True Time & True c: Exploring Light Speed & Relativity

[Aether]

Definition or convention, calling it "absolute" is still just semantics. The point is that you are free to label the FLRW coordinates as "absolute" and Idjot is free to label the CMBR as "true", but neither choice has any physical significance. It is simply a matter of personal preference.

I don't intend to label the FLRW coordinates in a non-standard way, and have already withdrawn the term "absolute" in favor of "definition" with respect to the standard simultaneity of FLRW coordinates. I am now only using the term "absolute" in reference to the simultaneity convention of the non-standard (Mansouri-Sexl, LET, GGT, etc.) formulation of SR that I am using. I don't understand your continuing objection to how I am describing the FLRW coordinates.

Yes. Since you are not using the term "absolute" in a standard manner your argument is semantic. I am not going to attempt to convince you to use the standard definition of "absolute" in order to promote clarity, but I am going to clearly point out that your use of the term is non-standard.

Since I am no longer using the term "absolute" in reference to simultaneity in FLRW coordinates, I do not understand your continuing objection. What you seem to be objecting to as a semantic argument was unintentional at first, and then withdrawn/corrected. I do not understand what your continuing objection is.

 

[Idjot]

Not sure using the CMBR as a spacecraft is the best analogy. I would rather use the SLS that generated the CBR as close enough to the single event of the Big Bang to be considered Simultaneous based on the SR Simultaneity rule that only local events can be truly Simultaneous.
It may lead to a similar result but for large scale measures I think it applies modern interpretations more directly.

That sounds like a good idea. Yet I have no knowledge of SLS. In fact I don't even know what SLS stands for. Please elaborate if you don't mind.

 

[Idjot]

Definition or convention, calling it "absolute" is still just semantics. The point is that you are free to label the FLRW coordinates as "absolute" and Idjot is free to label the CMBR as "true", but neither choice has any physical significance. It is simply a matter of personal preference.

The personal preference is in an aesthetic label, but what that label is intended to represent, in my case, is a reference point that cannot be replaced with just anything. It's been reiterated a few times already that there is nothing in GR that says anyone frame should be preferred over any another. But for reference sake, wouldn't it be just plain easier to compare everything to one universal frame that everyone agrees is moving slower than anything else ever measured?

Humor me for a moment please...

Suppose the scientific community accepted CMBR or SLS(?) as the universal frame, calculating a universal time as I did at the beginning of this thread, possibly tweaked for accuracy. Then we compare all objects' velocities relative to this new universal frame. Then we find the time dilation of each object relative to the universal frame. Then we determine how many Earth years old the objects are but at their own rates of time elapse according to their dilation relative to the universal frame.

Anyone would have to agree that if there really was something truly at rest in the universe, that all moving objects would experience real time dilation, right? They, not the object at rest, would age more slowly, but at different rates according to velocity of course. But, with everything relative and nothing at rest, calculating time dilation would seem almost pointless.

Using a universal frame like CMBR would allow us to use time dilation for more than just aesthetics. It would allow us to use time dilation to determine the ages of celestial bodies more accurately. They are, after all, aging at their own respective rates with regard to their velocity, whether or not we have found the absolute. Just because GR fanatics refuse to say that one thing is moving faster than another without the word "relative" in the sentence, does not mean that one is not in fact moving faster than the other. It only means that GR tells us we have no way of knowing which is which. Using a universal frame like CMBR will allow us to reasonably decide which is which and that decision will lead to determinations that will at least be closer to determinations in an absolute than what we have now, which is basically nothing according to GR.

I agree that the word "true" has no physical significance. But in my opinion neither does "simultaneity". It's an unanswered question that's been accepted as an answer.

 

[Dale]

Since I am no longer using the term "absolute" in reference to simultaneity in FLRW coordinates, I do not understand your continuing objection.

Sorry, I missed the retraction. I have no continuing objection, only continued posts on the original objection

 

[Aether]

Just because GR fanatics refuse to say that one thing is moving faster than another without the word "relative" in the sentence, does not mean that one is not in fact moving faster than the other.

Don't go there Idjot. Scientists are not fanatics.

Suppose the scientific community accepted CMBR or SLS(?) as the universal frame, calculating a universal time as I did at the beginning of this thread, possibly tweaked for accuracy.

