I am responding to this post by Lyndon.

This is not a matter of forgetting anything.

The value of this thread is for any readers who may be undecided; and the benefit comes when they don't take anyone at their word, but rather take the time to sit down and resolve the issues for themselves.

This is the major benefit of an interest in bad astronomy; or crank science of any kind. Understanding comes not when you are told the answers by me or Lyndon or the mechanic. It comes when you've developed the capacity to figure out who is using physics correctly.

Make no mistake; this is not about minor misunderstandings or forgetting some issue. I've read Lyndon's work. Lyndon has heard the criticisms.

At this stage, we are certainly dealing with crank physics from someone. It could be me that is making dreadful errors and yet claiming to understand the issues. Or it could be Lyndon. No-one is just forgetting things, but one of us has the physics badly wrong. If anyone out there can't tell which one is wrong, then asking us is not useful. You'll have to learn enough physics to tell for yourself, and working it out is a great learning experience.

I will list a few points of difference that the undecided can use to get leverage on the issues. If I am wrong, it is not from "forgetting" anything.

Lyndon believes that the details of these two interactions make a substantive difference of some kind.

I disagree.

I believe that conservation of energy and momentum can be applied to the before and after of an interaction, no matter how you break down the details. If the energy and momentum before is different to the energy and momentum after, then the details are, in my view, incorrect. I am comparing the initial state and the state after the two phases Lyndon lists above.

Lyndon and I also differ on the notion of "rest mass" of an electron. Lyndon treats this as some kind of variable, with a new value after the two interactions. But I calculate the rest energy for an electron without a nucleus as mc^2 where m is the rest mass of the electron.

Lyndon is correct in this. I consider that Lyndon's errors are so trivial that a simple Newtonian analysis can reveal the problems. This can be useful if we have readers who are unfamiliar with relativity. The only relativity you need is the formulae for energy and momentum of the photon as hf and hf/c.

For this approach, we only worry about kinetic energy of the electron, using mv^2/2, and use the momentum as mv, where v is the velocity of the electron and the end of the interaction(s). The energy of the electron is the change in energy for the photon, so mv^2/2 = h(f-F). The momentum of the electron is the change in momentum for the photon, so mv = h(f-F)/c [[ In edit: Altered H to h ]]
Solving the equations for conservation of energy and momentum in this case does indeed give you v = 0, or v = 2c.

A student who is aware that v = 2c is a bit of a problem may want to consider using a relativistic analysis. In this case, you can use E^2 = (pc)^2 + (mc^2)^2

E is the total energy, m is the rest mass of the electron, c is the speed of light, and p is the momentum of the electron. Note that the famous equation mc^2 shows up here as the rest energy of the electron. The conservation equations become
mc^2 + hf = E + hF
hf/c = hF/c + p

In this case, you can find p = 0, or in other words the final momentum of the electron is zero after the two interactions are complete, and f = F.

Lyndon believes both approaches should give the same result.

Sylas believes that both approaches have zero for the final momentum of the electron as a valid solution; but that the Newtonian approach admits an additional solution, which is not a real life interaction. My working is available in this post, in sufficient detail for those interested to repeat the calculation.

Lyndon has given an analysis, and I will single out where we differ.

Sylas believes that there is no such thing as absorption for a single electron. In my view, absorption occurs when an electron is bound to a nucleus, and is able to take up the energy of a photon by changing energy levels in its orbital around the nucleus. But for a single electron not bound to a nucleus, the only way it can take any energy from a photon is by gaining kinetic energy. I use the equations listed above for this analysis, and derive a contradiction, which means that either this alleged absorption is impossible, or else I am a klutz with physics.

At this point, Lyndon has calculated momentum and energy for an electron. He has used the same formulae as I used, and we agree on this. I've used frequency, but since λ * f = c, we can easily convert from one to the other and get the same result.

