Re: Can a photon be visualized ?
Post by: yor_on on 15/04/2019 10:18:43
https://www.livescience.com/19268-quantum-double-slit-experiment-largest-molecules.html

" Researchers have sent molecules containing either 58 or 114 atoms through the so-called "double-slit experiment," showing that they cause an interference pattern that can only be explained if the particles act like waves of water, rather than tiny marbles."
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 10:29:03
I would be amused to know how you think religion is involved in the very basic question what is a photon.
It isn't. Religion is the business of making the obvious obscure and the simple, complicated. Usually by introducing binary or triune mysteries.


Completely ducking the question, is not an answer  ;D

Yes I agree "
A photon is what we use to model some of the phenomena  associated with electromagnetic radiation. Its properties are all, only and exactly those we have observed that can be modelled by a massless particle travelling at the observed speed of light in vacuo."

A Photon is also considered an independent particle, such as a gamma ray a very high energy photon. Gamma rays unlike radio waves do not spread their energy out as they pass through space.

As electrons on shell change energy levels their momentum is converted into a photon, or maybe transferred to virtual photons(which is in close proximity to shell), which head of at c (not experiencing time), when it impacts something its momentum is absorbed by what it hits, if it has the correct energy level. Virtual photons transfer magnetic energy, electro static field energy and the like. Photons transfer momentum.
Would you agree the differences between photons transferring magnetic energy, electrostatic energy, and momentum is likely the shape of the field.


Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 10:38:53
https://www.livescience.com/19268-quantum-double-slit-experiment-largest-molecules.html

" Researchers have sent molecules containing either 58 or 114 atoms through the so-called "double-slit experiment," showing that they cause an interference pattern that can only be explained if the particles act like waves of water, rather than tiny marbles."

Firing a single particle at multiple locations at different times, on identical experiments can when the results are all brought together reproduce the double slit experiment, which can be explained by wave particle duality, or by bohemian theory and pilot waves. 

Which is the easiest to visualize a pilot wave surrounding a photon from bohemian theory, or wave particle duality whereby a wave collapses to become a particle.

ie a pilot wave encompassing a particle and interacting with the slits is easier to visualize than some wave that  passes through both slits before impacting something and having instantaneous wave collapse to become a particle.

Edit Nice link by the way, there is less mystery to the explanation using pilot waves surrounding single packets of energy/photons.

Title: Re: Can a photon be visualized ?
Post by: alancalverd on 15/04/2019 10:42:49
There is no discontinuity in the self-interference of electromagnetic radiation. x-rays diffract in exactly the same way as radio waves and visible light. There is no inherent difference between x- and γ-radiation apart from their source but at very short wavelengths it's difficult (nay impossible) to find a diffraction grating of commensurate dimensions, so the self-interference phenomenon is not practically demonstrable and we only use the particle model.

The problem here is the loose use of "explain" when you mean "model". Religion offers all sorts of explanations but none with the demonstrably predictive value of a scientific model. Pilot waves do not predict the photoelectric effect or the black body spectrum, and are not consistent with the fact that "old" photons (from distant stars) behave in exactly the same way as "new" ones from a local source.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 10:43:29
An outstanding question I have is. Can a photon be represented as two virtual particles with appropriate spins ? (surrounded by a pilot wave). 
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 11:05:44
There is no discontinuity in the self-interference of electromagnetic radiation. x-rays diffract in exactly the same way as radio waves and visible light. There is no inherent difference between x- and γ-radiation apart from their source but at very short wavelengths it's difficult (nay impossible) to find a diffraction grating of commensurate dimensions, so the self-interference phenomenon is not practically demonstrable and we only use the particle model.

Pilot waves do not predict the photoelectric effect or the black body spectrum, and are not consistent with the fact that "old" photons (from distant stars) behave in exactly the same way as "new" ones from a local source.

Yes electromagnetic waves and photons exhibit fringing effects especially around  corners.

Photons manintain there strength regardless of distance travelled. Radio waves do not, they get weaker.

Radio waves are generated via electric currents moving along radio masts, and creating a distortion in the electric field around around the mast which radiates away at c, dispersing as it moves.

The photo electric effect and Black body radiation  is not based on wave particle duality, what is your point here ?
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 15/04/2019 11:08:23
Can a photon bre representged as two vitrual particles and a pilot wave? Not usefully.

Just to go back to the buckyball. It has two layers of structure: the atoms themselves and the spatial relationship between the atoms, so there must be at least two distinct pilot waves that determine the position of any one atom in space. As you say,  you can get quite large molecules to self-interfere, but if their trajectory is defined by two pilot waves, you would expect the output to be all sorts of subspecies and isomers of the original molecule depending on the interference between the two pilot waves.

You need to decide what you mean by "strength". The intensity of a light field decreases with 1/r2
 at distance r from a point source, as does the intensity of a radio signal. It just happens that for very weak signals we can detect individual light or x-ray photons, but the individual photon energy of radio signals is too low to be detected.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 12:30:20
Can a photon bre representged as two vitrual particles and a pilot wave? Not usefully.

Just to go back to the buckyball. It has two layers of structure: the atoms themselves and the spatial relationship between the atoms, so there must be at least two distinct pilot waves that determine the position of any one atom in space. As you say,  you can get quite large molecules to self-interfere, but if their trajectory is defined by two pilot waves, you would expect the output to be all sorts of subspecies and isomers of the original molecule depending on the interference between the two pilot waves.


If I can find the link which put the idea into my skull, ref photons having a pair of virtual particles with appropriate spin, creating a photon, I will post it, at the moment I cant find it?

I think most of the above is not strictly correct. If you have the time here is a short critic of bohemian and quantum mechanics. It discusses both interpreatations . As you are aware there are many other interpretations. But for visualizing a photon I think pilot waves work. I do note the pilot wave described in this link is different to the description of pilot waves linked to earlier. However the picture is not difficult to understand.


Title: Re: Can a photon be visualized ?
Post by: alancalverd on 15/04/2019 13:24:08
Radio waves are generated via electric currents moving along radio masts, and creating a distortion in the electric field around around the mast which radiates away at c, dispersing as it moves.

No, not an electric field, but a selfpropagating electromagnetic wave as described by Maxwell.
Title: Re: Can a photon be visualized ?
Post by: yor_on on 15/04/2019 17:10:29
No. there is no 'pilot wave' involved in it.
You don't get HUP, do you?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 15/04/2019 20:53:28
Radio waves are generated via electric currents moving along radio masts, and creating a distortion in the electric field around around the mast which radiates away at c, dispersing as it moves.

No, not an electric field, but a selfpropagating electromagnetic wave as described by Maxwell.

WTF radio waves are generated by electicity in radio masts, and satellite dishes etc, which are explained by Maxwells electromagnetic equations. #

Photons are generated by electrons changing energy levels in atoms.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 16/04/2019 12:14:52
You need to decide what you mean by "strength". The intensity of a light field decreases with 1/r2 at distance r from a point source, as does the intensity of a radio signal. It just happens that for very weak signals we can detect individual light or x-ray photons, but the individual photon energy of radio signals is too low to be detected.

This is not the case for single photons.

Photons can be created from virtual particles as shown in this experiment Dynamic Casimir effect https://phys.org/news/2011-11-scientists-vacuum.html.

No, not an electric field, but a selfpropagating electromagnetic wave as described by Maxwell.

Here is a paper based around Maxwells equations and photons, explaining the double slit effect WITHOUT the requirement of wave particle duality http://www.jpier.org/PIERL/pierl01/14.07111101.pdf Some might find it interesting.