SLS is "surface of last scattering" and that's what most of the photons of the CMBR last reflected off of, a few hundred thousand years after the big bang, so that's what we are actually looking at when we look at the CMBR. When you see something with your own eyes you are seeing photons that came from the Sun or from a light bulb usually, and they were reflected by some SLS...which is what you would say that you are looking at.

 

[Aether]

Sorry, I missed the retraction. I have no continuing objection, only continued posts on the original objection

Understandable, thank-you.

 

[Dale]

The personal preference is in an aesthetic label, but what that label is intended to represent, in my case, is a reference point that cannot be replaced with just anything.

Why not? All of the stuff you describe could be done just as well in any reference frame. Tell me, do you think that Greenwich Mean Time is in any sense "true" or "absolute"? Accepting the CMBR as a universal frame would be no more significant than accepting GMT as the coordinated universal time.

By the way, I believe that the scientific community already does something similar in the field of cosmology, which is the only field where this would be a useful convention.

 

[Idjot]

Don't go there Idjot. Scientists are not fanatics.

Aether,

One's occupation does not decide whether or not they are fanatical about something. A scientist could be fanatical about killing insects around his home. The plumber next door may be fanatical about GR. There is nothing in GR that says a scientist cannot be a fanatic and there is nothing in GR that says a GR fanatic has to be a scientist. :)

 

[Idjot]

Seriously though, no offense to anyone ever! This thread turned out to be more fun and interesting than I expected. But now I've given all of what little knowledge I had to offer beyond the idea itself and I think I'll leave it to the experts now and just read along to see what I can learn, before I offend any more scientists with my crudeness. Thanks again to everyone for all the input and advice.

 

[russ_watters]

The plumber next door may be fanatical about GR. There is nothing in GR that says a scientist cannot be a fanatic and there is nothing in GR that says a GR fanatic has to be a scientist. :)

You seem to have the attitude that since people can be flawed, science is probably flawed too. You really need to get onboard with how science works. Sure, a person can be fanatical, but real scientific theories do not have personalities. Whether the plumber next door is fanatical about GR or not has nothing to do with whether GR is correct. That attitude of yours is what generates attitude in the responses to your post.

 

[Vanadium 50]

But for reference sake, wouldn't it be just plain easier to compare everything to one universal frame that everyone agrees is moving slower than anything else ever measured?

But, as has been pointed out before, it's not true that "everyone agrees [the CMBR frame] is moving slower than anything else ever measured".

Just because GR fanatics...

You are making an error. Calling people who do not make the same error "fanatics" is dangerously close to crackpottery.

 

[Dale]

Seriously though, no offense to anyone ever!

No offense? I guess you were just using a non-standard definition of "fanatic" too. One that doesn't lump scientists (or plumbers) with terrorists.

 

[RandallB]

That sounds like a good idea. Yet I have no knowledge of SLS. In fact I don't even know what SLS stands for. Please elaborate if you don't mind.

That sounds like a good idea. Yet I have no knowledge of SLS. In fact I don't even know what SLS stands for. Please elaborate if you don't mind.

When thinking of the SLS (surface of last scattering) as the source of the CMB; remember it is not a physical surface of something.

It is a matter of the universe as it aged from the Big Bang less than 0.4 G-Years became transparent basically everywhere.
[EDIT :Oops – off by a few decimal places. SLS is about 377,000 years after the Big Bang which is less than 0.0004 G-Years after the Big Bang.]
From the view of the Local Matter then from which we are made now the light at some distant radius from it could not be seen until it traveled that distance plus the distance we covered in moving away from it (Hubble expansion); That defines a set source distance or “surface” for what we see today as CBR.
CBR from a closer radius has already passed us by, and from a greater radius will not be seen by us until sometime in the future.

The point is:
from our view about 14 G-Years later, and the Big Bang being a single event, and all SLS light from all areas or radiuses starting out at less than 0.4 G-Years from the Big Bang - we can define SLS light as having an “Absolute” Simultaneous start time.

 

[MeJennifer]

the Big Bang being a single event

Feel free to argue how a big bang singularity is an event in GR.

I do not think it is.

 

[Idjot]

You seem to have the attitude that since people can be flawed, science is probably flawed too. You really need to get onboard with how science works. Sure, a person can be fanatical, but real scientific theories do not have personalities. Whether the plumber next door is fanatical about GR or not has nothing to do with whether GR is correct. That attitude of yours is what generates attitude in the responses to your post.

