# Can You Pinpoint A Photon Or Can It Only Be Expressed As A Probability Distribution ?

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### #1 petrushkagoogol

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Posted 24 January 2018 - 08:58 AM

Can a photon be represented in the form F(x,y,z) or is it necessary to include one more dimension t (time), so that it is represented as F(x,y,z,t) - an attribute of space - time, in the form of a probability distribution ?

### #2 exchemist

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Posted 24 January 2018 - 10:24 AM

Can a photon be represented in the form F(x,y,z) or is it necessary to include one more dimension t (time), so that it is represented as F(x,y,z,t) - an attribute of space - time, in the form of a probability distribution ?

Aha, a non-daft question! Kudos.

This is tricky. Since you can't stop a photon it makes no sense to think of a "wave function" for a photon in the way that we do for electrons, for example, whereby the square modulus of the wave function gives the density of the probability of finding the particle in a region of space. But there is something like it. Further reading here: https://www.eng.famu...le_a/phwav.html

It will need a time dimension, as it is a periodic, wavelike phenomenon.

### #3 LaurieAG

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Posted 25 January 2018 - 01:03 AM

In some SR based relativistic rolling wheel solutions (based on O Gron's paper) you only need x, y and t dimensions and you can even cross check your answer by checking that the velocity between the axles location at each emission event remains consistent i.e. x and t only, y and z = 0.

### #4 Little Bang

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Posted 31 January 2018 - 03:27 AM

Is it possible to have half a photon, say the positive going half?

### #5 exchemist

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Posted 31 January 2018 - 04:48 AM

Is it possible to have half a photon, say the positive going half?

No. You can't have just the "top half" of a wave, fairly obviously. You can have processes that change the energy of a photon, via inelastic scattering, and conceivably in some cases the energy might be halved. But it is usual to treat that as absorption of one photon and simultaneous re-emission of another one with a lower energy.

### #6 Vmedvil

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Posted 10 February 2018 - 04:53 AM

Yes, you can pin point the most likely location of a photon but that doesn't mean it will always be the location actually chosen as most likely.  This is one of the huge issues that Einstein's Equations have with QM, because Einstein's equation do not play dice always having a "Exact Solution" for the situation where QM never has a "Exact Solution" just a most probable.

For instance, QM' s Versions of  the equation of E = MC by Dirac which still has a Probability and Wave Function in it.

This is one of the reasons, I always try to bind QM and GR with that Laplace Symbol or ∇ or 2 it is one of the few things that GR and  QM can agree on that space is 3-D + 1.

If you look at this close that last equation by Dirac is actually very close to SR's Invariant form, just inverse as (d/dx) + (d/dy) + (d/dz) = ∇ , the time interval taking the same inverse form.

To be honest the thing that jacks with SR/GR the most in QM is one thing, Wave-Function  "ψ" as SR and GR are particle form equations, which where never adapted to it as Einstein thought QM was completely wrong.

Which is actually all due to the (Y,Z,t) Dimensions the entire idea concept of "ψ" is there because Einstein was wrong and (Y',Z' ,t')  ≠ (Y,Z,t) , or QM would be invalid if (Y',Z',t') = (Y,Z,t), but it doesn't countless experiments have proven that.

But no, the equation for photons is only valid with a time component and is a quanta or Quantum unit meaning cannot be split any smaller, you cannot have half a photon it is nonsense as they are already split as small as possible. ∇ does this. ∇ means "For Every unit of space no matter how small over (X,Y,Z)" saying a change over a 3-D matrix is here.

which d/dr = ∇ too being another property of this operator.

So when doing Quantum Gravity pin pointing of locations, you always get a volume as a answer and not a "Exact Solution" because of QM, which was outlined in this post.

http://www.sciencefo...e-pin-pointing/

Which basically, just says any location that is possible without going faster than the speed of light for the Wave-particle as that would violate Relativity if it did go faster than "C" or the speed of light.

