Ashmore's "paradox" Reloaded. - Page 14

Jim · #**391** (**permalink**) 26-May-2005, 02:41 AM

Quote:

Originally Posted by lyndonashmore

“Bet he can’t make it work in imperial units,” said a voice from the side.
“That’s right” said Ourlas ...

Well, "voice" and Ourlas are wrong. Newton's equation works just fine in any system of internally consistent units, even furlongs and fortnights.

But don't take my word for it. Try it yourself.

Gerbil94 · #**392** (**permalink**) 26-May-2005, 07:31 AM

Quote:

Originally Posted by lyndonashmore

Gravitational lensing? To be honest I want to look into this in detail and I thank you for the point and the references. I could just give you a quick response and ask if you have taken the change in 'n' into account around a 'gravitational lens'?

I assume you mean a sort of refractive index depending on the material in the lens? If so, then no.

Quote:

In the meantime though, I am onto it as i like areas where I can show Tired Light works. Biggs at Jodrell bank seems to a lot (good place jodrell bank visitors centre shop too)

Dr Biggs has been at JIVE for the past two or three years.

lyndonashmore · #**393** (**permalink**) 26-May-2005, 05:45 PM

Quote:

Originally Posted by Sylas

Quote:

Originally Posted by lyndonashmore

So if these photons are not absorbed and re-emitted, how is it that the group velocity is reduced and the phase velocity increased?

Sylas has a problem. How can the phase and group velocity change if the photons do not interact?

The answer was already given in my previous post. There are more ways than photo-absorption for light to interact with matter. Photons do interact with matter in the straight-line propagation of an electromagnetic wave through a transparent medium, but the interaction is not photo-absorption.

Lyndon, I don't mind honest disagreement. But it is merely deliberate obfuscation to ignore the bits of my post where I answer your question already. You may disagree with the answer, but just pretending it isn't there is dishonest.

Here is the bit from my post that Lyndon ignored.

Quote:

Originally Posted by Sylas

We can consider transparent transmission of light as photons being briefly delayed in an interaction with matter particles, but it is not the same interaction as photo-absorption and re-emission from an excited particle. With conventional photo-absorption, followed by emission, there is a random delay with a Poisson distribution for the excited atom to decay back to a ground state. This delay time reflects the stability of the excited state of an atom after absorption.

Transmission in a transparent medium, on the other hand, is modelled using the complex index of refraction, which depends on form factors and bears no relation to the stability of excited states for matter. You can find the relation between form factors and the complex index of refraction as equation 2 in chapter 1 of Chantler (1995), cited previously. The imaginary part of the complex refraction index is related to f2, and it is called the "extinction co-efficient". In a transparent material, like glass, this is zero. There is no absorption, no loss of energy and no redshift. But when f2 is non-zero, the electromagnetic wave is absorbed as it transfers energy into the medium.

Similar phenomena occur with transmission of electromagnetic waves in plasma. For light with frequency below the plasma frequency, the extinction co-efficient is non-zero and the wave does not pass through the plasma, because its energy is rapidly transferred to plasma oscillations. But for higher frequency light, there is no extinction.

Photo-absorption is covered within the complex index of refraction as the extinction factor, and this relates to f2. Extinction means that a signal is absorbed into the medium. Subsequent re-emission is not part of the refraction index, and it relates to the stability of excited atoms.

You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light, and it does not involve the photo-absorption interaction. It is generally analysed by considering the photon as a wave, though you can of course get right into quantum mechanics to deal with photons as particles. The group velocity can be obtained in terms of the derivative of the index with wavelength.

Your missing the whole point Sylas.
Sylas wrote

Quote:

You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light,

It is the speed at which the energy goes that we are interested in. The phase velocity is usually greater than 'c'. It is the group velocity that we need.
Sylas wrote

Quote:

Lyndon, I don't mind honest disagreement. But it is merely deliberate obfuscation to ignore the bits of my post where I answer your question already. You may disagree with the answer, but just pretending it isn't there is dishonest.

There are so many errors in your posts that it would take just too long to answer them all. We have sorted out the difference between group and phase velocity before and here you are dragging it back in again. Its wrong, not needed here and a distractor.

Quote:

PS. Don't just ignore the problem with photo-absorption cross section. The published formula is 2rλ.f_2. You ought to retract your claim that it is published as 2rλ.

There is no problem - it is absolutely correct. Why should I 'retract' something that is correct?
Cheers,
Lyndon

papageno · #**394** (**permalink**) 26-May-2005, 05:52 PM

So, lyndonashmore, you simply stick your fingers in your ears and yell "I am right and you are wrong!".

lyndonashmore · #**395** (**permalink**) 26-May-2005, 05:56 PM

Quote:

Originally Posted by Grey

First, I'll point out that I'm specifically addressing the subject of comparing H directly hr/m in this message, since that's what I've been asking about. I'll leave the entirely different matter of comparing H to 2nhr/m until we get this sorted out.

Quote:

Originally Posted by lyndonashmore

“F = GMm/r^2” he boldly said on the “Bad Alchemy” site.
“But it is impossible” said Mamageno, “the units are different on each side, F is in Newton and Mm/r^2 in kg^2 m^-2”
“Ah”, said Isaac, “but the constant has units itself so that makes it correct”

There's nothing wrong with introducing a constant of proportionality in a relation, of course, and that constant can indeed have units. But in that case, you should be talking about a realtionship like H = Lhr/m, where L is "Lyndon's constant". As Sylas has already pointed out, in Newton's relation, it's possible to determine G by measurement, and to determine experimentally whether F and Mm/r^2 really are proportional. So, depending on how you look at it, you're either arbitrarily assuming that L has a value of 1 m^-3, or else your actually just determing L from the known value of H. In neither of those case could you be said to be predicting the value of H, and in neither case are you directly comparing the values of H and hr/m.

Quote:

Originally Posted by lyndonashmore

“How big is this constant”
“6.67x10^-11 Nm^2kg^-2” Rreplied Newton.
“6.67x10^-11” said Heavenly blacksmith, that is a fiddle factor if ever I saw one, ‘2’, or ‘3’ I might accept but not “6.67x10^-11”. Your formula is 11 orders of magnitude out without your constant.

