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Goldilocks Frequencies And Photon Packet Frequencies

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#18 Mattzy

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Posted 07 June 2019 - 05:04 PM

I should also add that I would hate to cause any argument between old buddies. The attraction with this site compared to Wikipedia is that it finds people that can go to a misunderstanding and then help with a particular detail right away. The discussions can be stimulating too (even a little addictive) - rather than dry research. Nevertheless I will make better use of Wikipedia in future before spouting ideas.



#19 Mattzy

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Posted 07 June 2019 - 05:42 PM

I think the root cause of my ignorance is that I had the belief that when an electron loses energy it moves inwards in its orbit (shell) and gives off said energy as a photon. So I start thinking of packets or photons. Visible light is detected at the back of the eye which detects photons. There seems to be a gulf between visible light theory and radio wave theory even though they are said to be both electromagnetic radiation. Many years ago I was surprised to hear that visible light was electromagnetic - I will go to Wikipedia to find that proof - which I don't dispute. 

So I had this perception that in charging and discharging a metal rod, we emit photons and that these photons are the electromagnetic field itself. I had also thought that is what happens when we switch on a light bulb filament and see it glow - because our eyes detect those particular photons. This is my confusion from the past. I still have to conceive what a wave or field is made of if not photons.



#20 Dubbelosix

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Posted 07 June 2019 - 06:10 PM

Yes. They are one and the same. 

 

The issue is diffraction. Long wavelengths can diffract round obstructions, whereas short ones have a more line-of-sight behaviour. Essentially, obstructions that are smaller in size than the wavelength do not significantly interrupt the wave.  Conversely apertures in a blocking obstruction do not significantly pass waves that have a wavelength much larger than the aperture. If you look up diffraction you will be able to read more about this (I am just going from memory and may not have expressed it exactly right :)  ).

 

And you...

 

 

.... You speak so much sense... and yet, you are incredibly disingenuous towards me... I hope this changes. 



#21 rhertz

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Posted 07 June 2019 - 06:31 PM

I think the root cause of my ignorance is that I had the belief that when an electron loses energy it moves inwards in its orbit (shell) and gives off said energy as a photon. So I start thinking of packets or photons. Visible light is detected at the back of the eye which detects photons. There seems to be a gulf between visible light theory and radio wave theory even though they are said to be both electromagnetic radiation. Many years ago I was surprised to hear that visible light was electromagnetic - I will go to Wikipedia to find that proof - which I don't dispute. 

So I had this perception that in charging and discharging a metal rod, we emit photons and that these photons are the electromagnetic field itself. I had also thought that is what happens when we switch on a light bulb filament and see it glow - because our eyes detect those particular photons. This is my confusion from the past. I still have to conceive what a wave or field is made of if not photons.

 

Don't lose your peace of mind because of this dual behavior (explanation I should say).

 

The only thing that a purist physicist can criticize you is your first comment: they don't talk about orbits (Bohr) or shells (Schrodinger) anymore. It's a

thing of the past. The new explanation used at the core of Quantum Physics today is: a bounded electron (the one stuck at an atom) changes its

energy levels up (absorbing a photon) or down (emitting a photon).

 

Any other concept that I remarked in red is CORRECT, basicly.

 

If you want to be cool and always right about this topic, follow the master/creator of the Quantum Physics: Max Planck.

On his words "electromagnetic energy travels along the space as waves and are absorpted or emitted by matter in discrete amounts or

quantum of actions with E = hf".

 

You'll keep hearing about photons travelling the space, frequency or size of photons, etc. This is due to decades of sloppy education, nothing more.

 

Photons are used as an easy mean to explain discretness of energy of light. It's easy for people to visualize massless particles moving around with

hf energy per photon. Is not that it's wrong, only that it's incorrect to think that way. Using photons will prevent you to understand phenomena in the

macroworld like: reflection, refraction, difraction, radiation of energy, etc.

