[hamdani yusuf (OP)]

Hi Alancalverd,

   How old are you? 

You can see in his profile.

[hamdani yusuf (OP)]

   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?

When the microwave is reflected by the metallic surface of the box, only a small part is being absorbed.
I've tried to heat deionized water inside a metal container, and covered with a metal grating. The water got warm very slowly. The inner wall of the microwave was still cool. Eventually the fuse in the power supply blew up. It means that some portion of the reflected microwave energy comes back to the magnetron.

[Eternal Student]

Hi.
   Can I add another safety warning to Hamdani's latest comment:     Please don't try this at home.
Microwave ovens usually generate a high voltage where the microwave radiation is produced (e.g. the top of the microwave) and a maintain a lower voltage (usually a ground) near the bottom.   Putting a metallic object into the microwave that reduces the gap between these two regions can result in electical arcing.

   Add to this the reflection of the microwaves off the metallic object and the power that is returned to the microwave generator and you will often get the the fuse to blow and/or break the oven in some way.

[hamdani yusuf (OP)]

Hi.
   Can I add another safety warning to Hamdani's latest comment:     Please don't try this at home.
Microwave ovens usually generate a high voltage where the microwave radiation is produced (e.g. the top of the microwave) and a maintain a lower voltage (usually a ground) near the bottom.   Putting a metallic object into the microwave that reduces the gap between these two regions can result in electical arcing.

   Add to this the reflection of the microwaves off the metallic object and the power that is returned to the microwave generator and you will often get the the fuse to blow and/or break the oven in some way.

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.

AFAIK, the whole inner wall metallic surface of microwave oven is connected to ground. No significant voltage difference between bottom part and top part. The only high voltage supply is the feed of magnetron which comes from a step up transformer. There is a waveguide between magnetron and the cooking chamber, isolating it from high voltage.

[Eternal Student]

Hi Hamdani,

    I hope you are well and it sounds like you are being sensible.

    My old microwave oven has an interior that is mainly plastic (although there must be some metal or at least a metal mesh underneath most of this).  There is a metal spindle that comes through the bottom (floor) and rotates a plate.  I haven't tested it but that metal spindle is probably connected to ground.  I also don't know for certain where the transformer or microwave generator is located but my oven is supposed to produce the microwaves at the top.  The advice about not putting metallic objects into the microwave oven comes from the users guide and the risk of electrical arcing from the top of the oven to the bottom was mentioned.    Exact details probably depend on the oven and I have seen some industrial kitchens using metallic bowls inside their microwave ovens.

[Bored chemist]

Do most ovens have reflective surfaces and bounce the radiation around inside them,

Yes.

[Bored chemist]

Hi.
   Can I add another safety warning to Hamdani's latest comment:     Please don't try this at home.
Microwave ovens usually generate a high voltage where the microwave radiation is produced (e.g. the top of the microwave) and a maintain a lower voltage (usually a ground) near the bottom.   Putting a metallic object into the microwave that reduces the gap between these two regions can result in electical arcing.

   Add to this the reflection of the microwaves off the metallic object and the power that is returned to the microwave generator and you will often get the the fuse to blow and/or break the oven in some way.

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.

AFAIK, the whole inner wall metallic surface of microwave oven is connected to ground. No significant voltage difference between bottom part and top part. The only high voltage supply is the feed of magnetron which comes from a step up transformer. There is a waveguide between magnetron and the cooking chamber, isolating it from high voltage.

You may find it informative to consider how Hertz first detected radio waves
https://en.wikipedia.org/wiki/Heinrich_Hertz#/media/File:Hertz_micrometer_resonator.png

[yor_on]

All models are an oversimplification, which is why they are called models. A dead mouse is a perfect model of a live mouse, but only for an inifintesimal perod of time.

If you tie a string to its head and one each to the legs you can extend the model. A good name for this would be string theory.

That was evil Jeffrey

[yor_on]

Einstein's Nobel prize,

That's a theoretical work. What's the experimental evidence? Why can't it be interpreted in another way?

awh, ever heard about black body radiation?

[Europa]

In most theories up to the eighteenth century, light was pictured as being made up of particles. Since particle models cannot easily account for the refraction, polarization, diffraction and birefringence of light.

Photon model gains reputation in early 20th century due to photoelectric effect, especially that low frequency light cannot poduce emitted electron even with increased intensity. But newer development of laser can generate high enough intensity which can poduce emitted electron even with lower frequency than usual threshold.

Is photon model of electromagnetic wave an oversimplification?
Is it possible to explain wave-like phenomena in electromagnetism using photon model?
Is it possible to explain particle-like phenomena in electromagnetism using wave model?