This implies that a constant of proportionality should be expected to have some simple value, but actually that's almost exactly the opposite of what one would expect. I'd be extremely suspicious of a theory where a constant of proportionality came out to be exactly 1 in whatever my favorite units are. That's because I know that my choice of units is arbitrary, so there shouldn't be any particular reason for a constant to come out to 1 m^-3. The universe shouldn't give special preference to the meter, unless you think God really likes the metric system. Lyndon, can you name me any fundamental physical constants with a nice round value (other than in a case where the units in question were defined specifically to make that constant come out even)?

Let me give two examples of numerical coincidences, one which is a genuine coincidence, and one which led to a deeper understanding of physics, and try to show the difference between them.

First, have you noticed that the major axis of Earth's orbit (measured in kilometers) is exactly equal (well, within 0.2%) to the speed of light, measured in meters per second? Obviously, one might say, this is much too close to be a coincidence, so we must be missing something. Somehow the speed of light must be tied to Earth's orbit, and we should come up with a theory that explains this.

But on further reflection, if the Earth's rotation period were different, or we'd chosen to divide the day into more or less than 86,400 seconds (so the length of the second was different), these values wouldn't match at all. Similarly, if we had twleve fingers, we'd probably do our math in base twelve, and the metric system we developed would probably have a factor of 1,728 between a kilometer and a meter, so again, these numbers wouldn't match at all. So, realizing that these numbers are only close because of a particular choice of measurement system, I instead conclude that this similarity must be a genuine coincidence. Note that the fact that it's very easy to find coincidences like this should make one wary of assuming that any numerical coincidence must have some reason for it.

For the other, I'll mention something that you alluded to here, though if you were talking about what it sounded like, I think you're not quite right on the details. What Maxwell noticed was not a similarity between the speed of an electric pulse and the speed of light. Rather, there are two constants that show up when analyzing electric and magnetic fields, the permittivity of free space and the permeability of free space. These relate the strength of the fields to the charge and current present, and you can actually measure them directly just by working with static charges and magnets.

What Maxwell noticed was that, since changing electric fields induce magnetic fields and vice versa, it would be possible to have a self sustaining oscillation of both fields, and that it would propogate through space as a wave. Using his theory, he was able to show that this wave would have a velocity that depended on these two constants, and when he worked out that velocity, it turned out to match the speed of light, leading him to predict that light was in fact, just such an electromagnetic wave. Notice that in this case, Maxwell was directly comparing two values that were both velocities,* and if we were to convert the enitre calculation into some other arbitrary set of units, the two values would still match.

As you point out on your webstie, units have to match when comparing values. That doesn't mean, however, that you can just decide to arbitrarily decide to divide by one cubic meter, without explaining why you didn't instead decide to divide by a cubic foot, or a cubic parsec,

* This is actually a slightly tighter constraint than just that the units match. For example, if I multiply the acceleration due to gravity on the Earth's surface by the distance from the Earth to the Moon, and then divide by the speed of light (or just take the square root, if you'd prefer not to introduce an arbitrary constant), I'll get a result that is in units of length over time, but it's not actually a meaningful velocity.

Quote:

First, I'll point out that I'm specifically addressing the subject of comparing H directly hr/m in this message, since that's what I've been asking about. I'll leave the entirely different matter of comparing H to 2nhr/m until we get this sorted out.

But you cannot separate them. My point is that once I have shown H = 2nhr/m it is not surprising that a coincidence such as H = hrm in magnitude occurs. In the BB it is far too big a coincidence. One has to look at the paradox and H = 2nhr/m together
Cheers,
Lyndon

Grey · #**396** (**permalink**) 26-May-2005, 06:09 PM

Quote:

Originally Posted by lyndonashmore

My point is that once I have shown H = 2nhr/m it is not surprising that a coincidence such as H = hrm in magnitude occurs.

Why is it not suprising, since it depends on the length of the meter? If we used feet as our primary length unit, that coincidence, as you rightly call it, wouldn't occur at all.

(I see you haven't addressed the substance of my post at all.)

Lunatik · #**397** (**permalink**) 26-May-2005, 07:07 PM

Quote:

Originally Posted by lyndonashmore

Regarding ‘the paradox’ and the various posters, let me answer them all at once. Yes I do think it worthy of note in that one expects this sort of thing when the equation is of the correct form. Tired Light gives H = 2nhr/m so, when observation shows H = hr/m in each cubic metre of space, it is a result. Not an Earth shattering one but a result. More so in that it shows just how ludicrous the Bb is. Why does each and every length of space increase by hr/m for the electron every second if the expansion is not related to the electron. Ergo, it is the expansion bit that is wrong.
I can just imagine Newton announcing his theory of gravity on the Net!
“F = GMm/r^2” he boldly said on the “Bad Alchemy” site.
“But it is impossible” said Mamageno, “the units are different on each side, F is in Newton and Mm/r^2 in kg^2 m^-2”
“Ah”, said Isaac, “but the constant has units itself so that makes it correct”
But you can make any theory work if you trump up a constant with units chosen to fit the equation” said Ourlas.
“Bet he can’t make it work in imperial units,” said a voice from the side.
“That’s right” said Ourlas, “Plus it contravenes the conservation laws” said Ourlas, If a gravitational force acts on the Earth the we would speed up and the years would get shorter”.
But that’s how gravity works” said Isaac.
“Show me the mechanism” said Mamageno, “the space between the Sun and the earth is too sparse. There is no way that a force could be transmitted through it. Any particle is free and so couldn’t exert forces between them. Go on, show me the mechanism.”
“How big is this constant”
“6.67x10^-11 Nm^2kg^-2” Rreplied Newton.
“6.67x10^-11” said Heavenly blacksmith, that is a fiddle factor if ever I saw one, ‘2’, or ‘3’ I might accept but not “6.67x10^-11”. Your formula is 11 orders of magnitude out without your constant.
And so on, and so on.
See what I mean?
In fact Newton stopped publishing because of the criticisms – well he did wait till after Hooke’s death to prevent the whinging.
Cheers,
Lyndon.
P.S. the names used in this post are fictitious and any similarity between these names and those of real people is purely coincidental.