 

Planck created by his own the basis of the quantum physics when, at his Jan. 1901 paper, he explained the radiation inside a black body cavity. It

was known for decades that such radiation was electromagnetic, but any attempt to find a formula to describe it failed, because classical (Maxwell)

electromagnetism was used. Planck found the right equation when he asserted that any electromagnetic wave (a single monochromatic one)

emitted by his resonators (he didn't know that atoms existed by then) had a minimum value of energy E = h.f (h is the later called Planck's constant).

and also asserted that not any other EM wave could have an energy value lower than hf. Whith this discretization of energy in quantums, he

created the basis for the Quantum Physics (and photons).

 

This is the curve of the radiation of a black body cavity, from the times of Planck and valid today: You'll observe that cover any electromagnetic

frequency from AM radio (and lower yet) up to the lethal gamma rays. Visible light is in the region between 450 and 750 nanometers. Larger

wavelengths are called infrared radiation (in three groups), below which are the microwaves, etc. Above visible light (shorter wavelengths)

there is the region of UV radiation, X-ray radiation and, finally, gamma radiation (usually present at nuclear process and cosmic radiation).

 

1.png

 

These curves graph the radiation measured through a small hole in a black body cavity, and is a function of the temperature

within the cavity. The temperature is one variable that is changed easily.

 

Today, black body radiation generators of different ranges are manufactured and sold for industrial, medical, scientific and military

applications.

 

This is an example: https://www.newport.com/p/67032

 

LS-pg5-35a_800w.jpg?9

 

This is how the cavities are done (there are many materials and techniques) but this is the most frequent (using grafite):

 

 

2.png


Edited by rhertz, 07 June 2019 - 06:44 PM.

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#22 exchemist

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Posted 08 June 2019 - 03:34 AM

Roger that exchemist. Yes I should use wiki pedia more often. I forgot to answer your request. You can see a mention of goldilocks frequencies in relation to 5G networks. A friend of mine mentioned them a few months ago - he works in telecoms but he is an organiser and no more technically knowledgeable than I am. I have seen it mentioned on a site called "between towers" its the range 1 to 7GHz and said to be 'just right' hence the goldilocks term.

Ah, OK. I would imagine this relates to some happy medium, balancing the snags of the more line-of-sight behaviour of high frequencies (need more towers to cope with blocking by buildings etc) against whatever the advantage is of higher frequency (rhertz can probably fill you n on that side of things - I am not a radio engineer).


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#23 exchemist

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Posted 08 June 2019 - 03:39 AM

I think the root cause of my ignorance is that I had the belief that when an electron loses energy it moves inwards in its orbit (shell) and gives off said energy as a photon. So I start thinking of packets or photons. Visible light is detected at the back of the eye which detects photons. There seems to be a gulf between visible light theory and radio wave theory even though they are said to be both electromagnetic radiation. Many years ago I was surprised to hear that visible light was electromagnetic - I will go to Wikipedia to find that proof - which I don't dispute. 

So I had this perception that in charging and discharging a metal rod, we emit photons and that these photons are the electromagnetic field itself. I had also thought that is what happens when we switch on a light bulb filament and see it glow - because our eyes detect those particular photons. This is my confusion from the past. I still have to conceive what a wave or field is made of if not photons.

Yes it IS all photons. When a dipole antenna radiates, there are moving charges. When an electron drops to a lower level in the atom, it is a moving charge. In fact if you do quantum theory, you learn about something called the "transition dipole", which describes the process by which the electron emits a photon. It is just a question of scale, really.  

 

I really recommend this Wiki link: https://en.wikipedia...gnetic_spectrum. I suggest reading this and then maybe asking questions, if you have any. 


Edited by exchemist, 08 June 2019 - 03:41 AM.

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#24 Mattzy

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Posted 09 June 2019 - 02:27 AM

Ah, OK. I would imagine this relates to some happy medium, balancing the snags of the more line-of-sight behaviour of high frequencies (need more towers to cope with blocking by buildings etc) against whatever the advantage is of higher frequency (rhertz can probably fill you n on that side of things - I am not a radio engineer).

Yes, reducing cost by minimising hardware. I think its about penetration of walls and windows etc. I think in future there will have to be more frequencies in use within that range.