I agree. Scientific theories do not have personalities and I shouldn't confuse them with the people who sleep with them printed on their pajamas. Haha I'm sorry. I couldn't help myself there. I know what you mean. It was a bad choice of word.

.
You are making an error. Calling people who do not make the same error "fanatics" is dangerously close to crackpottery.

I agree. It did sound almost crackpottish.

No offense? I guess you were just using a non-standard definition of "fanatic" too. One that doesn't lump scientists (or plumbers) with terrorists.

, :sigh:, :burp:, :fart:

Yes. A non-standard definition and one I shouldn't have used.


Listen up! I admit it! I used the word "fanatic" in exaggeration!

In reality I only think it's a bit stubborn to deny the usefulness of using CMBR as a universal frame because of simultaneity. I really don't think it's fanatical and it was rude of me to say that.

But you could lighten up a little. Scientists aren't drama queens either (joke).

 

[Idjot]

When thinking of the SLS (surface of last scattering) as the source of the CMB; remember it is not a physical surface of something.
It is a matter of the universe as it aged from the Big Bang less than 0.4 G-Years became transparent basically everywhere. From the view of the Local Matter then from which we are made now the light at some distant radius from it could not be seen until it traveled that distance plus the distance we covered in moving away from it (Hubble expansion); That defines a set source distance or “surface” for what we see today as CBR.
CBR from a closer radius has already passed us by, and from a greater radius will not be seen by us until sometime in the future.

The point is:
from our view about 14 G-Years later, and the Big Bang being a single event, and all SLS light from all areas or radiuses starting out at less than 0.4 G-Years from the Big Bang - we can define SLS light as having an “Absolute” Simultaneous start time.

Thank you!

 

[atyy]

While we're on the subject of nonstandard definitions, I can't help thinking of this guy's definition of SLS as the "surface of last screaming". http://nedwww.ipac.caltech.edu/level5/March03/Lineweaver/Lineweaver7_2.html

 

[Idjot]

While we're on the subject of nonstandard definitions, I can't help thinking of this guy's definition of SLS as the "surface of last screaming". http://nedwww.ipac.caltech.edu/level5/March03/Lineweaver/Lineweaver7_2.html

Thank you too!

 

[RandallB]

Feel free to argue how a big bang singularity is an event in GR.

I do not think it is.

Personally I don’t believe the idea of a singularity, naked or otherwise Big Bang or Black-Holes, although it is favored speculation.
Plus I don’t think anyone even speculates as to how to apply GR to whatever was there before or even a couple minutes after the Big Bang began.

But there is a wide agreement on much of what happened after the Big Bang as a single event.
For most the timing of when the universe became transparent is 370,000 to 380,000 years after the Big Bang whatever that event might have been.
Most of direct measure of the age of the universe as 13.7 Billion years, nearly 14 G-Years, comes from measuring the that SLS or CBR.
And on a scale of 14 G-Years compared to 0.0004 G-years the SLS or CBR source is effectively simultaneous with the Big Bang itself.
IMO all SLS observations should be considered as coming from simultaneous SLS source events.

I don’t think Astrophysics can make most of its claims about expansion and large distance measurements without taking the Big Bang and its aftermath within just a short Million years as being a single simultaneous event.

 

[Dale]

In reality I only think it's a bit stubborn to deny the usefulness of using CMBR as a universal frame

Please, don't misunderstand me. I am not denying its usefulness (at least for cosmology) as a convention. However your thread was about it as "true" time, not just its usefulness.

Using the CMBR as a universal reference frame would be akin to the international date line, or the fact that red lights mean "stop", or right handed coordinate systems. All of those are very useful conventions, but nothing would be fundamentally different if we had chosen and agreed upon different conventions.

If you had started your posts simply talking about the usefulness of the CMBR frame nobody would have objected. That is not what I was denying.

 

[RandallB]

Using the CMBR as a universal reference frame would be akin to the international date line, or the fact that red lights mean "stop", or right handed coordinate systems. All of those are very useful conventions, but nothing would be fundamentally different if we had chosen and agreed upon different conventions.