I hear you. See The First Direct Measurement of Recoil Momentum from Physics Review Letter.
Don't know if this helps your cause, but finding momentum conservation in photon interaction with the atom was a surprise. My take on it is that if light recoils per index of refraction n, so that it behaves as per nh/lambda, then light redshift over cosmic distances should be a factor of all that dust'n'dgas in 'empty' space. Redshift should be a natural, whining notwithstanding.

papageno · #**398** (**permalink**) 26-May-2005, 07:15 PM

Quote:

Originally Posted by Lunatik

I hear you. See The First Direct Measurement of Recoil Momentum from Physics Review Letter.
Don't know if this helps your cause, but finding momentum conservation in photon interaction with the atom was a surprise. My take on it is that if light recoils per index of refraction n, so that it behaves as per nh/lambda, then light redshift over cosmic distances should be a factor of all that dust'n'dgas in 'empty' space. Redshift should be a natural, whining notwithstanding.

It was a dilute gas of neutral atoms, in the state of a Bose-Einstein condensate. The photons came from a laser.
This has little to do with Ashmore's "theory".

Fortis · #**399** (**permalink**) 26-May-2005, 11:36 PM

It all strikes me as rather strange. The real paradox seems to be that electrons are simultaneously strongly interacting with their neighbours (to have a vague stab at conserving both momentum and energy), and also non-interactiong and isolated so that you can just use the mass of electron in the recoil equation.

Hmmm.

Sylas · #**400** (**permalink**) 27-May-2005, 01:31 AM

Quote:

Originally Posted by lyndonashmore

Sylas wrote

Quote:

You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light,

It is the speed at which the energy goes that we are interested in. The phase velocity is usually greater than 'c'. It is the group velocity that we need.

Here is the full paragraph from my post.
You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light, and it does not involve the photo-absorption interaction. It is generally analysed by considering the photon as a wave, though you can of course get right into quantum mechanics to deal with photons as particles. The group velocity can be obtained in terms of the derivative of the index with wavelength.

Lyndon purports to be interested in group velocity, and yet he only extracts and quotes the portion of my paragraph on phase velocity!

Quote:

Originally Posted by lyndonashmore

There are so many errors in your posts that it would take just too long to answer them all. We have sorted out the difference between group and phase velocity before and here you are dragging it back in again. Its wrong, not needed here and a distractor.

LOL. Do a search on page 16 of the thread. I did not drag them in. Lyndon dragged them in, despite their irrelevance, in this post. He said:

Quote:

Originally Posted by lyndonashmore

So if these photons are not absorbed and re-emitted, how is it that the group velocity is reduced and the phase velocity increased?

The only way to answer this was to explain why it was irrelevant, by explaining the difference between lossless transmission and photo-absorption.

For reference, here are the formulae. The real part of the index of refraction is ck/ω where ω is frequency and k is wavenumber. Phase velocity is ω/k, group velocity is dω/dk. The complex part of the index is non-zero for substances that absorb as well as refract. For atoms with number density n and form factors f1 and f2, the complex index of refraction is 1 – r.λ^2.n.(f1+i.f2)/2.pi. The photo-absorption cross-section is 2rλ.f2

The point of this is to show that phase and group velocities are associated with lossless transmission and the real part of the index, and have no relation to f2 or the photo-absorption cross section.

Lyndon said earlier in the thread that the photo-absorption cross section is published as 2rλ. This is flatly wrong. It’s actually given as 2rλ.f2

Lyndon refers to f2 values for a Hydrogen atom; a poor model for an electron but let it pass. These are effectively zero for energies below 13.6 eV, and close to zero for energies above 50 eV. The cross section is therefore effectively zero as well. When this was pointed out, Lyndon brought up phase and group velocities as if that was some kind of relevant objection. It isn't. They have nothing to do with the photo-absorption cross section. When f2 is zero, the cross section of photo-absorption is zero, but phase and group velocities are unaffected.

Quote:

Originally Posted by lyndonashmore

Quote:

PS. Don't just ignore the problem with photo-absorption cross section. The published formula is 2rλ.f_2. You ought to retract your claim that it is published as 2rλ.

There is no problem - it is absolutely correct. Why should I 'retract' something that is correct?

Lyndon's own paper uses 2rλ.f_2. All his references use 2rλ.f_2. The additional and more up-to-date references I supplied from Chantler use 2rλ.f_2. Lyndon is incorrect in this post where he claims that the published result for the photo-absorption collision cross section is 2rλ, and he has not even tried to defend it other than by empty repetition.

Lyndon found plenty of time to post about my error in converting Angstroms to meters, and that's fine, because I like having my errors found for me.

Lyndon is blustering here because he's stuck. He's got nothing, but he loves that better than admitting error. The formula 2rλ is incorrect for calculating a photo-absorption cross-section. Lyndon's claim that this is the published result for the photo-absorption collision cross section is an error he can neither admit nor defend.

Cheers -- Sylas

Sylas · #**401** (**permalink**) 27-May-2005, 02:58 AM

Quote:

Originally Posted by Fortis

It all strikes me as rather strange. The real paradox seems to be that electrons are simultaneously strongly interacting with their neighbours (to have a vague stab at conserving both momentum and energy), and also non-interactiong and isolated so that you can just use the mass of electron in the recoil equation.

Bingo.

In his preprint paper, Lyndon cites a formula from an old special relativity text by A.P. French for the energy lost in a photoabsorption reaction. It is Q^2/2Mc^2

Lyndon's paper uses electron mass for M, but French uses the mass of the atom or lattice to which momentum is transferred. Lyndon's paper uses Q for the energy of the incoming photon, but French uses Q0 for the excitation energy of the atom.

French explains the Mossbauer effect as arising when M is extremely large due to the sharing of recoil with many atoms in a rigid crystal lattice. Lyndon waves his hands vaguely when speaking of how electrons are tightly bound in rarefied plasma, but then goes right ahead and uses the electron mass m as if there is no binding whatsoever.

Cheers -- Sylas

papageno · #**402** (**permalink**) 27-May-2005, 10:03 AM

Quote:

Originally Posted by Sylas

Quote:

Originally Posted by Fortis

It all strikes me as rather strange. The real paradox seems to be that electrons are simultaneously strongly interacting with their neighbours (to have a vague stab at conserving both momentum and energy), and also non-interacting and isolated so that you can just use the mass of electron in the recoil equation.

Bingo.

In his preprint paper, Lyndon cites a formula from an old special relativity text by A.P. French for the energy lost in a photoabsorption reaction. It is Q^2/2Mc^2

Lyndon's paper uses electron mass for M, but French uses the mass of the atom or lattice to which momentum is transferred. Lyndon's paper uses Q for the energy of the incoming photon, but French uses Q0 for the excitation energy of the atom.

