[alancalverd]

If it turns out that a kind of wave model can be used to explain all of observed phenomena, the use of other models, either wave or particle, would be unnecessary.

But we already know that you can't describe what happens when an electron-positron pair annihilates, or the photoelectric effect, with a wave model.

[hamdani yusuf (OP)]

If it turns out that a kind of wave model can be used to explain all of observed phenomena, the use of other models, either wave or particle, would be unnecessary.

But we already know that you can't describe what happens when an electron-positron pair annihilates, or the photoelectric effect, with a wave model.

What's the real thing being observed? What are the assumptions used in the experiment? How do they correlate?
Most of us agree that wave models based on Maxwell's equations can't explain them properly. That's why we needed a newer theory.

[hamdani yusuf (OP)]

We can see many videos on Youtube showing how microwave ovens work, and various experiments with them. They did it so we don't have to. I only do my own experiment when I can't find the answer from existing videos. I also learned some potential dangers related to operating microwave oven.

Here is an example

Micron thick steel wool in a microwave and how mirrors work

Super fine steel wool looks beautiful in a microwave. Tough to film but I'm really happy with the shots that I got! Along the way we get into how mirrors work.

[acsinuk]

The video was excellent and shows micro-wave photons penetrating steel wire and heating it. 
But the wire is on a glass plate insulating it from the metal casing so no DC current is flowing.   The wire is surely being over excited by the magnetic fields power =hf/second 

[Bored chemist]

The wire is surely being over excited by the magnetic fields power

It is still no more possible to separate magnetism and electricity in this context that when I pointed it out here

The likes of Ampere, Faraday and Gauss did the original experiments which show that electricity and magnetism are fundamentally linked.
So your statement is wrong because it requires them to work independently.


Why do you keep doing this?
Do you enjoy getting laughed at?

And this
"hf/second"
is still more or less meaningless.

[alancalverd]

What's the real thing being observed? What are the assumptions used in the experiment? How do they correlate?
Most of us agree that wave models based on Maxwell's equations can't explain them properly. That's why we needed a newer theory.

No assumptions. The key observation is two 511 keV photons being detected simultaneously at 180 degrees to each other. 

[hamdani yusuf (OP)]

No assumptions. The key observation is two 511 keV photons being detected simultaneously at 180 degrees to each other.

What's the objects being observed? How are they set up?
What's the polarization of the light? Is there only a single frequency? Or is it actually a bunch of similar frequencies, like Gaussian?
IMO, a photon with strictly single frequency is not a feasible mathematical model.

[alancalverd]

You can measure the photon energy with a proportional counter or a biased detector (we used to use GeLi but I've no doubt there are posher ones available these days). AFAIK it's never been anything other than 511 keV with a bit of wiggle depending on the kinetic energy of the annihilating pair (negligible in most cases).

Difficult to measure polarisation of a single photon at 511 keV - if indeed the concept is meaningful.

One point of the photon model is that it can have a single energy defined by the causative interaction. E= mc² ± 0

The simplest demonstration nowadays is to observe the decomposition of a neutron-deficient nuclide like Ga58 in a PET scanner. 

[Bored chemist]

IMO, a photon with strictly single frequency is not a feasible mathematical model.

The model we use includes the uncertainty principle. The energy of the photon is not strictly fixed.

[hamdani yusuf (OP)]

You can measure the photon energy with a proportional counter or a biased detector (we used to use GeLi but I've no doubt there are posher ones available these days). AFAIK it's never been anything other than 511 keV with a bit of wiggle depending on the kinetic energy of the annihilating pair (negligible in most cases).

Have you counted how many electrons and positrons before and after the annihilation?
Have you made sure that the detection was not caused by other factors, such as cosmic rays or radioactivity of some materials in the apparatus or instrumental devices?

[hamdani yusuf (OP)]

Difficult to measure polarisation of a single photon at 511 keV - if indeed the concept is meaningful.

Of course the concept is meaningful. If a polarizer is placed in the path, perpendicular to the polarization state of the light, it won't pass. The concept can produce observable difference.

[Bored chemist]

f a polarizer is placed in the path,

If no such polariser can be made...

[alancalverd]

Any suggestions for the material that might determine the polarisation of a 511 keV photon will be very welcome.

We have a rough idea of the collection efficiency of PET scintillators. It's mostly a geometric calculation as 511 keV penetrates the patient with very little loss. Anyway the numbers don't matter much  as the practical dose is small in comparison with the other risks associated wth whatever we are trying to diagnose.

Distinguishing from other factors is easy. No patient - measure the background radiation. Cosmic radiation: not much at 511 keV (pulse height discrimination eliminates other energies)  and very unlikely to produce two simultaneous pulses at 180 degrees. Fact is that the signal-noise ratio of PET is pretty good, even though its spatial resolution is poor, which is why it is usually combined with CT or MRI to get a good anatomical image of the hotspot.

BC: I'm not sure how the uncertainty principle applies to E = mc², which is a scalar equation. Δp.Δx is the scalar product of vectors.

[Bored chemist]

BC: I'm not sure how the uncertainty principle applies to E = mc2,

That's OK, lots of people don't.
http://hyperphysics.phy-astr.gsu.edu/hbase/uncer.html

[hamdani yusuf (OP)]

One point of the photon model is that it can have a single energy defined by the causative interaction. E= mc2 ± 0

Planck's law only asserts that energy of a system can only change by discrete multiple of electromagnetic radiation frequency times a constant. It doesn't say anything about quantization of frequency. Thus, radiation energy won't be quantized either.

[hamdani yusuf (OP)]

Meanwhile, Fourier transform tells us that infinitesimally precise frequency of a wave requires infinitely long sine wave. The most compact waveform in both frequency and time domains is Gaussian. It contains a range of frequency, and has non-zero time duration.
I've seen some sources said that uncertainty principle is not a problem of measurement. Instead, it's a fundamental principle inherently embedded to the math of wave models through Fourier transform.

[Bored chemist]

I've seen some sources said that uncertainty principle is not a problem of measurement.

They are right.
The uncertainty is intrinsic to the property.

Instead, it's a fundamental principle inherently embedded to the math of wave models through Fourier transform.

No.
It's a property of the universe.
The momentum of an electron is not an exact quantity.


If you do the calculations via wave mechanics you get the same answer as you do with the FT approach.

[hamdani yusuf (OP)]

No.
It's a property of the universe.
The momentum of an electron is not an exact quantity.

How do we know that?

[Bored chemist]

How do we know that?

It works.

[alancalverd]

Planck's law only asserts that energy of a system can only change by discrete multiple of electromagnetic radiation frequency times a constant. It doesn't say anything about quantization of frequency. Thus, radiation energy won't be quantized either.

Nothing to do with Planck or a closed system. ε⁺-ε^- annihilation is a single event in which a fixed mass is converted into electromagnetic energy. If we repeat the event with the same masses, we must get the same energy. And we do.