I have to disagree,
picking a place for the dateline is an arbitrary choice we make from our POV to establish a useful convention. What other arbitrary choice can we make to serve as an equivalent but different perspective than what we get from the CBR? IMO there is nothing arbitrary about the CBR, it is a fact presented to us by nature. And if we are to believe our interpretation of nature as our universe having a single beginning with what we define as the Big Bang and the CBR as coming from the resulting SLS, it gives us as far as I know the only know instance of simultaneous events we can see form our local view that is “outside the box” of the SR- simultaneity rule.

That does not automatically say it will resolve to something as “Absolute” or “Universal”. But IMO it rates more than just thinking it was some arbitrary reference choice that we somehow had a hand in picking.

 

[Dale]

I have to disagree,
picking a place for the dateline is an arbitrary choice we make from our POV to establish a useful convention. What other arbitrary choice can we make to serve as an equivalent but different perspective than what we get from the CBR? IMO there is nothing arbitrary about the CBR, it is a fact presented to us by nature. And if we are to believe our interpretation of nature as our universe having a single beginning with what we define as the Big Bang and the CBR as coming from the resulting SLS, it gives us as far as I know the only know instance of simultaneous events we can see form our local view that is “outside the box” of the SR- simultaneity rule.

That does not automatically say it will resolve to something as “Absolute” or “Universal”. But IMO it rates more than just thinking it was some arbitrary reference choice that we somehow had a hand in picking.

Do you think that any of the laws of physics will be different in the CMBR frame than in any other frame? If not then it is an arbitrary convention.

Certainly, if you live near a mountain or some other prominent geographical feature it would be convenient to measure coordinates relative to that feature which is as you say "presented to us by nature". But that does not make any other choice less valid, nor does it make that choice any more fundamental. For the purposes of defining distances and times the CMBR is the cosomlogical equivalent of an easily identifiable landmark.

Defining the CMBR as "at rest" is every bit as arbitrary as defining the solar system, our local group, or some other object "presented to us by nature" to be at rest. Or as arbitrary as defining any of those things to be moving at some specific velocity.

 

[RandallB]

Do you think that any of the laws of physics will be different in the CMBR frame than in any other frame? If not then it is an arbitrary convention.

Certainly, if you live near a mountain or some other prominent geographical feature it would be convenient to measure coordinates relative to that feature which is as you say "presented to us by nature". But that does not make any other choice less valid, nor does it make that choice any more fundamental. For the purposes of defining distances and times the CMBR is the cosomlogical equivalent of an easily identifiable landmark.

Defining the CMBR as "at rest" is every bit as arbitrary as defining the solar system, our local group, or some other object "presented to us by nature" to be at rest. Or as arbitrary as defining any of those things to be moving at some specific velocity.

I do not think how we understand Physics and the Laws that define it is “Complete” (if they were we would have unification forces and QM & GR). So, yes I think CBR might yet be a part of changes some of what we think we know. What and how exactly some law may change is speculation at this level, it is just my opinion the CBR could contribute more to helping complete our understanding of physics.

I understand picking one mountain as a reference point over a second, third, or other mountain option certainly cannot be thought of as a fundamental reference point.
But certainly, Astrophysics seems to regard the CBR as fundamental, and I’ve yet to see anyone point out a second option for the fundamental reference CBR provides them. Thus I find no grounds to support claiming their using it as fundamental was in fact an arbitrary choice.

Unless you include a completely different interpretation of, or completely reject, how they interpret the Big Bang; I don’t see where you can justify these fundamental assumptions of Astrophysics as being arbitrary.
But, you are entitled to your opinion. We just have differences here.

 

[Dale]

Is GR not the fundamental theory accepted by the Astrophysics/Cosmology community? If so then you are incorrect to claim that they regard the reference frame of the CMBR as fundamental. According to GR the rest frame of the CMBR is no different than a reference frame where it is moving at some arbitrary velocity.

 

[RandallB]

Is GR not the fundamental theory accepted by the Astrophysics/Cosmology community? If so then you are incorrect to claim that they regard the reference frame of the CMBR as fundamental. According to GR the rest frame of the CMBR is no different than a reference frame where it is moving at some arbitrary velocity.

I would not call GR exclusively “THE FUNDAMENTAL THEORY” of Astrophysics/Cosmology. Just one of the fundamental theories Astrophysics/Cosmology uses. Much of the conclusions drawn by them depends on the chemistry in space which is based on the Standard Model and therefore the fundamental theory of QM. Meaning it accepts working with two theories that are fundamentally incompatible.