The Lie group or "Probability Field"  over top of the light cone is the result of this fact that waves will be waves and have probability replacing the SR "Exact solutions" which QM would call impossible to have a "Exact Solution" that always happens, The trade that QM takes of this is it has forced to obey the "Limits" of SR being that light cone, which QM would say " I should be able to tunnel through that wall" and SR says "no, that impossible" making this structure below when merged Raw SR/GR + Raw QM/QFT

But, to answer your questions waves forms always must have Probability of location and not an "Exact Solution" to them, which as you can solve out visually that this allows for Wave and Particle forms to be viewed simultaneously, neither QM/QFT or SR/GR is happy about this. having to work within the rules of "Impossible" to the other but both agree it is fine within their respected rules to do this. Each Dot being a Possible Location of the electron and the different Color Gradients being the Probability of appearing at a dot within that location being limited by Einstein's rules of the light cone within GR/SR about the total net locations possible having to be within that Light cone's limits. Red Gradients being the highest chance and Blue Gradients being the lowest chance of appearing. The smaller Red Sphere labeled B is where SR/GR says it should always appear within the light cone being that "Exact Solution" QM cannot accept as true.  Satisfying  Wave-Particle duality showing both Simultaneously as previously explained.

Which is why in all my Quantum Gravity models ΔX2ΔY2ΔZ2 = d2/ or dX2 + dY2 + dZ2 = d2/saying in math, "Work together, I don't care what you say about each other, I accept both as True and Neither as False." This as you may imagine makes for some very complex and interesting answers for some of the most fundamental questions of the Universe, the solutions being in Wave-Particle Dualistic form Simultaneously produced.

Edited by Vmedvil, 10 February 2018 - 07:21 AM.

### #7 Vmedvil

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Posted 10 February 2018 - 07:27 AM

Furthermore, it is what we see in nature. The exact same picture with the light cone in this form of Duality as Wave-particles simultaneously.

Thus, you get a awkward way to look these situations like this one called Gravitonics.

In speculative theories of quantum gravity, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory.

Elementary particle
G
Theoretical
Mass0
0 e

Which most thing that apply to electrons also apply to photons in this respect. Both being Wave-Particles.

Edited by Vmedvil, 10 February 2018 - 08:26 AM.

### #8 Vmedvil

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Posted 10 February 2018 - 08:40 AM

Which Brought me to two a Simple and Complex solution to this.

The Simple solution "Breaks Down Einstein's Energy Stress Tensor into simpler components."

The Complex Solution. "Does not break down Einstein's Energy Stress Tensor into simpler components."

But, to all my knowledge neither QM/QFT or SR/GR are wrong both are correct.

This is the Longest post I have ever done as a answer, I think to explain the full depth of how much of a true mystery this area of physics really is. When QM/QFT and GR/SR are all needed to answer a question.

Edited by Vmedvil, 10 February 2018 - 06:50 PM.

### #9 Little Bang

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Posted 17 February 2018 - 04:23 PM

No. You can't have just the "top half" of a wave, fairly obviously. You can have processes that change the energy of a photon, via inelastic scattering, and conceivably in some cases the energy might be halved. But it is usual to treat that as absorption of one photon and simultaneous re-emission of another one with a lower energy.

Since no one knows what a photon is I'm not sure you can say (No. You can't have just the "top half" of a wave, fairly obviously.)

### #10 Vmedvil

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Posted 18 February 2018 - 01:53 AM

Since no one knows what a photon is I'm not sure you can say (No. You can't have just the "top half" of a wave, fairly obviously.)

Actually, it is one of the most studied particles in nature, we do know exact the properties of a photon and know it is a quanta which means that you cannot have part a photon being the smallest unit possible with definite certainty the quanta of any particle is the smallest possible, thus since photons are quanta of light, you cannot split or have part of one unlike "Light" which is many quanta in the form of photons. Light is Electromagnetic Radiation.

Edited by Vmedvil, 18 February 2018 - 03:51 AM.