The model is a theory and as such it is neither real nor fake.  In order to answer your question more info would be needed.

[acsinuk]

Looking at the wiring diagram we can see that the metal base is bonded to the DC power supply positive anode and the negative filament is 5,000 volts negative with an isolated/insulated AC filament heater inside a vacuum enclosure with a window into the waveguide. The physical design of the ovens microwave volumetric cavity which contains the magnetic massless spinning magnoflux is able to vibrate water molecules at 2.5 Giga Hertz heating it up.
The heating power is held within the spinning magnetic high frequency photons and has nothing to do with electron particles.

[Bored chemist]

Looking at the wiring diagram we can see that the metal base is bonded to the DC power supply positive anode

Yes

and the negative filament is 5,000 volts negative with an isolated/insulated AC filament heater

Yes

filament heater inside a vacuum enclosure with a window into the waveguide.

Well- you can't see that from the diagram, but it's correct.

which contains the magnetic massless spinning magnoflux

And there's where you descend into talking bollocks again.

The heating power is held within the spinning magnetic high frequency photons and has nothing to do with electron particles.

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?

[hamdani yusuf (OP)]

Einstein's Nobel prize,

That's a theoretical work. What's the experimental evidence? Why can't it be interpreted in another way?

awh, ever heard about black body radiation?

https://en.m.wikipedia.org/wiki/Photon

While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts.

So, it's an indirect evidence. In formula E=n.h.f, the only variable required to be an integer is n. E and f can have any real value.
Millikan's experiment shows that electric charge is quantized. Previously, J. J. Thomson have shown the ratio between mass and charge of electrons. Hence the mass of matter is also quantized. So, it's still possible to interpret the quantization of energy generation and absorption as due to quantization of mass and electric charge, instead of photon as a physical entity. When formulating his law, Planck himself didn't think that photon is a real particle.

[alancalverd]

How the photon model explains the effect of removing the outer edges (which makes it a thin wire diffraction, which according to Babinet’s principle, should produce the same pattern as single slit aperture)?
How the photon model explains the result of circular pattern when the diffraction grating is vertically tilted?

To repeat, for the nth time, it doesn't. Which is why we also have a wave model.

[alancalverd]

Hi Alancalverd,

   How old are you? 

Old enough to never eat pot noodles (life is too short) and a good enough physicist to realise that visible photons pass through the holes in the mesh so you can see what's going on in a microwave oven without frying your eyeballs.

Apropos heating times, if you have a strong absorber (water) in the oven along with a weak one (ice) you can end up boiling the water without significantly melting the ice, which is why "defrost" programs are pulsed - you have to warm the water in your partly-defrosted chicken and let it melt a bit of the ice by conduction, then repeat.

[acsinuk]

Hamdani,   Power is energy/second so therefore photon power is P= hf/second. 
 But we know it can be quantized so the formula needs to be Cosine ϴ  for real power and Sin ϴ for virtual power.
 The maths is then correct but not the physics, as if the photons are attracted forward by a voltage in the z direction then both the current in x direction and flux in y direction must be spinning at right angles to create a volume pulse of energy per second

[alancalverd]

Stanley Unwin lives!

[Bored chemist]

Hamdani,   Power is energy/second so therefore photon power is P= hf/second. 
 But we know it can be quantized so the formula needs to be Cosine ϴ  for real power and Sin ϴ for virtual power.
 The maths is then correct but not the physics, as if the photons are attracted forward by a voltage in the z direction then both the current in x direction and flux in y direction must be spinning at right angles to create a volume pulse of energy per second

What are you on, and can you get it on prescription?

[hamdani yusuf (OP)]

How the photon model explains the effect of removing the outer edges (which makes it a thin wire diffraction, which according to Babinet’s principle, should produce the same pattern as single slit aperture)?
How the photon model explains the result of circular pattern when the diffraction grating is vertically tilted?

To repeat, for the nth time, it doesn't. Which is why we also have a wave model.

Some light phenomena are easier to explain using wave models, some others are easier to explain using particle models. There are many different wave models known in physics. Some of them are compatible with some light phenomena, some of them don't.
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.

[Colin2B]

Hamdani,   Power is energy/second so therefore photon power is P= hf/second. 
 But we know it can be quantized so the formula needs to be Cosine ϴ  for real power and Sin ϴ for virtual power.
 The maths is then correct but not the physics, as if the photons are attracted forward by a voltage in the z direction then both the current in x direction and flux in y direction must be spinning at right angles to create a volume pulse of energy per second

You have been warned about posting new theories in the main sections. If you continue your posting will be restricted to new theories only.
Final warning