Now a significant part of what the Astrophysics/Cosmology community tells us about the history of our reality, especially as it relates to the sequence of events following the Big Bang up to when stars first began to form, is fundamentally based on the Big Bang including how that unique point of view cannot be replace by any arbitrarily chosen frame of reference.
To the extent that means they may well be working with three fundamental theories (by adding Big Bang CMR as something new) each in some respect incompatible with the others that is OK by me.

IMO your opinion requires rejecting the proposed reactions, interactions and formation of fundamental particles like quarks proceeding to the formation neutrons, protons, etc as not plausible.
Although that theory of fundamental particle and force development may not by 100% on the mark and complete; I consider to be largely correct and take to be very plausible. Thus I cannot reject the Big Bang or the uniqueness of a fundamental SLS benchmark as used in Astrophysics/Cosmology.

That remains my opinion. To the extend you can minimize the value of the Big Bang and the early history implied by it we just have different opinions. I only ask you give mine sincere consideration before rejecting it. However, unless you have something additional to offer to support it, I cannot adopt yours.

 

[Idjot]

I would not call GR exclusively “THE FUNDAMENTAL THEORY” of Astrophysics/Cosmology. Just one of the fundamental theories Astrophysics/Cosmology uses. Much of the conclusions drawn by them depends on the chemistry in space which is based on the Standard Model and therefore the fundamental theory of QM. Meaning it accepts working with two theories that are fundamentally incompatible.

Now a significant part of what the Astrophysics/Cosmology community tells us about the history of our reality, especially as it relates to the sequence of events following the Big Bang up to when stars first began to form, is fundamentally based on the Big Bang including how that unique point of view cannot be replace by any arbitrarily chosen frame of reference.
To the extent that means they may well be working with three fundamental theories (by adding Big Bang CMR as something new) each in some respect incompatible with the others that is OK by me.

IMO your opinion requires rejecting the proposed reactions, interactions and formation of fundamental particles like quarks proceeding to the formation neutrons, protons, etc as not plausible.
Although that theory of fundamental particle and force development may not by 100% on the mark and complete; I consider to be largely correct and take to be very plausible. Thus I cannot reject the Big Bang or the uniqueness of a fundamental SLS benchmark as used in Astrophysics/Cosmology.

That remains my opinion. To the extend you can minimize the value of the Big Bang and the early history implied by it we just have different opinions. I only ask you give mine sincere consideration before rejecting it. However, unless you have something additional to offer to support it, I cannot adopt yours.

Please keep arguing! I'm learning as you reply to him! Haha Thanks.

 

[russ_watters]

But certainly, Astrophysics seems to regard the CBR as fundamental, and I’ve yet to see anyone point out a second option for the fundamental reference CBR provides them.

Could you explain what you mean by "fundamental" in this context?

Heck, is the CMB even really a reference frame? It is a reference for zeroing a velocity, but it has no intrinsic xyz coordinate reference, unlike the prime meridian, which is one axis of a two-axis coordinate system and stationary.

And the date line may be completely arbitrary, but the equator is not. The equator (and the poles) couldn't be arbitrarily located anywhere else. Does that have implications for your usage of the word "fundamental"?

 

[Dale]

I would not call GR exclusively “THE FUNDAMENTAL THEORY” of Astrophysics/Cosmology. Just one of the fundamental theories Astrophysics/Cosmology uses. Much of the conclusions drawn by them depends on the chemistry in space which is based on the Standard Model and therefore the fundamental theory of QM. Meaning it accepts working with two theories that are fundamentally incompatible.

The principle of relativity is an integral part of both theories (GR and the SM). So I don't understand how you can make the leap from GR and the SM are fundamentally incompatible to the conclusion that one of the things that they do agree on is wrong. Neither of these two fundamental theories of astrophysics/cosmology support your claim that the rest frame of the CMBR would be anything more than a convenience.

The topic of this thread is simply whether the rest frame of the CMBR represents a "true" time or if it would merely be a convenient convention. Accepting the premise that it is anything other than a convenience is a rejection of the principle of relativity, which is certainly not supported by the theories used by the astrophysics community.

IMO your opinion requires rejecting the proposed reactions, interactions and formation of fundamental particles like quarks proceeding to the formation neutrons, protons, etc as not plausible.