I still havent found the actual link to the model of the photon I was thinking of which defines the photons spin and momentum in terms of two virtual particles :(

However ref virtual particles representing photons most forces are considered to be due to virtual particles

"Some field interactions which may be seen in terms of virtual particles are:
The Coulomb force (static electric force) between electric charges. It is caused by the exchange of virtual photons. In symmetric 3-dimensional space this exchange results in the inverse square law for electric force. Since the photon has no mass, the coulomb potential has an infinite range.
The magnetic field between magnetic dipoles. It is caused by the exchange of virtual photons. In symmetric 3-dimensional space, this exchange results in the inverse cube law for magnetic force. Since the photon has no mass, the magnetic potential has an infinite range.
Electromagnetic induction. This phenomenon transfers energy to and from a magnetic coil via a changing (electro)magnetic field.
The strong nuclear force between quarks is the result of interaction of virtual gluons. The residual of this force outside of quark triplets (neutron and proton) holds neutrons and protons together in nuclei, and is due to virtual mesons such as the pi meson and rho meson.
The weak nuclear force—it is the result of exchange by virtual W and Z bosons.
The spontaneous emission of a photon during the decay of an excited atom or excited nucleus; such a decay is prohibited by ordinary quantum mechanics and requires the quantization of the electromagnetic field for its explanation.
The Casimir effect, where the ground state of the quantized electromagnetic field causes attraction between a pair of electrically neutral metal plates.
The van der Waals force, which is partly due to the Casimir effect between two atoms.
Vacuum polarization, which involves pair production or the decay of the vacuum, which is the spontaneous production of particle-antiparticle pairs (such as electron-positron).
Lamb shift of positions of atomic levels.
The Impedance of free space, which defines the ratio between the electric field strength | E | and the magnetic field strength | H |: Z0 = | E | / | H |.[8]
Much of the so-called near-field of radio antennas, where the magnetic and electric effects of the changing current in the antenna wire and the charge effects of the wire's capacitive charge may be (and usually are) important contributors to the total EM field close to the source, but both of which effects are dipole effects that decay with increasing distance from the antenna much more quickly than do the influence of "conventional" electromagnetic waves that are "far" from the source. ["Far" in terms of ratio of antenna length or diameter, to wavelength]. These far-field waves, for which E is (in the limit of long distance) equal to cB, are composed of actual photons. Actual and virtual photons are mixed near an antenna, with the virtual photons responsible only for the "extra" magnetic-inductive and transient electric-dipole effects, which cause any imbalance between E and cB. As distance from the antenna grows, the near-field effects (as dipole fields) die out more quickly, and only the "radiative" effects that are due to actual photons remain as important effects. Although virtual effects extend to infinity, they drop off in field strength as 1/r2 rather than the field of EM waves composed of actual photons, which drop 1/r (the powers, respectively, decrease as 1/r4 and 1/r2). See near and far field for a more detailed discussion. See near field communication for practical communications applications of near fields." https://en.wikipedia.org/wiki/Virtual_particle


Title: Re: Can a photon be visualized ?
Post by: yor_on on 16/04/2019 17:33:09
I started to read the paper you linked flummoxed. Got stuck on "  At any instant moment its energy, momentum and spin angular momentum keep conservation. Its wavelike property originates from the periodicity of its helically rotating motion, instead of its wave spreading all over the place "

What do they mean by spin here? If you translated a electrons spin into classical spin it would spin faster than light speed in a vacuum?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 16/04/2019 19:59:53
I started to read the paper you linked flummoxed. Got stuck on "  At any instant moment its energy, momentum and spin angular momentum keep conservation. Its wavelike property originates from the periodicity of its helically rotating motion, instead of its wave spreading all over the place "

What do they mean by spin here? If you translated a electrons spin into classical spin it would spin faster than light speed in a vacuum?

The spin of the photon is related in the model to its angular momentum through the vector e which acts for a photon as the spin part of the wave function. They equate this to +1 or -1. At least this is how I read it. Nowhere is FTL indicated the limiting speed is c. The interesting thing about this model is that they appear to have a model of a single photon, that is based on Maxwells equations. Which I thought might be of interest to AlanCalverd. You may note they also mention the double slit experiment, and bohms theory as well as other photon theories to explain the double slit experiment.

I think I have a pretty plausible visual image of a photon now. I am still looking for the 2 virtual particle representation of a photon I stumbled across some time ago.  If I find it I will post it for completeness.   
Title: Re: Can a photon be visualized ?
Post by: yor_on on 16/04/2019 21:23:10
Yes, that's the only way I make sense of the paper. But it's also a fact that the spin of a electron is 'FTL' if you translate it into a classical 'speed'. So either the 'spin' they discuss for a photon, which it has, is uncoupled to the spin of a electron, or it isn't? In the first case we now have two definitions of what 'spin' means. One quantum mechanical in where 'spin' has no classical counterpart as shown by the electron, the other classical. The classical demands splitting 'spin' into two categories, one classical (photon) and the other strictly quantum mechanical (electron FTL).
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 17/04/2019 00:52:35
Yes, that's the only way I make sense of the paper. But it's also a fact that the spin of a electron is 'FTL' if you translate it into a classical 'speed'. So either the 'spin' they discuss for a photon, which it has, is uncoupled to the spin of a electron, or it isn't? In the first case we now have two definitions of what 'spin' means. One quantum mechanical in where 'spin' has no classical counterpart as shown by the electron, the other classical. The classical demands splitting 'spin' into two categories, one classical (photon) and the other strictly quantum mechanical (electron FTL).

You have me a little confused
 
Electrons are not involved in the pdf mentioned above. But yes lots of models of electrons exist also as spinning particles donuts and electron fogs/fields etc.

Are you perhaps relating to the pair of virtual particles representing a photon which I mentioned? I still havent found the link. The spins of the two massless virtual particles added up to 1.   

Nothing is FTL unless perhaps, information transfer via entanglement depending on your point of view, or maybe the expansion and contraction of space.

The spin of an electron must therefore must be <= light speed, which might indicate the model you are thinking of needs a smaller radius, or something is not right.   

An electron not connected to an nucleus in a orbital shell, does not give off photons, unless it is like a muon, which rapidly decays to an electron and a photon. Is this what you are getting at ?

When an electron loses energy in an atom it changes orbitals, releasing energy in the form of inertia which is locked inside a photon. The photon carries away the energy until it is reabsorbed. 

As I said You have me a little confused :) you will have to explain what you are getting at ??

Title: Re: Can a photon be visualized ?
Post by: flummoxed on 17/04/2019 12:32:21

No, not an electric field, but a selfpropagating electromagnetic wave as described by Maxwell.

A photon IS a quantum fluctuation in space, that MIGHT be surrounded by a pilot wave as explained in Bohm and de Broglie pilot wave theory.https://en.wikipedia.org/wiki/Pilot_wave_theory   

I have manged to convince myself that photons and virtual photons as used in QED are one and the same, they are not hypothetical. A virtual photon transfers a force as required by the virtual photon from A to B. A photon transfers a force from A to B. https://en.wikipedia.org/wiki/Quantum_electrodynamics#Basic_constructions

Feynman I think nails it, its a quantum representation of maxwells ideas :)
"
The key components of Feynman's presentation of QED are three basic actions.[1]:85
A photon goes from one place and time to another place and time.
An electron goes from one place and time to another place and time.
An electron emits or absorbs a photon at a certain place and time.
"

How are forces transferred from A to B at the quantum level? it is by photons. A photon has inertia, Einstein says so :) so the inertia is transferred or absorbed by photons when electrons change orbit.

Do Virtual photons work in the same way, certainly virtual particles have energy and momentum according to feynman. In the HUP virtual particles appear as pairs temporarily borrowing energy from the vacuum of space, they also exhibit momentum as shown in the Casimir effect, and can be converted to real particles as shown in the dynamic casimir effect.

If an electron emits a photon or transfers its energy to a virtual photon, it is electrically neutral and has no magentic field, it has spin and polarization. To achieve this using a virtual particles a pair is required with correct spin and charge to give spin 1. and I cant still cant find the link I am looking for  >:(
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 17/04/2019 16:29:26

Photons are generated by electrons changing energy levels in atoms.


Or by free electrons decelerating in a target, or accelerating in a wiggler. Same principle as radio waves, just higher energies. And of course some nuclei emit photons with no electron involvement at all. 

Fascinating stuff, physics.


Title: Re: Can a photon be visualized ?
Post by: flummoxed on 17/04/2019 17:14:06

Photons are generated by electrons changing energy levels in atoms.


Or by free electrons decelerating in a target, or accelerating in a wiggler. Same principle as radio waves, just higher energies. And of course some nuclei emit photons with no electron involvement at all. 

Fascinating stuff, physics.

Yes radio waves will induce electrons to move, via electro magnetic induction. A solitary electron decelerating as it hits a target is not the same as a radio wave, which has different properties. I dont think radio waves can make a TV screen glow, the same way an electron beam can, or even reproduce a double slit experiment results in the same way a particle can. Radio waves can heat stuff up in a microwave.