French explains the Mossbauer effect as arising when M is extremely large due to the sharing of recoil with many atoms in a rigid crystal lattice. Lyndon waves his hands vaguely when speaking of how electrons are tightly bound in rarefied plasma, but then goes right ahead and uses the electron mass m as if there is no binding whatsoever.

It is not the first time that the issue of effective electron mass* comes up.
Even then Ashmore did not seem to realize the contradiction between using the electron rest mass and claiming there are "restoring forces" acting on the electron in the plasma.

* Effective mass is often introduced when the electron is interacting with something. Changing the mass takes into account the different response of the electron to external forces (because there are other forces acting on it). A prime example of this are electrons in semiconductors.

czeslaw · #**403** (**permalink**) 27-May-2005, 11:45 AM

I want to help Lyndon
Every Neutron Star, Magnetar or Black Hole ejects electron-positron pairs. They use a transformation of the energy into matter. That way is the Universe’s space cooled and the whole radiation may be redshifted due to electron’s creation .

I do not think , the whole redshift is caused by this energy-matter transformation, but may be a part of it ?

lyndonashmore · #**404** (**permalink**) 27-May-2005, 02:00 PM

Quote:

Originally Posted by Sylas

Quote:

Originally Posted by lyndonashmore

Sylas wrote

Quote:

You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light,

It is the speed at which the energy goes that we are interested in. The phase velocity is usually greater than 'c'. It is the group velocity that we need.

Here is the full paragraph from my post.
You can't ignore f1 and the real part of the refraction index. This defines the phase velocity for light, and it does not involve the photo-absorption interaction. It is generally analysed by considering the photon as a wave, though you can of course get right into quantum mechanics to deal with photons as particles. The group velocity can be obtained in terms of the derivative of the index with wavelength.

Lyndon purports to be interested in group velocity, and yet he only extracts and quotes the portion of my paragraph on phase velocity!

Quote:

Originally Posted by lyndonashmore

There are so many errors in your posts that it would take just too long to answer them all. We have sorted out the difference between group and phase velocity before and here you are dragging it back in again. Its wrong, not needed here and a distractor.

LOL. Do a search on page 16 of the thread. I did not drag them in. Lyndon dragged them in, despite their irrelevance, in this post. He said:

Quote:

Originally Posted by lyndonashmore

So if these photons are not absorbed and re-emitted, how is it that the group velocity is reduced and the phase velocity increased?

The only way to answer this was to explain why it was irrelevant, by explaining the difference between lossless transmission and photo-absorption.

For reference, here are the formulae. The real part of the index of refraction is ck/ω where ω is frequency and k is wavenumber. Phase velocity is ω/k, group velocity is dω/dk. The complex part of the index is non-zero for substances that absorb as well as refract. For atoms with number density n and form factors f1 and f2, the complex index of refraction is 1 – r.λ^2.n.(f1+i.f2)/2.pi. The photo-absorption cross-section is 2rλ.f2

The point of this is to show that phase and group velocities are associated with lossless transmission and the real part of the index, and have no relation to f2 or the photo-absorption cross section.

Lyndon said earlier in the thread that the photo-absorption cross section is published as 2rλ. This is flatly wrong. It’s actually given as 2rλ.f2

Lyndon refers to f2 values for a Hydrogen atom; a poor model for an electron but let it pass. These are effectively zero for energies below 13.6 eV, and close to zero for energies above 50 eV. The cross section is therefore effectively zero as well. When this was pointed out, Lyndon brought up phase and group velocities as if that was some kind of relevant objection. It isn't. They have nothing to do with the photo-absorption cross section. When f2 is zero, the cross section of photo-absorption is zero, but phase and group velocities are unaffected.

Quote:

Originally Posted by lyndonashmore

Quote:

PS. Don't just ignore the problem with photo-absorption cross section. The published formula is 2rλ.f_2. You ought to retract your claim that it is published as 2rλ.

There is no problem - it is absolutely correct. Why should I 'retract' something that is correct?

Lyndon's own paper uses 2rλ.f_2. All his references use 2rλ.f_2. The additional and more up-to-date references I supplied from Chantler use 2rλ.f_2. Lyndon is incorrect in this post where he claims that the published result for the photo-absorption collision cross section is 2rλ, and he has not even tried to defend it other than by empty repetition.

Lyndon found plenty of time to post about my error in converting Angstroms to meters, and that's fine, because I like having my errors found for me.

Lyndon is blustering here because he's stuck. He's got nothing, but he loves that better than admitting error. The formula 2rλ is incorrect for calculating a photo-absorption cross-section. Lyndon's claim that this is the published result for the photo-absorption collision cross section is an error he can neither admit nor defend.

Cheers -- Sylas

Lyndon is neither stuck nor blustering.
Not content with doing all his sums on the wrong model Sylas has now shifted to try to apply bulk properties to the individual photon electron interaction!
This is a ‘light is a photon’ theory and so let’s keep our discussion to that please.
Now where were we? Ah yes! When photons of light travel through a transparent medium they are absorbed, there is a delay, and then they are re-emitted. This is why we must use the photoabsorption collision cross section.
Lets look at the X rays traveling through matter first.
You see, we can look at it like this, if the photon arrives within an area of size 2rλ centered on the electron then it will be absorbed. Absorbed, no matter what. As to what happens next depends upon the energy of the incoming photon and hence f_2.
If the energy of the incoming photon is equal to an energy level within the atom then resonance occurs and the energy eventually is taken up by the whole of the material. The photon is absorbed never to return. The photoabsorption coefficient f_2 has the value unity for Hydrogen with its single electron (OK before you nitpick, 0.95ish).
If the energy of the incoming photon is totally different to the resonant energy of the atom then the energy of the absorbed photon is not retained but is re-emitted as a new photon. The photoabsorption coefficient f_2 has the value zero(ish) for Hydrogen with its single electron.
What determines whether the photon was absorbed in the first place is 2rλ, the f_2 term just tells you whether resonance takes place or not and modulates the 2rλ.
Now if the energy is not exactly equal to an energy level but close to it then the photon may be retained or it may not, the absorption edge is not sharp. This is why f_2 has values between 0 and 1 for energies close to an energy level. However, as Sylas says, if the energy is ‘way off’ resonance, f_2 is zero meaning that no way is the photon retained is is re-emitted.
Now the same thing takes place in the plasma of IG space. If the photon comes within an area of 2rλ centered on the electron then it will be absorbed. If the photon has a frequency corresponding to the natural resonant frequency of the plasma then the whole plasma will oscillate and the photon absorbed never to return. However, since this frequency is about 6Hz (using Sylas’ own sums – which are correct in this case) then we can ignore this situation and declare that the photon is always re-emitted.
Why should we believe that we can use Hydrogen as a good example for electrons in a plasma? Because the photoabsorption coefficient for an atom is just the sum of the individual coefficients in that atom. Therefore it is fine to use it.
Cheers,
Lyndon

Quote:

Lyndon found plenty of time to post about my error in converting Angstroms to meters, and that's fine, because I like having my errors found for me.

