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Author Topic: polarisation of electromagnetic wave and light for rude people  (Read 13104 times)

Offline sorincosofret

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The message is dedicated specially for those rude people and without extended knowledge in physics


The specific manner in which a beam of light at a specific polarization is reflected (and refracted) at interface between two different media can be used to determine the refractive index of the solid.
Specifically, for a particular interface, there is a particular angle of incidence (relative to the normal vector of the surface), called the Brewster angle, which is related to the refractive index of a material. At this angle, the reflection coefficient of light polarized parallel to the plane of incidence is zero. Thus, if the incident light is non-polarized and impinges on the material at the Brewster angle, the light reflected from the solid will be polarized in the plane perpendicular to the plane of incidence. If the incident light is polarized parallel to the plane of incidence, the intensity of the reflected light will be theoretically zero at the Brewster angle.

For the beginning is necessary to highlight that the refractive index defined for light has no significance in case of microwave (by extension also to other radio waves).
It is worth to be reminded a study made by a team of Oklahoma University available at link: http://www.nhn.ou.edu/~johnson/Education/Juniorlab/Microwave/2003SP_MicrowaveOptics.ppt#27
In the experiment, the polarized microwaves reflected by a polyethylene foil are counted for different angle of incidence. They obtained maximum of reflection not for a single value of incidence angle but for more values. Their conclusion: We are unable to detect Brewster angle in proposed experiment. 
 The results obtained are without meaning in the frame of actual physics.
In proposed theory the refractive index is a characteristic of photons interaction with matter.
Electromagnetic wave interacts in a different way with matter. In case of electromagnetic waves, depending on the material, it is possible to have more then one maximum of reflection or to have no maxim at all.
Consequently, in a double mirror polarization device, using a microwave or a UHF radio source, when the second mirror is rotated, the intensity of microwave does not modify according to Malus law. It is possible for different angle to have more then expected maximum of  reflected polarized microwave  or to have no maximum and the conclusion is clear: radio wave does not follow the same rules like polarized photons (IR, VIS, UV etc) at reflection.

« Last Edit: 04/06/2008 14:53:09 by sorincosofret »


 

Offline Soul Surfer

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Again you are not looking at the whole problem.  The critical term is "polyethylene foil"  this means it is relatively thin, presumably thinner than one wavelength of the microwave frequency used.  Conventional refractive index effects only apply to materials that are significantly thicker than the wavelength of the radiation used and wavelengths significantly longer than the spaces between the atoms.  A thin film will not demonstrate normal polarisation or reflection effects and can be essentially invisible.  You can see the same effect in light by using soap films using a frame or a bubble.  As the water drains down in the film it gets thinner and eventually becomes equal to and less than the wavelength of light if you then observe the reflection of a white light source the film first goes through a sequence of colours caused by interference between reflections from the front and rear surface of the film and eventually becomes invisible as reflection almost completely stops because the front and rear surface reflections cancel each other out because they are in antiphase.

You can see the same effect with thin films of oil on water.

You really need to understand the whole problem before you criticise the accepted laws of physics.  most scientists are not stupid and have thought through the problem thoroughly.  If you find something does not agree with theory as you see it first question your own understanding.  It has always worked with me.
 

Offline syhprum

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when Heinrich Hertz first demonstrated in 1887 that the the refraction of microwaves was similar to that of light he used a large lens and a prism made of pitch.
He well understood that a thickness of several wavelengths was required
 

Offline BenV

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The message is dedicated specially for those rude people and without extended knowledge in physics

Are you accusing people of being rude because they disagree with you?
 

Offline sorincosofret

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I'm not accusing someone when the contradictory discusion is made at a minimum respect manner. When the invective are the way of discussion, the forum is useless so it need to be deleted and so I did it.
In the meantime I've contacted some persons who works really in the field of microwave and it seems that the situation is more complex as I guessed and of course different as is presented in known scientific books.
It seems that in case of p-polarised microwaves (vertical) the Brewster angle (for dielectrics) has no meaning, and confirm the results of Oklahoma University and proposed theory.
But for a s-polarised (horizontal) microwave it is possible to measure a Brewster angle.
Still I wait for some confirmations .... and of course I ordered a new and increased power microwave toolkit (www.electron.it) in order to perform independently the experiments.

If the ideas are correct it should be nice to see how the same piece of material (of course in experiments made up to date thinner then 3 wavelengths), does not present a Brewster angle for vertical polarised microwave but present for horizontal one.
The cost of a piece of polyethylene or other common material is not a problem in order to repeat the experiment with thicker materials.

