Why Haven't Two Clocks on a Table Been Used to Measure Light's One-Way Speed?

[outandbeyond2004]

If we take the beat frequency from a ringlaser like in the last post and that of a same rl but twice as big, that would be more than three x the fun <wild and insane laughter>.

 

[outandbeyond2004]

The beat frequency from a combination of Earth revolution (orbit about Sun) and Earth rotation is certainly going to be much more complex. I will just await wisp's numerical results for this (Earth rotation only) case before considering the revolution + rotation case, if that's OK.

edit - the position of the beater of the equatorial ringlaser is fixed wrt the Earth, so the rotational modification to the Sagnac effect is constant. To measure that, one needs to know the other contributions to the overall effect, such as that of Earth's revolution about the sun. So, it would be better to look at that instead. But, why not consider the Sun's "orbit" about the Milky Way center? Even better, the Milky Way galaxy's orbit about the barycenter of the local group of galaxies . . . the motion wrt the CRB?

In the next post, I will just consider a simple case to see if it's all right to calculcate each effect separately and add 'em up afterwards (principle of superposition).

 

[wisp]

Outandbeyond2004

I've done some calculations using mathcad and thought on how jiggle affects light in the ring laser. Two things happen:

1. Light is slowed by jiggle in the perpendicular direction and this slows light in all directions by the same amount because, light cannot change its path (unlike its affect on the MM experiment where it can change its path). The result is that all light slows in the ring laser by a factor of jiggle.
2. We must apply the "rules for time dilation compensation" (wisp theory 7.15.4). An observer moving with the ring laser records the speed of light in the ring laser as being increased by gamma (gamma has the same value as jiggle). The result is that the speed of light will be measured as being unaffected by jiggle.


(We ignoring the refractive index for glass and will consider the motion of the Earth through the cosmic ether - not its orbit around the sun).
If we assume that the ring laser moves thought the ether at 340km/s in the direction suggested in your message #165. Then the speed of light will slow by 1 part in 1038422 according to your classical ether calculations. And because jiggle and time dilation cancel out, I see no reason to doubt that this does happen.
If the ring laser is perpendicular to the ether flow then the speed of light will remain fixed at c.
If the tilt of the Earth causes the a component of the perpendicular ether flow to move in the x-axis direction by [sin (35.5) = 0.4] then the variation in light speed is 0.4*(1 part in 1038422) or 1 part in 4153689.

The question that I feel needs answering is:
How does the speed of the Earth through the ether combined with the Earth's tilt affect the beat frequency?
I believe that a very sensitive laser ring device will detect a small sidereal variation in beat frequency.

I will do some calculations using your formula.

 

[outandbeyond2004]

Whoa, wisp! (1)Either you are getting something wrong, or I am. I don't see how you get the 1 in 1038422 thing. I would have thought it was more like 340e3/c ~ 1.1/1000. See, expand in powers of v/c and sort of use the principle of superposition for the first power. I suspect you assumed that the rl does not rotate to produce the Sagnac effect. You merely assumed zero rotation, did you? If so, well it would indeed be something for the rl to produce a difference in trip time of even that relative size, all right. However zero or very small rotation is simply not practical for at least one technical reason that I won't go into here. You must let the rl rotate with the earth. Not at the equator, either. See (2) please.

(2) To be practical, you have to consider ringlasers lying flat on the ground of the spinning AND moving earth. I have been struggling to get results, and I am getting there. I was never good with multiple reference frames, especially this: One is moving wrt another, which is moving wrt yet another. Right now I am going over the calculations several times to be sure I have everything straight. I can't say when I feel confident enough to post the results here. Maybe Monday evening, if not sooner. Would you wait until then?

 

[outandbeyond2004]

This is the first part of a three-part post.

A spherical planet of radius $R_p$ (p for planet) hurtles through ether space with velocity $\vec v_e$ (e for ether -- not Ethel!), which is treated as constant for sufficiently brief intervals of time. The planet's angular velocity wrt ether space is $\vec\omega_e$, also treated as constant. Attached flat to the planet's surface is a circular ringlaser of radius $R_L$ (L for laser). The ringlaser's center is represented by location $\vec P_p$. The location of a photon in the rl is represented by $\vec P_L$.

