the notion of ether, absolute speed of light, absolute speed of objects, absolute dimensions of objects, absolute simultaneity, along with the spontaneous mental representation of space and time in 3D plus absolute time, are all natural and obvious way of human mind to see, represent and communicate the reality around us.
and it is how nature really behaves, here, now and everywhere.

to me this is not to dispute, its objectivity is obvious, the obvious is based only in the our immediate intuition.

said the above, for the ones who are still reading, I want to describe a way to detect the absolute motion for an inertial moving observer, based on a visual phenomenon easy to, mentally, visualize: assuming the follows:
absolute SOL, absolute contraction of the ruler, absolute speed of ruler in fraction of SOL(SOL=speed of light):

we put a ruler in front of our eye, the incoming light will cross the ruler from the far end of the ruler to our eye, if we are moving at v approaching the light, the ruler lenght will appear as having a apparent visual length of:
sqrt(1-v^2)/(1+v), see the drawing:
https://digilander.libero.it/bedaalpi/images/visual.ruler.at.6C.JPG

instead, if we are moving in the opposite direction: receding from the incoming light then the visual appearance of the ruler will be:
sqrt(1-v^2)/(1-v):
https://digilander.libero.it/bedaalpi/images/visual.ruler.at.6C1.JPG

now hoping you are able to see the drawings, and be able to grasp their content, the conclusion:
in a closed lab, the moving observer would not see any difference
around him, the ruler, yet visually contracted or enlonged, he cannot be aware of it: has not any comparison possible to make.

if he is in the open, the effects of the contracted or enlonged ruler, would be: the stationary universe in the front of him, in the direction of the movement, will appear further away and concentrate ahead of him.

in the opposite direction of the movement, the stationary universe will appear nearer and squashed on him.

the phenomenon described above enable any inertialy moving observer to be perfectly aware of his absolute movement, given that the universe is uniform, any visual anisotropy implies an absolute movement.

actually the ruler is not necessary: a moving observer automatically would see the "stationary" universe around him be compared against its comoving objects and appear visually distorted as described above.

cheers
beda

On Friday, May 14, 2021 at 8:54:10 AM UTC-7, beda-p...@libero.it wrote:
> snip imbecilities<

On Friday, May 14, 2021 at 8:54:10 AM UTC-7, beda-p...@libero.it wrote:
> I want to describe a way to detect the absolute motion for an inertial moving observer...

But you haven't done that. All you have noted is that, due to local Lorentz invariance, there is an essentially unique local system of inertia-based coordinates around any event in terms of which the CMBR and the incident light from distant galaxies are both maximally isotropic. This is not only consistent with Lorentz invariance, it is a *consequence* of Lorentz invariance. And the way in which the local inertial coordinate systems merge into a global system (and also the local effects of gravity) are in accord with general relativity, which of course is founded on local Lorentz invariance too.

> actually the ruler is not necessary...

Right, the whole thing with the ruler is obviously completely superfluous (so why did you type it?). You are just declaring that you assign the word "pink" or "absolute" to the inertia-based coordinates in terms of which the CMBR is isotropic. As explained many times, this is perfectly consistent with local Lorentz invariance. No ether drag has ever been detected. Instead, we have established that every quantity of energy E has inertia E/c^2, which implies local Lorentz invariance.

On 5/14/21 10:54 AM, beda pietanza wrote:
> to me this is not to dispute, its objectivity is obvious, the obvious
> is based only in the our immediate intuition.

Which means you are not doing science, you are creating your own
religion. That's useless, and completely unrelated to the world we inhabit.

I have no interest in religious disputes with fools like you. Goodbye.