I don't know how you conclude that I reject the Big Bang or any of the fundamental particles. You are way off-base here.

 

[RandallB]

The principle of relativity is an integral part of both theories (GR and the SM).

I don’t understand this sentence, it offers nothing to this debate. It seems to say SM is a relativity theory but still calls it one of “both theories”. SM is fundamentally a QM theory that to the best that a QM theory can, it tries to respect the principle of relativity. But I know of no one that considers SR/GR and SM/QM as compatible, they are two independent view with fundamentally incompatible ideas of how gravity works. If we are not on the same page here then there we are having an argument (seems to delight Idgot) and I am not interested in dealing with augmentative rhetoric so let's try to this a rational debate.

… how you can make the leap from GR and the SM are fundamentally incompatible to the conclusion that one of the things that they do agree on is wrong. Neither of these two fundamental theories of astrophysics/cosmology support your claim that the rest frame of the CMBR would be anything more than a convenience.

You are repeating my point here. As we both say nether SR/GR or SM/QM can directly support or define the idea that the Big Bang and nearby events to it can be taken as a single simultaneous event relative to our view 14 Billion years later. And yet Astrophysics/Cosmology takes as a fundamental truth that the SLS events are simultaneous much like as Russ puts it, the equator or pole locations have a fundamental truth about where they are located and cannot be arbitrarily positioned anywhere on a spinning globe.

The topic of this thread is simply whether the rest frame of the CMBR represents a "true" time or if it would merely be a convenient convention. Accepting the premise that it is anything other than a convenience is a rejection of the principle of relativity, which is certainly not supported by the theories used by the astrophysics community.
I don't know how you conclude that I reject the Big Bang or any of the fundamental particles. You are way off-base here.

I didn’t say your claim would lead to rejecting the existence of any fundamental particles, I said it would reject how the astrophysics community explains they were created.

I understand the OP, what we a debating is your assertion that the OP idea should not even be considered because the astrophysics community use of the SLS was an “arbitrary choice”. My point is that astrophysics/cosmology use of SLS is not arbitrary but recognizes it as a fundamental thing that allows them to build the early history of how fundamental particles were made.

Now if all we have left is an argument about which opinion is better than this discussion was done a few posts ago – we have different opinions and I have no interest in arguing about it, that’s non-productive.

But if you have a debatably point that you think can change my opinion I’m willing to continue as a debate, but not an argument. For that you need to answer my question from post 56 :

“What other arbitrary choice can we make to serve as an equivalent but different perspective than what we get from the CBR?”
Include with that how this alternate “mountain” choice can be used by astrophysics/cosmology to build a new description that is:
A) Still identical to the currently defined Big Bang history.
or
B) Builds an alternative to the Big Bang and the history of particle creation it defines that is considered by anyone to be viable.

Unless there are such addition choices the way astrophysics/cosmology uses CBR & SLS is “Fundamental” and that is the extent of my point.

How or IF that might impact on ideas about “Absolute” or “Universal” time is a topic for Journal Papers. But I cannot deny anyone in astrophysics the right to consider it.

 

[Aether]

My point is that astrophysics/cosmology use of SLS is not arbitrary but recognizes it as a fundamental thing that allows them to build the early history of how fundamental particles were made.

The SLS is calculated using GR (FLRW metric + GR --> Friedmann equations, Friedmann equations + CMBR --> SLS). How would you know that there was an SLS without GR?

 

[Idjot]

The SLS is calculated using GR (FLRW metric + GR --> Friedmann equations, Friedmann equations + CMBR --> SLS). How would you know that there was an SLS without GR?

1. You use a shovel to unearth a buried rock.
2. You use a wet saw to cut that rock into pieces.
3. You use a microscope to study the pieces.

Maybe GR was the shovel here.