You are a lucky man Sylas. Not many have something they like happening every minute of every day!
To be honest, not had much time this week. Too buisy at work.

lyndonashmore · #**405** (**permalink**) 27-May-2005, 02:12 PM

Quote:

Originally Posted by Sylas

Quote:

Originally Posted by Fortis

It all strikes me as rather strange. The real paradox seems to be that electrons are simultaneously strongly interacting with their neighbours (to have a vague stab at conserving both momentum and energy), and also non-interactiong and isolated so that you can just use the mass of electron in the recoil equation.

Bingo.

In his preprint paper, Lyndon cites a formula from an old special relativity text by A.P. French for the energy lost in a photoabsorption reaction. It is Q^2/2Mc^2

Lyndon's paper uses electron mass for M, but French uses the mass of the atom or lattice to which momentum is transferred. Lyndon's paper uses Q for the energy of the incoming photon, but French uses Q0 for the excitation energy of the atom.

French explains the Mossbauer effect as arising when M is extremely large due to the sharing of recoil with many atoms in a rigid crystal lattice. Lyndon waves his hands vaguely when speaking of how electrons are tightly bound in rarefied plasma, but then goes right ahead and uses the electron mass m as if there is no binding whatsoever.

Cheers -- Sylas

We may be getting through to Sylas a little bit here. You see Sylas, as the density of electrons increases the 'effective mass' of the electron increases and so the energy lost in recoil decreases. As a result, the amount by which the photon is redshifted also reduces. this is why one doesn't get the huge redshifts one would expect in dense plasma around the sun etc. You only get redshifts in plasma clouds if they are sparsely populated so that the 'effective mass' of the electron is close to its rest mass.
You see in French's book (good book isn't it? ) He uses the whole atom because it all oscillates including the nucleus. In plasma the larger protons are less mobile and so only the electrons 'move'. Now the effective mass is slightly higher than the rest mass but not much.
This is one of the many good things about my theory, it explains why we get redshifts in IG space but not in the denser plasmas. As Papgeno says, we have talked about this before.
Cheers,
lyndon

lyndonashmore · #**406** (**permalink**) 27-May-2005, 02:16 PM

Quote:

Originally Posted by papageno

Quote:

Originally Posted by Sylas

Quote:

Originally Posted by Fortis

It all strikes me as rather strange. The real paradox seems to be that electrons are simultaneously strongly interacting with their neighbours (to have a vague stab at conserving both momentum and energy), and also non-interacting and isolated so that you can just use the mass of electron in the recoil equation.

Bingo.

In his preprint paper, Lyndon cites a formula from an old special relativity text by A.P. French for the energy lost in a photoabsorption reaction. It is Q^2/2Mc^2

Lyndon's paper uses electron mass for M, but French uses the mass of the atom or lattice to which momentum is transferred. Lyndon's paper uses Q for the energy of the incoming photon, but French uses Q0 for the excitation energy of the atom.

French explains the Mossbauer effect as arising when M is extremely large due to the sharing of recoil with many atoms in a rigid crystal lattice. Lyndon waves his hands vaguely when speaking of how electrons are tightly bound in rarefied plasma, but then goes right ahead and uses the electron mass m as if there is no binding whatsoever.

It is not the first time that the issue of effective electron mass* comes up.
Even then Ashmore did not seem to realize the contradiction between using the electron rest mass and claiming there are "restoring forces" acting on the electron in the plasma.

* Effective mass is often introduced when the electron is interacting with something. Changing the mass takes into account the different response of the electron to external forces (because there are other forces acting on it). A prime example of this are electrons in semiconductors.

I realised very much the importance since it explains why we do not get large redshifts in dense plasma. It helps my theory.
Of course in semiconductors, the effective mass can become negative - (Papageno and myself are both solid state physicists)

lyndonashmore · #**407** (**permalink**) 27-May-2005, 02:21 PM

Quote:

Originally Posted by czeslaw

I want to help Lyndon
Every Neutron Star, Magnetar or Black Hole ejects electron-positron pairs. They use a transformation of the energy into matter. That way is the Universe’s space cooled and the whole radiation may be redshifted due to electron’s creation .

I do not think , the whole redshift is caused by this energy-matter transformation, but may be a part of it ?

Thanks for the information czeslaw
Cheers,
Lyndon

papageno · #**408** (**permalink**) 27-May-2005, 02:33 PM

Quote:

Originally Posted by lyndonashmore

Quote:

Originally Posted by papageno

It is not the first time that the issue of effective electron mass* comes up.
Even then Ashmore did not seem to realize the contradiction between using the electron rest mass and claiming there are "restoring forces" acting on the electron in the plasma.

* Effective mass is often introduced when the electron is interacting with something. Changing the mass takes into account the different response of the electron to external forces (because there are other forces acting on it). A prime example of this are electrons in semiconductors.

I realised very much the importance since it explains why we do not get large redshifts in dense plasma. It helps my theory.

By using the electron rest mass for low-density, you implicitly admit that the restoring forces in low-density plasmas are negligible.
Hence there is no "SHM" and the electrons are free. Hence their scattering with photons (on the rare occasions it actually happens) is correctly described by Compton effect.
Bottom line, no red-shift.

It is obvious that you do not realize that you are contradicting yourself.

Quote:

Originally Posted by lyndonashmore

Of course in semiconductors, the effective mass can become negative - (Papageno and myself are both solid state physicists)

Considering that you have shown that you cannot grasp the concepts units of measurements (see all the mess about your first "paradox"), I doubt any self-respecting organisation would recognize you as physicist.
But labels are not important: you have given plenty of proof that you seriously lack understanding about basic physics, let alone solid state physics.
If you actually had any knowledge about solid state physics, you would not confuse free electron with atoms, and the motion of charge carriers with charge density oscillations.

