Cosmological Red Shift

Ok, Englishman......


https://en.wiktionary.org/wiki/pretention

 

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Your spelling pretention: I'll stick to my original claim thank you.....
http://www.oxforddictionaries.com/spellcheck/english/?q=pretention
No exact match found for “pretention” in British & World English
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But as per usual, you side step and avoid the main issue in which once again you have been found in error.

Let me again rehash........
The effects of Doppler and Cosmological redshift are the same: ie, the stretching or lengthening of the wavelength of light/photons.
And of course, the fact that mainstream cosmology is not going to be rewritten or even corrected, by amateurs or cranks on a science forum.
You need to accept that last sentence to even begin to imagine that you have any credibility.

 

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You seemed to have it right in your last post, but I'll reiterate:

This idea of a "mechanism" is a red herring because redshift in any form is just a simple geometric consequence of relative motion between a source and receiver of a wave. So the "mechanism" isn't really a mechanism for redshift, it is a mechanism for causing relative motion. It can be a car engine, a running person or the expansion of space. Doesn't matter.

Often (as with Farsight's attempt), the idea that there needs to be a "mechanism" is a reflection of the erroneous belief that redshift is a manifestation of energy loss and that energy loss needs a "mechanism" that absorbs the energy. It isn't, so it doesn't.

 

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origin:

Thanks for your polite enquiry, origin. I made no claim either way about such a mechanism. I have posted an answer to OP question. That answer was effectively: none know the answer to satisfy The God's OP question. That answer was based on the result of extensive reading in the conventional Cosmological Expanding Spacetime Theory models; which reading did not uncover where such a mechanism was discussed or identified let alone explained in any way consistent with what is physically happening to the photon during its expanding space traversal. If there is a mechanism, none have yet provided the current models with its description and explanation in physical terms that would satisfy any reasonable enquiry as to its nature and mode of action to attenuate a photon's wavelength in transit.

If I read your question to me correctly, are you implying there is such a mechanism known and described in the models? A physically consistent and explicable mechanism by which Einsteinian spacetime can expand and, in doing so, physically 'stretch' a photon during transit as claimed in the relevant Cosmological models?

If there is such a mechanism that I have not come across in my reading, can you please make reference to it or link to it in the literature? Thanks.

Please forgive me if that inference I drew from your question was not correct.

 

Russ_Watters:

Unless I am mistaken in my reading of the current cosmological expanding space models and claims, the cosmological expansion does not involve actual motion through spacetime, only along with it, as I explained in my first post to the OP. In which case the cosmological 'recession' is not the normal type of relative separational motions of the source and receiver 'through space'; as used by the Doppler relative motion type explanations. That component is always there, yes. But in addition there is the cosmological motions 'with space' which would not produce any effect at emission or reception, since once the photon has 'traversed' expanding spacetime, the process of absorption of photon is only determined by what effective wavelength it had in the receivers frame of reference, which is also moving 'with the space' in which it is imbedded (as distinct from its ordinary Doppler separational motion 'through space').

Have I clarified sufficiently to make myself clear about the two types of motions and two types of redshifting that implies; as claimed in the current models, which, if I read and understood them correctly, actually distinguish between the 'with space' Cosmological component and the 'through space' Doppler type motions component of the total composite redshift measurements for photons from cosmologically distant sources in expanding spacetime?

 

As I said, this is not an open question. There isn't, nor does there need to be such a "mechanism" because nothing is happening to photons during their transit of space.

That's all correct, but it has no impact whatsoever on the effect. It works the same, regardless of what is causing the distance to change with time.

 

Russ_Watters:

Now you have me confused. Isn't the whole point of cosmological expansion to explain the effect on photons in transit? To distinguish it from the classical relative 'through space' motion between source and receiver, the effect which is explained by the classical Doppler effect which is supposed to be different from the cosmological expanding space effect?

My confusion is even further increased now. I have stated my understanding, which is consistent with the cosmological expanding space model descriptions and explanations, that, in the frames of reference of both source and receiver, there is no Doppler type motion 'through space', only 'along with space'. From which I understand that the cosmological component of redshifting effect on the photon can only occur while the photon is in transit. This is a separate component and effect to the classical Doppler type relative motion through space which does occur at reception according to the receiver's differential motional separation speed between itself and the source; this Doppler effect being only due to actual through space separation velocity differentials.

I stress that an effect on photon in Doppler terms is component of relative motion through space, where the reception process is in a frame which is actually moving through space while the photon is being absorbed. Which is physically and effectively totally different situation in the cosmological component effect, because the latter cannot be a Doppler type effect since in the expansion theory and models, the source is not moving through space but with the expanding space locally, and so is the remote receiver. Which logically means that the Doppler effect component is what it would also be if there was no expanding spacetime; since at emission and at reception there is no cosmological relative motion between the receiver and the photon while it is being absorbed. Only the normal Doppler relative motions would apply, as the cosmological recession component is not actively involved like in normal through-space Doppler scenarios.