#25 Mattzy

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Posted 09 June 2019 - 02:29 AM

Yes it IS all photons. When a dipole antenna radiates, there are moving charges. When an electron drops to a lower level in the atom, it is a moving charge. In fact if you do quantum theory, you learn about something called the "transition dipole", which describes the process by which the electron emits a photon. It is just a question of scale, really.  

 

I really recommend this Wiki link: https://en.wikipedia...gnetic_spectrum. I suggest reading this and then maybe asking questions, if you have any. 

Thanks, I'll check it out.



#26 Mattzy

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Posted 09 June 2019 - 03:57 AM

Don't lose your peace of mind because of this dual behavior (explanation I should say).

 

The only thing that a purist physicist can criticize you is your first comment: they don't talk about orbits (Bohr) or shells (Schrodinger) anymore. It's a

thing of the past. The new explanation used at the core of Quantum Physics today is: a bounded electron (the one stuck at an atom) changes its

energy levels up (absorbing a photon) or down (emitting a photon).

 

Any other concept that I remarked in red is CORRECT, basicly.

 

If you want to be cool and always right about this topic, follow the master/creator of the Quantum Physics: Max Planck.

On his words "electromagnetic energy travels along the space as waves and are absorpted or emitted by matter in discrete amounts or

quantum of actions with E = hf".

 

You'll keep hearing about photons travelling the space, frequency or size of photons, etc. This is due to decades of sloppy education, nothing more.

 

Photons are used as an easy mean to explain discretness of energy of light. It's easy for people to visualize massless particles moving around with

hf energy per photon. Is not that it's wrong, only that it's incorrect to think that way. Using photons will prevent you to understand phenomena in the

macroworld like: reflection, refraction, difraction, radiation of energy, etc.

 

Planck created by his own the basis of the quantum physics when, at his Jan. 1901 paper, he explained the radiation inside a black body cavity. It

was known for decades that such radiation was electromagnetic, but any attempt to find a formula to describe it failed, because classical (Maxwell)

electromagnetism was used. Planck found the right equation when he asserted that any electromagnetic wave (a single monochromatic one)

emitted by his resonators (he didn't know that atoms existed by then) had a minimum value of energy E = h.f (h is the later called Planck's constant).

and also asserted that not any other EM wave could have an energy value lower than hf. Whith this discretization of energy in quantums, he

created the basis for the Quantum Physics (and photons).

 

This is the curve of the radiation of a black body cavity, from the times of Planck and valid today: You'll observe that cover any electromagnetic

frequency from AM radio (and lower yet) up to the lethal gamma rays. Visible light is in the region between 450 and 750 nanometers. Larger

wavelengths are called infrared radiation (in three groups), below which are the microwaves, etc. Above visible light (shorter wavelengths)

there is the region of UV radiation, X-ray radiation and, finally, gamma radiation (usually present at nuclear process and cosmic radiation).

 

1.png

 

These curves graph the radiation measured through a small hole in a black body cavity, and is a function of the temperature

within the cavity. The temperature is one variable that is changed easily.

 

Today, black body radiation generators of different ranges are manufactured and sold for industrial, medical, scientific and military

applications.

 

This is an example: https://www.newport.com/p/67032

 

LS-pg5-35a_800w.jpg?9

 

This is how the cavities are done (there are many materials and techniques) but this is the most frequent (using grafite):

 

 

2.png

Great stuff rhertz! And it cheers me up that I at least have the excuse to blame the education system of the 1970's (we had a lot of black-outs!). I will now have to re-confirm a very simple baseline to start from. Could you give me just true or false and I will go away and ask why or why not. I don't want to take too much of your time. 1. The radio wave is not a microwave.  2. When we charge an antenna, we increase energy in its atoms (electrons). 3. When we discharge an antenna we decrease energy in its atoms and quanta are emitted from some of its electrons. 4. The quanta unify into a single monochromatic EM wave? (this is where I'm really lost - I keep seeing an increasing gradient of quanta that make up a wave - which I was calling a pulse)  5. This wave is just pure EM energy and that's all there is to it, and it can't be thought of as a microwave or visible photon - this is the macroworld?