Anyone interested may perform a conservation of energy and momentum analysis at this point in the interaction, using the initial photon which is totally absorbed into the final state of the electron. Photon kinetic energy is hc/ λ , which equals mv^2/2.

This analysis implies that there is no other contribution to energy. Lyndon seems to consider an extra energy term from a gain in rest mass of the electron. My competence in physics stands or falls on this point. I insist that there is no such thing. The rest mass of an electron is fixed, and there is no atomic nucleus in the picture where the electron can jump energy levels, which would introduce a form of potential energy.

My position is that Lyndon's use of two different rest masses for an electron without being bound to a nucleus is a trivial error in elementary physics. An electron bound to a nucleus can have a (negative) potential energy, and in quantum physics this potential energy can take a number of discrete values corresponding to quantum orbitals around the nucleus. But if there is no nucleus, then there is no potential energy term, no excitation apart from kinetic energy, and a constant rest mass term.

On the other hand, if Lyndon is correct that it is just accepted physics to introduce different rest mass terms for electrons in thin plasma, then I'm totally clueless in physics.

Cheers -- Sylas

In reply to Sylas' post, one way of checking who is right or wrong is to look at the answers at the back of the book.
It is I who correctly calculates the Hubble constant and I who correctly calculates the CMB photons.
So, if the answers in the back of the book are anything to go by, it is I who is correct.
Cheers,
lyndon

Which means nothing if you have a SS universe, as you claim, since the Hubble constant is a measure of how much the universe is expanding. How about providing the calculations showing a match of the redshift of a galaxy whose distance has been measured using a independent method, say with cephid variables.

Ahhh no. You have shown an approximate match to the peak only. You have yet to provide the rest of the curve and you've been asked to provide this several times going back to the previous thread. Without the rest of the CMB curve, you have nothing but a slim posibility.

__________________
Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

I'm cool with this. The answer to the questions I posed above are not the answers Lyndon is looking up here; but that's fine. If people prefer to look up answers to the questions I was asking, I have no objection.

As for what Lyndon is looking up in the back of the book, this relates to the Hubble constant, and the CMB photon wavelengths. This is another good chance for beginners to practice applying physics for themselves.

Lyndon gives two ways to calculate the Hubble constant.

The first is H = hr/m. H is the Hubble constant, h is Planck's constant, and m and r are the mass and classical radius of the photon. H is usually given in km/s/MegaParsec; you'll have to convert it to inverse seconds. Try looking up the length of a MegaParsec, and do the conversion.

The result looks good when you plug in standard values in SI units, but not when you plug in values in cgs units. You can find values for the constants in both unit systems here. The basic physics for managing equations that give equality in one sets of units and not another is called dimensional analysis. You can learn about it here.

The other equation Lyndon gives is H = 2nhr/m. The new term n is the density of electrons in the intergalactic medium. Try using this to calculate the Hubble constant. You'll need a value for n. Try finding a value for this term.

Lyndon also claims to calculate the CMB photons. I claim he does not. If anyone is unsure, they should look and see for themselves what is being calculated. There are some calculations in this post, which also appear in Lyndon's published paper.

Is Lyndon calculating the wavelength of CMB photons? Or is he calculating something else?

Cheers -- Sylas

I have to stick up for Lyndon here. It's not true that Hubble constant is meaningless in a SS universe.

Lyndon proposes a tired light model, in which photons get more and more redshifted the further they travel through space. Such models have a long history. They were particularly common early in the twentieth century when the value of the Hubble constant was greatly overestimated to be much larger than an expanding space interpretation could easily explain.

Tired light is legitimately an interpretation of the Hubble relation between redshift and distance. It's also a testable interpretation, and thereby lies another tale... but the claim that the Hubble constant is meaningless for SS models is wrong.