Jim · #**409** (**permalink**) 27-May-2005, 08:12 PM

Quote:

Originally Posted by lyndonashmore

How about cubic cubits? its not a problem, once one has seen the dimensional analysis the whole thing works. But it takes time and this software, whilst extremely good, does not lend itself to mathematical notation.
The relation H = 2nhr/m holds true in any units. its a fact and true. The Bb cannot predict H, I do.
end of story.
Cheers,
lyndon.
might take a day or two (invigilating all day tomorrow)

The above was posted May 23; it's now May 27.

How ya comin', Lyndon?

Have you tried converting Newton's equation into another set of units?

lyndonashmore · #**410** (**permalink**) 27-May-2005, 09:20 PM

Quote:

Originally Posted by Jim

Quote:

Originally Posted by lyndonashmore

How about cubic cubits? its not a problem, once one has seen the dimensional analysis the whole thing works. But it takes time and this software, whilst extremely good, does not lend itself to mathematical notation.
The relation H = 2nhr/m holds true in any units. its a fact and true. The Bb cannot predict H, I do.
end of story.
Cheers,
lyndon.
might take a day or two (invigilating all day tomorrow)

The above was posted May 23; it's now May 27.

How ya comin', Lyndon?
Jim,
Just as a favour to you I will do it.
It is not a problem.
H = 2nhr/m works in any units.
I have only promised to do this for you because i like you. Once I showed that dimensionally they were the same it was obvious to everyone else that it will work in any system of units,
but for you and you alone I will do it, in the next few days.
Cheers,
lyndon

Have you tried converting Newton's equation into another set of units?

Sylas · #**411** (**permalink**) 27-May-2005, 11:12 PM

Lyndon has claimed that the published formula for photo-absorption cross section is 2rλ, and has never defended this. The question is about published formula; not Lyndon’s private notions.

The published formula for cross-section is actually 2rλ.f_2.

Lyndon’s response is series of blanket assertions on his own behalf, which bear no relation to conventional physics or the published literature, and which don’t answer the question of what is the published formula.

I am fine with Lyndon proposing his own theories for physics. I am more than happy to let them be seen side by side with more conventional ideas, for a fair comparison. I am less than delighted with his persistent stone-walling about what is actually used more widely, and his failure to frankly acknowledge or recognize where his notions differ from the mainstream.

Quote:

Originally Posted by lyndonashmore

When photons of light travel through a transparent medium they are absorbed, there is a delay, and then they are re-emitted. This is why we must use the photoabsorption collision cross section.

Conventional physics recognizes more ways than photo-absorption for light to interact with matter, and they all involve delays. Therefore physicists will see a gap in Lyndon’s argument at the point where he asserts we must use a photo-absorption cross section for any delay calculation.

My previous post showed the formulae in more conventional use. They calculate group velocity without reference to f2 or photo-absorption interactions. Photo-absorption is a specific kind of interaction, unrelated to phase or group velocities or the delays in a transparent medium.

Quote:

Originally Posted by lyndonashmore

Lets look at the X rays traveling through matter first.
You see, we can look at it like this, if the photon arrives within an area of size 2rλ centered on the electron then it will be absorbed. Absorbed, no matter what. As to what happens next depends upon the energy of the incoming photon and hence f_2.

Several differences here with conventional physics.

First, in conventional physics, photo-absorption is a probabilistic interaction, with a probability depending on distance. The cross section is not a sharp barrier for which you are absorbed inside that distance and not absorbed outside the distance. The cross section is actually an integration of probabilities over the whole plane normal to the photon’s path; a useful abstraction for calculating how many interactions will occur, but not a physical disk you either hit or miss.

Second, the cross section for photo-absorption in more conventional physics is 2rλ.f_2, which means that f_2 is related to probability of the interaction occurring at all; not to what happens after.

Third, in conventional physics, what happens after an absorption-interaction depends on the stability of an excited atom, and has no relation to any of the form factors or optical constants. There is a Poisson random delay, before the atom decays back to ground state and emits a characteristic photon.

Fourth, to look at X-rays travelling through matter, there are a number of other interactions which can occur, and which have their own formulae and cross sections independent of the photo-absorption cross section. The group delay is unrelated to photo-absorption interactions.

Quote:

Originally Posted by lyndonashmore

If the energy of the incoming photon is equal to an energy level within the atom then resonance occurs and the energy eventually is taken up by the whole of the material. The photon is absorbed never to return. The photoabsorption coefficient f_2 has the value unity for Hydrogen with its single electron (OK before you nitpick, 0.95ish).

At the energy of 13.6eV, the value of f_2 is indeed close to 1. This gives a large cross section and a high probability of the absorption reaction occurring. If f_2 is close to zero… as it is for nearly all other energies, then the cross section is small, and there is a low probability of the absorption reaction occurring.

There are other interactions to consider. There is still a non-zero f_1 in the forum factors, and this is used in the calculation of some of those other interactions. One other effect… quite unrelated to photo-absorption… is that the photon as an electromagnetic wave packet will interact with the electromagnetic fields which have strong gradients near the atom. This is where you find the delays involved in transmission of light; not in the photo-absorption interaction.

Quote:

Originally Posted by lyndonashmore

If the energy of the incoming photon is totally different to the resonant energy of the atom then the energy of the absorbed photon is not retained but is re-emitted as a new photon.

In conventional physics, the photon is not absorbed at all. You never lose the original photon.

Quote:

Originally Posted by lyndonashmore

The photoabsorption coefficient f_2 has the value zero(ish) for Hydrogen with its single electron. What determines whether the photon was absorbed in the first place is 2rλ, the f_2 term just tells you whether resonance takes place or not and modulates the 2rλ.

In conventional physics, 2rλ has no such special significance, and is never used in this way. f_2 is directly proportional to the cross-section the probability of interaction.

Quote:

Originally Posted by lyndonashmore

Now if the energy is not exactly equal to an energy level but close to it then the photon may be retained or it may not, the absorption edge is not sharp. This is why f_2 has values between 0 and 1 for energies close to an energy level. However, as Sylas says, if the energy is ‘way off’ resonance, f_2 is zero meaning that no way is the photon retained is is re-emitted.

What Sylas says is that the photon is not absorbed at all at low energies. Other interactions occur, and there is still a positive f1 value that can be used to calculate their magnitudes.

