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  4. Is there a minimum and a maximum frequency for radiation on the EM spectrum?
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Is there a minimum and a maximum frequency for radiation on the EM spectrum?

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Offline alancalverd

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #20 on: 11/07/2017 19:11:05 »
Quote from: timey on 09/07/2017 22:10:11


Is there any chance that you could answer the question I posed?
I am (have been for a long time) interested in understanding if a clock that shifts to a higher frequency in a higher gravity potential compared to a lower gravity potential (within the mathematical framework of GR) is shifting to the same magnitude as a photon shifts to a lower frequency when moving from the same lower potential to the same higher potential (within the mathematical framework of GR)...

We've been round this loop several times before. Yes, the gravitational effect on clock synchronisation is exactly the same as on photon frequency, as predicted and measured.
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #21 on: 11/07/2017 19:42:30 »
Quote
:wiki
Zero-point energy (ZPE) or ground state energy is the lowest possible energy that a quantum mechanical system may have. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state due to the Heisenberg uncertainty principle.[1] As well as atoms and molecules, the empty space of the vacuum has these properties. According to modern physics the universe can be thought of not as isolated particles but continuous fluctuating fields: matter fields, whose quanta are fermions (i.e. leptons and quarks), and force fields, whose quanta are bosons (e.g. photons and gluons). All these fields have zero-point energy.[2] These fluctuating zero-point fields lead to a kind of reintroduction of an aether in physics,[1][3] since some systems can detect the existence of this energy. However this aether cannot be thought of as a physical medium if it is to be Lorentz invariant such that there is no contradiction with Einstein's theory of special relativity.[1]

Physics currently lacks a full theoretical model for understanding zero-point energy, in particular the discrepancy between theorized and observed vacuum energy is a source of major contention.[4] Physicists Richard Feynman and John Wheeler calculated the zero-point radiation of the vacuum to be an order of magnitude greater than nuclear energy, with one teacup containing enough energy to boil all the world's oceans.[5] Yet according to Einstein's theory of general relativity any such energy would gravitate and the experimental evidence from both the expansion of the universe, dark energy and the Casimir effect show any such energy to be exceptionally weak. A popular proposal that attempts to address this issue is to say that the fermion field has a negative zero-point energy while the boson field has positive zero-point energy and thus these energies somehow cancel each other out.[6][7] This idea would be true if superstring theory were an exact symmetry of nature. However, the LHC at CERN has so far found no evidence to support supersymmetry. Moreover, it is known that if supersymmetry is valid at all, it is at most a broken symmetry, only true at very high energies, and no one has been able to show a theory where zero-point cancellations occur in the low energy universe we observe today.[7] This discrepancy is known as the cosmological constant problem and it is one of the greatest unsolved mysteries in physics. Many physicists believe that "the vacuum holds the key to a full understanding of nature"

Jeff - please take note:
'These fluctuating zero-point fields lead to a kind of reintroduction of an aether in physics,[1][3] since some systems can detect the existence of this energy. However this aether cannot be thought of as a physical medium if it is to be Lorentz invariant such that there is no contradiction with Einstein's theory of special relativity.'

ChiralSPO - if you are wondering where the little wet patch on your butt cheek came from, it's from when Pete kissed it, post 18.  He does have a point though, and I was wondering if you might speak a little on "the axis of evil' preffered direction observations in relation to the inflation model here:
https://www.thenakedscientists.com/forum/index.php?topic=70532.msg516048#msg516048

Ah Alan - good, you answered.  I have further questions for you and will be back.
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Offline jeffreyH

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #22 on: 11/07/2017 20:49:33 »
If we have a problem with vacuum energy then we are not thinking of this energy in the correct way.
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #23 on: 11/07/2017 20:55:52 »
Quote from: alancalverd on 11/07/2017 19:11:05
Quote from: timey on 09/07/2017 22:10:11


Is there any chance that you could answer the question I posed?
I am (have been for a long time) interested in understanding if a clock that shifts to a higher frequency in a higher gravity potential compared to a lower gravity potential (within the mathematical framework of GR) is shifting to the same magnitude as a photon shifts to a lower frequency when moving from the same lower potential to the same higher potential (within the mathematical framework of GR)...

We've been round this loop several times before. Yes, the gravitational effect on clock synchronisation is exactly the same as on photon frequency, as predicted and measured.