Tom Roberts

Il giorno sabato 15 maggio 2021 alle 06:27:22 UTC+2 Cliff Hallston ha scritto:
> On Friday, May 14, 2021 at 8:54:10 AM UTC-7, beda-p...@libero.it wrote:
> > I want to describe a way to detect the absolute motion for an inertial moving observer...
>
> But you haven't done that. All you have noted is that, due to local Lorentz invariance, there is an essentially unique local system of inertia-based coordinates around any event in terms of which the CMBR and the incident light from distant galaxies are both maximally isotropic. This is not only consistent with Lorentz invariance, it is a *consequence* of Lorentz invariance. And the way in which the local inertial coordinate systems merge into a global system (and also the local effects of gravity) are in accord with general relativity, which of course is founded on local Lorentz invariance too.
beda
but I am not speaking of a observer associated to a SR frame
I am speaking of an observer that is moving inertialy in space on his own,
this observer when looking ahead of his movement, he sees all the universe in front of him appear far away and concentrate in front of him,
if he looks instead, in the opposite direction, he sees all the universe in the back, appear nearer and squished towards him
this phenomenon is more and more intense as the inertial speed is higher,
which indicate to the inertial observer the entity of his absolute movement..

I used the ruler put between the eye of the observer and the incoming light to make it easy and evident this visual effect.

now, if we consider an observer comoving, or at rest, in his SR frame, nothing at all changes of what he sees of the surrounding outer universe, he will still see the part of the universe in the direction of his movement more distant, and the part of the universe in the opposite direction more closer to him.

Of course, if the moving observer is enabled to detect his absolute speed, this implies that all possible frame can have their clocks adjusted to the preferred rate and have them absolutely synched, so all absolute frames can go at a unique absolute time.

just an addendum, we can consider how a inertial moving observer see a incoming light, carrying information about a ruler, after this light has traversed a ruler going at a different speed situated along his line of sight, this is also interesting, we will encounter well known figures given by the Doppler effect on light, the visual effect that I am describing is, practically, a visual Doppler effect applied on rulers and objects (visual apparent) length.

>
> > actually the ruler is not necessary...
>
> Right, the whole thing with the ruler is obviously completely superfluous (so why did you type it?). You are just declaring that you assign the word "pink" or "absolute" to the inertia-based coordinates in terms of which the CMBR is isotropic. As explained many times, this is perfectly consistent with local Lorentz invariance. No ether drag has ever been detected. Instead, we have established that every quantity of energy E has inertia E/c^2, which implies local Lorentz invariance.
beda
be careful here, the visual appearance of the outer universe is not a local physical phenomenon that undergoes to your local Lorentz invariance, what the observer "sees" is determined, only, by the combine of his absolute inertial speed and the absolute speed of the light, and it is completely independent of anything else.
I don't quite understand what you mean by "no drag of the ether has been detected", if you agree on the phenomenon I am describing, can we conclude that a inertialy moving observer "sees" with his eyes the ether passing by him and bending the incoming light from sideways of his movement generating the known effect called aberration of light.
the "visual Doppler and the aberration of light" are the same phenomenon seen one in the direction of the movement and the other orthogonality of the movement.
cheers
beda

On Saturday, May 15, 2021 at 2:19:43 PM UTC-7, beda-p...@libero.it wrote:
> I am speaking of an observer that is moving inertialy...

I know, and as explained before, there is an essentially unique state of motion at any time and place for which the frequency of the incident CMBR is maximally isotropic, as is the light from the distant galaxies. (To assess directions in order to evaluate the isotropy requires at least a projective system of coordinates, but your brain is incapable of grasping this, so you can never hope to really understand this subject.) This is perfectly consistent with special relativity. In fact, we use special relativity to compute the anisotropy as a function of the velocity relative to that distinguished state of motion.

> Of course, if the moving observer is enabled to detect his absolute speed....

Correction, you are referring to the speed relative to the system of inertial coordinates in terms of which the local CMBR is maximally isotropic. Assigning it the label "pink" or "splendiferous" for "absolute" is just empty semantic posturing with no scientific content. Remember?

> this implies that all ... clocks [can be] adjusted to the [CMBR isotropic frame]...