 

[outandbeyond2004]

Second part of a three-part post

Wrt a particular rf attached to the rl,

$$\vec P_L = R_L(cos\phi, sin\phi, 0)$$

where $\phi = \phi_0$ at time t = 0.

If we orient a reference frame attached to the planet (rfP) so that its z axis runs through $\vec\omega_e$ and the angle from $\vec\omega_e$ to $\vec P_p$ is $\theta_p$, then wrt rfP

$$\vec P_L = R_L(cos\theta_p cos\phi, sin\phi, -sin\theta_p cos\phi) + \vec P_p$$

Let us orient a reference frame attached to ether space (rfE) so that its x-axis runs through $\vec v_e$ and its y-axis points in the direction of $\vec \omega_e \times \vec v_e$ . Let the angle from the z axis to the angular velocity be $\theta_e$ . Then wrt rfE,

$$\vec P_L = R_L( (cos\theta_e cos\theta_p - sin\theta_e sin\theta_p)cos\phi,$$
$$sin\phi,$$
$$-(sin\theta_e cos\theta_p + cos\theta_e sin\theta_p)cos\phi )$$
$$+ \vec P_p + \vec P_e$$


where $\vec P_e$ is the position of the planet's center wrt rfE.

 

[outandbeyond2004]

Third part of a three-part post

Let

$$v_L = \mbox{velocity of photon in rl}$$

$$\phi = \frac{v_L}{R_L}t + \phi_0$$
where $\phi_0$ = constant

$$\vec Y = ((-cos\theta_e cos\theta_p + sin\theta_esin\theta_p)sin\phi ,$$
$$cos\phi,$$
$$(sin\theta_e cos\theta_p + cos\theta_e sin\theta_p)sin\phi )$$

$$\phi_p = \omega_e t + \phi_{p0}$$
where $\phi_{p0}$ = constant

$$\vec P_p = R_p(cos\theta_e cos\phi_p ,$$
$$sin\phi_p ,$$
$$-sin\theta_e cos\phi_p )$$

$$\vec \omega_e = \omega_e (sin\theta_e,0,cos\theta_e ); \omega_e = |\vec \omega_e |$$

$$\vec v_e = v_e(1,0,0); v_e = |\vec v_e|$$

Now we can write

$$v_L^2 + Av_L - B = 0$$

where we take all velocities to be in units of c ( = 1; e.g. if you have a velocity in m/s, divide by c = 299 etc m/s) and

$$A = 2\vec Y \cdot ((\vec \omega_e \times \vec P_p) + \vec v_e ),$$

$$B = 1 - v_e^2 - 2(\vec \omega_e \times \vec P_p)\cdot \vec v_e$$

Note that B is an approximation, a constant term was omitted as being small compared to 1.

This is such a complex formula that computer simulation is necessary to comprehend fully what happens in the beat frequency. I still hope to see a nicely complex time-varying signal in it of the order of v_e.

 

[wisp]

Outandbeyond2004

Your right, my calculation on the variation on light speed around the ring laser didn't take rotation into account. I was interested in seeing how light speed varied before taking things further.
The ether flow will alter the speed of light moving in the ring laser, but the effect will be too small to be detected by measuring changes in the time interval.
A variation in light speed of 1 part in 4153689 will result in a time variation of 10^-24 second or less – too small to be detected.

Taking rotation into account, you end up with the standard sagnac equation for time delay in the ring laser. And even though the ether does affect the speed of light slightly, the affect of the rotation dominates the final time delay by many orders of magnitude. I don’t think the results will show up any differences that can be experimentally checked.

 

[outandbeyond2004]

Wisp, you seem to have forgotten this group thinks it can resolve the sagnac effect of Earth's rotation to 1 part in a billion:
https://www.physicsforums.com/showpost.php?p=173214&postcount=149

I don't pretend to know what "resolution" in this case means exactly, but I hope it means that the group can detect time-varying signals in the beat frequency even though they may be several orders of magntitude smaller than the main effect. What I would like to do is to calculcate what the time varying signals should be if Galilean R is correct blah blah, then write the group to ask, can you detect such signals?