Cheers -- Sylas

Checking the answers in the back doesn't work. It's pretty easy to get the right answer by using an invalid method, especially if you know ahead of time what the answer needs to be. For example, here is a case where someone seems to get the right result, but it's pretty clear that the numbers and interpretation were tweaked to match the known result. Or, as a more entertaining example, if I want to reduce the fraction 16/64 to lowest terms, I can cancel the 6's to get 1/4. Since that's the right answer, the method I used to determine it must be correct, right?

It's too late for me to want to bother looking this up myself, but in reading Sylas's post above, this is quoted:

Is it significant that Lyndon has a potential error in his calculations here? He sets c=1 p=h(*c)/ λ. (Sylas' p=hf is correct, and c=λ*f.) That's a potential error of 17 orders of magnitude in SI units, so I thought I'd ask. Just a simple question, please don't take it any other way.

Goodnight.

No error. You'll be kicking yourself over this one; but in fact I don't use p = hf. That would be wrong. I use E = hf, and p = hf/c.

In wavelengths, this is E = hc/λ and p = h/λ; and the rest falls out as Lyndon gives it above.

The real error is that Lyndon does not use E = hc/λ properly in his analysis. This energy needs to be taken up as kinetic energy of the electron, and gives an additional equation that allows us to solve for v, obtaining the results I have described. Working left as an exercise.

Lyndon does not use this equation, because he has an unphysical additional energy term for an electron carrying some extra energy by somehow increasing its rest mass.

Cheers -- Sylas

PS. Grey: thanks for the example of reducing 16/64 by cancelling the 6. That's great; I'm sure I'll find occasion to use it.
{Added in edit. I've confirmed the basic technique by rigourous random sampling.
19/95 = 1/5
26/65 = 2/5
49/98 = 4/8 }

Isn't this what Feynman describes in his book about Quantum Electrodynamics (you know, the one Ashmore likes to quote even though he does not understand what he quotes).

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

Sylas wrote
Am I reading you correctly here Sylas?
Are you saying that the entire energy of the photon E = hf = hc/λ goes entirely to KE of the electron when the photon is absorbed i.e a perfectly elastic collision?
Cheers,
Lyndon

If the photon is absorbed by the electron, it is not an elastic collision.
The only place the energy of the photon can go, is in the kinetic energy of the electron, because there is no potential energy since the electron is free (it is not bound to any positive charge).

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

But it is not free, we agreed that it oscillates. Most of the energy goes there, only a small part goes to recoil.
Glad we sorted that out.
Cheers,
Lyndon

Wrong.
You are still confusing the motion of the free charge carriers inside the plasma with the fluctuations in the charge density.

We sorted out that you won't acknowledge that you were wrong and that you will never correct your mistakes.

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

So what you are saying Papageno is that Sylas and Celestial Mechanic have been doing their sums on the wrong theory!
Great.
Cheers,
Lyndon

You are trying to obfuscate the issue.

Fact is, a free electron in a plasma does not perform a SHM as you claim, hence your "criticism" to Sylas' and Celestial Mechanic's arguments is wrong.
Ignoring corrections to your mistakes, will not make those mistakes go away.

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

papageno wrote

Nope,
If you want to show my theory wrong then you have to do the sums on MY THEORY. doing your sums on Mr Compton's theory is fine on a thread about Compton Effect.
Why take us all on a wild goose chase with sums that are not in any way related to the theory in question?
Seems weird to me.
Cheers,
Lyndon

Your "theory" is wrong before we get to the sums: your basic mechanism is wrong.
You have no experimental evidence that the scattering of a photon with a free electron is not Compton scattering.
It has been shown to you that, from a theoretical point of view, Compton scattering is the only that conserves energy and momentum.
Against all the evidence you keep claiming that free electrons in a plasma are somehow "restrained" or oscillate about equilibrium positions.
Despite your insistence, it is your "theory" that is not related to reality.

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

You'd think I'd learn to not post things like this at 3am, wouldn't you? Some people just never learn. :roll: #-o

Yes, this is correct. I really am saying that analysis of this alleged absorption should transfer all the energy of the photon to kinetic energy of the electron. I also go one step further and show that this is impossible by conservation of energy-momentum, and so the absorption is not physically possible.

