[hamdani yusuf (OP)]

The QM  interpretation of things like Raman spectra, frequency mixing and doubling involve these.
https://en.wikipedia.org/wiki/Virtual_state

At some point in the past, this was a new theory. And prior to that, it was merely a hypothesis. It survives because there's no better alternatives to explain known observations. Yet.

[evan_au]

The crystal is supposed to be macroscopic, and consists of many atoms. How can a single photon know where to go after interacting with it, instead of scattered at random direction?

I expect it would be a diffraction effect, as a result of interacting with many atoms.
- One of the ways to generate entangled photons is to use "spontaneous parametric down-conversion"
- There is a different diffraction pattern for vertically vs horizontally-polarised photons
- Each pattern is a circle
- Where the two circles overlap you are most likely to find the entangled photons.
- As per normal quantum effects, you can't predict where an individual photon will appear before you detect it...

See the diagram here: https://en.wikipedia.org/wiki/Spontaneous_parametric_down-conversion#Applications

[hamdani yusuf (OP)]

This is the comparable image using a diffraction grating (rather than a single slit) at an angle to the beam.
Again, it's curved as expected.

slit expte 4 resized.jpg (37.13 kB . 760x225 - viewed 5896 times).

What's the expectation based on? Is it derived from Huygen's principle? How?

[hamdani yusuf (OP)]

I expect it would be a diffraction effect, as a result of interacting with many atoms.

It would require a photon to interact with many atoms at once. Consequently, we are forced to reject locality. And the distance can be very large for lower frequency light.
Experiment using microwave and radio frequency would require a photon to interact with extremely large number of atoms over large volume of space. Some people don't mind to accept this concepts. Some others find it hard to believe, and try to look for alternatives.

[hamdani yusuf (OP)]

- One of the ways to generate entangled photons is to use "spontaneous parametric down-conversion"

What's the mechanism? How the photons know where to go?

[hamdani yusuf (OP)]

And here's the more interesting one.

slit expte 2 resized.jpg (44.04 kB . 775x302 - viewed 3784 times)


As you can see it curves, but it's essentially the same.

You can get full circle with higher inclination angle, as close as possible to 90 degree.

[alancalverd]

Experiment using microwave and radio frequency would require a photon to interact with extremely large number of atoms over large volume of space. Some people don't mind to accept this concepts. Some others find it hard to believe, and try to look for alternatives.

Which is why we associate a wavelength λ = hc/E with any photon of energy E. The concept has been around since 1900, and where E is very small (as in radio waves) we tend to use wavelength and frequency to describe the phenomena we most often observe.

[hamdani yusuf (OP)]

Experiment using microwave and radio frequency would require a photon to interact with extremely large number of atoms over large volume of space. Some people don't mind to accept this concepts. Some others find it hard to believe, and try to look for alternatives.

Which is why we associate a wavelength λ = hc/E with any photon of energy E. The concept has been around since 1900, and where E is very small (as in radio waves) we tend to use wavelength and frequency to describe the phenomena we most often observe.

Is there an experiment demonstrating particle behavior of radio or microwave?

[Bored chemist]

Is there an experiment demonstrating particle behavior of radio or microwave?

Countless "experiments" are done with this every day.
https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
https://en.wikipedia.org/wiki/Electron_paramagnetic_resonance

[Bored chemist]

It would require a photon to interact with many atoms at once. Consequently, we are forced to reject locality.

No.
Nobody ever said how big a photon is.
It turns out that they are soft.
You can squeeze them through small holes, or you can stretch them out across diffraction gratings.
So their size is not well defined.

[Bored chemist]

This is the comparable image using a diffraction grating (rather than a single slit) at an angle to the beam.
Again, it's curved as expected.

slit expte 4 resized.jpg (37.13 kB . 760x225 - viewed 5896 times).

What's the expectation based on? Is it derived from Huygen's principle? How?

To be honest, I don't really know. It seems reasonable to me that you get a curve because, if you imagine looking at a grating in this way, you would see it as foreshortened more at one side than the other. I realise that's not a clear explanation.

