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So you are an aether believer Bill 6 ... Lorentz or one of the newer variations they seem to be makign a bit of a comeback at the moment?

I have a question however based on you comment above if light is losing energy to the aether in space doesn't that mean there is actually a finite distance you can send it before it ends up losing all it's energy to the space aether?


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Originally Posted By: Bill 6
If a beam of light is projected through a glass block that object will heat up and remain warm long after the beam has departed.

This accrued energy must come from the photons that passed through the object thus they would emerge from that medium redshifted compared to their frequency upon entry of same.

This is not associated with the scattering challenge aimed at Zwicky's intervening particle suggestion.

Hi Bill. Just a quick summary of what I've gleaned on this (this is not out of my head, as I know precious little about it):

There is no known way in which the photons can lose energy (Compton scattering is ruled out by the absence of blurring). Each photon passing through the material is either absorbed or not absorbed. There's no half-measure whereby the photon simply loses energy. The energy does come from the photons - but only from those photons that are removed.

http://www.stolaf.edu/people/jacobel/courses/phys245/Gamma%28photon%29_Absorption.pdf

The Absorption Coefficient:
...Absorbers are inserted between a radioactive source and a gamma sensitive detector. For the latter we shall use a scintillation counter, since it is sensitive to the gamma ray energy. The count rate is determined for several different absorber thicknesses. As one might expect, that rate will decrease exponentially as the thickness increases. The reason for this is that a single interaction completely removes the photon from the beam. (This is unlike the case of a charged particle going through matter. There the charged particle loses energy through many small energy transfers, not a single transfer that removes the particle from the beam.)


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Thats a cool explaination redewenur I suspect we could even do better than that these days we could actually use a single photon source and send it in an check we either get a photon at the far end or not at all.

However that does not really completely rule it out in a vacuum it certainly explains the behaviour in other media. If Bill 6 was using it just as a sort of indication not literal we still have not dealt with vacuums.

I still think the bigger issue is consider it is bleeding energy as it goes at some point there is going to be an energy crisis what happens at that point?


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I am NOT an aether believer!

My understanding of 'an aether' is that of a medium which transmits light whereas I'm of the opinion that light requires no medium to travel through space.

Quote:
I have a question however based on you comment above if light is losing energy to the aether in space doesn't that mean there is actually a finite distance you can send it before it ends up losing all it's energy to the space aether?


Several authors (e.g. Davies-Gribbin) write that the light from far-distant galaxies (that are receding at superluminal rates) is moving away from us hence is undetectable.

Alternatively, their distance is so great that their light redshifts to nonvisible frequencies.

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Originally Posted By: Bill 6
Several authors (e.g. Davies-Gribbin) write that the light from far-distant galaxies (that are receding at superluminal rates) is moving away from us hence is undetectable.

That is what I found when I started looking for information on the subject. This is what I posted then.
Originally Posted By: Bill
I have spent some time trying to digest the information I got from a paper I found on ARVIX .

The idea is that indeed the light from those distant galaxies is "red shifted" down to an undetectable frequency. I used quotes around red shifted because the red shift isn't really a result of velocity, it is because as space has stretched the light has also stretched.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
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Originally Posted By: redewenur
There is no known way in which the photons can lose energy

The operative term being 'no known way'.

Originally Posted By: redewenur
(Compton scattering is ruled out by the absence of blurring).

We have no way of knowing if the image of a distant galaxy is blurred or not due to the fact that we can obtain no image which does not contain the intervening particles.

Originally Posted By: redewenur
Each photon passing through the material is either absorbed or not absorbed.

My understanding is that ALL of the photons passing through the material are absorbed/emitted by the atoms they encounter which explains why a beam of light takes longer to travel through a medium than to cover the same distance via a vacuum.

Originally Posted By: redewenur
There's no half-measure whereby the photon simply loses energy. The energy does come from the photons - but only from those photons that are removed.

Your note refers to absorbers that are inserted between a radioactive source and a detector; it seems obvious to me that said absorbers will ABSORB some of those particles whereas the atoms in a glass block will, according to quantum theory, absorb the original photon then emit their own photon.

You refer to "..those photons that are removed." This obviously relates to the photons that are removed by the absorbers!

There are no purposefully inserted absorbers in a glass block. The atoms absorb then emit.

You further refer to charged particles "...going through matter that loses energy through many small energy transfers." This is what I believe takes place when a group of photons (a beam of light) travel through space encountering free particles along the way. One way to find out if the beam loses energy (redshifts) along the way would be to project one through a medium (e.g. horizontally through a lake).