If I conceive a microwave as a dot of energy traveling on a path describing a concertinaed rattle snake - as I have seen depicted - I can see how it can't pass through a 1mm hole, so here we are thinking photons. But it would have to be a single quanta or photon? The visible light photon is depicted as a tiny rattle snake that will pass through the hole. The radio wave is much bigger, so here we are in the macro world where we think about reflection and diffraction etc. ??? Thanks again rhertz, please let me know as briefly as you like if I'm starting to get it.



#27 exchemist

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Posted 09 June 2019 - 05:35 AM

Great stuff rhertz! And it cheers me up that I at least have the excuse to blame the education system of the 1970's (we had a lot of black-outs!). I will now have to re-confirm a very simple baseline to start from. Could you give me just true or false and I will go away and ask why or why not. I don't want to take too much of your time. 1. The radio wave is not a microwave.  2. When we charge an antenna, we increase energy in its atoms (electrons). 3. When we discharge an antenna we decrease energy in its atoms and quanta are emitted from some of its electrons. 4. The quanta unify into a single monochromatic EM wave? (this is where I'm really lost - I keep seeing an increasing gradient of quanta that make up a wave - which I was calling a pulse)  5. This wave is just pure EM energy and that's all there is to it, and it can't be thought of as a microwave or visible photon - this is the macroworld?

If I conceive a microwave as a dot of energy traveling on a path describing a concertinaed rattle snake - as I have seen depicted - I can see how it can't pass through a 1mm hole, so here we are thinking photons. But it would have to be a single quanta or photon? The visible light photon is depicted as a tiny rattle snake that will pass through the hole. The radio wave is much bigger, so here we are in the macro world where we think about reflection and diffraction etc. ??? Thanks again rhertz, please let me know as briefly as you like if I'm starting to get it.

Mattzy, if I can just interject on one point, the emission of radio-frequency photons from an antenna is not the result of electrons changing levels within the atoms. That is how visible light is produced, but the energy gaps between atomic levels are far too big (i.e too much energy is emitted each time) to make radio waves. (As you may know by now the higher the frequency, the more energy the photon has, by Planck's relation E=hν.  So a radio-frequency photon has a lot less energy than a visible light photon.)

 

In a solid metal, as a consequence of the chemical bonding between atoms (what we call "metallic bonding"), the outermost orbitals (energy levels) of the atoms overlap and merge together, into a band of energies called the "conduction band". Electrons in the conduction band are no longer bound to any particular atom and can travel fairly freely through the solid (this is what makes metals conduct electricity and heat so well). In the antenna they are accelerated by the alternating voltage, first in one direction and then the other and it is this that leads to them emitting radio-frequency photons. You can view it as very tiny changes in energy level, but all taking place within the conduction band. 

 

The wave issues I'll leave to rhertz. :)


Edited by exchemist, 09 June 2019 - 05:38 AM.

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#28 rhertz

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Posted 09 June 2019 - 09:35 AM

Great stuff rhertz! And it cheers me up that I at least have the excuse to blame the education system of the 1970's (we had a lot of black-outs!). I will now have to re-confirm a very simple baseline to start from. Could you give me just true or false and I will go away and ask why or why not. I don't want to take too much of your time. 

 

1. The radio wave is not a microwave.  

2. When we charge an antenna, we increase energy in its atoms (electrons).

3. When we discharge an antenna we decrease energy in its atoms and quanta are emitted from some of its electrons.

4. The quanta unify into a single monochromatic EM wave? (this is where I'm really lost - I keep seeing an increasing gradient of quanta that make up a wave - which I was calling a pulse) 

5. This wave is just pure EM energy and that's all there is to it, and it can't be thought of as a microwave or visible photon - this is the macroworld?

 

If I conceive a microwave as a dot of energy traveling on a path describing a concertinaed rattle snake - as I have seen depicted - I can see how it can't pass through a 1mm hole, so here we are thinking photons. But it would have to be a single quanta or photon? The visible light photon is depicted as a tiny rattle snake that will pass through the hole. The radio wave is much bigger, so here we are in the macro world where we think about reflection and diffraction etc. ??? Thanks again rhertz, please let me know as briefly as you like if I'm starting to get it.