I suspect you, wisp, are correct. They probably would say, no, they cannot. But I think the possibility is there. It is somewhat like a mom managing to hear her child in a noisy room full of dozens of squalling tots.

 

[outandbeyond2004]

Given the following equation:

$$d\phi/dt = 1/R + f(\phi, t)$$

and

$$f << 1/ R$$

how would one obtain the "corrections" to the solution of the following equation that the f term gives rise to?

$$d\phi/dt = 1/ R$$
?

 

[outandbeyond2004]

This talks about detecting the motion of the solar system relative to the CRB! (Scroll to the last paragraph):
http://www.phys.canterbury.ac.nz/research/ring_laser/ring_open.html

It also talks about special relativity tests. If Gal R were right and SR incorrect, would we know about them?

In the ringlaser, Gal R and SR agree to zero order. However, in the second order (v/c)^2, they disagree. Gal R does not demand that a factor be included to account for the slow rate of the beat detector's proper time compared to the time in an inertial frame whose center is momentarily at rest at the center of the ringlaser's center.

I will continue to work on my theory. Unfortunately, my three-part posts contain errors, which I will not (as of now) bother to edit.

Let the ringlaser be at the North Pole of Earth, and let there be no motion relative to ether space otherwise. Then

$$2\pi = (\frac{c}{R} - \omega_e)T_+$$

$$2\pi = (\frac{c}{R} + \omega_e)T_-$$

Rearrangement leads to this equation:

$$T_+ - T_- = 4\pi \frac{R}{c}\frac{\omega_e\frac{R}{c}}{1-(\omega_e\frac{R}{c})^2}$$

 

[Nereid]

That is a very cool set of experiments outandbeyond2004!

I particularly like the idea of a 'new' instrument/technique - ring lasers - being used to test GR (and be of use in other areas of physics and geophysics too).

The webpage has a 1997 date on it; do you know if they have published much of their results yet?

 

[outandbeyond2004]

By honey, I didn't know it was that old! I sort of assumed that it was much more recent than that. I looked up the list of collaborators, and guess what, Okla State University Hans R. Bilger is my thesis prof! I will write him as soon as I get his address. i am sorry to say that we have been out of touch for decades.

Incidentally, if anyone wants a copy of my PhD thesis, The Generalized Sagnac Effect in the PPN [Parameterized Post Newtonian] Formalism, just pm me. Gravitational effects on the ringlaser, published 1976.

Thank you, Nereid, for your kind remarks.

 

[wisp]

Outandbeyond2004

All the work I have done on mathcad relates to a circular ring laser on the Earth's surface, in which light is forced into a circular path. Because of this, the effects of jiggle and time dilation cancel each other out, and I believe that the change in the result cause by ether flow is too small to be detected.
Your last link show four mirrors arranged in a square, and so the path light takes is dependent on the velocity of the ether flow. In this case the jiggle and time dilation effects should not fully cancel out.
I will rework my mathcad equations and see if it produces a change that can be detected experimentally.
With SR there is no difference between a square and circular paths. But things should be different for ether theories. And I believe there is a difference in results between circular and square laser devices.

 

[outandbeyond2004]

Not only do we have to apply a time dilation factor for the velocity of the beat detector relative to the central irf, we have to apply another for the centrifugal force + gravitational force on the detector (General Relativity "gravitational redshift") as well.

People using mathematics more sophisticated than that in my PhD thesis have come up with General Relativity formulas for the Sagnac Effect, which are claimed to be experimentally verified. Since I already have shown ether theory yields a formula different from GenR, . . .

 

[meemoe_uk]

Hi there guys, sorry I took so long getting here. Acording to meemoe_uk's time theory, the clocks will behave in accordance with SR even if the trip is one way. Glad I could clear up any uncertaintys you had about it.

 

[Ray Tomes]

Because you must first synchronise the two clocks and then move them apart. This process of motion causes a discrepancy which means that you are always measuring half of the two way effect.

 

[outandbeyond2004]

Ray Tomes, is that a summary of what meemoe's theory really is? If it always makes the same predictions that SR does, why should we be interested in it?

 

[meemoe_uk]

No it isn`t. People should be interested in my theory because it's a quantum theory of relativity aimed at the layman.