Ref nuclei its down to stability and flavour. There are many ways of brewing up reactions that make things glow :) Nuclear reactions are explained by quantum mechanics not maxwells equations as are photons. Q.E.D  ;)   

I agree 100%. It is Fascinating. Whilst being aware of QED I never really paid it much attention before.
Title: Re: Can a photon be visualized ?
Post by: yor_on on 17/04/2019 17:41:48
I don't know flummoxed, it's just logic. Either you have electrons spin doing FTL, which can be checked. Or they don't?

what a photon and a electron have in common is this idea of a 'spin'.  In the case of a 'photon' if you want it to be classical, its 'spin' needs to be covered by relativity. Which then bring it down under 'c'. In the case of a electron it was confirmed somewhere in the thirties that if you wanted to translate it into a 'classical spin' (as in a carousel)  its 'speed' would be FTL.

That's where I got stuck
 
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 17/04/2019 18:10:55
I don't know flummoxed, it's just logic. Either you have electrons spin doing FTL, which can be checked. Or they don't?

what a photon and a electron have in common is this idea of a 'spin'.  In the case of a 'photon' if you want it to be classical, its 'spin' needs to be covered by relativity. Which then bring it down under 'c'. In the case of a electron it was confirmed somewhere in the thirties that if you wanted to translate it into a 'classical spin' (as in a carousel)  its 'speed' would be FTL.

That's where I got stuck

Have you not answered your own question FTL is not possible therefore the classical interpretation is not quite correct. 
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 17/04/2019 18:16:53
Sorry, flummoxed, but you seem to be ploughing a lonely furrow to nowhere. If you can't accept the basic fact that accelerating electrons generate photons, you won't harvest any physics or understand why we abondoned orbits and invented quantum mechanics.

Good luck in your quest, and farewell.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 17/04/2019 18:34:39
If you can't accept the basic fact that accelerating electrons generate photons, you won't harvest any physics or understand why we abondoned orbits and invented quantum mechanics.

Good luck in your quest, and farewell.

I have never disputed electrons can generate photons. That is a strawman argument typical of southerners :)
Enjoy your warm lager :) and fixed speed of c in your Maxwells equations :)  So you have switched to Quantum theory now excellent. 

Farewell.
Title: Re: Can a photon be visualized ?
Post by: yor_on on 17/04/2019 18:43:24
Let us put it this way.
I don't know flummoxed?

They need a argument for how to treat other particles spin.
If they find it it will be interesting.

Myself I lean to the quantum mechanical approach.
Which shouldn't be read as I 'know'
Title: Re: Can a photon be visualized ?
Post by: yor_on on 17/04/2019 19:25:37
And Flummoxed
The point of physics is not in relations, it's in the logic you apply to a problem.
And what you can learn

That's what makes a theory
Don't let relations scare you away
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 17/04/2019 23:17:14
Haven’t had time to respond to this thread as been busy and lots of spam etc hitting, but have made a few notes along the way, some may overlap with @alancalverd

Photons have spin 1, am I correct in thinking the spin of a photon is related to its angular momentum, and wave shape? ie polarization.
Spin 1, helicity h two components of classical RH & LH circular polarisation.

Is it possible a photon consists of 2 virtual particles with opposite charges, spinning around each other?  :-\

My photon picture at the moment is a virtual particle pair inside a pilot wave from bohemian theory. Is this plausible ?
Not unless you are proposing a new theory ;-)

There are many problems with the Bohmian theory.
Eg, as @PmbPhy  points out “Note that the Schrodinger equation only holds for non-relativistic particles and photons are relativistic particles. “
But, it is not necessary to postulate the existence of a pilot wave. Take the double slit experiment and consider that one photon doth not a diffraction pattern make; we need more than one to build the pattern. Once you have more than one there is a finite probability that a photon will pass through one of the slits, and we can assume equal probability for each slit. Clearly, when the photon hits the screen, being a wave, its phase is determined by the distance between slit and screen (as in the classical wave model) and the relative phase of 2 photons will determine the superposition effect. However, when modelling a single photon we still have to say that it passed through both slits in order to apply the probabilistic and superposition models.

A photon can be visualised as a quantum of the em/photon field, propagating with the oscillating E and B field vectors rotating around the z axis (direction of travel) such that the vectors describe a helical wave in spacetime.

The big difference between a virtual photons and real photons is life time.
No. Unlike photons, virtual photons do not have a relationship between ω and k, nor between energy and momentum. They don’t propagate and can appear in the context of a direct interaction between charged particles, while real photons are the electromagnetic waves send out.
Reread Strassler on the subject, he is very clear.

Photons are generated by electrons changing energy levels in atoms.
That’s not the only way, they are also generated by “radio waves are generated by electicity in radio masts, and satellite dishes etc”.
A photon is a quantisation of the em wave and radio waves also have them, we just don’t use them in ordinary radio as they have very low energy so quantum effects don’t become apparent and classical wave theory works fine.

wave particle duality whereby a wave collapses to become a particle.
The wave does not collapse to become a particle. There are situations where an interaction, eg when the photon gives up its energy to an atom, which can be modelled as a particle interaction. Don’t make the mistake of thinking that these models represent some ‘reality’. 

Photons maintain there strength regardless of distance travelled. Radio waves do not, they get weaker.
This is a total red herring due to a misunderstanding about the difference between individual photons and the en-mass effect of billions of photons. Photons leaving a point source (by the billions in all directions) disperse and result in a reduction in intensity following the inverse sq law in just the same way as the wave model.
A plane em wave, eg from a distant star, does not get weaker with distance and some of the maths used to model a photon show it as a group of plane waves.

I dont think radio waves can make a TV screen glow, the same way an electron beam can, or even reproduce a double slit experiment results in the same way a particle can.
You have obviously never worked with high power radio transmitters. I can assure you that nearby tv screens will glow, and it is possible to do the double slit experiment with radio waves - I did myself and it is a standard undergraduate experiment eg https://www.haystack.mit.edu/edu/pcr/vsrt-ret/Files/Unit4Interference/Interference%20Method%20to%20Measure%20the%20Wavelength%20of%20Radio%20Waves.pdf
and it works at lower frequencies.
It is responsible for some radio interference.

I have manged to convince myself that photons and virtual photons as used in QED are one and the same
I don’t see how you have done that. Strassler makes it clear that they are not - if you understand what he is saying. They are certainly excitations of the same field.

I cant still cant find the link I am looking for  >:(
It won’t help you. There are numerous papers published that don’t pass peer review analysis and are clearly spurious. As has been said here before, just because a paper has been written doesn’t make it correct.

There is a lot of conjecture in this thread. As @evan said to you in a previous life, conjecture belongs in new theories rather than in this part of the forum. There are also a large number of statements made as if they are fact, whereas as @alan has pointed out they are incorrect. Alan has a great deal of experience of practical QM, it’s a pity you’ve driven him away.
At the moment this thread is such a mishmash of cherrypicked ideas and false statements that its value in this section is questionable. You are in danger of flummoxing yourself.

Title: Re: Can a photon be visualized ?
Post by: flummoxed on 18/04/2019 11:34:07
Quote from: flummoxed on Yesterday at 12:32:21I have manged to convince myself that photons and virtual photons as used in QED are one and the sameI don’t see how you have done that. Strassler makes it clear that they are not - if you understand what he is saying. They are certainly excitations of the same field.

I did a massive response to all your answers above, but when I posted, the website had logged me out.

Basically before starting the thread I already new Maxwells equations did not explain individual photons. So was a little flummoxed that Alan kept bringing them up, with statements like Maxwells equations prove the speed of light is constant, which clearly was not correct along with a few other nit picky other things.

Feynman convinced me not Strassler  :) that virtual photons and photons have exactly the same properties. In what way are they not? Both transfer momentum and vanish etc.



There are also a large number of statements made as if they are fact, whereas as @alan has pointed out they are incorrect. Alan has a great deal of experience of practical QM, it’s a pity you’ve driven him away. At the moment this thread is such a mishmash of cherrypicked ideas and false statements that its value in this section is questionable. You are in danger of flummoxing yourself.

I think Peter pointed out where Alan was wrong in the link he posted. In all the mishmash, Alan did not introduce Quantum mechanics and spin into the thread, and he didn't post the Matt Strassler link and introduce QED that was all ME.