*Of course* they can. They can also be adjust to the rest frame of your navel. Of to the inertial coordinates in which they are at rest. Or to any other system of inertial coordinates. In fact, they can be adjusted to match non-inertial coordinates, or even to match no well-defined coordinates at all. Again, there is a very special and distinguished class of coordinate systems, called inertia-based coordinates, in terms of which all the laws of physics take the same homogeneous and isotropic form. Nothing you have said contradicts this fundamental and profound symmetry, and you yourself make essential use of this symmetry.

> The visual appearance of the outer universe is not a local physical phenomenon
> that undergoes to your local Lorentz invariance...

You are, as always, mistaken. At any location, the relativistic Doppler and aberration formulas give the frequency and angular difference between any two given systems of *local* inertial coordinates at a given time and place. This is entirely a local transformation. Of course, the distribution of the galaxies throughout space is global and requires a coordinate system to describe, as explained to you previously, but you complained that it overwhelmed your brain to try to grasp the actual spatial distribution (coordinates), so you insisted you were only talking about the incident light for a given world line.

> I don't quite understand what you mean by "no drag of the ether has been detected",

An object not subjected to any external forces via known laws of physical interactions (which are all Lorentz invariant) undergoes no acceleration at all, and this has been verified for objects up to 0.99999c, and even for speeds up to second order in v/c for planets and stars. No ether drag has ever been detected.

> A inertialy moving observer "sees" with his eyes the ether passing by him and
> bending the incoming light from sideways of his movement generating the known
> effect called aberration of light.

No, as always, you are grossly misinformed. Aberration is not any kind of bending or drag or acceleration, and it doesn't just apply to light, it applies to everything, including trajectories and orientations of solid objects. A trajectory or ruler has a certain direction in terms of one local system of inertial coordinates, and a different direction in terms of a different local system of inertial coordinates. The object does not bend, and the trajectory of motion does not bend, and neither of them accelerates. You simply *must* learn the basics of special relativity before trying to criticize it. Right now you head is filled with nothing but misinformation and misunderstanding.

Il giorno domenica 16 maggio 2021 alle 00:38:00 UTC+2 Cliff Hallston ha scritto:
> On Saturday, May 15, 2021 at 2:19:43 PM UTC-7, beda-p...@libero.it wrote:
> > I am speaking of an observer that is moving inertialy...
>
> I know, and as explained before, there is an essentially unique state of motion at any time and place for which the frequency of the incident CMBR is maximally isotropic, as is the light from the distant galaxies. (To assess directions in order to evaluate the isotropy requires at least a projective system of coordinates, but your brain is incapable of grasping this, so you can never hope to really understand this subject.) This is perfectly consistent with special relativity. In fact, we use special relativity to compute the anisotropy as a function of the velocity relative to that distinguished state of motion.
>
> > Of course, if the moving observer is enabled to detect his absolute speed...
>
> Correction, you are referring to the speed relative to the system of inertial coordinates in terms of which the local CMBR is maximally isotropic. Assigning it the label "pink" or "splendiferous" for "absolute" is just empty semantic posturing with no scientific content. Remember?
>
> > this implies that all ... clocks [can be] adjusted to the [CMBR isotropic frame]...
>
> *Of course* they can. They can also be adjust to the rest frame of your navel. Of to the inertial coordinates in which they are at rest. Or to any other system of inertial coordinates. In fact, they can be adjusted to match non-inertial coordinates, or even to match no well-defined coordinates at all. Again, there is a very special and distinguished class of coordinate systems, called inertia-based coordinates, in terms of which all the laws of physics take the same homogeneous and isotropic form. Nothing you have said contradicts this fundamental and profound symmetry, and you yourself make essential use of this symmetry.
>
> > The visual appearance of the outer universe is not a local physical phenomenon
> > that undergoes to your local Lorentz invariance...
>
> You are, as always, mistaken. At any location, the relativistic Doppler and aberration formulas give the frequency and angular difference between any two given systems of *local* inertial coordinates at a given time and place. This is entirely a local transformation. Of course, the distribution of the galaxies throughout space is global and requires a coordinate system to describe, as explained to you previously, but you complained that it overwhelmed your brain to try to grasp the actual spatial distribution (coordinates), so you insisted you were only talking about the incident light for a given world line.
> > I don't quite understand what you mean by "no drag of the ether has been detected",
> An object not subjected to any external forces via known laws of physical interactions (which are all Lorentz invariant) undergoes no acceleration at all, and this has been verified for objects up to 0.99999c, and even for speeds up to second order in v/c for planets and stars. No ether drag has ever been detected.
>
> > A inertialy moving observer "sees" with his eyes the ether passing by him and
> > bending the incoming light from sideways of his movement generating the known
> > effect called aberration of light.
> No, as always, you are grossly misinformed. Aberration is not any kind of bending or drag or acceleration, and it doesn't just apply to light, it applies to everything, including trajectories and orientations of solid objects. A trajectory or ruler has a certain direction in terms of one local system of inertial coordinates, and a different direction in terms of a different local system of inertial coordinates. The object does not bend, and the trajectory of motion does not bend, and neither of them accelerates. You simply *must* learn the basics of special relativity before trying to criticize it. Right now you head is filled with nothing but misinformation and misunderstanding.
beda
there is an observer that can be at rest versus the CMBR, in open space away from near masses,
this observer is in a privileged condition: for him light is isotropic, all object inertialy moving in the area around this privileged observer can refer to him,
this condition is not shared by no other observer having different inertial speed versus the CMBR.