 

[outandbeyond2004]

mee_moe, I am mildly curious, but I am skeptical because you say it is aimed at the layman! Not ducking the real pros, are we? Theory Development is a free for all anyway, so feel free to expound on your theory here or just start a new thread. And, wisp & you ought to get together sometime, you are fellow theorizing countrymateys.

 

[outandbeyond2004]

Readers know already that a irf theoretically consist of a rigid lattice of clocks, one at each point of the rf. The problem is, what procedure should the experimentalist follow to ensure that all these clocks are synchronized, especially in the light (pun not intended) of Einstein's conclusion in SR that there is no such thing as universal time? The following paper disucsses this problem and gives two conditions.
http://faculty.luther.edu/~macdonal/Synch.pdf
As far as I can tell, the paper is sound. Still, I would appreciate your reading it for errors.

If an experiment that should be affected by the anisotropy of light propagation is analyzed in SR with irfs set up as prescribed in the paper and yet shows no evidence of anisotropy beyond experimental uncertainity, I would consider it evidence that Martin Miller is wrong, even if we should be yet unable to meet his demand for direct one-way speed of light measurements.

 

[Eyesaw]

Readers know already that a irf theoretically consist of a rigid lattice of clocks, one at each point of the rf. The problem is, what procedure should the experimentalist follow to ensure that all these clocks are synchronized, especially in the light (pun not intended) of Einstein's conclusion in SR that there is no such thing as universal time? The following paper disucsses this problem and gives two conditions.
http://faculty.luther.edu/~macdonal/Synch.pdf
As far as I can tell, the paper is sound. Still, I would appreciate your reading it for errors.

If an experiment that should be affected by the anisotropy of light propagation is analyzed in SR with irfs set up as prescribed in the paper and yet shows no evidence of anisotropy beyond experimental uncertainity, I would consider it evidence that Martin Miller is wrong, even if we should be yet unable to meet his demand for direct one-way speed of light measurements.

He made some errors in his referencing to the equations and I can't figure out what he's trying to say in the last paragraph. I like his way of synchronizing the two clocks using one way light flashes- the process is basically a way to ensure the two clocks are at rest with respect to one another. If light is source independent though, and propagates at c relative to the vacuum, I don't see how it's possible for him to synchronize the clocks using equation 1 or 3 if the two clock-system were moving relative to the vacuum in which light propagates at a constant c. tp-to will never equal to tp'-to' since light will have traveled a longer path from one clock to the other in one direction than the trip back. Einstein called this effect "the relativity of simultaneity"- this is actually anisotropy inside an inertial frame (moving relative to the vacuum) due to light being source independent.

 

[Martin Miller]

[outandbeyond2004 noted:]
If an experiment that should be affected by the anisotropy of
light propagation is analyzed in SR with irfs set up as prescribed
in the paper and yet shows no evidence of anisotropy beyond
experimental uncertainity, I would consider it evidence that
Martin Miller is wrong, even if we should be yet unable to meet
his demand for direct one-way speed of light measurements.

[Martin Miller replies:]
The cited work actually pertains experimentally only to light's
round-trip speed, which, as we all know, is invariant & isotropic.

Here is what the author himself stated:
Conversely, the results of these experiments provide strong
motivation for our definition of "synchronized" clocks: if
the twoway speed of light has always the same value, what
could be more natural than to _define_ "synchronized" clocks
so that the one-way speed has always this value?
[from page 4 of the cited paper][my quotes][my underscore]

Not only has no experiment shown one-way isotropy/invariance, but
it is easy to show that experiment proves just the opposite, as
in the case of the following extremely simple experiment:

Inertial observers Oa and Ob meet in passing as a single
light ray approaches them.

-----Oa
------------------------------------<~~~~~light ray
-----Ob

----------Oa
-----------<~~~~~~~~~~~~~~~~~~~~~
Ob

For simplicity, we let each observer be at his frame's origin.
Given this, anything at any point common to both frames' X axis as
the observers meet in passing will be the same distance from both
observers in terms of each observer's own ruler. In other words, as
the observers meet in passing, the tip of the approaching light ray
must be the same frame distance X from both observers per their own
on-board rulers. (Xa = Xb = X)

However, since nothing, including the leading edge of a light ray,
can be in two places at once, it is clear that the ray arrives at
the observers at absolutely different times. We can (qualitatively)
label these times Ta and Tb.