 

Use this universal chart:

 

Imagen3.png

 

 

 

 

1) As a convention, a radiowave is anything that is transmitted, propagates in the space and received by using power transmitters, antennae and

    receivers. Due to the current technology (and nothing more than that) we could put an upper limit for radiowaves 300 Ghz (300,000 Mhz).

    This is by 2019, and cover EM waves having 1mm wavelength (300 Ghz) down to 1,000 meters   (300 Khz). Any EM oscillation below 300 Khz

    usually doesn't propagates into open space as an "aerial" wave, but follow the surface of the Earth (terrestrial EM wave).

 

    Electromagnetism is very wide on this matter, and is related to the length of the primary dipole (or monopole). EM waves below 300 Khz still are

    EM waves, but they don't propagates into the air but following the Earth's surface. This kind of waves can penetrate deep under water, as they

    have a lower frequency and can be as low as 10Khz or lower (you'll need a very long antenna). This kind of EM waves can penetrate water as

    far as hundred of meters, and is the method by which SUBMARINES are connected with surface stations located at the other end of the world.

    The problem is that the ability to transmit data in the carrier falls to very low speeds (10-50 bits/second), but it works for the military.

    A sub, specially a nuclear one, carries behind a long wire to capture this kind of waves.

    This is the way the world works.

 

2 and 3) We don't charge or discharge antennae. We have a power amplifier (1 watt to 100 Kwatts or more) and we connect this amplifiers to any

    antennae (a monopole, a dipole, a complex array of dipoles (Yagi), a parabollic antennae, etc.).

    Electrons in atoms are freed and are accelerated by the sinewave that the power (current in amperes) forces them to MOVE under acceleration.

    Usually, dipole antennae in HF, VHF and UHF are designed to have a resonant resistance of 50 Ohms and the power RF amplifier has a 2 Amps

   peak current, a dipole at 150 Mhz is supplied with 200 Watts peak of RF power, and this constitutes the radiant peak power (except some losses).

 

   To do so, a current of 2 Amps peak  oscillates along the dipole 150 million times per second. As the current is provided by the flow of electrons,

   which are the radiating source, to find out how many electrons are involved at the whole antenna, you calculate the peak charge Q = 2 A x 1sec.

   This is equal to 2 Coulombs peak. Each electron has a charge of 1.6.10-19 coulombs, so 1.25.1019 electrons are involved at the peak value.

 

   If you assume that each electron is responsible for the emission of a single EM wave (a gross approximation), then the FLUX of EM waves is

   (rounding off) 1.25.1019 single EM waves. If you want to call them "RF photons", do so. But remember that this is a SIMPLIFICATION.

   This is the peak amount of electrons that are being displaced along the antenna, each one resonating at 150 Mhz.

 

4) I suggest you that don't use the words "quanta" or "quantum", or people will look at you in a funny way. Better use "photons" and everyone will be

    happy. Keep "quanta of energy hf" for yourself.

 

    Also, when you talk about radiating "substance" in radio, you use WATTS (power), not JOULES (energy). Energy is commonly used at physics and

    chemistry, but not at RF engineering. POWER =  TOTAL ENERGY EXPENDED/ TIME INVESTED ( 1 Watt = 1 Joule/second).

 

    If you have an electron which continuously radiates energy with frequency f = 150 Mhz, then it has an energy E = h.f = 10-25 Joules.

    If this energy is continuously radiated (or at least for millions of wavelengths), then the power emitted per electron  P = E/Period of the wave.

    In this case, the power emitted during a long period of time would be: P = 10-25 Joules/ 6.67.10-9 sec = 1.5.10-17 Watts (per electron)

 

5) Think of the Black Body used to develop the Planck's theory of radiation. It always radiate EM energy, visible or not.

     If you start to heat the Black Body in an oven, it will stay black from ambient temperature up to 600 ºC, while emitting radiation at microwave

     and infrared frequencies.