Alan was not driven away, I was nice to him all along. The little banter you see ref drinking lager, is because he is from down south and made some jokes about people from up north, and Leeds airport, cos ther's no reason to fly anywhere else outside Yorkshire. He also made jokes about the Yorkshire cricket team. I don't live in Yorkshire, but know there are is at least 3 airports you can fly between without having to leave Yorkshire . Alan was wrong yet again     ;)
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 18/04/2019 19:46:31
I don't live in Yorkshire, but know there are is at least 3 airports you can fly between without having to leave Yorkshire
I know - I have flown to at least 5 of them. Having been conceived in Co Durham I have the right to consider Yorkshire as a bit inferior, or at least south.
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 18/04/2019 22:56:16
I think Peter pointed out where Alan was wrong in the link he posted.
I looked back and couldn’t see Alan posting any link

But I did find this:
In a double-slit experiment with visible light the distance between two slits can be macroscopic, e.g. 0.1 millimeter, or something like that. In order to get an interference pattern, the photon lump should be no smaller than this size.
The photon lump can (in theory) be much smaller than this because it doesn’t need to go through both slits it just needs to be diffracted by one of them.
There is a diffraction angle which determines the separation of the bright bands in the interference pattern, this angle is inversely proportional to the distance between the slits. So, if the distance between slits is large the bands become so close together that they cannot be separated, they just merge.
The crucial point is that photons going through a single slot are diffracted and where they superpose with photons diffracted from the other slot you get interference.

Feynman convinced me not Strassler  :) that virtual photons and photons have exactly the same properties. In what way are they not? Both transfer momentum and vanish etc.
I did go to the trouble of listing the differences between the properties of virtual and real photons.
If there are differences they cannot be exactly the same  ;)

Glad to see Alan hasn’t left us.







Title: Re: Can a photon be visualized ?
Post by: alancalverd on 19/04/2019 00:05:20
The crucial point is that photons going through a single slot are diffracted and where they superpose with photons diffracted from the other slot you get interference.
And this is the holy mystery.

Taylor's experiment showed that you still get an interference pattern when the photon intensity is so low that there is only one photon present at a time, and subsequent experiments show electrons and  atoms doing the same thing.

Now if the projectile really "interferes with itself", a single projectile will end up smeared across the detector, so the energy of the detected "partial photons" will be less than that of the incident photon, and each massive particle event will consist of a partial electron or atom atriking the detector. But these entities have never been detected. Thus whilst the "pilot wave" model predicts the longterm average distribution of photons or whatever, it cannot represent the reality of a single projectile.

Hence my objection to almost every classical or continuum model of quantum behavior. It is fundamentally dishonest and misleading. You have to start with the profound observation that "this is the way stuff actually behaves" and admit that any attempt to model it by continuum mathematics only predicts what happens for very large numbers of events.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 19/04/2019 11:18:32
where they superpose with photons diffracted from the other slot you get interference.

Doing the experiment with single photons/particles in seperate locations and bringing the results together displays the same results. With single photons in seperate locations there can be no photon photon interaction or superposition

Here is a good link explaining the history of what we have been waffling on about, with a photo of a photon https://www.zmescience.com/science/what-is-photon-definition-04322/

The basic properties of photons are: from the link
They have zero mass and rest energy. They only exist as moving particles.
They are elementary particles despite lacking rest mass.
They have no electric charge.
They are stable.
They are spin-1 particles which makes them bosons.
They carry energy and momentum which are dependent on the frequency.
They can have interactions with other particles such as electrons, such as the Compton effect.
They can be destroyed or created by many natural processes, for instance when radiation is absorbed or emitted.
When in empty space, they travel at the speed of light.

Gravity isnt mentioned in the link but we know photons are affected by gravity and therefore must also have a gravitational field around them. (not unlike a pilot wave fieldy type of thing  ;) )

Let a source emit a photon at A and it arrive at B where a detector registers it. The particle model states that the photon is emitted at and absorbed at B. No need to re-emit. And this holds for distances from 1 nm to any number of light years.

Am I correct "the superposition of particles is not required to explain the double slit experiment" ? 

The experiment here mentioned preciously by Colin, is interesting. https://www.haystack.mit.edu/edu/pcr/vsrt-ret/Files/Unit4Interference/Interference%20Method%20to%20Measure%20the%20Wavelength%20of%20Radio%20Waves.pdf It leaves a few questions unanswered :(

Would the experiment be affected by individual photons leaving the emitter from different parts of the emitter at slightly different angles, seperated by microns perhaps. Would the photons trajectory be affected by the atmoshere it is travelling through towards the double slits. Is the photons path as straight as invisaged in the experiment. Fringing affects around the slots are not mentioned. Are there anyother things not considered in the experiment. ?????

Title: Re: Can a photon be visualized ?
Post by: alancalverd on 19/04/2019 12:18:04
No requirement for a photon to have a gravitational field. Indeed it can't as it has no mass. Please don't make unwarranted assertions - this is physics, not politics. The gravitational bending of light is evidence of gravity warping spacetime.

Also incorrect to say they are particles. Electromagnetic radiation can be modelled as particles or waves. Don't allow outdated classical models to determine your opinion of quantum phenomena if you want to understand physics.

To quote your source 
Quote
Not only is light made up of photons, but all electromagnetic energy (i.e. microwaves, radio waves, X-rays) is made up of photons.
which should put you straight on that matter. However some of the rest of the source is poorly expressed and potentially confusing.
 
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 19/04/2019 12:41:52
I dont think radio waves can make a TV screen glow, the same way an electron beam can,
It's a matter of definition
There are about a million YT videos of tesla coils lighting fluorescent tubes.
A solitary electron decelerating as it hits a target is not the same as a radio wave,
It's the traditional way to get Xrays.
Lower energy electrons would produce radio waves- rather inefficiently.
I dont think radio waves can..., or even reproduce a double slit experiment results in the same way a particle can.
Reality doesn't agree with you. It's  high school experiment
http://www.dartmouth.edu/~physics/labs/descriptions/microwave.interference.diffraction/microwaves.writeup.pdf
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 22/04/2019 17:40:18

I am on holiday and answering this, I cant believe it, I must  need a holiday.

No requirement for a photon to have a gravitational field. Indeed it can't as it has no mass. Please don't make unwarranted assertions - this is physics, not politics. The gravitational bending of light is evidence of gravity warping spacetime.

Of course there is, photons are attracted to each other by gravity. This is due to gravitational warping of space around all forms of energy. E=m.c.c + p.v includes photons which have energy in the form of inertia.

Also incorrect to say they are particles. Electromagnetic radiation can be modelled as particles or waves. Don't allow outdated classical models to determine your opinion of quantum phenomena if you want to understand physics.

It is absolutely correct to say they are particles, and it is also absolutely correct to say they are not waves. You are misunderstanding the meaning of the wave particle duality. The wave is a probability wave, ie a mathematical probanility of finding the particle in a particular position. This might help you https://www.physicsoftheuniverse.com/topics_quantum_probability.html
The wave is a mathematical probability wave of finding a particle along that path. It s not a real thing, the only thing real about the photon is the particle, which moves erratically so the location can only be predicted by using a probality wave.

which should put you straight on that matter. However some of the rest of the source is poorly expressed and potentially confusing.

It is easy to get confused with terminology, especially when dealing with pop science threads that talk about wave particle duality as if they are both real things, when they are not. A mathematical probability wave is not the same as a real wave, or particle.

PS I lived in Durham for a number of years, before moving further north. But yes I was born in North Yorkshire :) Now I live 1200Nm ish SSW of England.

It's a matter of definition
There are about a million YT videos of tesla coils lighting fluorescent tubes.

Yes, its great fun confusing electricians with fluorescent tubes that wont turn off, but potentially dangerous microwaving them.



 
Would the experiment be affected by individual photons leaving the emitter from different parts of the emitter at slightly different angles, seperated by microns perhaps. Would the photons trajectory be affected by the atmoshere it is travelling through towards the double slits. Is the photons path as straight as invisaged in the experiment. Fringing affects around the slots are not mentioned. Are there anyother things not considered in the experiment. ??
Reality doesn't agree with you. It's  high school experiment

Its a question of interpretation, in high school people are taught they are observing a wave particle effect, in an idealized experiment showing a particle hit a photographic screen, without discussing the mathematical probability wave function.