Cheers -- Sylas

Lunatik · #**412** (**permalink**) 28-May-2005, 02:28 AM

Quote:

Originally Posted by Sylas

What Sylas says is that the photon is not absorbed at all at low energies. Other interactions occur, and there is still a positive f1 value that can be used to calculate their magnitudes.

Could you be referring to the photoelectric effect? We know this from Earth based observations, for which Einstein got a Nobel, but do we know it from an IG space perspective?

Could it be that out there, where energy is very low, a more 'lyndonashmoric' effect takes place, so that light redshifts for the reasons described? Of course, if so, this would beg the question, that if deep space leads to this other effect, what would be the cause of it? What in deep IG space would account for the photoelectric effect to take place at much lower levels of energy, or perhaps, hypothetically, to make the lyndonashmoric effect work?

Tobin Dax · #**413** (**permalink**) 28-May-2005, 02:48 AM

Quote:

Originally Posted by Lunatik

Could it be that out there, where energy is very low, a more 'lyndonashmoric' effect takes place, so that light redshifts for the reasons described? Of course, if so, this would beg the question, that if deep space leads to this other effect, what would be the cause of it? What in deep IG space would account for the photoelectric effect to take place at much lower levels of energy, or perhaps, hypothetically, to make the lyndonashmoric effect work?

No, because the energies out there are no different than the energies here. The energies referred to in that diagram are for photons, and their energies are dependent solely on their own properties.

Another point here is that since there is no ionization energy for free electrons, the value for f_2 should stay small (near zero) in IG plasma. It approaches one only for the bound system of an atom.

Sylas · #**414** (**permalink**) 28-May-2005, 04:47 AM

Quote:

Originally Posted by Lunatik

Quote:

Originally Posted by Sylas

What Sylas says is that the photon is not absorbed at all at low energies. Other interactions occur, and there is still a positive f1 value that can be used to calculate their magnitudes.

Could you be referring to the photoelectric effect? We know this from Earth based observations, for which Einstein got a Nobel, but do we know it from an IG space perspective?

No, I'm not refering to photoelectric effect.

The major other effect to which Lyndon and I both refer is refraction of light. There are also various kinds of scattering considered. The Chantler reference at NIST identifies the other major interaction to be coherent scattering.

Quote:

Could it be that out there, where energy is very low, a more 'lyndonashmoric' effect takes place, so that light redshifts for the reasons described?

No. Lyndon's work not some new theory or a possibility for unusual circumstances. It's based on using known physics incorrectly. It's not something that might be right in another place. It's just mistakes in physics.

Of course, you can't take my word for that, because Lyndon claims that I'm making lots of mistakes in physics.

The real benefit in such an exchange comes when someone is unsure, and rather than just taking either of us at our word, goes and checks the information or formulae for themselves.

This is actually a very good way to learn physics. Pick an aspect of the issue, and see if you can sort it out for yourself, to the point of being able to identify specifically and on your own authority a point of error in either my work or Lyndons. We both agree that there are plenty of errors to be found!

I'll be happy to explain my own working more clearly on any specific point, and I am sure Lyndon would do the same.

Cheers -- Sylas

Lunatik · #**415** (**permalink**) 28-May-2005, 07:58 AM

Thanks Sylas, for your kind response.

I must confess that I do not know Lyndon's work well enough, having read it only in a cursory manner, so not studied in detail. My fault too that I am not a physicist, so cannot verify errors where they exist. The only thought I had to offer is that perhaps we are too hasty to assume that what we observe from Earth, which we do very well in our understanding of physics, applies to intergalactic space, of which we know very little. Just a thought, but certainly not a statement of fact. I can imagine where such a disparity may apply, but as yet have nor concrete facts to apply them to.

Appreciate your thoughts, enjoyable to read your clear reasoning. Will read more to see if I can offer something, later.

Lunatik · #**416** (**permalink**) 28-May-2005, 08:06 AM

Quote:

Originally Posted by Tobin Dax

Quote:

Originally Posted by Lunatik

Could it be that out there, where energy is very low, a more 'lyndonashmoric' effect takes place, so that light redshifts for the reasons described? Of course, if so, this would beg the question, that if deep space leads to this other effect, what would be the cause of it? What in deep IG space would account for the photoelectric effect to take place at much lower levels of energy, or perhaps, hypothetically, to make the lyndonashmoric effect work?

No, because the energies out there are no different than the energies here. The energies referred to in that diagram are for photons, and their energies are dependent solely on their own properties.

Another point here is that since there is no ionization energy for free electrons, the value for f_2 should stay small (near zero) in IG plasma. It approaches one only for the bound system of an atom.

My thought on this, cursory that it was, was that if energy is Energy, then it may be a function of both gravity-energy and electromagnetic-energy. What I mean to say, I think, is that if there is a derth of one, then the other prevails, either way. Energy is always conserved, but in a diffirent fashion from what we know on Earth. For example, if we live in a very rich e.m. energy region close to a hot productively radiant star, then the gravity-energy is slight; our gravity in this region is very weak. If we are in intergalactic space very far from hot stars, which is most of space out there, then the gravity-energy is very great, something we as yet cannot experience. We know of neutron stars, for example, but our understanding of them is that they are collapsed stars where the electron and proton fused into neutrons. But what if.... and here I am on dangerous ground... what if our understanding of this is wrong, and neutron stars are merely evidence of an e.m. energy poor star subject to very great gravity energy? That was my thinking, though all should be aware that I do not believe any of this had been entertained in any of our physics, and rightly so. Without evidence to show this may be a possibility, it is merely a speculative, nay philosophical, question.

The corollary to this, Lyndon's idea perhaps, is that if deep intergalactic space is very different from here, then the refraction ratio of light may act differently from what we know it to be here, which might account for why light traveling cosmic distances tends to redshift. But this should be stated more as a question, with lots of ??? in it.

Cheers, thanks for your response.

lyndonashmore · #**417** (**permalink**) 28-May-2005, 04:16 PM

Quote:

Originally Posted by Sylas

Lyndon has claimed that the published formula for photo-absorption cross section is 2rλ, and has never defended this. The question is about published formula; not Lyndon’s private notions.

The published formula for cross-section is actually 2rλ.f_2.

Lyndon’s response is series of blanket assertions on his own behalf, which bear no relation to conventional physics or the published literature, and which don’t answer the question of what is the published formula.