« Last Edit: 04/06/2008 10:34:55 by sorincosofret »
 

Offline Bored chemist

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He might reasonably accuse me of being rude for calling him an idiot- except that he was being an idiot at the time.

Im going to do it again too because only an idiot would say
"For the beginning is necessary to highlight that the refractive index defined for light has no significance in case of microwave (by extension also to other radio waves). "
 since the refraction of microwaves is well documented. you can use lenses or prisms made of wax to bend and focus microwave beams in exactly the same way as you can use glass ones for light.
Come to think of it, you could use quartz for either form of radiation.
Best of all, you could use the stuff they use in slide 8 of the presentation he has helpfully cited.
Lets make this clear- the same web page he is using as evidence for the "idea" that you can't talk about a refractive index for microwaves, includes a slide about measuring the refractive index of something using microwaves.
Does anyone think that's not idiotic behaviour?
Well, it gets better. The next couple of slides give details of the efects of polarisation that he didn't seem to believe in in an earlier post.
In fact, the whole presentation (and my compliments, btw, to its authors) shows how in virtually every respect, the microwaves behave exactly like light.
They didn't see brewster angle reflection because they failed to take account of thin film interference.
 

Offline sorincosofret

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Bored chemist,
You probably are an idiot much greater then you imagine...
Probably you have learned physics like a papagal because only a incompetent confuse the polarisation by reflection with diffraction as you give the first link in the first discussion.
The fact that a lens work with light and concentrate a fascicle of light in a focus again has nothing to do with the polarisation and to bring this proof means you are not able to see that we speak about polarisation and not about image of objects.. so please read the topic, and I hope you will understand the meaning.
I don't speak about refraction, and I presented only the conclusion of a independent study. But it seems that you are not able to read even in English so why I loose the time with a idiooooooooooot.
 

Offline rosy

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Sorincosofret... I'm afraid despite having more education in physics than the average graduate of the English educational system, have no idea what you may mean by a fascicle. This may be because it is a technical term used in the field (in which case you're not going to communicate effectively with non-experts), or because it is not the word used in English. I don't know what papagal means, either, but I don't think I want to.

Also, if you want anyone less persistent than Bored Chemist to read your posts you will need to spend more time proof reading your written English, I am not going to make the effort because I think it very unlikely I will be able to work out what you're trying to say.
 

Offline sorincosofret

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Rose,
Can you help me with the English corrections for my texts?
I recognise I didn't learned English in the school, but this not means the texts are completely unreadable and it is so difficult to observe the idea behind it.
 

lyner

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I suggest we stop using words like "idiot"; it doesn't help the argument and just lowers the tone. There are many more polite ways of inferring the same thing.
 

Offline sorincosofret

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polarisation of electromagnetic wave and light for rude people
« Reply #10 on: 05/06/2008 07:43:36 »
Soul surfer,
Let's look at the whole problem as you say...
I give you a paragraph from text regarding the process of manufacturing optically mirrors available at : http://www.freepatentsonline.com/EP1808880.html

The first thin metal film 51 can have a thickness thin enough to transmit no light. For example, the film thickness can be 40 to 500 nm for an aluminum film, and substantially the thickness may be 50 to 100 nm. The second thin metal film 41 is adjusted in film thickness so as to work as a half mirror. In the case of aluminum, for instance, the film thickness may be 5 to 40 nm, and substantially it may be 10 to 30 nm. The film thickness of the first thin metal film 51 may also be the same as that of the second thin metal film 52. In the case of aluminum, for instance, the film thickness may be 5 to 40 nm, and substantially it may be 10 to 30 nm. In addition, an undercoat 45 may be provided on the surface of the keytop 4 before the film is formed thereon in order to make the first thin metal film 51 easy to form.


Why in case of light in order to have a good reflection there is enough a layer thinner then wavelength (400-800 nm) and in case of a microwave there is necessary a thicker layer?
If we look at proportion there is necessary a 100 nm layer of aluminium this means approx 1/5 of wavelength size.
Why in case of a half silvered mirror for visible light there is no phenomena of interference for reflected or transmitted light?
 
« Last Edit: 05/06/2008 08:15:15 by sorincosofret »
 

lyner

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polarisation of electromagnetic wave and light for rude people
« Reply #11 on: 05/06/2008 08:45:17 »
Quote
Why in case of light in order to have a good reflection there is enough a layer thinner then wavelength (400-800 nm) and in case of a microwave there is necessary a thicker layer?
Have you heard of and do you understand the terms 'skin depth' and 'evanescent modes'? Both of these are relevant if you want to discuss the effect of an interface on the propagation of an em wave.
 