Ref a radio wave, could that be viewed as virtual photons, rather than real :(.
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 22/04/2019 17:59:41

I am on holiday and answering this, I cant believe it, I must  need a holiday.
It would be a better use of your time!
Quote

No requirement for a photon to have a gravitational field. Indeed it can't as it has no mass. Please don't make unwarranted assertions - this is physics, not politics. The gravitational bending of light is evidence of gravity warping spacetime.

Of course there is, photons are attracted to each other by gravity.
If photons are atracted to one another, why does light always diverge from its source?
Quote

This is due to gravitational warping of space around all forms of energy. E=m.c.c + p.v includes photons which have energy in the form of inertia.
energy and inertia are quite distinct quantities, with different dimensions.
Quote
   

Also incorrect to say they are particles. Electromagnetic radiation can be modelled as particles or waves. Don't allow outdated classical models to determine your opinion of quantum phenomena if you want to understand physics.

It is absolutely correct to say they are particles, and it is also absolutely correct to say they are not waves. You are misunderstanding the meaning of the wave particle duality. The wave is a probability wave, ie a mathematical probanility of finding the particle in a particular position. This might help you https://www.physicsoftheuniverse.com/topics_quantum_probability.html
The wave is a mathematical probability wave of finding a particle along that path. It s not a real thing, the only thing real about the photon is the particle, which moves erratically so the location can only be predicted by using a probality wave.
On the contrary, photons move through space in absolutely straight lines (alright, geodesics if you must) at a constant speed. Nothing remotely erratic about it.

Title: Re: Can a photon be visualized ?
Post by: flummoxed on 23/04/2019 12:18:55
It would be a better use of your time!
This is absolutely my last response until I get back to my house :)
If photons are atracted to one another, why does light always diverge from its source?
Individual Photons which transmit the electro magnetic force perhaps interact, and the emf is a stronger effect than the gravity effect  :)
energy and inertia are quite distinct quantities, with different dimensions.
When a photon transfers its inertia to an atom, it effectively increases its mass, and energy. A hot vibrating atom has more energy and mass than the same atom when it is cold.
On the contrary, photons move through space in absolutely straight lines (alright, geodesics if you must) at a constant speed. Nothing remotely erratic about it.
Would they diverge in close proximity to each other, or perhaps have there paths bent by gravity as pointed out by einstein.

I dont think Feynman would agree with you. But photons bashing their way through the atmosphere are deflected, by air molecules, and there is no such thing as empty space, its got dust and a very small amount of hydrogen. You also have the dark matter effect, causing allsorts of speculation.

A photon is a quantum thing best explained at the quantum level, and movement is best predicted by a probaility wave, its movement is therefore slightly random, and a little erratic.

Here is an interesting discussion ref light, with a mildly amusing picture of a photon. https://www.nobeliefs.com/light.htm
There are things in the paper I disagree with and anyone else reading it might find things they disagree with also. But it is an interesting discourse on light; for them as are interested :)

I'm off to the festa. ate logo
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 23/04/2019 13:46:36
Its a question of interpretation, in high school people are taught they are observing a wave particle effect, in an idealized experiment showing a particle hit a photographic screen, without discussing the mathematical probability wave function.
No it isn't.
In school, pupils are shown the diffraction of waves by two slits- in much the same way they are shown the phenomenon with light
So your view as expressed here
I dont think radio waves can make a TV screen glow, the same way an electron beam can, or even reproduce a double slit experiment results in the same way a particle can.

is just plain wrong.
Why not accept that?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 23/04/2019 21:05:35
Quote from: flummoxed on 17/04/2019 17:14:06I dont think radio waves can make a TV screen glow, the same way an electron beam can, or even reproduce a double slit experiment results in the same way a particle can. is just plain wrong.Why not accept that?

You are not looking close enough.
A photon or electron is a single particle, (ie a localized fluctuation in a field ) that stimulates a single point on contact, a radio wave is under QED made up of virtual photons, in classical theory a radio wave (In the common communication ranges) is purely electromagnetic and electrostatic based on Maxwells equations.
In any case when a single photon is absorbed it ceases to exist. When part of a radio wave is absorbed by a receiver, the rest of the radio wave continues to exist. There is no instantaneous wave function collapse.

Taking a microwave as another example if the correct frequency is applied your food will heat up, using gamma rays or xrays might have a similar effect if they do not pass straight through.

A single photon is not a radio wave. A radio wave can be described as a fluctuation in a field represented under QED by virtual photons and under classical theory via an electromagnetic field described by Maxwells equations. Virtual photons the same as real photons do not have mass, charge or a magnetic field, and interact by imparting inertia. They are not affected by magnetic fields or electric fields. etc

and I am on holiday :) 
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 23/04/2019 21:07:40
When part of a radio wave is absorbed by a receiver, the rest of the radio wave continues to exist.
Prove it.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 23/04/2019 21:09:18
When part of a radio wave is absorbed by a receiver, the rest of the radio wave continues to exist.
Prove it.
Do you use a mobile phone or watch tv Q.E.D
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 23/04/2019 21:34:39
When part of a radio wave is absorbed by a receiver, the rest of the radio wave continues to exist.
Prove it.
Do you use a mobile phone or watch tv Q.E.D
Yes I do. And the bloke next door is watching the same programme, but he and I receive different photons.
A single photon is not a radio wave.
Give or take a matter of timing  and/ or  scale, that's like saying  a single photon is not a light wave.
But the experiments show otherwise.
So what actual evidence do you have WRT your suggestion?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 25/04/2019 22:07:21
Quote from: alancalverd on 22/04/2019 17:59:41
If photons are atracted to one another, why does light always diverge from its source?
Individual Photons which transmit the electro magnetic force perhaps interact, and the emf is a stronger effect than the gravity effect
Since you are not going to correct this i will, Photons have no charge or magnetic field and are not deflected by them in any way. Which leaves you with > they are deflected by something else, like the air they are moving through or quantum foam.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 25/04/2019 22:16:01
Yes I do. And the bloke next door is watching the same programme, but he and I receive different photons.
Are these photons real or virtual? What frequency are your different photons working on E=hf ?  Do they perhaps have no frequency, or wave, or electro magnetic properties other than perhaps inertia E=pv which they impart onto electrons which are willing to move in your mates TVs.
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 26/04/2019 17:55:09
What frequency are your different photons working on
Not sure; I think it's typically something like 500MHz.
Do they perhaps have no frequency, or wave, or electro magnetic properties other than perhaps inertia
No
They have a frequency that I can look up or measure.
They have wave properties that I can demonstrate by using different antenna designs and they have EM properties that I can demonstrate by things like Faraday rotation, polarisation etc.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 26/04/2019 20:09:50
What frequency are your different photons working on
Not sure; I think it's typically something like 500MHz.
Do they perhaps have no frequency, or wave, or electro magnetic properties other than perhaps inertia
No
They have a frequency that I can look up or measure.
They have wave properties that I can demonstrate by using different antenna designs and they have EM properties that I can demonstrate by things like Faraday rotation, polarisation etc.

Radio waves are normally something you can measure with an antennae, so I assume you are talking about radio waves and virtual photons, not real photons, with localized measurable spin and momentum.

Your virtual photons are oscillating in the UHF range, with polarization according to your antennae.  Virtual photons are the suggested method of conveying the electro magnetic force, would you agree?

Radio waves are not influenced by electric fields or magnetic fields once they have left the transmitting antennae. On reception they generate an emf in the receiver. They carry no charge or magnetic field on route between transmitter and receiver.

Photons carry inertia and when an atom absorbs this inertia an electron goes to a higher orbital.

How do virtual photons in radio waves cause an EMF in a receiving antennae? Is it inertia?
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 26/04/2019 23:52:43
so I assume you are talking about radio waves and virtual photons, not real photons, with localized measurable spin and momentum.
Virtual photons are something else entirely.

How have you come to the conclusion that radio waves are different from light waves (or, equivalently, how have you come to the conclusion that radio photons are different from light photons)?

Apart from the human scale- an accident of evolution- what's the difference?