I am fine with Lyndon proposing his own theories for physics. I am more than happy to let them be seen side by side with more conventional ideas, for a fair comparison. I am less than delighted with his persistent stone-walling about what is actually used more widely, and his failure to frankly acknowledge or recognize where his notions differ from the mainstream.

Here is a table of form factors. In one column we have the number of electrons in the atom and in another column we have the form factor.
Now Sylas refuses to believe that the collision cross section for an electron is 2rλ. He insists this is wrong.
what I say is let the people look at the data and decide for themselves. Look at how many electrons there are in the atom, look at the form factor and ask yourself what the form factor for a single electron is. If you decide it is 'one' then you agree with me that the photoabsorption collision cross section is 2rλ.
If you decide that the form factor has some other value then you agree with Sylas. It is as simple as that.
Cheers,
Lyndon

Sylas · #**418** (**permalink**) 29-May-2005, 04:17 AM

Quote:

Originally Posted by lyndonashmore

Quote:

Originally Posted by Sylas

Lyndon has claimed that the published formula for photo-absorption cross section is 2rλ, and has never defended this. The question is about published formula; not Lyndon’s private notions.[…]

Here is a table of form factors. In one column we have the number of electrons in the atom and in another column we have the form factor.
Now Sylas refuses to believe that the collision cross section for an electron is 2rλ. He insists this is wrong.
what I say is let the people look at the data and decide for themselves. Look at how many electrons there are in the atom, look at the form factor and ask yourself what the form factor for a single electron is. If you decide it is 'one' then you agree with me that the photoabsorption collision cross section is 2rλ.
If you decide that the form factor has some other value then you agree with Sylas. It is as simple as that.

Apart from the major difficulty that Lyndon is mixing up several different form factors, yes.

Sylas believes that the formula photo-absorption cross section is 2rλ.f2, just as it appears in every published source offered so far. If you think the form factor f2 is equal to one, then yes; the photo-absorption cross section is 2rλ. If you think that the form factor f2 is a number that varies widely, and is zero below 10 eV (wavelength 1.24e-7 m), then you had better use the published formula.

Just check any of the references for f2 that have been given in the thread and the matter is settled.

But what of Lyndon's new contribution above? The form factor is indeed very close to 1. How can this be? Looking into it is hilarious. It's all irrelevant. Lyndon is citing the wrong form factor, with the wrong energy photons, for a different interaction, for which the cross section is not 2rλ by form factor in any case.

Lyndon is now citing RTAB: the Rayleigh scattering database by Lynn Kissel, section 8. Those interested can read more of the text, and also check my comments using the query engine or ftp datafile download.

The form factor he is looking at here is not f2, but MF, the modified relativistic form factor. It is a high energy correction closely related to the Henke ASF factor f1 (see section 3 of Chantler, or section 7 of Kissel)
The process he is looking at here is Rayleigh scattering; a (mostly) elastic collision. It has nothing to do with the photo-absorption interaction.
The table he has cited is the limiting case of zero momentum transfer, or zero scatter angle. The corresponding cross section is given in barns/steradian. The total cross section is properly integration over all angles. (See Chantler section 8). Both zero scatter and total Rayleigh cross sections can be obtained from the query engine, and neither one is anywhere near 2rλ times the form factor. No reason it should be; the whole process is completely different.

Here is a plot of f1 and f2 form factors for Hydrogen, over energies 10 to 1000 eV.

Note that f2 is effectively zero, except for a very small window above the ionization energy. Note that f1 becomes asymptotically 1 for high energies. Lyndon is now looking at f1 and ignoring the f2; exactly the wrong thing to do for considering photo-absorption.

There is another point that needs to be kept in mind with all of this. The form factor approach is a useful approximation at high energies. That's why all the tables refer to energies well in excess of visible light. This is noted explicitly in Lyndon's new reference on Rayleigh scattering. See section 2, which notes: "The form factor approximation, valid for photon energies much greater than electron binding energies and for non-relativistic momentum transfers, has been extensively tabulated."

Finally, Lyndon's objections notwithstanding, electrons bound to a proton behave very differently from electrons in ionized plasma, especially for photons that have energies well below the Hydrogen ionization energy of 13.6 eV. Data obtained by bouncing photons off Hydrogen are an absolutely hopeless way to discover how visible light interacts with ionized plasma.

Summary:

Lyndon still has not backed up his claim that the published photo-absorption cross section is ever given as 2rλ!

He rather argues that it should be 2rλ; and his latest argument uses the wrong form factors, the wrong scattering process, the wrong energies and even then still fails to find cross sections that are 2rλ.

Cheers -- Sylas

Tensor · #**419** (**permalink**) 29-May-2005, 04:38 AM

Quote:

Originally Posted by Sylas

Lyndon is now citing RTAB: the Rayleigh scattering database by Lynn Kissel, section 8. Those interested can read more of the text, and also check my comments using the query engine or ftp datafile download.

The form factor he is looking at here is not f2, but MF, the modified relativistic form factor. It is a high energy correction closely related to the Henke ASF factor f1 (see section 3 of Chantler, or section 7 of Kissel)
The process he is looking at here is Rayleigh scattering; a (mostly) elastic collision. It has nothing to do with the photo-absorption interaction.
The table he has cited is the limiting case of zero momentum transfer, or zero scatter angle. The corresponding cross section is given in barns/steradian. The total cross section is properly integration over all angles. (See Chantler section 8). Both zero scatter and total Rayleigh cross sections can be obtained from the query engine, and neither one is anywhere near 2rλ times the form factor. No reason it should be; the whole process is completely different.

But Sylas, if Lyndon uses the actual published form factor for a single electron photo absorbtion, he won't get his numbers to match his idea. This is such an excellent example of finding something so he can fit his data or misapply a process to get the numbers he wants. He still hasn't shown a qualitative analysis on his claimed effect and I don't think he ever will.

Sylas · #**420** (**permalink**) 29-May-2005, 04:51 AM

Quote:

Originally Posted by Tensor

But Sylas, if Lyndon uses the actual published form factor for a single electron photo absorbtion, he won't get his numbers to match his idea.

In logic, if the premise of an argument is false then any inference is valid.

Since there is no such thing as single electron photo absorption, we can safely say without fear of contradiction that if Lyndon uses such a thing he could get any result he wishes.

You only get photoabsorption when an electron is bound to an atom.

Plasma will absorb light with a frequency below the plasma frequency, but this is not a single electron interaction, and has nothing to do with photo-absorption cross sections.

Cheers -- Sylas

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