 

[JesseM]

I don’t understand this sentence, it offers nothing to this debate. It seems to say SM is a relativity theory but still calls it one of “both theories”. SM is fundamentally a QM theory that to the best that a QM theory can, it tries to respect the principle of relativity. But I know of no one that considers SR/GR and SM/QM as compatible

Everyone recognizes that SM/QM are fundamentally not compatible with GR (one reason is that in quantum theories, the Planck scale should be associated with large energy fluctuations which in GR would themselves contribute significantly to the curvature of spacetime on those scales, but existing quantum theories assume a fixed background spacetime--see http://64.233.169.104/search?q=cache:96vSRqNGD6AJ:hyperphysics.phy-astr.gsu.edu/Hbase/quantum/string.html+%22conflict+between+the+uncertainty+principle+and+general+relativity%22&hl=en&ct=clnk&cd=1&gl=us for a discussion). However, the Standard Model and quantum field theories in general are both compatible with SR (which does not assume energy curves spacetime) because they are Lorentz-invariant theories. So, an absolute definition of simultaneity is every bit as incompatible with the Standard Model as it is with SR.

And yet Astrophysics/Cosmology takes as a fundamental truth that the SLS events are simultaneous much like as Russ puts it

No it doesn't. Where did you get the idea that cosmologists could not analyze the surface of last scattering in a coordinate system where different points on the surface are non-simultaneous? I'm sure it is most convenient to use a coordinate system where all points on this surface are assigned the same time-coordinate, but there are no fundamental physical considerations that forbid you from using other coordinate systems.

 

[RandallB]

The SLS is calculated using GR (FLRW metric + GR --> Friedmann equations, Friedmann equations + CMBR --> SLS). How would you know that there was an SLS without GR?

I don’t see your point. - - Did you think I’d denied SR/GR was used by astrophysics?
I think I was clear that they use both SR/GR and SM/QM.

My contention is that they are successfully using not only those two theories while they are technically incompatible (yet to be unified on the gravity issue) with each other. And my main point is that astrophysics use of SLS is not an arbitrary selection of a reference point. But that they fundamentally recognize the Big Bang and the SLS as we observe it as effectively from our POV sourced from simultaneous events. And they depend upon using all three things without allowing anyone of them to invalidate either of the other two.

I suppose I should acknowledge they did not need modern CBR observations to develop this mixed view of reality. The Hubble expansion model modified how they applied GR (with was approved of by Einstein) that lead to the development of the big Bang Bang idea before the SLS was indentified. Prior to the SLS and CRB they were using the distant star background in much the same way they now define SLS.

And again:
I already asked what arbitrary selection of a reference point differing from a fundamental use of all SLS points coming from simultaneous events, would allow astrophysics to define the early Timeline of Cosmology as they have.

No one has provided one yet.
So the rest is just argumentative rhetoric, that will not change my opinion.
It is a legit question so unless someone cares to address it seriously I choose not to continue this further – it can only turn to pointless arguments and IMO that is not the purpose of PF.

 

[JesseM]

But that they fundamentally recognize the Big Bang and the SLS as we observe it as effectively from our POV sourced from simultaneous events. And they depend upon using all three things without allowing anyone of them to invalidate either of the other two.

Totally wrong. Again, GR allows you to use any coordinate system and still get the same predictions about all empirical observations like how the CMBR will look from our perspective--nothing would stop you from using a coordinate system where different points on the surface of last scattering were non-simultaneous, it wouldn't have any effect on predictions about how the CMBR looks.

 

[Aether]

I don’t see your point. - - Did you think I’d denied SR/GR was used by astrophysics?

Do you want to consider the SLS as being outside of the context of GR? How would you know that there was an SLS without GR?

And again:
I already asked what arbitrary selection of a reference point differing from a fundamental use of all SLS points coming from simultaneous events, would allow astrophysics to define the early Timeline of Cosmology as they have. No one has provided one yet.

The definition of simultaneity in the FLRW metric, which comes from assuming that the universe is spatially homogeneous, is the only justification that I know of for taking all SLS points to be simultaneous. Do you know of another justification? We could easily change the FLRW metric around, compute modified versions of the Friedmann equations, and then show the SLS as something that looks quite different; no problem. The real questions are "what are dark matter and dark energy?", which are both required to project the CMBR back onto a SLS.

So the rest is just argumentative rhetoric, that will not change my opinion.
It is a legit question so unless someone cares to address it seriously I choose not to continue this further – it can only turn to pointless arguments and IMO that is not the purpose of PF.

Can you show how to find/detect/model/describe the SLS without first assuming that the universe is spatially homogeneous? It isn't just argumentative rhetoric to point out that the concept of an (symmetric) SLS is based mathematically on a certain definition of simultaneity, and that you're limited by that definition unless you can describe the SLS without making that assumption.