Title: Re: Can a photon be visualized ?
Post by: alancalverd on 26/04/2019 23:54:51
It would help if you used the term momentum rather than inertia. They are not the same. Inertia is dimensionless, meaningless for a particle with zero mass,  and is not related to photon energy.

You can measure the momentum of radiofrequency photons (in principle, though it's very difficult in practice) and it is as calculated, E/c.

The means by which a photon is detected does not make the photon any more or less real. There is a place for virtual photons in describing the near-field of a transmitting antenna, but what you receive from a broadcast is the genuine article.

You need to study photon interactions in a lot more detail to understand what happens when energetic photons interact with individual atoms: everything from outer shell resonances via ionisation and pair production to photonuclear reactions. And of course the interaction of electromagnetic radiation with covalent bonds or conduction band electrons to produce global warming or radio signals is hugely important.

I really don't see why you are trying to make this everyday, fundamental process more complicated than it is. 
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 27/04/2019 10:33:29
so I assume you are talking about radio waves and virtual photons, not real photons, with localized measurable spin and momentum.
Virtual photons are something else entirely.

How have you come to the conclusion that radio waves are different from light waves (or, equivalently, how have you come to the conclusion that radio photons are different from light photons)?

Apart from the human scale- an accident of evolution- what's the difference?

I think I stumbled on the answer in wiki

" Actual and virtual photons are mixed near an antenna, with the virtual photons responsible only for the "extra" magnetic-inductive and transient electric-dipole effects, which cause any imbalance between E and cB. As distance from the antenna grows, the near-field effects (as dipole fields) die out more quickly, and only the "radiative" effects that are due to actual photons remain as important effects. Although virtual effects extend to infinity, they drop off in field strength as 1/r2 rather than the field of EM waves composed of actual photons, which drop 1/r (the powers, respectively, decrease as 1/r4 and 1/r2). See near and far field for a more detailed discussion. See near field communication for practical communications applications of near fields.
"
I really don't see why you are trying to make this everyday, fundamental process more complicated than it is.

Hey it was not me that complicated it, I just wanted to visualize a single solitary photon

Edit, thanks for all the answers. It made me revise my view of photons.

Would I be correct in thinking that virtual particle pairs coming into existence momentarily around the transmitting antennae, are separated by the electro magnetic field, become real, but not stable so decay into real photons. Not unlike Hawking radiation without the BH gravity.?????

Does the receiving antennae, absorb the inertia of the photons, or is their some other virtual particle interaction.?
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 27/04/2019 22:03:14
Can a photon be visualized?

We can describe a photon as having both wave and particle properties

This statement is patently incorrect since a particle structure of a photon negates the continuity of Maxwell's electromagnetic field that forms the coherency of Maxwell's electromagnetic wave. Also, an expanding electromagnetic field cannot maintain the particle structure of a propagating electromagnetic photon. The wave-particle duality theory of light is mutually exclusive as Harvard is to yale.
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 28/04/2019 09:32:21
This statement is patently incorrect since a particle structure of a photon negates the continuity of Maxwell's electromagnetic field that forms the coherency of Maxwell's electromagnetic wave.

Actually, it's experimentally  known to be true.

If reality does not agree with your ideas ,it isn't because reality has made a mistake.
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 28/04/2019 09:34:50
I think I stumbled on the answer in wiki
Glad you’ve found what you are looking for. From our point of view these things are ‘givens’ and it’s hard to know quite what you are looking for amid all your searchings.
To clarify some things and hopefully help your understanding:

Would I be correct in thinking that virtual particle pairs coming into existence momentarily around the transmitting antennae, are separated by the electro magnetic field, become real, but not stable so decay into real photons.
The best way to visualise this is to start with the standard illustration of the em wave/photon. In this the oscillating electric and magnetic field vectors have a definite amplitude/phase relationship and the 2 field vectors are clearly linked and interdependent.
Around the antenna, there are high intensity (relatively) electric and magnetic fields and some of these can be thought of as feeding back both into the antenna and into the near fields - similar to back emf in a coil. So there is no clear, stable relationship between the field vectors and the field intensities are irregular, and so no stable propagation.

Does the receiving antennae, absorb the inertia of the photons, or is their some other virtual particle interaction.?
As Alan said, best not to call it inertia, therein lies confusion.
When the photon/wave reaches the receiving antenna the oscillating fields move the free electrons in a similar oscillating motion. Because we are not trying to explain particle creation or anything esoteric there is no reason to propose a virtual particle interaction.

I was in the middle of replying to some of your earlier post, so I’ll put them in to help your visualisation.

In any case when a single photon is absorbed it ceases to exist. When part of a radio wave is absorbed by a receiver, the rest of the radio wave continues to exist. There is no instantaneous wave function collapse.
If you switch on a light bulb it illuminates the whole room, just because some photons hit your eye and cease to exist (wave function collapse) doesn’t mean the room goes dark.

A single photon is not a radio wave.
No one ever said it is, just that radio waves also consist of photons.
You quote: “Here is a good link explaining the history of what we have been waffling on about, with a photo of a photon https://www.b.com/science/what-is-photon-definition-04322/ “
If you look at the end of that link you will see it says:
Not only is light made up of photons, but all electromagnetic energy (i.e. microwaves, radio waves, X-rays) is made up of photons.

You are misunderstanding the meaning of the wave particle duality.
No, you are misunderstanding the meaning. At the end of the same article it says:
The theory that states that light behaves both like a wave and a particle is called the wave-particle duality theory.
It is the behaviour that is important.

Individual Photons which transmit the electro magnetic force perhaps interact, and the emf is a stronger effect than the gravity effect  :)
Nooooo. Photons do not experience emf interaction between one another.
They do carry energy and under GR would create a grav field, but it is so minuscule that it will not influence the divergence. Wheeler did some work on this and concluded that parallel photons do not attract,  but anti-parallel do.

On the contrary, photons move through space in absolutely straight lines (alright, geodesics if you must) at a constant speed. Nothing remotely erratic about it.
I dont think Feynman would agree with you. But photons bashing their way through the atmosphere are deflected, by air molecules, and there is no such thing as empty space, its got dust and a very small amount of hydrogen. You also have the dark matter effect, causing allsorts of speculation.
Feynman would agree. He developed the many paths integral which considers the total possible paths the photon can take and shows that the most likely is the shortest distance between 2 points - usually a straight line - all the other paths destructively interfering and cancelling out. Although there is a finite, but extremely small probability the photon takes a different path it does not wander around.

Since you are not going to correct this i will, Photons have no charge or magnetic field and are not deflected by them in any way. Which leaves you with > they are deflected by something else, like the air they are moving through or quantum foam.
If you are going to correct your error the at least correct it correctly.
Let’s take the laser beam which is the least divergent light source we have. Its divergence is determined by diffraction as the beam leaves the aperture/front face of the source and is determined by both the wavelength of the light and inversely by the diameter of the aperture.
Once the beam is on its way then, yes, it will be subject to scattering etc by material on its path.

A photon is a quantum thing best explained at the quantum level, and movement is best predicted by a probaility wave,
The wave is a mathematical probability wave of finding a particle along that path. It s not a real thing,
It is important to be clear which ‘wave’ we are talking about.
A wave function allows you to calculate the probabilities of the various values of measured characteristics of a system, however, the textbook interpretation of Schrodinger wavefunctions is not applicable to photons. In particular it is impossible to find, for photons, a vector-valued position operator with commuting coordinates which transforms under rotations like a vector. This implies that there is no consistent notion of probability density for a photon along its path. However, it is possible to define a probability of detecting a photon at a particular location.

In QFT particles are waves and a photon is now described under QFT which uses the normal modes of the (source-free) electromagnetic field from Maxwell’s equations and views them as quantum oscillators. So the waves we are talking about are the same waves as described by Maxwell, and the photon as a quantisation of this wave.

Am I correct "the superposition of particles is not required to explain the double slit experiment" ? 
On the contrary, in QFT superposition (interference) is key to double slit description and is treated in a similar way to the classical view of a plane wave passing through both slits and interfering.


Note: Inertia is an intrinsic characteristic of the object related to its mass. Inertia tells you how much force it will take to cause a particular acceleration on the object. Momentum is a function of an object's mass and velocity. Momentum is a measure of the kinetic energy of the object
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 28/04/2019 12:09:43
Can a photon be visualized?