Here are the experimental results:

Light's one-way speed per Oa = X/Ta

Light's one-way speed per Ob = X/Tb

This very simple experiment shows that light's one-way speed varies
directly with frame velocity, contrary to Einstein's claim of one-way
invariance, which of course was the basis of SR.

 

[russ_watters]

This very simple experiment shows that light's one-way speed varies
directly with frame velocity, contrary to Einstein's claim of one-way
invariance, which of course was the basis of SR.

Certainly, if you don't conform to the theory, it is simple to prove it doesn't work. Try the math again using the framework of relativity and see if the results make any sense. Even better, get some experimental evidence and see that the math you did wouldn't fit the data collected in a real experiment.

 

[Martin Miller]

[russ_watters noted:]
Certainly, if you don't conform to the theory, it is simple
to prove it doesn't work. Try the math again using the
framework of relativity and see if the results make any sense.
Even better, get some experimental evidence and see that the
math you did wouldn't fit the data collected in a real experiment

[MM replies:]
Hmmm...
Uhhhh...
Ehhhh...
Duhhhh...
Well, yes, if you use clocks which have been forced by
Einstein's definition to obtain one-way invariance, then,
by George, I agree that you will certainly obtain one-way
invariance, but, as my simple experiment showed, one does
not even need clocks to simply qualitatively compare light's
one-way speed in different frames.

For those who may be lost, my above paragraph is making fun of
watters' absurd demand that I "conform to the theory" in order
to have a valid disproof of it.

And as for his claim that my experiment is not a "real" one,
which part of it does he think is not real?

 

[russ_watters]

Well, yes, if you use clocks which have been forced by
Einstein's definition to obtain one-way invariance, then,
by George, I agree that you will certainly obtain one-way
invariance, but, as my simple experiment showed, one does
not even need clocks to simply qualitatively compare light's
one-way speed in different frames.

Einstein's relativity does not even enter into the design project of an atomic clock.

My point was that you used Newtonian physics in your calculation to disprove Relativity. You can't use a theory to counter another theory, you need to use data collected in an experiment to see if they match the calculations.

And as for his claim that my experiment is not a "real" one,
which part of it does he think is not real?

If it is a real experiment, please post the data you have collected.

And my point on that was that if you actually did this experiment, you would find that the data you collect would match Relativity, not Newtonian physics.

 

[russ_watters]

To be more specific, this statement is the issue

For simplicity, we let each observer be at his frame's origin.
Given this, anything at any point common to both frames' X axis as
the observers meet in passing will be the same distance from both
observers in terms of each observer's own ruler. In other words, as
the observers meet in passing, the tip of the approaching light ray
must be the same frame distance X from both observers per their own
on-board rulers. (Xa = Xb = X).

This is true in Newtonian physics but not true in Relativity. Which is correct? Do the experiment and find out.

 

[WWW]

If we use two groups of clocks (not just two clocks) for the clocks experiment and compare between the average results of each group, can we get better results?

 

[russ_watters]

If we use two groups of clocks (not just two clocks) for the clocks experiment and compare between the average results of each group, can we get better results?

Meaning two clocks sitting next to each other in each frame? Unnecessary: for the purpose of the thought experiment, a clock is assumed to have absolute precision and accuracy. For a real experiment, the experiment will be set up so that the clock has at least the required precision and accuracy for showing the phenomenon intended to be measured.

 

[Martin Miller]

[russ_watters wrote:]
(Re the simple fact that even in SR anything that is at a
single point is certainly equidistant from any coincident
frame origins:)
This is true in Newtonian physics but not true in Relativity.
Which is correct? Do the experiment and find out.

[MM replies:]
Well, it's a darn good thing that you posted your specific
complaint, because my experiment was flawless, which means
that I would not have been able to pinpoint your area of
contention sans your help.

Since you have made the incredible counterclaim that it is
not true in SR, we would all love to see your proof of same,
but you can't produce proof because you are wrong; however,
just out of curiosity, what is your version of SR's version
of the two distances?