So - I take it from your answer that you are telling me that when subject to the same differences in gravity potential, that the gravitational shift of electron transitions and the gravitational shift of photons are equal in magnitude.

On the basis that we just look at this as a logical venture rather than a text book quotation, now I would like you to consider 'where' these observations are taking place:
The gravitational shift in electron tansitions will be obseved to be of a higher frequency in the higher potential than the electron transitions observed in the lower potential, 'from' the lower potential.
The gravitational shift in photons will be observed to be of a lower frequency than they were observed to be in the lower potential, 'in' the higher potential.

Photons cannot be observed unless they are 'in' the observers reference frame.
Electron transitions can be observed 'in' another reference frame 'from' the observers reference frame.

A clock shifts to a higher frequency 'in' the higher potential.  If we go to this higher potential the clock apears to be ticking normally, but this is because 'in' the higher potential we won't be measuring the electron transitions of this clock from the clock with the lower frequency 'in' the lower potential.

The light in the lower potential is measured via the clock with a lower frequency of electron transitions.
The light in the higher potential is measure via the clock with a higher frequency of electron transitions.
...Yet the light measured in the higher potential via the clock with the higher frequency of electron transitions has a lower frequency than the light measured in the lower potential via the clock with the lower frequency of electron transitions.

In the framework of GR, the clock's electron transitions are shifting to higher frequencies in the higher potential. (time gets faster at elevation)
In the framework of GR, the photon is shifting to a lower frequency in the higher potential 'according' to the clock in the higher potential.

If the magnitude of the shifts of both electron transitions and photons is equal, then has the light actually shifted frequency?
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Offline PmbPhy

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #24 on: 11/07/2017 21:49:27 »
Quote from: jeffreyH on 11/07/2017 19:02:36
Zero point energy
Quote from: jeffreyH on 11/07/2017 19:02:36
Quote from: jeffreyH on 06/07/2017 17:36:17
Ok so let's think about the maximum wavelength. That implies an infinite length. That equates to a frequency of zero or maybe undefined. Let's think about a minimum wavelength. It can't be zero because of zero point energy. This all implies some limit on the range.

Well spot the stupid mistake. Zero point energy relates to an infinite wavelength. A wavelength approaching zero is also approaching infinite energy. And no one spotted THAT?
Zero point energy does not mean that a particle has zero energy. It means that its lowest energy a system can have. See:
https://en.wikipedia.org/wiki/Zero-point_energy#Redefining_the_zero_of_energy
Quote
Zero-point energy (ZPE) or ground state energy is the lowest possible energy that a quantum mechanical system may have.
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Offline evan_au

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #25 on: 11/07/2017 22:28:09 »
Quote from: PmbPhy
BTW - How to I do a "Thank you" for a post? I can't see a link to do it with.
Look at the Top RHS of the Post - there is a dark blue button labelled "ACTIONS".
Click this button; the top menu item under this is "Say Thanks".
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #26 on: 11/07/2017 22:43:56 »
To continue from post 23:

The clue: (time gets faster at elevation).

If the clock's electron transitions are increased in frequency because time is running faster at elevation, then the light measured at elevation will also have increased in frequency as the clock's electron transitions have, but this increase in frequency has been gravitationally shifted to a lower frequency.

Logically speaking, the gravitational shift of the light and the gravitational shift of the electon transitions of the clock are not going to 'actually' be equal and opposite, the light has shifted twice as much as the clock has.
« Last Edit: 11/07/2017 22:46:35 by timey »
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Offline alancalverd

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #27 on: 12/07/2017 00:44:36 »
Oh dear. Here we go again.

The clock at altitude appears faster to an observer on the ground. Fact.

The photon emitted at altitude appears blueshifted to an observer on the ground. Fact.

Same phenomenon, same equation.
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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #28 on: 12/07/2017 01:06:02 »
Alan - sigh, you are not reading the posts properly, and I am trying to understand 'how' the equation is 'physically' working.

I am referring to a gravitationally red shifted photon viewed 'in' the higher potential and it's frequency compared to the frequency it was when it was at ground level.  I am not referring to a gravitationally blue shifted photon viewed 'in' the lower potential.