since you are interested in symmetries and invariance, you build a set of coordinate systems ad och to achieve them, you can enjoy your game, I am not interested in that for the moment.

since I only want to understand what happens to a ruler and a clock when they are inertialy moving, any change in their characteristics are to be compared to themselves when they were at rest at rest,
and I assume that when inertialy moving a ruler shorten from 1 to sqrt(1-v^2) and the clock rate drops from 1 to sqrt(1-v^2): it seems that, for low terrestrial speed, this is true.

I base all my reasoning on this simple scheme.

now, let us look at your peculiar SR frames, you claim that those frames are characterised for being based upon the isotropy of inertia,
I pictured them as follow:
an object of a unit of mass being at rest (in CMBR) is accelerated by a thrust of a unitary intensity to a inertial speed v, then again the mass is accelerated to a new inertial speed by the same thrust, and again and again,
the plot of the increasing speed versus the unitary intensity of the thrust is asymptotically reaching a limit=c, the efficacy of the thrust is less and less effective in producing an increasing of the speed of the accelerated mass.
you assign at each possible speed a inertial SR frame, in that frame you assume that the inertia is isotropic.
see if you agree in this my picture of your SR scheme.

now, since I don't believe that the laws of physics (empirically experimented using a system of reference at terrestrial speeds) can be extended to all range of speeds from 0 to c,
in my attempt of understanding what is going on, I stick to the most simplistic conditions : the unicity of the local speed of light, the local preferred frame and the Lorentz conjecture ( prudentially limitated to low speeds)

cheers
beda

On Sunday, May 16, 2021 at 2:52:51 PM UTC-7, beda-p...@libero.it wrote:
> There is an observer that can be at rest versus the CMBR, ...for him light is isotropic

It's incorrect to say "at rest versus the CMBR", because the background radiation is moving in every direction, so it has no coherent frame of reference. The second clause is the correct one, i.e., at any event there is a trajectory for which the incident CMBR (and light from galaxies) is maximally isotropic. This is what I've been telling you all along. It is entirely consistent with local Lorentz invariance. In fact, we can compute the anisotropy versus speed in terms of the CMBR isotropic frame using special relativity.

> I assume that when inertially moving a ruler shorten from 1 to sqrt(1-v^2) and the
> clock rate drops from 1 to sqrt(1-v^2)...