It has been many years since I referred to the subject but I believe that when light travels radially down into the ocean it redshifts thus red colored objects - fish and coral - stand out more?

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Originally Posted By: Bill 6
The operative term being 'no known way'.

True, but if there isn't a known way then you will have to come up with a way that wasn't previously known, and then you will have to provide a solid theoretical basis for your new way.
Originally Posted By: Bill 6
... the atoms in a glass block will, according to quantum theory, absorb the original photon then emit their own photon.

There is a Wikipedia article about refractive index that explains the lower speed of light through a medium. The photons are not absorbed and re-emitted by the atoms of the medium. Instead they interact with the atoms to drag them off a little and then let them go back where they were. This produces a drag on the photon motion that slows the photon down.

Bill


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Originally Posted By: Bill 6
Originally Posted By: redewenur
(Compton scattering is ruled out by the absence of blurring).

We have no way of knowing if the image of a distant galaxy is blurred or not due to the fact that we can obtain no image which does not contain the intervening particles.

Are you quite sure of that, Bill? Isn't the resolution of the HST and other modern photon receivers - able to 'see' billions of parsecs - sufficient to rule out scattering as the cause of the measured redshift? Have you taken a look at the Hubble Ultra-Deep Field image?

http://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field


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Originally Posted By: Bill 6
If a beam of light is projected through a glass block that object will heat up and remain warm long after the beam has departed.


If a beam of light is projected through a glass block it slows down. By the same token, in the tired light model, would light not be measured as travelling at less than "c" after travelling through space?


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We had quite a long discussion about the variation in the speed of light in different media in another thread.

The following is an extract from the notes I distilled from that discussion. I would be interested to know if others feel that I "got the right end of the stick".

Manifestly, light slows down when passing through any medium denser than a vacuum, but how does it do that? One explanation goes something like this: Consider a single photon passing through a block of glass; for simplicity, have the glass surrounded by a vacuum. It approaches the glass at “c”. Once it enters the glass, it is absorbed by an atom, then re-emitted. This process is repeated as it continues to pass through the glass. In fact it is not a single photon that travels through the glass; it is a succession of new photons, created at each new emission. Any travelling done by the photon within the glass is at “c”; the apparent slowing results from a succession of minute instants during which the photon does not exist. We have, therefore, to regard it as travelling at “c” whatever medium it is travelling through.

Would that explanations were that simple, but of course they are not. It turns out that if this were what actually happened, then the absorption spectrum would be discrete because atoms have only discrete energy states. Yet, in glass for example, we see almost the whole visible spectrum being transmitted with no discrete disruption in the measured speed. In fact, the refractive index (which reflects the speed of light through that medium) varies continuously, rather than abruptly.

The reason for this is that a solid is composed of a network of ions and electrons fixed in a "lattice". Because of this, they have what is known as "collective vibrational modes", sometimes called phonons. These are quanta of lattice vibrations, and it is these vibrational modes that can absorb a photon. So when a photon enters a solid, and it can interact with these phonons, it can be absorbed by the solid and then converted to heat. The solid then becomes opaque to this particular photon (i.e. at that frequency). Unlike the atomic orbitals which are discrete, the phonon spectrum can be broad and continuous over a large frequency range.

If a photon has an energy beyond the phonon spectrum, the solid cannot sustain this vibration, because the phonon mode is not available. So the lattice does not absorb this photon and it is re-emitted but with a very slight delay. This appears to be the origin of the apparent slowdown of the light speed in that particular medium. The emitted photon may encounter other lattice ions as it makes its way through the material and the resulting reactions accumulate to cause the delay.


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You can actually bring the speed of light down to that of sound with a bit of clever physics and prove it absorbs and reemits at each and every atom point in the media
(http://www.physorg.com/news/2011-07-scientists.html)

CSharpner gets the theory right in the comments

When light moves through a medium, each photon is absorbed by an electron in the median, stored for a (very) short while, then it (or a new photon, with identical quantum properties) is then emitted in the same direction. Between electrons, it's moving through empty space and travels at full speed (c). The repetitive stalls while each photon is absorbed by electrons causes more and more of a delay. The light, itself, never slows down. When an electron absorbs a photon, the photon ceases to be "light" and instead is an electron with a higher energy state. Eventually, the electron loses the higher energy state, creating a new photon. While it's a photon, it's always traveling at c.

Photon @ c -> high energy electron state (delay) -> photon @ c, etc...