Offline Soul Surfer

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polarisation of electromagnetic wave and light for rude people
« Reply #12 on: 05/06/2008 08:56:09 »
Again sorincosofret  you are demonstrating your lack of understanding of the physics. There is a very great difference between the behaviour of dielectrics and conducting materials to electromagnetic radiation.

Polyethelene is a dielectric and subject to the rules I mentioned in my earlier reply.  

Aluminium is a conductor and electromagnetic waves do not propagate normally inside conducting materials. The propagation waveform is a decaying exponential not a sine wave. this means they are mostly reflected from the surface or absorbed in the resistive element in the skin depth of the waves.  This skin depth is very much less than the wavelength of the radiation for good conductors and becomes less as conductivity increases.  All that is needed is to ensure that a reasonable number of skin depths of material are used to ensure good reflection.  In general all waves are reflected from conductors regardless of polarisation.
« Last Edit: 08/06/2008 11:30:18 by Soul Surfer »
 

Offline sorincosofret

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polarisation of electromagnetic wave and light for rude people
« Reply #13 on: 05/06/2008 09:31:15 »
OK .... let's see how a conducting material reflect the microwave at general case and let's see how the same conducting material reflect the polarised microwave and the Brewster angle in this case.
After that a comparison with light is more then necessary ....
I don't think in this scientific world there aren't study about this subject.
There are experiments without a clear possibility of discrimination between two theories and in this case there are necessary other clear cut off experiments.
Further proposed experiments (NMR and quanta hypothesis as example) will be with a clear discrimination between actual and proposed theory
 
« Last Edit: 05/06/2008 10:52:12 by sorincosofret »
 

Offline lightarrow

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polarisation of electromagnetic wave and light for rude people
« Reply #14 on: 05/06/2008 17:46:59 »
Sorincosofret... I'm afraid despite having more education in physics than the average graduate of the English educational system, have no idea what you may mean by a fascicle. This may be because it is a technical term used in the field (in which case you're not going to communicate effectively with non-experts), or because it is not the word used in English. I don't know what papagal means, either, but I don't think I want to.

Also, if you want anyone less persistent than Bored Chemist to read your posts you will need to spend more time proof reading your written English, I am not going to make the effort because I think it very unlikely I will be able to work out what you're trying to say.
With "fascicle" and "papagal" he probably intended "beam" and "parrot".
 

lyner

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polarisation of electromagnetic wave and light for rude people
« Reply #15 on: 05/06/2008 18:51:01 »
Quote
Again you are demonstrating your lack of understanding of the physics. There is a very great difference between the behaviour of dielectrics and conducting materials to electromagnetic radiation.
That's an unfair comment. I have studied ionospheric propagation and I am well familiar with the concept of a complex refractive index. AND, if you use complex refractive index in your em calculations, you get the right answer whether you use polythene, silver, seawater or wet mud at whatever wavelength you care to use.
Composites make life harder and I have no idea what you have to do about that.

To my mind, getting the right answer is all you need to justify a theory - as far as it goes. Do you get the right answer with yours?

btw, you never did say whether you know what is meant by skin depth or evanescent modes. Or are they too humdrum for your theory?
 

Offline Bored chemist

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polarisation of electromagnetic wave and light for rude people
« Reply #16 on: 05/06/2008 19:48:36 »
"Probably you have learned physics like a papagal because only a incompetent confuse the polarisation by reflection with diffraction as you give the first link in the first discussion."
Sorin,
However well parrots learn physics they might be taught the difference between a diffraction grating and a polariser. That would put them one step above you.
Do you really think this
is about diffraction- it's just that the guys from MIT got the name wrong?

Also it's questionable for you to say "I don't speak about refraction" when you have been on about refractive index all the time.
Similarly, to say "I presented only the conclusion of a independent study. But it seems that you are not able to read even in English " is to ignore the fact that I read and commented on the presentation. I also pointed out the fault with it specifically that it ignores thin film interference effects.
Did you forget to read that bit of my English?

Never mind, lets have a look at the second post.
"OK .... let's see how a conducting material reflect the microwave at general case and let's see how the same conducting material reflect the polarised microwave and the Brewster angle in this case."
Well that's 2 cases- for reflection from metal it's relatively easy. The microwaves are reflected from the metal surface in exacltly the same way as light. The angle of incidence is equal to the angle or reflection and practically 100% of the radiation- light or µwave is reflected.