We can describe a photon as having both wave and particle properties

This statement is patently incorrect since a particle structure of a photon negates the continuity of Maxwell's electromagnetic field that forms the coherency of Maxwell's electromagnetic wave. Also, an expanding electromagnetic field cannot maintain the particle structure of a propagating electromagnetic photon. The wave-particle duality theory of light is mutually exclusive as Harvard is to yale.
Your knowledge of physics is so poor that you are continually posting incorrect information and speculations. Such speculations are more appropriate to our new theories section and if you insist on posting them here you will be limited to posting them in the new theories section.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 28/04/2019 14:33:17
Quote from: flummoxed on Yesterday at 10:33:29
Would I be correct in thinking that virtual particle pairs coming into existence momentarily around the transmitting antennae, are separated by the electro magnetic field, become real, but not stable so decay into real photons.
The best way to visualise this is to start with the standard illustration of the em wave/photon. In this the oscillating electric and magnetic field vectors have a definite amplitude/phase relationship and the 2 field vectors are clearly linked and interdependent.
Around the antenna, there are high intensity (relatively) electric and magnetic fields and some of these can be thought of as feeding back both into the antenna and into the near fields - similar to back emf in a coil. So there is no clear, stable relationship between the field vectors and the field intensities are irregular, and so no stable propagation.

Can I just clarify this, are you saying there is no clear link between virtual particle pairs around the transmitter, acquiring energy, momentum. Followed by them becoming real photons due to either instability or coming back together and annihilating each, not unlike a positron electron collision, but at much lower energy levels.

This link is on a bit bigger scale than what I had in mind with an antennae, but pulsars can produce particles from virtual particles.
https://phys.org/news/2019-04-bright-space.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter

In QFT particles are waves and a photon is now described under QFT which uses the normal modes of the (source-free) electromagnetic field from Maxwell’s equations and views them as quantum oscillators. So the waves we are talking about are the same waves as described by Maxwell, and the photon as a quantisation of this wave.

Are you viewing the photons in a quantized radio wave as individual photons, or something else?

 
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 29/04/2019 19:13:58
This statement is patently incorrect since a particle structure of a photon negates the continuity of Maxwell's electromagnetic field that forms the coherency of Maxwell's electromagnetic wave.

Actually, it's experimentally  known to be true.

If reality does not agree with your ideas ,it isn't because reality has made a mistake.

Really, does an electromagnetic field expand?
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 29/04/2019 19:31:10
We can describe a photon as having both wave and particle properties
Who cares.
Please get back to the point.
You said that this "We can describe a photon as having both wave and particle properties" is false.
In fact it is clearly true- because we do, in fact, describe photons that way.

Why did you say something which is plainly wrong?
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 29/04/2019 22:04:31
An expanding electromagnetic field cannot form the structure of Planck's EM photon, Einstein's EM photon, QED photon or a string photon.
Title: Re: Can a photon be visualized ?
Post by: Kryptid on 29/04/2019 23:01:40
An expanding electromagnetic field cannot form the structure of Planck's EM photon, Einstein's EM photon, QED photon or a string photon.

Modern science never said that it did, so you are misinformed at best and straw-manning at worst.
Title: Re: Can a photon be visualized ?
Post by: alancalverd on 29/04/2019 23:06:17

You said that this "We can describe a photon as having both wave and particle properties" is false.
In fact it is clearly true- because we do, in fact, describe photons that way.

Oddly, he is actually correct, though I  doubt whether he understands why. Depending on the circumstances we describe electromagnetic radiation with wave or particle mathematics, but not both at once.
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 03/05/2019 18:18:12

You said that this "We can describe a photon as having both wave and particle properties" is false.
In fact it is clearly true- because we do, in fact, describe photons that way.

Oddly, he is actually correct, though I  doubt whether he understands why. Depending on the circumstances we describe electromagnetic radiation with wave or particle mathematics, but not both at once.

Since the electromagnetic field of Maxwell's theory based on Faraday's induction effect is expanding, how do you depict the particle STRUCTURE of a Planck's EM photon, Einstein's EM photon, QM photon, QED photon, QFT photon or a string photon.
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 03/05/2019 18:58:48
How do you depict the structure of an electromagnetic photon?
Usually with a purple marker pen.

Fortunately, it doesn't actually matter.

You said that this "We can describe a photon as having both wave and particle properties" is false.
In fact it is clearly true- because we do, in fact, describe photons that way.

Oddly, he is actually correct, though I  doubt whether he understands why. Depending on the circumstances we describe electromagnetic radiation with wave or particle mathematics, but not both at once.
No, he's still wrong.
A photon has both sets of properties (wave and particle).
Not at the same time, but it has both properties.
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 05/05/2019 23:24:06
How do you depict the structure of an electromagnetic photon?
Usually with a purple marker pen.

Fortunately, it doesn't actually matter.

If you cannot explain how an expanding electromagnetic field forms a particle structure you would have essentially discredit all of theoretical physics (quantum mechanics, quantum electrodynamics, string theory, quantum field theory, quantum chromodynamics, plasma physics, condense matter physics, and particle physics that use the gauge) and you would be the greatest physicists that ever lived!
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 06/05/2019 09:30:17
How do you depict the structure of an electromagnetic photon?
Usually with a purple marker pen.

Fortunately, it doesn't actually matter.

If you cannot explain how an expanding electromagnetic field forms a particle structure you would have essentially discredit all of theoretical physics (quantum mechanics, quantum electrodynamics, string theory, quantum field theory, quantum chromodynamics, plasma physics, condense matter physics, and particle physics that use the gauge) and you would be the greatest physicists that ever lived!
Well, it's nice of you to say so, but I doubt it's true.
"If you cannot explain how an expanding electromagnetic field...you would be the greatest physicists that ever lived!"

Well, I can't.
But I rather doubt that I am.

Of course, it still doesn't matter how I depict photons.
If I want to work out what they do I use maths, not pictures.
I leave questions of why they do it to the philosophers (and then I don't bother with listening to their answers).
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 06/05/2019 15:56:35
IF (note big IF) a photon has a shape approximately like a spinning circle, can red and blue shift be explained solely in terms of special relativity. ie blue shifted its radius is shrunk and spin rate increases, red shifted it's is stretched and spin rate would be reduced.
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 06/05/2019 16:18:59
IF (note big IF) a photon has a shape approximately like a spinning circle, can red and blue shift be explained solely in terms of special relativity. ie blue shifted its radius is shrunk and spin rate increases, red shifted it's is stretched and spin rate would be reduced.
What if they are shaped like unicorns?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 06/05/2019 16:19:31

If you cannot explain how an expanding electromagnetic field forms a particle structure you would have essentially discredit all of theoretical physics (quantum mechanics, quantum electrodynamics, string theory, quantum field theory, quantum chromodynamics, plasma physics, condense matter physics, and particle physics that use the gauge) and you would be the greatest physicists that ever lived!

I think Colin partly answered this on page 3 of this thread " A photon is a quantisation of the em wave and radio waves also have them, we just don’t use them in ordinary radio as they have very low energy so quantum effects don’t become apparent and classical wave theory works fine."

If you take a EM wave and model it as low energy overlapping photons, they would have the same effect as a single EM wave.

A mathematical model does not need to model exactly how something works, it just needs to give accurate predictions on the outcome.

For instance maxwells equations state an EM wave travels from A to B, and shows how it spreads out. They do not indicate the wave is made up of photons, or how those photons are created.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 06/05/2019 16:24:09
IF (note big IF) a photon has a shape approximately like a spinning circle, can red and blue shift be explained solely in terms of special relativity. ie blue shifted its radius is shrunk and spin rate increases, red shifted it's is stretched and spin rate would be reduced.
What if they are shaped like unicorns?

A spinning disc is easier to visualize than a unicorn chasing its tail. The shape is arbitrary, so using your hypothetical spinning unicorn.

Would a massless unicorn travelling at c after being emitted from a moving object, shrink or expand and spin at different rates, depending on if the object it originated from was moving towards or away from an observer,  according to special relativity. ?