Prediction and experimental verification I am not sure you can do much better than that unless you want to try and explain the result some other way.

You have two things to consider the light moves at one speed if you dont rotate the glass and this really slow speed if you do ... why if you have a different theory?


Last edited by Orac; 07/18/11 06:37 AM.

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Orac, as usual you have come up with something authoritative. I am certainly not equipped to argue with the experts. One question that does seem still to remain is why the absorption/emission spectral lines are not discrete if the absorption and re-emission are due to the quantised absorption and re-emission of electrons.


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LOL I am not sure if I am authoritive about anything QM has completely destroyed my world :-)

The questions that are being asked on the forum at the moment are the same ones that are sort of being asked by everyone in physics.

Some of the tests are not that hard to do given equipment today it's thinking okay if that true then if I do this it should do that ... I really liked that experiment because it is simple yet so compelling because the media remains unchanged just spinning.

So now it boils down to a very simple question why would spinning a media slow down the speed of transmission through it.


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And speaking of QM get ready for it

http://www.newscientist.com/article/dn20712-how-to-be-in-two-places-at-the-same-time.html

The team is very confident it will go into superposition and then pandora's box is really open.


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Originally Posted By: Bill

True, but if there isn't a known way then you will have to come up with a way that wasn't previously known, and then you will have to provide a solid theoretical basis for your new way.

It was redewenur who suggested that there is no known way - not me.

Originally Posted By: Bill
There is a wikipedia article about refractive index that explains the lower speed of light through a medium.

I do not accept wikipedia as THE ultimate reference.

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Originally Posted By: redewenur

Are you quite sure of that, Bill? Isn't the resolution of the HST and other modern photon receivers - able to 'see' billions of parsecs - sufficient to rule out scattering as the cause of the measured redshift.

It is my understanding that scattering has no relationship to redshift but only to sharpness (or blurring).

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Originally Posted By: Bill S.
If a beam of light is projected through a glass block it slows down. By the same token, in the tired light model, would light not be measured as travelling at less than "c" after travelling through space?

I assume that it would however to the best of my knowledge no-one has as yet successfully measured a one way speed of light particularly emanating from outer space.

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Originally Posted By: redewenur
Originally Posted By: Bill 6
Originally Posted By: redewenur
(Compton scattering is ruled out by the absence of blurring).

We have no way of knowing if the image of a distant galaxy is blurred or not due to the fact that we can obtain no image which does not contain the intervening particles.

Are you quite sure of that, Bill? Isn't the resolution of the HST and other modern photon receivers - able to 'see' billions of parsecs - sufficient to rule out scattering as the cause of the measured redshift? Have you taken a look at the Hubble Ultra-Deep Field image?

http://en.wikipedia.org/wiki/Hubble_Ultra-Deep_Field

Originally Posted By: Bill 6
It is my understanding that scattering has no relationship to redshift but only to sharpness (or blurring).

Just for the record, as you probably know, it has been a matter of controversy:

"The Big Bang theory of the universe is wrong because the cosmological red shift is due to the Compton effect rather than the Doppler effect"
- John Kieren:
http://www.angelfire.com/az/BIGBANGisWRONG/index.html

"Kierein's Erroneous Compton Model for the Redshift" (Last modified 4-Feb-1998)
- Edward L.Wright:
http://www.astro.ucla.edu/~wright/kierein.html

E Wright's Home Page:
http://www.astro.ucla.edu/~wright/intro.html

BTW, do you still think we have no way of knowing if the image of a distant galaxy is blurred or not, despite the HUDF images? Surely, if blurring has occurred during the several billion lt yr journey, then it must be of an extremely small order. don't you agree?


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Originally Posted By: Bill 6
I assume that it would however to the best of my knowledge no-one has as yet successfully measured a one way speed of light particularly emanating from outer space.


Fair comment!
I still think you should give us an account of your understanding of the whole tired light theory, including the origin of the Universe. Picking, as we are, at little bits makes it so easy to be sidetracked.


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Originally Posted By: redewenur
BTW, do you still think we have no way of knowing if the image of a distant galaxy is blurred or not, despite the HUDF images?

Those images are just as affected by any free matter in outer space as are those of our personal telescopes.

Originally Posted By: redewenur
Surely, if blurring has occurred during the several billion lt yr journey, then it must be of an extremely small order. don't you agree?

How can a person possibly know the difference between the amount of blurring affecting a close up photograph and that of a long distance one unless the camera has been located there?

Being of the opinion that there have been no close up photographs of those distant galaxies I have no way of evaluating the extent of any blurring.

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