To be correct, in terms of any given system of inertial coordinates in which a ruler and clock are moving at speed v, we have L/L0 = dtau/dt = sqrt(1-v^2/c^2) where L0 is the length of the ruler in terms of inertial coordinates in which it is at rest. This has been demonstrated in terms of many different systems of inertial coordinates, although *not* (to my knowledge) in terms of the CMBR isotropic coordinates.

> it seems that, for low terrestrial speed, this is true.

Not just for low speeds, and not just in terms of the CMBR isotropic coordinates. These things have been evaluated for speeds of aggregates of hundreds of elementary particles up to 0.999999c in terms of the CMBR isotropic coordinates, and have also been evaluated up to second order in v/c for speeds in terms of coordinate systems moving relative to the CMBR isotropic coordinates (such as on earth moving at 67000 mph around the sun, and at 1% of the speed of light cosmically, and stars moving at 8% of the speed of light). Also, all the laws of physics for fundamental entities and their interactions have been verified for speeds up to 0.999999c, and since those laws are Lorentz invariant, this signifies that the laws of physics take the same isotropic and homogeneous form in terms of every system of inertia-based coordinates. There is no ether drag. Your denialist fantasies are thoroughly falsified.

> The efficacy of the thrust is less and less effective in producing an increasing
> of the speed of the accelerated mass.

The acceleration of an object, in terms of any given system of inertial coordinates, resulting from the application of a given amount of force to the object is lower at high speeds because the inertia of the object increases in proportion to its increased kinetic energy. Work is the product of force and distance, and the amount of work done to accelerate a mass m to speed v is mc^2[(1/sqrt(1-v^2/c^2) - 1]. This has been shown to be correct to speeds up to 0.999999c, even in terms of the earth's system of coordinates which are moving at significant speed relative to the CMBR isotropic coordinates. There is no ether drag.

> You assign at each possible speed a inertial SR frame, in that frame you assume
> that the inertia is isotropic.

That isn't an assumption, it is a demonstrated fact.

> now, since I don't believe that the laws of physics (empirically experimented using a
> system of reference at terrestrial speeds) can be extended to all range of speeds from 0 to c,

But your misunderstanding about this has been explained to you countless times. Remember, all the fundamental laws of physics governing the fundamental entities *and their interactions* have been demonstrated for speeds up to 0.99999c in terms of the lab frame, and these laws are mathematically Lorentz invariant, which signifies that they take the same form when expressed in terms of any system of coordinates related to the lab coordinates by a Lorentz transformation. You are free to fantasize flying pink elephants will some day overturn these facts, but your fantasies have no scientific value.

