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Doppler
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| Joined: | Wed Jun 11th, 2008 |
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| Posts: | 4 |
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Posted: Wed Jun 11th, 2008 06:04 pm |
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Interesting theory Ashmore! Not sure it's a paradox, except to Big Bangers. I found your site while searching for problems with the cosmic redshift because it occurred to me that, in being absorbed and re-emitted, the motion of the (mostly H2) atoms would have an effect, that the longitudinal component of that motion should be roughly equal toward and away from the source, and should cancel out, but the transverse component of motion, in the plane perpendicular to the direction of propagation, should in all cases tend to reduce the energy of the photon. Even though such motion may be quite minimal, its effect would accumulate over great distance. Your theory is that each interaction results in some recoil of the electron, leaving the photon with diminished energy and therefore longer wavelength, regardless of the initial momentum of the electron. I can see your point of view, although quantum interactions are generally considered to be without friction and recoil may be indistinguishable from friction, so that is a question. Even if there is a recoil, I wonder if the total redshift is a combination of your longitudinal recoil, plus transverse doppler effect? Perhaps this is necessary because, as you've noted, the magnitude of shift is proportional to wavelength, while the magnitude of each longitudinal recoil would be inversely proportional to the wavelength. The number of electrons or atoms with which the photon interacts is also proportional to wavelength, and must be to counteract the diminution in recoil due to reduction in initial energy. Why does a weaker photon reach out to and interact with more distant electrons that a stronger photon passes by? The wave is longer, but the magnitude is lesser. Now there's a paradox. I believe it has to do with the nature of interaction between charged particles, which I don't think is well-explained by virtual particles. Thanks for putting this site up.
Doppler
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lyndonashmore
Administrator
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Posted: Fri Jun 13th, 2008 06:23 pm |
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Hi Doppler,
Thanks for your post. re my theory, quantum and friction??
Basically the effect I use is based on the mossbauer effect which is well tested experimentally.
As for transverse doppler.....
You are correct in that for the radial case, any doppler shift on absorption is cancelled by the doppler toffee on reemission.
That is for a particle moving towards us there is doppler stretching on absorption and doppler squashing on reemission - cancel.
As far as transverse doppler shifts then wouldn't these photons be going in a different direction to us and not arrive at our telescopes?
The photons we detect are radial ones
Cheers,
Lyndon
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Doppler
Member
| Joined: | Wed Jun 11th, 2008 |
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| Posts: | 4 |
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Posted: Sat Aug 2nd, 2008 09:41 pm |
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| Transverse Doppler effect is where motion of a medium perpendicular to the direction of the propagation of the wave being measured causes a diminution. Imagine an airplane flying a path perpendicular to a wind. To go on a straight path perpendicular to the wind, it must point itself slightly into the wind. Its progress in terms of land speed perpendicular to the wind is thus reduced. Random transverse motion of gas in space would redshift light heading to Earth, and that is the point I was making. Longitudinal motion of the gases would either redshift it or blue shift it, depending on the direction of the longitudinal motion, which should cancel out, leaving only the effect of the transverse motion. The farther away the source, the more transverse motion of the intervening medium, therefore, the greater the redshift.
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lyndonashmore
Administrator
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Posted: Fri Aug 15th, 2008 08:42 pm |
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Do you have a reference or proof of "transverse doppler" as it is new to me?
Cheers
Lyndon
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Doppler
Member
| Joined: | Wed Jun 11th, 2008 |
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| Posts: | 4 |
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Posted: Sun Aug 17th, 2008 06:34 pm |
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See http://en.wikipedia.org/wiki/Transverse_Doppler_effect
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lyndonashmore
Administrator
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Posted: Sun Aug 24th, 2008 05:05 pm |
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Fair enough.
But then how do you get the redshift distance relationship? i.e objects twice as far away would have to have twice the transverse redshift. Does that mean that the universe is like some big wheel with the Earth at the centre. Twice as far out gives twice the transverse velocity and hence twice the transverse doppler effect.
Thanks for the reference though.
Interesting.
Cheers,
Lyndon
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Doppler
Member
| Joined: | Wed Jun 11th, 2008 |
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| Posts: | 4 |
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Posted: Tue Aug 26th, 2008 06:58 pm |
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| No. It's simple. Each time a photon interacts with a transparent gas molecule, it is extinguished and re-emitted. If that gas molecule has a transverse element of motion, the transverse Doppler effect acts to diminish the energy on re-emission, causing a redshift. The cumulative effect over distance is just the multiplication of the number of times this occurs. This is purely a function of the average density of the gas, the distance traveled, and the average transverse velocity component. You also have to make an assumption about how close to a molecule a photon has to approach for extinction/re-emission to occur, which is probably related to the wavelength.
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lyndonashmore
Administrator
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Posted: Tue Aug 26th, 2008 07:48 pm |
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Hi Doppler,
This is interesting.
BUT. molecules will not be travelling exactly at 90 degrees to our lines of sight.
So the relativistic doppler effect will only apply to the component of the molecules velocity in that direction.
What about the 'normal' doppler redshift due to the component along the line of sight?
Cheers,
lyndon
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