I don't have access to this paper but, based on the abstract, I think it covers the maths you want.

https://aip.scitation.org/doi/pdf/10.1063/1.347388

Personally, I'm prepared to leave it at that.
I know someone else can do the maths, so I accept that the maths works.
You may wish to gain access to the paper to check.

If anyone reading this has (free) access, I'd be grateful if they could check on whether it explains what I think it does.

[Bored chemist]

See fig 6 here
https://www.spiedigitallibrary.org/journals/optical-engineering/volume-58/issue-08/087105/Understanding-diffraction-grating-behavior--including-conical-diffraction-and-Rayleigh/10.1117/1.OE.58.8.087105.full?SSO=1&tab=ArticleLinkFigureTable

[hamdani yusuf (OP)]

If anyone reading this has (free) access, I'd be grateful if they could check on whether it explains what I think it does.

It's unfortunate that some basic stuff like this are not opened to public. It should be part of physics textbooks on optics.
Thanks anyway for your efforts.

[hamdani yusuf (OP)]

Is there an experiment demonstrating particle behavior of radio or microwave?

Countless "experiments" are done with this every day.
https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
https://en.wikipedia.org/wiki/Electron_paramagnetic_resonance

How do they differentiate between the particle behavior of photon and energy transfer among discrete number of resonators?

[Bored chemist]

Is there an experiment demonstrating particle behavior of radio or microwave?

Countless "experiments" are done with this every day.
https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance
https://en.wikipedia.org/wiki/Electron_paramagnetic_resonance

How do they differentiate between the particle behavior of photon and energy transfer among discrete number of resonators?

I doubt  they bother.
But  things like the intensity of the absorptions as a function of temperature only make sense if the energy involved is quantised.

[alancalverd]

NMR and EPR are interactions between bound particles and radio waves. The RF component is of such low energy that it is easier to manipulate  and analyse by waveguides, coils and dipoles - you need a hell of a lot of photons to produce a discernible signal. At higher energies we can use a photomultiplier to detect individual events  (photons) in a focussed beam (astronomical telescope) or weak diffraction pattern (particularly x-ray diffraction), the geometry of which is predicted by the wave model. Increasing the energy to the point of photon-nucleon interaction or pair production, the particle model works best.

[acsinuk]

I found that pulsed EMR  on Wiki  "  https://en.wikipedia.org/wiki/Pulsed_electron_paramagnetic_resonance  " which shows how a standard microwave cooker works and has the best 3D moving images of the spinning magnoflux.      Photons are made of this spinning magnetic stuff but if the angle of the wave guide is not 90 degrees to the spinning flux there will be power losses and virtual quantum light will be formed. 

[Bored chemist]

I found that pulsed EMR  on Wiki  "  https://en.wikipedia.org/wiki/Pulsed_electron_paramagnetic_resonance  " which shows how a standard microwave cooker works

It does not show how a microwave over works.


EPR spectra are only obtained for free radical species and food doesn't generally contain many.
On the other hand, a microwave oven uses the absorbance of microwaves (at about 2.4 GHz) by water- there is lots of water in most food.
The page you cited also does not mention "manganflux", because that's bollocks which you made up.
So is

virtual quantum light

[alancalverd]

Come off it, BC. If you look closely into a microwave cooker, you can see the fairies dancing on your lunch  and tossing photons to each other. Premier-league fairies give the photons a magnetic spin - especially the scrum halves and slow bowlers.

[Eternal Student]

Hi Alancalverd,

   How old are you?  Don't look into a microwave oven, especially when it's turned on.   Appliances may have been without leaks when they were new but the wire mesh in the glass door can become corroded.
   Also, it won't make your dinner cook any faster.

   Here's another microwave question that may take a minute to think about:  Do most ovens have reflective surfaces and bounce the radiation around inside them,  or  does the radiation just tend to be absorbed and wasted in the sides of the oven?
    Specifically, if 1 pot of noodles can be cooked in 1 minute,   then  will it take 2 minutes to cook 2 pots simultaneously,   or just 1 minute since both pots are being showered by the same intensity of radiation from above (assuming the microwave generator is at the top of the oven)?
     In practice I can heat 1 pot in 1 minute and 2 pots in about  1.5  minutes - a sort of hybrid of the two possibilities.

Best wishes.