The clock at altitude not only appears to be ticking faster from the ground, it IS ticking faster according to the mathematical framework of GR.
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Offline jeffreyH

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #29 on: 12/07/2017 05:53:23 »
Timey. It all depends upon where the observer is with respect to the origin of the observed event. That is all there is to it. You can't mix up reference frames and get a sensible answer.
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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #30 on: 12/07/2017 06:10:00 »
Quote from: PmbPhy on 11/07/2017 21:49:27
Quote from: jeffreyH on 11/07/2017 19:02:36
Zero point energy
Quote from: jeffreyH on 11/07/2017 19:02:36
Quote from: jeffreyH on 06/07/2017 17:36:17
Ok so let's think about the maximum wavelength. That implies an infinite length. That equates to a frequency of zero or maybe undefined. Let's think about a minimum wavelength. It can't be zero because of zero point energy. This all implies some limit on the range.

Well spot the stupid mistake. Zero point energy relates to an infinite wavelength. A wavelength approaching zero is also approaching infinite energy. And no one spotted THAT?
Zero point energy does not mean that a particle has zero energy. It means that its lowest energy a system can have. See:
https://en.wikipedia.org/wiki/Zero-point_energy#Redefining_the_zero_of_energy
Quote
Zero-point energy (ZPE) or ground state energy is the lowest possible energy that a quantum mechanical system may have.


It was all very badly worded.
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #31 on: 12/07/2017 11:16:40 »
Hey Jeff - thanks for the answer.  Btw, bad wording or not, I understood exactly what you were referring to in your posts.  In my posts I did in fact state quite clearly which reference frames I was referring to.  Please remember that light cannot be measured 'in' any other frame apart from the observers frame, and the clock can only be measured as time dilated 'from' another reference frame.
In fact what I am going to do is re-post my question:
Quote
:timey post 23
So - I take it from your answer that you are telling me that when subject to the same differences in gravity potential, that the gravitational shift of electron transitions and the gravitational shift of photons are equal in magnitude.

On the basis that we just look at this as a logical venture rather than a text book quotation, now I would like you to consider 'where' these observations are taking place:
The gravitational shift in electron tansitions will be obseved to be of a higher frequency in the higher potential than the electron transitions observed in the lower potential, 'from' the lower potential.
The gravitational shift in photons will be observed to be of a lower frequency than they were observed to be in the lower potential, 'in' the higher potential.

Photons cannot be observed unless they are 'in' the observers reference frame.
Electron transitions can be observed 'in' another reference frame 'from' the observers reference frame.

A clock shifts to a higher frequency 'in' the higher potential.  If we go to this higher potential the clock apears to be ticking normally, but this is because 'in' the higher potential we won't be measuring the electron transitions of this clock from the clock with the lower frequency 'in' the lower potential.

The light in the lower potential is measured via the clock with a lower frequency of electron transitions.
The light in the higher potential is measure via the clock with a higher frequency of electron transitions.
...Yet the light measured in the higher potential via the clock with the higher frequency of electron transitions has a lower frequency than the light measured in the lower potential via the clock with the lower frequency of electron transitions.

In the framework of GR, the clock's electron transitions are shifting to higher frequencies in the higher potential. (time gets faster at elevation)
In the framework of GR, the photon is shifting to a lower frequency in the higher potential 'according' to the clock in the higher potential.

If the magnitude of the shifts of both electron transitions and photons is equal, then has the light actually shifted frequency?
Quote
:timey post 26
To continue from post 23:

The clue: (time gets faster at elevation).

If the clock's electron transitions are increased in frequency because time is running faster at elevation, then the light measured at elevation will also have increased in frequency as the clock's electron transitions have, but this increase in frequency has been gravitationally shifted to a lower frequency.

Logically speaking, the gravitational shift of the light and the gravitational shift of the electon transitions of the clock are not going to 'actually' be equal and opposite, the light has shifted twice as much as the clock has.
Alan has said:
Quote
:Alan
Oh dear. Here we go again.

The clock at altitude appears faster to an observer on the ground. Fact.

The photon emitted at altitude appears blueshifted to an observer on the ground. Fact.

Same phenomenon, same equation.
...But I am talking about light that is emitted 'in' the lower potential that has been redshifted on it's way 'to' the higher potential, and is being measured 'in' the higher potential in comparison to the shift of the clock 'in' the higher potential compared to the lower potential that is observed 'from' the lower potential.  All reference frames are clearly stated.