### #11 bangstrom

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Posted 18 February 2018 - 03:50 AM

Actually, it is one of the most studied particles in nature, we do know exact the properties of a photon and know it is made of quanta which means that you cannot have part a photon being the smallest unit possible with definite certainty the quanta of any particle is the smallest possible, thus since photons are quanta of light, you cannot split or have part of one unlike "Light" which is many quanta in the form of photons. Light is Electromagnetic Radiation.

Light quanta can, on rare occasions, be split in half by passing a light beam through certain crystals. The result is two photons with twice the original wavelength and half the original energy. The effect is known as spontaneous parametric down-conversion. This may be the result of one photon being absorbed and two being emitted. https://en.wikipedia...down-conversion

### #12 Vmedvil

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Posted 18 February 2018 - 04:00 AM

Light quanta can, on rare occasions, be split in half by passing a light beam through certain crystals. The result is two photons with twice the original wavelength and half the original energy. The effect is known as spontaneous parametric down-conversion. This may be the result of one photon being absorbed and two being emitted. https://en.wikipedia...down-conversion

I want you to notice it says "Photon Beams" which does imply multiple photons not a single photon. That page I think incorrectly worded as "Photon Beams" which would mean "Light" and not quanta of photon being a single photon and not a beam of them. Ya, "used to split Photon Beams" is the dead give away they are indeed talking about splitting "light" and not single photon.

Edited by Vmedvil, 18 February 2018 - 04:02 AM.

### #13 exchemist

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Posted 18 February 2018 - 03:06 PM

Since no one knows what a photon is I'm not sure you can say (No. You can't have just the "top half" of a wave, fairly obviously.)

What on Earth do you mean by that?  Electromagnetic radiation and its quanta, i.e. photons, are among the most completely specified and modelled entities in the whole of physics.

### #14 bangstrom

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Posted 18 February 2018 - 09:42 PM

I want you to notice it says "Photon Beams" which does imply multiple photons not a single photon. That page I think incorrectly worded as "Photon Beams" which would mean "Light" and not quanta of photon being a single photon and not a beam of them. Ya, "used to split Photon Beams" is the dead give away they are indeed talking about splitting "light" and not single photon.

Photon beams are necessary because the occurrence of a "split" photon is a rare event when the beam is passed through a SPDC crystal. The crystal does not split the beam itself as does a half silvered mirror but it splits a rare passing single photon. The photon is split into two halves with each half having 1/2 the energy of the original and 2x the wavelength. The beam is then blocked by a colored filter that allows only the pairs of split single photons to pass through.

### #15 exchemist

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Posted 19 February 2018 - 02:15 AM

Photon beams are necessary because the occurrence of a "split" photon is a rare event when the beam is passed through a SPDC crystal. The crystal does not split the beam itself as does a half silvered mirror but it splits a rare passing single photon. The photon is split into two halves with each half having 1/2 the energy of the original and 2x the wavelength. The beam is then blocked by a colored filter that allows only the pairs of split single photons to pass through.

My understanding is that this is modelled as one photon being absorbed while another two are simultaneously generated, rather as with reflection, Raman scattering, etc. It seems to me a bit misleading to describe it as one photon being split into two, although that is certainly the net effect.

### #16 Vmedvil

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Posted 19 February 2018 - 03:56 AM

Well, I will put it this way, if the "photon" can be split then it is not the Quanta of Light there is a smaller Quanta but at some point you will hit a point to where that is as small as you can get and that IS the Quanta, if a single photon can be split it is not truly the quanta and someone made a error on the actual size of a single photon being the Quanta of light or the smallest size the universe will render the object's parts. The object we are talking about is "Light" and its smallest parts used in the universe being Photons being the smallest detail it renders.

It would be like buying a LED TV then trying to count each individual LED, the LED in this case is the Quanta or smallest unit of the TV's Screen, that is what the photons are to light. If you find you can split the LED's Size then it was not truly a "Single" LED, you miscalculated the smallest size not that there is not a single unit of LED on that TV's Screen.

Edited by Vmedvil, 19 February 2018 - 04:37 AM.

### #17 bangstrom

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Posted 21 February 2018 - 04:10 AM

A quantum is a single unit of something and not necessarily the smallest possible unit of the same measure.