Il giorno lunedì 17 maggio 2021 alle 01:01:36 UTC+2 Cliff Hallston ha scritto:
> On Sunday, May 16, 2021 at 2:52:51 PM UTC-7, beda-p...@libero.it wrote:
> > There is an observer that can be at rest versus the CMBR, ...for him light is isotropic
>
> It's incorrect to say "at rest versus the CMBR", because the background radiation is moving in every direction, so it has no coherent frame of reference. The second clause is the correct one, i.e., at any event there is a trajectory for which the incident CMBR (and light from galaxies) is maximally isotropic. This is what I've been telling you all along. It is entirely consistent with local Lorentz invariance. In fact, we can compute the anisotropy versus speed in terms of the CMBR isotropic frame using special relativity.
>
> > I assume that when inertially moving a ruler shorten from 1 to sqrt(1-v^2) and the
> > clock rate drops from 1 to sqrt(1-v^2)...
>
> To be correct, in terms of any given system of inertial coordinates in which a ruler and clock are moving at speed v, we have L/L0 = dtau/dt = sqrt(1-v^2/c^2) where L0 is the length of the ruler in terms of inertial coordinates in which it is at rest. This has been demonstrated in terms of many different systems of inertial coordinates, although *not* (to my knowledge) in terms of the CMBR isotropic coordinates.
> > it seems that, for low terrestrial speed, this is true.
> Not just for low speeds, and not just in terms of the CMBR isotropic coordinates. These things have been evaluated for speeds of aggregates of hundreds of elementary particles up to 0.999999c in terms of the CMBR isotropic coordinates, and have also been evaluated up to second order in v/c for speeds in terms of coordinate systems moving relative to the CMBR isotropic coordinates (such as on earth moving at 67000 mph around the sun, and at 1% of the speed of light cosmically, and stars moving at 8% of the speed of light). Also, all the laws of physics for fundamental entities and their interactions have been verified for speeds up to 0.999999c, and since those laws are Lorentz invariant, this signifies that the laws of physics take the same isotropic and homogeneous form in terms of every system of inertia-based coordinates. There is no ether drag. Your denialist fantasies are thoroughly falsified.
>
> > The efficacy of the thrust is less and less effective in producing an increasing
> > of the speed of the accelerated mass.
> The acceleration of an object, in terms of any given system of inertial coordinates, resulting from the application of a given amount of force to the object is lower at high speeds because the inertia of the object increases in proportion to its increased kinetic energy. Work is the product of force and distance, and the amount of work done to accelerate a mass m to speed v is mc^2[(1/sqrt(1-v^2/c^2) - 1]. This has been shown to be correct to speeds up to 0.999999c, even in terms of the earth's system of coordinates which are moving at significant speed relative to the CMBR isotropic coordinates. There is no ether drag.
>
> > You assign at each possible speed a inertial SR frame, in that frame you assume
> > that the inertia is isotropic.
> That isn't an assumption, it is a demonstrated fact.
> > now, since I don't believe that the laws of physics (empirically experimented using a
> > system of reference at terrestrial speeds) can be extended to all range of speeds from 0 to c,
> But your misunderstanding about this has been explained to you countless times. Remember, all the fundamental laws of physics governing the fundamental entities *and their interactions* have been demonstrated for speeds up to 0.99999c in terms of the lab frame, and these laws are mathematically Lorentz invariant, which signifies that they take the same form when expressed in terms of any system of coordinates related to the lab coordinates by a Lorentz transformation. You are free to fantasize flying pink elephants will some day overturn these facts, but your fantasies have no scientific value.
beda
look cliff, there is a kind of absolute rest, the one experienced by an observer that sees the incoming light from all direction almost isotropic, from that condition macroscopic bodies can be send at different speeds, light can be send at c in all directions,.

this condition is unique for the observer at rest versus the incoming isotropic light

now the fact that you build a special class of frames that all mock the condition of that privileged observer, it is possible locally, but the preferred observer can tell that each of them are characterised uniquely by their
two ways time travel of light along a ruler being 2sqrt(1-v^2)/(1-v^2).

from this reality above we can discuss anything, any other arrangement or procedure, but the above preferred condition of a preferred observer is not associated to any theoretic scheme it is a pure raw physical fact to start with.
cheers
beda

On Monday, May 17, 2021 at 3:17:40 PM UTC-7, beda-p...@libero.it wrote:
> There is a kind of absolute rest, the one experienced by an observer that sees the
> incoming light from all direction almost isotropic...

You are simply defining the phrase "absolute rest" to refer to the inertial coordinates in terms of which the CMBR and light from galaxies are maximally isotropic. The point is that there is no physically meaningful content in assigning the words "absolute rest" to those coordinates. It changes nothing about what those coordinates represent, and of course it is perfectly consistent with local Lorentz invariance.

> You build a special class of frames that all mock the condition of that privileged observer...

Not at all. What is unique about the CMBR isotropic coordinates is that the CMBR is isotropic in terms of those coordinates. The CMBR is not isotropic in terms of other inertial coordinate systems. Likewise the Sun is at rest in terms of the unique system of inertial coordinates in which the Sun is at rest, but the Sun is not at rest in terms of other systems of inertial coordinates. An observer may (or may not) consider himself to be "privileged" to be at rest in terms of the same system of coordinates in which the Sun is at rest, but that is a subjective application of the concept of "privilege".