Edit: And where Alan has said:
Quote
:Alan
The clock at altitude appears faster to an observer on the ground. Fact.
It is important to remember that the clock not only appears to be faster to an observer on the ground, it IS physically ticking faster according to the mathematical structure of GR.
« Last Edit: 12/07/2017 11:29:07 by timey »
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #32 on: 12/07/2017 12:03:03 »
Maybe I should pose the question around your answer Alan...same question, just reversed.
Quote
:Alan
The clock at altitude appears faster to an observer on the ground. Fact.

The photon emitted at altitude appears blueshifted to an observer on the ground. Fact.

Same phenomenon, same equation.
OK - so now we are comparing the clock 'in' the higher potential with the clock in the lower potential which is observed 'from' the higher potential to have a lower frequency. (time running slower).
And we are comparing the frequency of light emitted 'in' the higher potential, with it's blue shifted frequency as measured 'in' the lower potential via the tick rate of the lower potential clock.

You have said that subject to the same differences in gravity potential, the shift of the light and the shift of the clock are equal in magnitude.
The blue shifted light measured 'in' the lower potential via the lower potential clock (slower rate of time) is of a higher frequency than it was when measured 'in' the higher potential via the higher potential clock (faster rate of time).

The light moving into the lower potential will be affected by this slower rate of time which will affect it's frequency, yet it's frequency is observed 'in' the lower potential to be greater then it was 'in' the higher gravity potential where the rate of time is faster.
Logically speaking, the shift of the light between these higher and lower potentials will be twice the magnitude of the shift of the clock between these higher and lower potentials.
« Last Edit: 12/07/2017 12:05:51 by timey »
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Offline alancalverd

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #33 on: 12/07/2017 16:53:47 »
Just stick to simple and factual.

Everything works normally when viewed from the same gravitational potential. But if the observer is at a lower potential than the source, the source appears blue shifted, whether the source is an atomic clock (low energy photon) or a mossbauer (high energy) photon.  These are experimental facts. A simple mathematical model is that spacetime is warped by gravity.
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Offline jeffreyH

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #34 on: 12/07/2017 19:07:04 »
My déjà vu is having déjà vu.
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Offline alancalverd

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #35 on: 12/07/2017 21:42:37 »
Not again, surely?
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Offline timey

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #36 on: 12/07/2017 22:18:22 »
Quote from: jeffreyH on 12/07/2017 19:07:04
My déjà vu is having déjà vu.
Yeah - Mine too!

Quote from: alancalverd on 12/07/2017 16:53:47
Just stick to simple and factual.

Everything works normally when viewed from the same gravitational potential. But if the observer is at a lower potential than the source, the source appears blue shifted, whether the source is an atomic clock (low energy photon) or a mossbauer (high energy) photon.  These are experimental facts. A simple mathematical model is that spacetime is warped by gravity.
Erm, I'm not sure what your point is... You seem to be stating the basic facts laid out in every physics book I've read, again, as you have done so many times before, to what end I do not know, it's not like I'm unfamiliar.  You certainly are not following the remit of examining 'the choice of reference frames' as part of a discussion that pertains to the correct answer to the thread title question which I posted in post 1.

What I want to take part in here at this forum Alan is a dissection of these simple facts by examining physical process, which is what my questions are regarding.  But since you have responded with the so called simple and factual let's dissect that first:
Quote from: alancalverd on 12/07/2017 16:53:47
Everything works normally when viewed from the same gravitational potential
I think this could be better defined as: Everything is measured as normal when measured by the tick rate of a clock in the same gravity potential.
Quote from: alancalverd on 12/07/2017 16:53:47
But if the observer is at a lower potential than the source, the source appears blue shifted, whether the source is an atomic clock (low energy photon)
Electron transitions are not low energy photons.  General Relativity states within its mathematical framework that the clock is not just appearing to be ticking faster in the higher potential, it IS ticking faster in the higher potential.  That IS factual.
Quote from: alancalverd on 12/07/2017 16:53:47
or a mossbauer (high energy) photon
When the observer is at a lower potential to the 'source', the photon the observer is observing is not 'in' the higher potential.  It is 'in' the lower potential when it is observed by the observer.  A photon cannot be observed anywhere except 'in' the reference frame of the observer.  That IS factual
Quote from: alancalverd on 12/07/2017 16:53:47
These are experimental facts. A simple mathematical model is that spacetime is warped by gravity.
Where the simple fact is that this mathematical model clearly states that it does not know 'how' spacetime is warped by gravity.