That is my understanding. That is why I am confused by your assertion that: "nothing is happening to photons during their transit of space." because it is counter to everything I read regarding current cosmological expanding space theory and models. I know I have probably not explained my understanding or confusion as well as could be, but I hope it is enough to pinpoint where my concerns lay. Thanks for your patience and kindness in responding to me as you have.

 

No. Nothing happens to the photon. Redshift from motion or from expansion of space has the same equation and cause: distance between source and receiver changing over time. The only difference is what causes the distance to change over time, not that something different is happening to the photon -- because in both cases, nothing happens to the photon.

The effect is different because of what causes distance between source and receiver to change over time. But that has nothing to do with something happening to the photon: nothing happens to the photon.

Correct.

The effects of expansion and proper motion look exactly the same, because as far as the observation is concerned, they are exactly the same. Scientists differentiate between them so that they can tell how the universe is evolving, but that has nothing to do with an individual photon.

Expanding universe theory arose because scientists noted that the motion of galaxies wasn't random. They noticed the pattern, which led to the different mechanism for the "motion" of the objects. But again, what causes the "motion" of the objects has nothing to do with the photon that passes between them.

Again: redshift does not affect photons -- it is not a change to the photon itself. It affects how they are sent and detected. The photon itself never changes. And how could it -- it would have to have an infinite number of different frequencies simultaneously!

There is simply no need for there to be anything happening to the photon. I'm aware some people describe it that way, but it is an unnecessary complication of what is a very simple concept.

 

Let's try an analogy:

A train is moving past me at 3 m/s while I'm standing still on the ground. I turn and run toward the train at 3 m/s. How (by what mechanism) did I make the train stop?

 

Russ_Watters:

No references necessary for that part. It is my recollection from extensive reading of literature, where the essential message is that the photon is stretched by universal expansion. That message differs from what you now tell me; ie, that it is the motions that determine the photon received ferquency, not the expanding space effect on the photon itself.

The confusion seems to lay in the definition of "motion" itself, as it pertains to expanding or non-expanding universe concepts. Following is my understanding of the distinction between them.

Real relative "motion": is through space Motions in a non-expanding universe would all be of such type, and the Doppler measurements and techniques would apply universally and involve only one universal set of values reflecting the classical range from zero, no relative motions between two co-moving bodies, to maximal, relative motions between two bodies separating or closing at speed of light.

Perceived relative "motion": may be due to causes and processes not involving any "Real relative motion though space".

Any expanding space concept that has no physical explanation for expanding space and the consequent increased distances between source and receiver in "through space" terms does not explain what expanding type "motion" involves physically.

My confusion arose at that point in your response to me. To clarify:

My understanding is that once the photon is emitted, it crosses whatever 'distance' is actually physically effective between source and remote receiver. The photon's (light)speed does not change.

Eventually comes the remote reception and absorption process. This is where it gets tricky and requires explanation of receiving body's "motion" type that is actually involved during that absorption process. Normally we have the classical motion through space, irrespective of that local space being part of the global expansion or not. Whatever the receiver's motion in the direction away from that of remote source, the only things that determine 'frequency' of photon at reception is the relative motions of the photon itself and the receiver itself at that moment; the remote source is no longer an active participant in what happens locally at receiver.

There is the problem. If the motion of the receiver in local space is that part of normal Real "motion" like any between two bodies in a non-expanding universe, then only the relative motion between the photon and receiver applies. And since no remotely related cosmological component of "motion" is active or added locally to receiver or photon "motion" in the local frame, wherein neither photon nor receiver is actually moving in 'cosmological motion and distance increasing terms' because only the local through space Real motion component applies.

In other words, Doppler measurement "values" can involve and reflect only "through space" relative motion differentials between photon and receiver. All other effects on "perceived" photon wavelength or frequency must be due to expanding spacetime action affecting in-transit photon itself. That is why your comment has confused me.

If I am not clear enough what I mean, that is my fault entirely; and I will understand if you now tell me to get my thoughts in order before again imposing on your kind and patient nature in this matter. Either way, thank you very much for allowing me to expound on my concerns and confusions on this.



Late edit: in response to your additional response below:

I am aware of and understand the classical (and Einstenian modification of) relativity of motion concept. That is why I made the distinction between motion through space and motion along with space. The former is classical and applies even in non-expanding scenario, which gives the observed Doppler values for the range of such differential motional cases, as I already allowed in my earlier responses. The classical Doppler is what is in question in "Perceived" but not real relative motion differentials in the local motion "along with space" local space, wherein the receiver is effectively 'stationary' relative to that local cosmological component of the expanding space scenario, which scenario has distance increasing but no real through space motional component locally other than what would apply locally to the non-expanding space scenario anyway in classical Doppler scenario you just described. If I have not made clear my reasons and understandings that the two separate components, Doppler and Cosmological, motions are entirely separate considerations which do not add in the way you assert, then it's my fault. Thanks anyway for your efforts, which I have appreciated very much.

 

Well, you have certainly confused me!