What all inertial coordinate systems have in common is not how the matter and radiation of the universe is described in terms of those systems, but the fact that the fundamental laws of physics (including inertia) take the same homogeneous and isotropic form in terms of every such system. In this sense, they are all symmetrical.

> It is possible locally, but the preferred observer can tell that each of them are characterised
> uniquely by their two ways time travel of light along a ruler being 2sqrt(1-v^2)/(1-v^2).

No, that is dimensionless, where as the time of travel must have units of time. (Duh.) Let L0 denote the length of the ruler in terms of inertial coordinates in which it is at rest, and let this ruler be moving at speed v (longitudinally) in terms of *any* system S of inertial coordinates x,t. Then the two-way time of travel in terms of S is dt = 2*L0/sqrt(c^2 - v^2). Of course, letting L denote the spatial length of the ruler in terms of S, the time is dt = 2Lc/(c^2 - v^2). This all applies to *any* system of inertial coordinates S, not just to the one in which the Sun is at rest, nor the one in which the CMBR is isotropic.

Now do you understand your mistake?

Il giorno martedì 18 maggio 2021 alle 01:21:49 UTC+2 Cliff Hallston ha scritto:
> On Monday, May 17, 2021 at 3:17:40 PM UTC-7, beda-p...@libero.it wrote:
> > There is a kind of absolute rest, the one experienced by an observer that sees the
> > incoming light from all direction almost isotropic...
>
> You are simply defining the phrase "absolute rest" to refer to the inertial coordinates in terms of which the CMBR and light from galaxies are maximally isotropic. The point is that there is no physically meaningful content in assigning the words "absolute rest" to those coordinates. It changes nothing about what those coordinates represent, and of course it is perfectly consistent with local Lorentz invariance.
>
> > You build a special class of frames that all mock the condition of that privileged observer...
>
> Not at all. What is unique about the CMBR isotropic coordinates is that the CMBR is isotropic in terms of those coordinates. The CMBR is not isotropic in terms of other inertial coordinate systems. Likewise the Sun is at rest in terms of the unique system of inertial coordinates in which the Sun is at rest, but the Sun is not at rest in terms of other systems of inertial coordinates. An observer may (or may not) consider himself to be "privileged" to be at rest in terms of the same system of coordinates in which the Sun is at rest, but that is a subjective application of the concept of "privilege".
>
> What all inertial coordinate systems have in common is not how the matter and radiation of the universe is described in terms of those systems, but the fact that the fundamental laws of physics (including inertia) take the same homogeneous and isotropic form in terms of every such system. In this sense, they are all symmetrical.
beda
you jump immediately into your SR mental trap.
just take a ruler and a clock as standards, any, go in space away from near masses, there check that light comes istropically from all directions.
you are in a privileged conditions, you will see the universe uniform in its visual appearance: light is arriving at you isotropically speed wise and energy wise.
no other obserever, in the same basic condition, can experience such peculiarities, the SR arrangement is only locally
equivalent, the inertially moving observer will visually see the outer universe altered, in any cases.
as I keep telling you, this basic acknowledgement is fundamental for any rational analysis of any empiric, operative or heuristic procedure, from this basis we have a solid common ground to set back and restart constructively in any logical direction.