Therefore, in that it is know fact of physics that the best mathematical model of gravity cannot physically describe itself, and a well known fact at that, I would like to discuss know physics experiments in a dissection of examining 'how' the known equations are working in physical terms.  This is not unlike the type of considerations that I read about in books written by physicists.  These books have taught me physics and I am merely following suit on the style of investigation of known physics that I read about in books, and programs, made by prominent physicists in the field.

So - now we have cleared up the simple and the factual, can we please move onto the consideration that I outlined?
« Last Edit: 12/07/2017 22:27:08 by timey »
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Offline PmbPhy

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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #37 on: 12/07/2017 22:41:36 »
Quote from: alancalverd on 12/07/2017 16:53:47
Just stick to simple and factual.

Everything works normally when viewed from the same gravitational potential. But if the observer is at a lower potential than the source, the source appears blue shifted, whether the source is an atomic clock (low energy photon) or a mossbauer (high energy) photon.  These are experimental facts. A simple mathematical model is that spacetime is warped by gravity.
The presence of such a blue shift does not prove that spacetime is curved spacetime. In fact Einstein's predictions of this phenomena is based on physics on the flat spacetime approximation, i.e. by assuming the field is a uniform gravitational field. In fact he utilized the equivalence principle which states that a uniform gravitational field is equivalent to a uniformly accelerating frame of reference (in flat spacetime). Then he used the physics of accelerated frames to make the prediction. In the Pound-Rebka experiments it was this uniform g-field (flat spacetime) approximation that the results of the experiment were compared to. In fact a perfectly uniform gravitational field has zero spacetime curvature.

If you'd like you can look it up in the article Does a gravitational red shift necessarily imply that spacetime is curved? by G.E. Marsh and C. Nissim-Sabat. Am. J. Phys. Vol. 43, No. 3, March (1975)

This article is available online at: http://booksc.org/book/34148429/e7d2fe
Quote
Abstract

Schild’ has proposed a heuristic agrument which attempts, to show that any gravitational red shift requires that the geometry of space−time be curved. It is our intention to show that this argument is fallacious and we believe that no argument which attempts to infer space−time curvature solely from the gravitational red shift can be valid.
Does a gravitational red shift necessarily imply that spacetime is curved? by G.E. Marsh and C. Nissim-Sabat. Am. J. Phys. Vol. 43, No. 3, March (1975)
Or I can derive it myself here if anybody would like? Of you can read about it in a paper I wrote which is online here
https://arxiv.org/abs/physics/0204044
« Last Edit: 12/07/2017 22:50:10 by PmbPhy »
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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #38 on: 13/07/2017 03:26:35 »
Ah Pete - I'm not sure if you are actually observing my posts or not (you keep saying that you have placed me on ignore) - but I cannot thank you enough for posting this excellent link!

http://www.geocities.ws/physics_world/gr/grav_red_shift.htm

Alan - note that Marsh and Nissim-Sabat directly echo the considerations I outlined.

@Mike Gale
You might want to check this link out Mike

edit: - and Pete's paper too.

https://arxiv.org/ftp/physics/papers/0204/0204044.pdf

Great paper Pete.  I identified with Einstein's "Relativity, The Special and General Theory" much more than the other modern books I've read dedicated to the subject.  It's such a shame (as far as I'm concerned) that you refuse to speak to me because I do not converse in the language of mathematics.
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Re: Is there a minimum and a maximum frequency for radiation on the EM spectrum?
« Reply #39 on: 13/07/2017 03:48:37 »
Quote from: timey on 13/07/2017 03:26:35
Ah Pete - I'm not sure if you are actually observing my posts or not (you keep saying that you have placed me on ignore) - but I cannot thank you enough for posting this excellent link!

http://www.geocities.ws/physics_world/gr/grav_red_shift.htm
You're welcome. After all, that's what the website is for. But it's odd. I was told that website was going to be deleted. Hmmmmmm.....

And yes, you're in my ignore list. However, since I'm now a moderator I'm responsible for making sure that members don't violate forum rules. It's difficult to juggle this combination, i.e. when to read and when not to so I have to do my best.
« Last Edit: 13/07/2017 04:08:13 by PmbPhy »
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