The reflection at Brewster's andgle is more difficult because, for a conductor, the refractive index is complex (in more ways than one) and the Brewster's angle is not properly defined.
Sorry, but that bit of the question is meaningless.
"I don't think in this scientific world there aren't study about this subject."
True- the experiments are done as school physics experiments. The answers are well known. The results for reflection from a conductor are exactly the same for light as for microwaves.


I'm not sure what you mean by "Further proposed experiments (NMR and quanta hypothesis as example) will be with a clear discrimination between actual and proposed theory"
But so far your proposed "theory" seems totally devoid of validity. It gave, for example, the wrong predicted result for the magnetic field produced by a stream of charged particles or current passing through a semiconductor.

face it; your theory doesn't agree with reality and it's not because of a fault with reality.



BTW, I can't find the original post about the much loved ten euro experiments. That's a pity because I just did another of them. I got a long thin fluorescent tube and passed a large current through it to get a deflection on a compass next to it.
What happened to the original?



« Last Edit: 05/06/2008 21:23:01 by Bored chemist »
 

Offline syhprum

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polarisation of electromagnetic wave and light for rude people
« Reply #17 on: 05/06/2008 22:09:44 »
It is quite amusing running fluorescent tubes on DC which I presume is what you did, of course you have to include a resistor as the normal inductor is ineffective with a DC supply.
I used to do this in my workshop 50 years ago to avoid the annoying buzz from the choke but I found the light output migrated to one end and a I had to to periodically reverse the power supply.
 

lyner

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polarisation of electromagnetic wave and light for rude people
« Reply #18 on: 05/06/2008 23:13:15 »
They started using fluo tubes with a conventional tungsten lamp in series before they thought of the choke idea, I believe.
 

Offline Bored chemist

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polarisation of electromagnetic wave and light for rude people
« Reply #19 on: 06/06/2008 07:12:13 »
They did, and it improved the colour balance too.
I did put a dropper resistor in the circuit. I didn't measure the current- it would have been limited to 3 A but I doubt it was that high.

BTW, does anyone want a second hand fluorescent tube that's as dead as Sorin's theory?
 

lyner

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polarisation of electromagnetic wave and light for rude people
« Reply #20 on: 06/06/2008 07:49:27 »
It will probably shed more light than Sorin's theory even if it is broken.
« Last Edit: 06/06/2008 10:45:08 by sophiecentaur »
 

Offline sorincosofret

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polarisation of electromagnetic wave and light for rude people
« Reply #21 on: 07/06/2008 20:28:21 »
Probably syhprum  refers to the deleted post regarding the tubes in DC current. It will be post again probably next year when I will make the details for the experiment. It is necessary to have a current limitation in other case the discharge in tube goes in avalanche.

 

Offline Bored chemist

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polarisation of electromagnetic wave and light for rude people
« Reply #22 on: 08/06/2008 14:09:46 »
It was me who raised the subject of current through a gas here.
That's because I actually  did the experiment you sugested and- of course- I got the answer that the normal laws of physics predict rather than the one you predicted.
Now, perhaps you would like to tell us why you think the video clip I linked to is about diffraction when the title says it's about polarisation.
Do you understand the difference?
Do you realise that diffraction relates to altering the direction of a beam?
Do you think that the direction of the microwave beam in that demonstration is actually changed?
Are you ever going to admit that you are just plain wrong about this and many other things, or are you going to continue to act like an idiot?
 

Offline sorincosofret

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polarisation of electromagnetic wave and light for rude people
« Reply #23 on: 08/06/2008 21:42:49 »
B.C,
I'm not interested to respond at your comments.
Please make a mental control, learn to speak polite, and after that maybe I will answer to you.
« Last Edit: 08/06/2008 22:00:10 by sorincosofret »
 

Offline Soul Surfer

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polarisation of electromagnetic wave and light for rude people
« Reply #24 on: 08/06/2008 23:13:13 »
sorincosofret   Reading through all your contributions, you appear to be very well read in certain aspects of science and very naive in others.  you are also very sensitive about politeness in others and do not appear to be very polite youself.  This leads me to the belief that you are not a somewhat misguided but enthusiastic scientist but what is commonly known as a Troll who's aim is purely to start and foment arguments.  I would therefore advise all contributors to ignore inputs from you and also request the moderators to remove all the topics that sorincosofret has originated to the new theories area where they truly belong.
 

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polarisation of electromagnetic wave and light for rude people
« Reply #24 on: 08/06/2008 23:13:13 »

 

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