>
> > It is possible locally, but the preferred observer can tell that each of them are characterised
> > uniquely by their two ways time travel of light along a ruler being 2sqrt(1-v^2)/(1-v^2).
> No, that is dimensionless, where as the time of travel must have units of time. (Duh.) Let L0 denote the length of the ruler in terms of inertial coordinates in which it is at rest, and let this ruler be moving at speed v (longitudinally) in terms of *any* system S of inertial coordinates x,t. Then the two-way time of travel in terms of S is dt = 2*L0/sqrt(c^2 - v^2). Of course, letting L denote the spatial length of the ruler in terms of S, the time is dt = 2Lc/(c^2 - v^2). This all applies to *any* system of inertial coordinates S, not just to the one in which the Sun is at rest, nor the one in which the CMBR is isotropic.
>
> Now do you understand your mistake?
beda
that is you that are circling endlessly into your SR trap
before any choice of a measuring procedure you must
have a clear vision of what is the raw physical phenomenon you are approaching.
out of such a vision you are groundless: you can construct an
illimited number of models, that mocking the reality behavior, don't give you any
explanation of the model it self, nor of the reality the model is representing.

so, you SR scheme can have some resemblance of plausibility, only including
the presence of a preferred frame as part of the class of your SR frame, with its unicity
and explanatory power, and in doing so, the physical concrete limit of the SR applicability would
emerge clearly to you.

cheers
beda

On Tuesday, May 18, 2021 at 3:23:58 AM UTC-7, beda-p...@libero.it wrote:
> you jump immediately into [explaining special relativity]...

As always, you missed the point. Remember, you falsely claimed that inertial coordinate systems "mock the condition of the privileged" coordinate system, and I pointed out that you are mistaken, because inertial coordinate systems do not in general have isotropic CMBR radiation, which is the unique "condition" of the CMBR frame. Likewise the frame in which the Sun is at rest is unique for the Sun being at rest. Duh. But what all inertial coordinate systems have in common is that the laws of physics take the same form in terms of all of them, and in this sense they are perfectly symmetrical..

> As I keep telling you, acknowledging [invisible flying pink elephants that violate conservation
> of momentum] is fundamental for any rational analysis...

No, it's insane. If it was fundamental for any rational analysis, you would be able to explain why, but every time you attempt it, you just reveal another blatant misunderstanding.

> > > It is possible locally, but the preferred observer can tell that each of them are characterised
> > > uniquely by their two ways time travel of light along a ruler being 2sqrt(1-v^2)/(1-v^2).
> >
> > No, that is dimensionless, where as the time of travel must have units of time. (Duh.) Let L0 denote the length of the ruler in terms of inertial coordinates in which it is at rest, and let this ruler be moving at speed v (longitudinally) in terms of *any* system S of inertial coordinates x,t. Then the two-way time of travel in terms of S is dt = 2*L0/sqrt(c^2 - v^2).. Of course, letting L denote the spatial length of the ruler in terms of S, the time is dt = 2Lc/(c^2 - v^2). This all applies to *any* system of inertial coordinates S, not just to the one in which the Sun is at rest, nor the one in which the CMBR is isotropic. Now do you understand your mistake?
>
> [no]

Can you explain what part of the explanation you don't understand? Remember, you erroneously quoted an expression for the two-way travel time, which I corrected, and then you erroneously claimed that it applies only to the inertial coordinates in which the CMBR is isotropic, and I explained why you are mistaken. It applies in terms of every system of inertial coordinates, due to the Lorentz invariance of all physical laws. Now do you understand your mistakes?

On Tuesday, 18 May 2021 at 13:12:54 UTC+2, Cliff Hallston wrote:
> On Tuesday, May 18, 2021 at 3:23:58 AM UTC-7, beda-p...@libero.it wrote:
> > you jump immediately into [explaining special relativity]...
>
> As always, you missed the point. Remember, you falsely claimed that inertial coordinate systems "mock the condition of the privileged" coordinate system, and I pointed out that you are mistaken, because inertial coordinate systems do not in general have isotropic CMBR radiation, which is the unique "condition" of the CMBR frame. Likewise the frame in which the Sun is at rest is unique for the Sun being at rest. Duh. But what all inertial coordinate systems have in common is that the laws of physics take the same form in terms of all of them, and in this sense they are perfectly symmetrical.

Another common property of them is that they only
exist in sick imagination of brainwashed halfbrains
like you; and even your idiot guru had to abandon the
concept in the long run.