     If the temperature of the black body keep rising, you'll observe how the black color changes to gray, then to dark red (visible), then keep

     changing to yellow (maybe at 1500 ºC), then to yellow-orange and finally to pure white (it's emitting at every possible visible wavelength).

     When you observe the color being increasingly white (more and more energy emitted), the body has also started to emit UV radiation (which

     you can't observe) and could keep going up until it mealts completely (before reaching X-ray frequencies).

 

     Only specialized materials reach a temperature at which enough UV radiation es emitted to be measured (beyond 3000 to 4000 ºC).

 

Well, I hope this can help you.


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#29 Mattzy

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Posted 10 June 2019 - 03:02 AM

Thanks rhertz and exchemist. I'll do some reading on the links you recommend. It's all very interesting - and a bit mysterious at this stage - but that's good. I'm glad I can go back to saying photon! I'll be back after a while on this one.



#30 Mattzy

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Posted 10 June 2019 - 03:08 AM

Mattzy, if I can just interject on one point, the emission of radio-frequency photons from an antenna is not the result of electrons changing levels within the atoms. That is how visible light is produced, but the energy gaps between atomic levels are far too big (i.e too much energy is emitted each time) to make radio waves. (As you may know by now the higher the frequency, the more energy the photon has, by Planck's relation E=hν.  So a radio-frequency photon has a lot less energy than a visible light photon.)

 

In a solid metal, as a consequence of the chemical bonding between atoms (what we call "metallic bonding"), the outermost orbitals (energy levels) of the atoms overlap and merge together, into a band of energies called the "conduction band". Electrons in the conduction band are no longer bound to any particular atom and can travel fairly freely through the solid (this is what makes metals conduct electricity and heat so well). In the antenna they are accelerated by the alternating voltage, first in one direction and then the other and it is this that leads to them emitting radio-frequency photons. You can view it as very tiny changes in energy level, but all taking place within the conduction band. 

 

The wave issues I'll leave to rhertz. :)

Very good interjection exchemist! All new to me too. I think it's going to help me on the issue of photons that do and don't go through a microwave screen (maybe not). I'll go to those links first.



#31 exchemist

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Posted 10 June 2019 - 03:29 AM

Very good interjection exchemist! All new to me too. I think it's going to help me on the issue of photons that do and don't go through a microwave screen (maybe not). I'll go to those links first.

I'm not sure it will help much with that. You could read this, though: http://hyperphysics....ves/mwoven.html

 

But it is useful for you to know that EM radiation can be generated by a large variety of different things, depending on the wavelength. For X-rays and visible light, it is electrons changing levels in atoms and molecules. For infra red it is vibrations of molecules. For microwaves it is rotations of molecules (and motion of electrons in cavity magnetrons etc). For radio waves it is motion of electrons in an antenna.  The common feature is that In all cases you have motion of an electric charge.


Edited by exchemist, 10 June 2019 - 03:30 AM.


#32 exchemist

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Posted 10 June 2019 - 05:05 AM

I'm not sure it will help much with that. You could read this, though: http://hyperphysics....ves/mwoven.html

 

But it is useful for you to know that EM radiation can be generated by a large variety of different things, depending on the wavelength. For X-rays and visible light, it is electrons changing levels in atoms and molecules. For infra red it is vibrations of molecules. For microwaves it is rotations of molecules (and motion of electrons in cavity magnetrons etc). For radio waves it is motion of electrons in an antenna.  The common feature is that In all cases you have motion of an electric charge.

Later note: I have found in several internet sources (e.g. this one: https://physics.stac...-by-small-holes) the information that the transmitted power through a hole is proportional to (d/λ)⁴, where d is the diameter of the hole and λ is the wavelength.

 

So you can see from this that when λ>>d, d/λ will be much less than 1 and, raised to the 4th power, it is absolutely minuscule. So if your microwave has a wavelength of 12cm and the holes are 0.5cm diameter, d/λ will be about 0.04, and raised to the 4th power it will be 0.00000004.  


Edited by exchemist, 10 June 2019 - 05:10 AM.

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