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as to what you are trying to say.
Before I elaborate on the situation in question, your typing style is difficult to read without paragraphs...it resembles a mass of jumbled words, and I'm sure you would like to clear up that problem first.
On the issue of Doppler and/or gravitational redshift, again, the effects are the same, ie the stretching/lengthening of a light wave/photon.....That much is certain.
As to what causes the stretching and the mechanism behind it, let me say that science models theories that describe what we see and make successful predictions: There is really no argument on the fact that theories over time do grow in certainty, the more they match observation and keep making successful predictions.
Why does expanding space stretch a photon? Firstly we have no doubt over the validity of both Doppler and Cosmological red and or blue shift.
Why does the same photon also warp/curve spacetime, albeit by a tiny amount? The same reason that expanding spacetime lengthens the photon I suggest...Why does mass warp/curve/twist spacetime?
It just does. Why does colliding astronomical objects make spacetime gravitational waves? For the same reasons as why mass curves/warps it I suggest.
And as I did say earlier, science/cosmology does not yet know everything.
Science/cosmology constructs models that describe what we see and are as close to reality as possible: If they happen to hit that reality on the head, all well and good: Otherwise the main object is successful predictions and observational detail. In that our physicists and cosmologists have been outstandingly successful as I'm sure you'll agree.
Factually, as spacetime expands the wavelengths of the light in it also expands:
I would also add due to the confusing nature of your post and in case you were making some reference to this, that since we cannot assume that we have a special place in the Universe, this is evidence for a generally expanding universe as distinct from everything moving away from us, [doppler] which would suit our religious adherents quite nicely.

Cosmological redshift is a fact and that's the crux of the matter.
Hope that helps somewhat.

 

Wrong......should we talk about CMBR ? What happened to them with that inflationary expansion ? You think no change ?

It is foolish to say that mechanism is irrelevant or red herring or not needed. lack of knowledge of mechanism means either our theory is incomplete or we are ignorant...

Now coming to the main issue...again as I explained to you in Post #11/12 itself that cosmological red shift is an entirely different animal. Associating cosmological redshift with relative motion itself is incorrect and shows ignorance of the deeper understanding of the subject...there is no relative motion between Earth (observer) and distant galaxy as determined by cosmological redshift (which could be as high as 7 recorded, if I recall correctly). It is the stretching / expansion of the spacetime not any kind of physical relative motion. Infact as I suggested you earlier, why not read about the more general Gravitational Red/Blue shifting (Pound Rebka Experiment)...there is no relative motion, still it happens, cosmological redshift could be considered as a special case of Gravitational Redshift....

PS: Doppler red shift is associated with the peculiar velicities of various galaxies, not with the spacetime expansion....

 

I'll bring this back to concise:

It looks to me like what The God was intending to imply by his OP and what expletives deleted also believes is that there is a missing piece - something that is currently unexplained - in mainstream cosmology; a "mechanism" for cosmological redshift whereby space itself interacts with and stretches photons.

That premise for the thread is wrong. There is no such missing piece in mainstream cosmology.

 

?? Yes but its you who seems confused as to what each is and the effects of each.
Doppler redshift and cosmological redshift, both achieve the same result, ie the stretching/lengthening of light waves albeit by different means: Dopple via the emitter and the source moving away from each other, and Cosmological via the expansion of intervening spacetime.
The plain simple old truth of the matter.

Why does this happen? Why did the BB bang? Why does gravity exhibit itself when spacetime is curved in the presence of matter?
Those are questions yet to be answered: The point is though, they happen or have happened, and we are able to predict quite accurately as a result of those excellent models. They are as close to reality as we can get.
Science does not know everything, but what it does not know is not going to be revealed by anyone on a science forum.

 

Don't divert, the premises for the thread is not wrong.

You are wrong on many counts.....correct yourself as you are taking a mainstream position.

1. Equating (in whatever manner) Cosmological Redshift with Doppler Shift, rather pushing cosmological redshift as Relative Motion based. Not able to distinguish between SR and GR.

2. Calling absence of Mechanism as Red herring or needless.

3. Claiming that nothing happens to Photon due to expansion of spacetime.

 

Pl enlighten me how and which post of mine gives you a feeling that I am confused ?

 

Probably near all of them at some stage or other, particularly when you are shown to be wrong.

 

Pl be specific, and please start with recent one of them (as against all of them) as that will reduce your trouble of sifting through old records........otherwise retract or I will report.

 

Report all you like.....no retraction.
Obviously the most recent though is your failure to recognise that Doppler and Cosmological redshifts have the same effect on light/photons....that is stretching/lengthening them.........Just as obviously they do so by different explainable mechanisms...another point you seem confused about.
Those explainable methods of course are : Doppler: due to mass/matter physically moving apart or away from each other, and Cosmological: The expansion of intervening space.
Let me reiterate, both have the same effect on light/photons.

And of course what other opinion other than confusion, could anyone have re your recent ludicrous claims that GP-B and LIGO are both fraudulent.

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Nope.