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Offline sorincosofret

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Cerenkov effect and its interpretation
« on: 29/11/2008 21:01:16 »
Cerenkov effect and its interpretation

Background and actual explanation

Pavel Cerenkov discovered this radiation in 1934, while he studied the effects of radioactive substances on liquids, when he observed a faint blue glow in water close to a radioactive substance.
The explanation accepted to date for Cerenkov radiation was first given by Tamm and Franc. The observed light is attributed to a shock wave phenomenon caused by particles entering the water at speeds greater than the speed of light in the water. As the particles slow down to the local speed of light, they produce a cone of light roughly analogous to a sonic boom.
It is assumed that electrically charged particles have electric fields around them as a result of their charge. When such charged particle is moving, the electrical field moves along with the particle. However, since the electrical field is carried by photons, it can only travel at the speed of light. If the particle is traveling faster than the speed of light in a certain medium (water), then the electrical field that is left behind and forms a shock front which manifests itself in the form of light. There are two reasons for blue color apparition:
1.   The atoms in the water become excited by the Cerenkov shock wave and then de-excite, emitting directly blue light photons.
2.   The number of photons emitted by such a charged particle is inversely proportional to wavelength. This means that more photons are emitted with shorter wavelengths, and consequently the spectrum is tilted to the blue region.
This radiation is emitted in a forward cone, and can be seen with the naked eye (as a blue glow) if there are enough particles creating it. The Cherenkov radiation emitted by even a single such particle can be detected by devices such as photomultiplier tubes,
On the other hand, if the velocity of the particle is less than the velocity of light in the medium, the light is destroyed by destructive interference.
   In some scientific book a more ,,fantasist” explanation of Cerenkov phenomena is provided.  More precisely, a  fast moving charged particle moving through a dielectric medium causes local, non-isotropic polarizations in the atoms of the dielectric. These atoms return to normal states by emitting light. If the velocity of the particle is less than the velocity of light in the medium, the light is destroyed by destructive interference. If the velocity of the particle is greater than the velocity of light in the medium, the light remains due to constructive interference.

What is wrong in actual explanation?

At beginning it should be highlighted that all phenomena in the frame of actual physic should respect the quantum hypothesis. In macroscopic world this think is not evident, but this condition is implicitly supposed to be respected.
Cerenkov effect is a quantum effect. It can be observed when a single particle is moving in a certain material medium. Let’s analyze how quantum hypothesis is respected in this case.
   At quantum level an ,,electrical field that is left behind and forms a shock front which manifests itself in the form of light” does not respect the quantum hypothesis.  When a particle hit another particle it is ,,possible” to admit a transfer of energy in chunks. But for an electric field it is impossible to have a quantum variation. Actual physics suffer from absence of ideas so maybe some theoreticians will start to quantify the electric field even this is an aberration; Such quantification will not fit with experimental results because Cerenkov spectra has a continuous variation and not a discrete one. Even with our eyes, we see a blue color an instrument will show that maximum of radiation is in the blue domain, but the spectrum is not monochromatic.
   Let’s analyze a little bit what’s happen at super luminal and sub luminal speeds in a material according with actual physics.
 For a particle traveling faster than light, the wave-fronts do overlap, and constructive interference is possible, leading to a significant, observable signal as is presented in fig. 1.



Fig. 1

Why in this case, for an electron moving at a subluminal speed, the produced electromagnetic waves are interfering and no light appear for an external observer?
From the waves theory, it is known that ,,interference” produce alternations of more and less illuminated regions. To date I haven’t seen a book of physics admitting that an interference of two waves lead to a complete annihilation of both waves in the entire space of interference. Maybe in this case a source of light which is moving in air at a subluminal speed can disappear for an observer, because the electromagnetic waves emitted at different moments cancel one another.
The actual explanation of Cerenkov effect must be ruled out.
In a coherent explanation of Cerenkov effect, in frame of actual physics, only the form of the light distribution should be different when an electron pass from subluminal to hyperluminal speeds as is presented in the following animations:

http://www.shef.ac.uk/physics/teaching/phy311/animations.html

So, when electron passes to subluminal speeds, the light should be emitted in the form of ellipsoid in comparison with superluminal speed when light is emitted as a cone distribution. Why is not happened this?
The possible polarization of atoms in the dielectric and their return to the initial state with light emission does not need any commentary. The quantum hypothesis is again disrespected. A simple and easy to perform experiment can prove the contrary. A non-insulating conductor found at a high potential immersed into a dielectric medium can produce a local polarization of molecules around it. In this case if the potential is cut, the return of molecules at their initial stage should produce electromagnetic waves (light, IR, etc). This is not the case in reality.

With this text, I start the work to a book related to elementary particle, so I don’t have a complete and definite explanation for Cerenkov effect. There is enough time ….
« Last Edit: 29/11/2008 21:09:31 by sorincosofret »


 

lyner

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Cerenkov effect and its interpretation
« Reply #1 on: 30/11/2008 00:36:28 »
Your publisher must be snowed under with all your books.
Done any experiments on Cerenkov Radiation yet?

I seem to remember being told CR was a consequence of momentum conservation.
« Last Edit: 30/11/2008 00:38:23 by sophiecentaur »
 

Offline Bored chemist

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Cerenkov effect and its interpretation
« Reply #2 on: 30/11/2008 15:01:49 »
"The atoms in the water become excited by the Cerenkov shock wave and then de-excite, emitting directly blue light photons. "
If water had an excited state coresponding to the energy of a blue photon then water would be yellow.
It isn't.
Once again reallity doesn't agree with your idea, and it's not reallity that's wrong.