Absorption only occurs for electrons bound to an atomic nucleus, because this allows additional potential energy terms. Without this, the kinetic energy of the electron is the only place energy can go.

There is no such thing as a perfectly elastic absorption reaction. Elastic means a perfect bounce, with no change in potential energy. The same happens in Newtonian physics. If you fire a particle at another particle, and it gets absorbed, you can prove that the kinetic energy is not conserved. There must be some extra energy term; usually heat in large scale collisions; and this is by definition inelastic.

So what are the energy terms available in this case?

There is no other particle involved to allow excitation energy of the electron. Excitation of electrons occurs when they move between energy levels in an atom, and this is a form of potential energy. There is no nucleus here.

Electrons don't have excitation levels on their own, and so your use of two different rest masses for an electron is a trivial error in elementary physics. The rest energy of the electron is mc^2 where m is 9.11*10^-31 kg.

When an electron moves around within a field, there can be potential energy terms due to location in the field, but this can only occur over a significant period of time. That does not apply here either, because we are speaking of before and after an alleged absorption interaction, and the electron obtains a sudden change in velocity at the one location of the collision.

The only energy terms are the energy of the photon, the rest energy of the electron, and the kinetic energy of the electron.

Your effect does not exist. It violates very basic physics.

Cheers -- Sylas

And this is why it is so much more fun to discuss with people who have no capacity for physics. The surest sign of ability in physics is not a god-like immunity to error. It is the capacity for swift recognition of the errors when they are pointed out; and suddenly the debate is all over. It's boring. But there are some folks around here who can just keep the entertainment going for page after page after page.

Cheers -- Sylas

I know what you mean Sylas, But your wrong it isn't boring at all when one meets these people. I take it as a challenge to teach them some physics. Now, where were we?
Ah yes, Sylas contradicts himself - which in science means he's wrong!
It is an experimental fact that photons of light are slowed by plasma. They use this fact in satellite ranging. Send a out a pulse, probe returns it, measure the time interval and using the speed of e-m waves in plasma we can determine how far away it is. It is used all the time and well published - followers of the Pioneer 10 thread will have seen that it is included in their sums too.

So we know that photons are delayed by the elctrons in plasma. This is not in doubt.
Now, let us ignore the fact that Sylas did his sums on the wrong theory (never mind, it can happen to anyone - well maybe two people). In his last post he tells us that an electron absorbs a photon elastically. that is that the KE of the electron is tranferred to the electron in its entirety, and then, after a short while re-emitted. Fine , this allows for a delayed signal in plasma but he is accepting Compton scatter which he discounted in an earlier thread on John's theory since Sylas said this meant that the signal would not go in a straight line and we know that it does. Fine by me, the theory is consistent with my paradox but Sylas said no way, this mechanism could not work.
So that only leaves my theory. We know that electrons in dense plasma oscillate so I say why not in sparse plasma too? I do my sums and get the answers in the back of the book. What is wrong with that? But no says Sylas, the electrons in plasma can't oscillate, it must be Compton!
So here is our first contradiction from Sylas. He tells John it can't be Compton and he tells me it must be Compton - for surely it must be one or the other since it is an experimental fact that photons are delayed by the electrons in the plasma of space.
Unless of course, Sylas has his own theory?
Cheers,
Lyndon

Slowing of light is not the same as redshifting of light. A redshift involves a decrease in energy of the photon. A delay does not.

That's not quite what I said; but let it pass. It's close enough for the purpose. Delay in a light transmission does not violate the conservation laws.

The delayed straight line transmission of light in a transparent medium is not Compton scattering. The Compton effect most certainly involves scatter.

The Lyndon effect is neither a Compton effect (because it is straight line transmission) nor is it simply a delay (because there is a redshift and energy loss).

