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profloater
2011-Apr-15, 10:28 AM
In mainstream, free electrons are actually within solids. In space electrons are presumably spaced out by their charge (please pardon the pun) They are exposed to photons coming from all directions. QED theory says we consider all the possible probabilities of finding an electron and a photon in new positions in space time but simplistic view would be that if a collision occurs, the electron will gain momentum in the direction of the incoming photon and will have a real velocity and free path until it either gets hit by another photon or emits a photon. This would be a kind of Brownian motion of electrons in free space. The fact that we can see very distant stars suggests that the re-emitted photons retain the momentum of the original and thus follow the same vector despite the multitude of interactions. There is no rule however for a free electron to be quantised into discrete energy levels so there is a probability that after emitting a photon it retains some velocity and energy, and the photon vector loses energy or is red shifted. If a second photon were to hit the electron before it gets a chance to re-emit, it would seem more probable that it would later emit a blue shifted photon. However in general this second scenario seems less likely than the first, so red shift would predominate. (This would depend on the photon flux in free space and the electron density of free space) Now any electron with velocity would experience a retarding force due to all the other electrons, so it would actually oscillate and this oscillation should produce low energy photons all over the universe in all directions. So that would be the CMBR? I am suggesting red and blue shift of photons both occur but red has more magnitude. Can we reproduce this in a vacuum tube in the lab?

korjik
2011-Apr-15, 01:29 PM
In mainstream, free electrons are actually within solids.
No, actually free electrons in solids arent free, just mostly free, and there are plenty of free electrons elsewhere. A free electron is one not part of an atom.


In space electrons are presumably spaced out by their charge (please pardon the pun) They are exposed to photons coming from all directions. QED theory says we consider all the possible probabilities of finding an electron and a photon in new positions in space time but simplistic view would be that if a collision occurs, the electron will gain momentum in the direction of the incoming photon and will have a real velocity and free path until it either gets hit by another photon or emits a photon.

Not really how Thomson scattering works. A free electron has a trajectory before the photon scatters off of it, and the direction of scattering is dependent on the details of the interaction. The electron does not in general scatter in the direction of the photon's path, that only happens in a head on collision.


This would be a kind of Brownian motion of electrons in free space.

Not quite. Most photons dont scatter much.


The fact that we can see very distant stars suggests that the re-emitted photons retain the momentum of the original and thus follow the same vector despite the multitude of interactions.

Actually, it says that there arent alot of free electrons in deep space, so that there arent alot of interactions.


There is no rule however for a free electron to be quantised into discrete energy levels so there is a probability that after emitting a photon it retains some velocity and energy, and the photon vector loses energy or is red shifted. If a second photon were to hit the electron before it gets a chance to re-emit, it would seem more probable that it would later emit a blue shifted photon. However in general this second scenario seems less likely than the first, so red shift would predominate. (This would depend on the photon flux in free space and the electron density of free space) Now any electron with velocity would experience a retarding force due to all the other electrons, so it would actually oscillate and this oscillation should produce low energy photons all over the universe in all directions.

If the electron would experience a force due to all the other electrons, then the electron isnt free. Free electrons in deep space dont interact with other electrons.


So that would be the CMBR? I am suggesting red and blue shift of photons both occur but red has more magnitude. Can we reproduce this in a vacuum tube in the lab?

No, we cant reproduce that in a lab, cause that isnt how it works. The density of free electrons in space is restricted to very low values due to the fact that we can see other stars and galaxies. If there was enough of a density of electrons, they would either repulse one another until they were not interacting, thereby not causing the effect you are thinking about, or they would be in a plasma, which would be detectable, and would generally make space opaque.

Amber Robot
2011-Apr-15, 03:48 PM
Sounds like you should look into such things as "interstellar dispersion" and "interstellar scintillation". Discussions of these effects may address your questions about the interactions between photons and interstellar free electrons.

Nereid
2011-Apr-15, 08:14 PM
I am suggesting red and blue shift of photons both occur but red has more magnitude. Can we reproduce this in a vacuum tube in the lab?
Is this the ATM idea you are presenting (and defending), in this thread, profloater?

EigenState
2011-Apr-15, 09:11 PM
Greetings,

Just one point to mention at the moment.


I...The fact that we can see very distant stars suggests that the re-emitted photons retain the momentum of the original and thus follow the same vector despite the multitude of interactions. ...

That assertion is not consistent with photon-electron scattering. Below is an image (courtesy of Wikipedia) of the Klein-Nishina distribution of photon scattering angles over a range of energies. Note the blue line which corresponds to photon energies within the visible. Electrons scatter visible light over all angles with little angular dependence. It is only when one gets to very high photon energies that forward scattering as required by your postulate is observed.

http://upload.wikimedia.org/wikipedia/commons/0/09/Klein-Nishina_distribution.png

Best regards,
EigenState

Amber Robot
2011-Apr-15, 09:31 PM
Besides.. what's the cross-section for this kind of photon electron interaction?

John Mendenhall
2011-Apr-16, 10:58 PM
Are you suggesting that the red shift is due to photon scattering? IIRC, not likely. You may be in the wrong venue. Such questions are readily answered on Q&A.

profloater
2011-Apr-20, 10:07 PM
Greetings Eigenstate,
Again a very comprehensive answer and very helpful to my progress! Thanks

profloater
2011-Apr-20, 10:12 PM
I am not so much suggesting an hypothesis as testing the assumptions around the redshift to try to fully understand the interpretation and the possible strength of alternative interpretations.

Geo Kaplan
2011-Apr-20, 10:50 PM
I am not so much suggesting an hypothesis as testing the assumptions around the redshift to try to fully understand the interpretation and the possible strength of alternative interpretations.

For answers to questions, there is a Q&A section devoted to exactly that.

Swift
2011-Apr-24, 06:53 PM
I am not so much suggesting an hypothesis as testing the assumptions around the redshift to try to fully understand the interpretation and the possible strength of alternative interpretations.
As Geo Kaplan said, if you are "just asking questions" to understand the mainstream astronomy/physics, you can do it in Q&A. ATM is only for presenting and defending your non-mainstream idea.

Given that it does not sound as if you are prepared to defend a hypothesis, I am closing this thread. If you wish to defend your non-mainstream idea before the 30 day expiration date if past on May 15, you may Report this post and we'll reopen the thread.