Can special relativity explain red and blue shift of objects with no mass like photons or your hypothetical unicorn  :-\
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 06/05/2019 17:04:38
an special relativity explain red and blue shift of objects with no mass
Yes.
https://en.wikipedia.org/wiki/Relativistic_Doppler_effect
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 06/05/2019 18:12:56
Sorry, missed this

Can I just clarify this, are you saying there is no clear link between virtual particle pairs around the transmitter, acquiring energy, momentum. Followed by them becoming real photons due to either instability or coming back together and annihilating each, not unlike a positron electron collision, but at much lower energy levels.
If you look at the fields in the near field you see something akin to what sailors call a confused sea, many small (compared to a propagating photon) disturbances with no clear relationship. The E field is often greater than the H and then this will reverse, the phase relationship between E and H varies, and all polarisations are present. Although all these field disturbances will superpose there is not enough consistency to generate  a regular supply of photons - although some can be found in this zone - and the confused disturbances will be viewed as virtual photons. As the fields get further from the influence of the inductance and capacitance of the antenna the fields become more coherent with E and H becoming orthogonal and having a clear phase relationship, polarisation settles to that of the antenna and we begin to see what we would describe as coherent photons (as with a laser).
By the way, you might want to read this which puts what Strassler was saying in different words. https://www.livescience.com/55833-what-are-virtual-particles.html
One of my pet hates is the way people take physics shorthand and reinterpret it as a ‘thing’.

Are you viewing the photons in a quantized radio wave as individual photons, or something else?
They are individual photons. Not so obvious as the low energy means they are in the thermal noise and you need cooled detectors to find them.

Since the electromagnetic field of Maxwell's theory based on Faraday's induction effect is expanding, how do you depict the particle STRUCTURE of a Planck's EM photon, Einstein's EM photon, QM photon, QED photon, QFT photon or a string photon.
The em field is only expanding for a point source spherical wave. The photon is a plane wave group so propagates in one direction only.

For instance maxwells equations state an EM wave travels from A to B, and shows how it spreads out.
Maxwell’s equations do not show how an em wave spreads out. The inverse sq law spread is only valid for point source spherical waves. Maxwell’s equations are equally valid for plane waves, which do not spread out. Photon equations in qft use Maxwell’s equations.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 06/05/2019 19:45:35
an special relativity explain red and blue shift of objects with no mass
Yes.
https://en.wikipedia.org/wiki/Relativistic_Doppler_effect

Would I be correct in thinking that a blue shifted unicorn would spin faster than a red shifted unicorn?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 06/05/2019 19:54:52

By the way, you might want to read this which puts what Strassler was saying in different words. https://www.livescience.com/55833-what-are-virtual-particles.html
One of my pet hates is the way people take physics shorthand and reinterpret it as a ‘thing’.

Are you viewing the photons in a quantized radio wave as individual photons, or something else?
They are individual photons. Not so obvious as the low energy means they are in the thermal noise and you need cooled detectors to find them.

Thanks for the link, I think I understand the concept of fields merging with each other. Which is where the original question in the OP came from. Does a Photon interact with the virtual particles/quantum foam of space as it moves through space. ie is it absorbed and reemitted by quantum foam existing in the electromagnetic field, does it just bulldoze straight through, or does it get bounced around by occasional interactions with the quantum froth.


A further question arises is a photons speed limited by quantum foam,
Title: Re: Can a photon be visualized ?
Post by: Kryptid on 06/05/2019 22:52:07
Would I be correct in thinking that a blue shifted unicorn would spin faster than a red shifted unicorn?

No. If an object appears blue-shifted in your reference frame, all that means is that the distance between you and the object is decreasing over time. If red-shifted, then it is increasing instead. Unless gravity is involved, that is. Gravity can cause blue-shifting and red-shifting as well.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 07/05/2019 00:32:21
Would I be correct in thinking that a blue shifted unicorn would spin faster than a red shifted unicorn?

No. If an object appears blue-shifted in your reference frame, all that means is that the distance between you and the object is decreasing over time. If red-shifted, then it is increasing instead. Unless gravity is involved, that is. Gravity can cause blue-shifting and red-shifting as well.


What I am driving at is. A blue shifted photon has more energy than a red shifted photon. Using E=pc its speed in all none accelerated reference frames is c, how does is its energy increase. The only variable appears to be momentum.

This is where the discs or unicorns come in, the shape of the photon is irrelevant :) Do they spin faster and contract when blue shifted, and spin slower and expand when red shifted.   
Title: Re: Can a photon be visualized ?
Post by: Kryptid on 07/05/2019 00:40:59
how does is its energy increase.

Its wavelength decreases.

Do they spin faster and contract when blue shifted, and spin slower and expand when red shifted.   

No, they don't.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 07/05/2019 10:25:50
Maxwell’s equations do not show how an em wave spreads out. The inverse sq law spread is only valid for point source spherical waves. Maxwell’s equations are equally valid for plane waves, which do not spread out. Photon equations in qft use Maxwell’s equations

I am a simple fella and was thinking in terms of a dipole or monopole transmitters and point source waves.


 
Quote from: flummoxed on 28/04/2019 14:33:17Are you viewing the photons in a quantized radio wave as individual photons, or something else? They are individual photons. Not so obvious as the low energy means they are in the thermal noise and you need cooled detectors to find them.

You wouldn't happen to have a reference for this experiment that you could post ?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 07/05/2019 10:29:54
how do you depict the particle STRUCTURE of a Planck's EM photon, Einstein's EM photon, QM photon, QED photon, QFT photon or a string photon.

They are all photons/quantum fluctuations explained by different mathematical models. None of which give a picture of what the quantum fluctuation looks like in space. They just make mathematical predictions based on known/assumed properties derived by measurement. The way the experiment is set up influences what is measured.
Title: Re: Can a photon be visualized ?
Post by: alright1234 on 07/05/2019 20:33:18
how do you depict the particle STRUCTURE of a Planck's EM photon, Einstein's EM photon, QM photon, QED photon, QFT photon or a string photon.

They are all photons/quantum fluctuations explained by different mathematical models. None of which give a picture of what the quantum fluctuation looks like in space. They just make mathematical predictions based on known/assumed properties derived by measurement. The way the experiment is set up influences what is measured.

Are all based on Maxwell's expanding electromagnetic field? I can read through physics rhetoric. The field structure has precedence. Do you know the meaning of the word precedence?
Title: Re: Can a photon be visualized ?
Post by: Bored chemist on 07/05/2019 20:40:57

Do you know the meaning of the word precedence?

Yes.
Do you know the meanings of the words "evidence" and "credible"?
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 08/05/2019 10:43:57
an special relativity explain red and blue shift of objects with no mass
Yes.
https://en.wikipedia.org/wiki/Relativistic_Doppler_effect

Would I be correct in thinking that a blue shifted unicorn would spin faster than a red shifted unicorn?

I think the question has been partly answered on another thread, if you try and increase the energy of an object travelling at c, or close to c, the mass / inertia must increase. In the case of the photon this must be the inertia parameter increases, this increases the photons momentum.

Which leaves a little bit of a slippery picture.

Ice skaters are better to consider than unicorns https://en.wikipedia.org/wiki/Moment_of_inertia





Title: Re: Can a photon be visualized ?
Post by: flummoxed on 10/05/2019 11:30:16
These links give a much better picture of how photons work, than any of the descriptions on this thread.

https://van.physics.illinois.edu/qa/listing.php?id=2348&t=photons-as-carriers-of-the-electromagnetic-force
https://van.physics.illinois.edu/qa/listing.php?id=414
Title: Re: Can a photon be visualized ?
Post by: Colin2B on 12/05/2019 14:56:22
These links give a much better picture of how photons work, than any of the descriptions on this thread.
Excellent, frees us up from having to respond to your other posts eg https://www.thenakedscientists.com/forum/index.php?topic=76713.msg574595#msg574595 and https://www.thenakedscientists.com/forum/index.php?topic=76916.0

I have a great deal of respect for the Van, but if you understand what is in the links you quoted then you know that they are essentially saying the same as we’ve been saying.
Title: Re: Can a photon be visualized ?
Post by: flummoxed on 13/05/2019 02:20:07
These links give a much better picture of how photons work, than any of the descriptions on this thread.
Excellent, frees us up from having to respond to your other posts 

I didn't think anyone had to respond to anything. Did you have a reference to what you claimed ref individual photons in radio waves being detected, using an ultra cold detector? I cant find one, were you making it up? Guess I will never know. Good night