If John or Lyndon or anyone is looking at redshift with straight line transmission, then they are not looking at the Compton effect, nor are they looking at simple delay.

ANY effect can be considered in the light of conservation laws. Compton scattering, and transparent transmission, are both consistent with energy conservation.

The Lyndon effect is not.

Cheers -- Sylas

It's so nice to be told I'm boring. :wink:

Sorry for the brief hijack, but I do want to point out that the benefit of discussing such things with physicists is that they understand. Within less than a week, recently, I've explained to two different good friends what my current research is (recurrent novae, in binary systems, if you're curious), and the biochemist understood what I said, but the physicist knew what I was talking about and got it. That was my favorite part of meeting up with this friend from undergrad--she really understood what I was talking about. My family and most other friends don't have that background. Actually, when I said I was modelling nuclear explosions, the biochemist was worried I would blow up Chicago. I then explained that it was with a computer program, but he didn't really get the rest of it either.

Without the background in physics, it's hard to really understand what's going on in a lot of these situations. You might find it fun (I enjoy it most of the time as well), but that's also why these threads are so long and why they pop up over and over again. Most of these ATM guys don't quite have the background to really know what they're saying and to see why it doesn't work. (So maybe this is less of a hijack than I thought.)

Now I need to go catch up on the thread here.

I look back, I don't see a reply by Lyndon to my statement about real-world tests of this theory.


Does or can an electron beam focus a light beam?
Can one focus an image using solely any variety of rarefied plasma at all?
Does glass cause redshift?


Failure on all three points is, really, failure of any real-world effects that we should see in any world in which "Ashmore's Paradox" exists.

I am still curious as to why estimates of Hubble's constant from gravitational lensing are claimed as support for this theory if the known lenses are actually examples of some sort of plasma lensing (!).

Electrons, my friend. The answer is always electrons. They can do anything! Shine your shoes, take your sister to Prom, make you younger, smoother, and brighter. Just one bottle of "Ashmore's Paradox" packed to the gills with electrons and you'll be that much better than your fellow man!

Hi Pat,
I thought we had done this one.
Will This do you,
They use schlieren optics to investigate the change in refractive index caused by changes in electron density in a plasma.
I think it is the similar effect that one gets when one lights a BBQ and look across the top of it. Images behind are distorted because the light is absorbed and re-emitted by the plasma above the fire. Due to the delay between absorption and re-emission the plasma 'moves' and so the image is distorted and 'wavy'.
Cheers,
lyndon

Wow- so you don't even understand refraction of light through heated air of different densities. And here I was, sure you wouldn't bring this up as part of your proof, sure that you understood the difference.

Besides which, that paper you referenced- did you see the two lenses in the diagram? The plasma was being imaged. That was like me saying "people focus light, I have pictures as proof." Did you even look at it?

Good luck with Ashmore's Theory of the Lit Barbecue at the next Plasma Physics group.

Have you noticed what it says on top of the page in that document?
High Power Laser Programme.
And the electron density reported in the paper?
n ~ 10^26 m^-3.
So, again you present a source about high-power laser light in high-density plasma.
Now, can you explain in detail how this relates to low-power light in IG plasma, or is it just the usual attempt of obfuscation?

__________________
papageno


"Why waste time learning, when ignorance is instantaneous?" - Hobbes (Calvin and Hobbes)

"It's all about context!" - Vince Noir (The Mighty Boosh)

"I've never heard of such a brutal and shocking injustice that I cared so little about!" - Zapp Brannigan (Futurama)

"...because the logic of the lines traced from reality is as poor of aesthetic value as it is strict in consistency. " - Paolo Bozzi (Naive Physics - free translation)

Being somewhat naive in physics, but if Lyndon is is saying that free electrons in a plasma have a rest energy and an exicted state, wouldn't the excited state be quantizied by the energy of the plasma? And couldn't this be measured and why hasn't anyone seen it?

__________________
"If you don't understand it, don't screw with it".