And again!
"The number of photons emitted by such a charged particle is inversely proportional to wavelength. This means that more photons are emitted with shorter wavelengths, and consequently the spectrum is tilted to the blue region. "
So an infinite number of photons must be emited with zero wavelength. Not very plausible is it?

That was one of the problems with calssical physics and was solved by quantum theory.
http://en.wikipedia.org/wiki/Ultraviolet_catastrophe

 

lyner

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Cerenkov effect and its interpretation
« Reply #3 on: 30/11/2008 19:52:36 »
When you say 'shock wave' do you mean phonons?
 

Offline sorincosofret

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Cerenkov effect and its interpretation
« Reply #4 on: 04/12/2008 04:33:54 »
Only a stupid theory can speak about imaginary particle (phonons) or imaginary concepts (vacuum energy, vacuum polarization, etc).  When an experiment will provide the existence of a phonon or a vacuum energy, the proposed theory will incorporate these concepts. The actual experiments are wrong interpreted so in proposed theory, these concepts are ruled out.
The application of quantum hypothesis to Franck Hertz experiment is proposed in order to see the ,,ultraviolet catastrophe".
« Last Edit: 04/12/2008 04:40:36 by sorincosofret »
 

Offline Bored chemist

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Cerenkov effect and its interpretation
« Reply #5 on: 04/12/2008 07:13:21 »
I guess that makes many theories stupid.

The UV catastrophe is indeed solved by QM for the Franck Hertz experiment.
I was asking about your idea that you would get an infinite number of zero wavelength photons from Cherenkov radiation(those photons are imaginary and so, by your definition, make your theory stupid)
 

Offline sorincosofret

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Cerenkov effect and its interpretation
« Reply #6 on: 06/12/2008 08:09:38 »
Photons are particle so by definition they have zero wavelength.
 

lyner

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Cerenkov effect and its interpretation
« Reply #7 on: 06/12/2008 10:15:25 »
UH?
 

Offline Bored chemist

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Cerenkov effect and its interpretation
« Reply #8 on: 06/12/2008 18:03:21 »
Sorin,
for the sake of the sanity of those of us who understand scioence, please learn some physics or stop posting.
 

Offline sorincosofret

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Cerenkov effect and its interpretation
« Reply #9 on: 06/12/2008 19:45:57 »
As far as I saw, you are not able to count up to four in English ( not in another language). Is it necessary to remind you the Daniel and concentration cell and the process of numbering? Maybe you need an abacus?
I will stop in the next life or if the forum ban my messages. So convince the administration of the forum to do this and of course I will use another forum. I suppose you wrote a lot of books about actual orthodox physics and you have a good job in a top level British University. Maybe it is time to think what will be the consequences of your actions upon your career and your university rank when my theory will be accepted. I'm sure that you will not be retired at that time and I don't think you will remain a ,,hero member" here or a researcher or professor.  You don't realise that I play chess with actual science .... !!! in what purpose ???
« Last Edit: 06/12/2008 19:51:51 by sorincosofret »
 

Offline ghostofdavinci

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Cerenkov effect and its interpretation
« Reply #10 on: 06/12/2008 20:15:33 »
Photons are particle so by definition they have zero wavelength.  [V]
 

Offline Bikerman

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Cerenkov effect and its interpretation
« Reply #11 on: 06/12/2008 20:28:31 »
Save us from idiots writing books.
Sorin - your lack of knowledge is matched only by your deluded self-confidence. It would be futile to address your misconceptions in a systematic way because you need a basic course in physics before you will even understand why you are spouting nonsense.
 

lyner

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Cerenkov effect and its interpretation
« Reply #12 on: 06/12/2008 20:39:50 »
Quote
You don't realise that I play chess with actual science .
Go away and play chess then. Your opponents may appreciate your input more than I do.
 

Offline BenV

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Cerenkov effect and its interpretation
« Reply #13 on: 06/12/2008 22:13:45 »
Okay everyone - lets not let this deteriorate into personal insults.  Sorin, do you have anything to add?  You have stated your theory, and the problems have been pointed out.  I will lock this thread now, please send me a message if anyone has anything to add.

Edit - Unlocked for Bored Chemist to defend the attack on his ability to count, and the implied attack on his credentials
« Last Edit: 06/12/2008 22:35:45 by BenV »
 

Offline Bored chemist

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Cerenkov effect and its interpretation
« Reply #14 on: 07/12/2008 14:25:48 »
If Sorin thinks I, or anyone else, ever got to be something senior in a university without being able to count then I guess his lack of understanding of physics isn't his biggest problem.
Strange to relate, I can count and I don't work for a University.
It will be about 20 years before I retire, but it will be a cold day in Hell before anyone takes Sorin's ideas seriously.
In any event, my recollection of the discussion of the Daniel cell was that Sorin didn't understand it.
http://www.thenakedscientists.com/forum/index.php?topic=16401.0

I will leave it to Sorin to state his own credential.
In a post here
http://www.thenakedscientists.com/forum/index.php?topic=16430.25
 he said of himself that "My entire genius consists in the fact that I've learned to count up to four and to distinguish the colours. "
Perhaps he thinks that the ability to count to 4 is more highly prized than any actual understanding of what he's counting.
 

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Cerenkov effect and its interpretation
« Reply #14 on: 07/12/2008 14:25:48 »

 

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