Re your request that I do the experiment and find out, this
shows that you haven't a firm grasp of SR because you are
blissfully unaware of that fact that SR's relativity of
simultaneity was based on the same experiment.

Specifically, it was based on Einstein's famous thought
experiment (which everyone who believes in SR accepts as
being as good as an actual experiment) involving the
observers on the embankment and the train.
[See Chap. IX of Einstein's _Relativity_]
http://www.bartleby.com/173/9.html

Even more specifically, we note that Einstein's two observers
in this experiment _both_ considered themselves to be _midway_
between the two events. Thus, they also considered themselves
to be equidistant from either event. Therefore, each observer
used the _same_ value X as the frame distance (in his own frame)
from either event when the events occurred.

So even Einstein agrees with me that when two observers meet in
passing as a light ray approaches that the tip of the ray is at
the same frame distance X from both observers.

Any more complaints?

 

[Doc Al]

For simplicity, we let each observer be at his frame's origin.
Given this, anything at any point common to both frames' X axis as
the observers meet in passing will be the same distance from both
observers in terms of each observer's own ruler. In other words, as
the observers meet in passing, the tip of the approaching light ray
must be the same frame distance X from both observers per their own
on-board rulers. (Xa = Xb = X)

Imagine that each observer's frame has a huge ruler extending along the x axis. You seem to be assuming that just because the two observers agree that the origins of their respective frames (x = x' = 0) are at the same place at the same time, that that somehow implies that they would agree that all points on their rulers (for example, ruler markings x = 10 meters) are simultaneosly coincident. Not true at all!

 

[russ_watters]

So even Einstein agrees with me...

Einstein's experiment and yours are different.

Since you have made the incredible counterclaim that it is
not true in SR, we would all love to see your proof of same,
but you can't produce proof because you are wrong; however,
just out of curiosity, what is your version of SR's version
of the two distances?

Since its your experiment and your claim, why don't you do the derivation instead of just asserting it over and over again?

Or are you suggesting that SR and Newtonian physics are mathematically equivalent?

 

[DrChinese]

So even Einstein agrees with me that when two observers meet in passing as a light ray approaches that the tip of the ray is at
the same frame distance X from both observers.

From your cited reference of Einstein:

"Events which are simultaneous with reference to the embankment are not simultaneous with respect to the train, and vice versa (relativity of simultaneity). Every reference-body (co-ordinate system) has its own particular time; unless we are told the reference-body to which the statement of time refers, there is no meaning in a statement of the time of an event."

Seems pretty simple. Einstein says that simultaneity is in the eye of the beholder. Therefore, observers in different reference frames may see simultaneity or they may not. Perhaps you can construct examples in which they do. Fine. That wouldn't change Einstein's conclusion one iota, nor would it invalidate anything about SR. Clearly, he says that you need to know information about the observer's reference frame to determine the times of 2 events. And just as clearly, there are reference frames in which the timing of the lightning strikes will change in order. SR accounts for this, and classical notions do not.

 

[Martin Miller]

[russ_watters claimed:]
Einstein's experiment and yours are different.

[MM replies:]
How do they differ?

[russ_watters asked:]
Since its your experiment and your claim, why don't you
do the derivation instead of just asserting it over and
over again?

[MM replies:]
Because you keep raising your silly, irrelevant objection
over and over.

But I can easily close this simple case, as follows:

Let Observer A be at the origin of Frame A.
Let Observer B be at the origin of Frame B.
Let these two frames' x axes be parallel.
When these two frames' origins meet in passing,
let an explosive event occur at some point along
these frames' positive x axes. In the context of
SR, this explosion will occur at the same frame
point in both frames, which means that Xa = Xb,
which means that we can simply call this point X
for both frames. Indeed, since this explosive event
left its mark in each frame, the observers in each
frame can easily check where the event occurred after
the fact by looking for the burn marks left behind,
and these marks will be at the same x location in
each frame.

Case closed.

 

[DrChinese]

But I can easily close this simple case, as follows:

Let Observer A be at the origin of Frame A.
Let Observer B be at the origin of Frame B.
Let these two frames' x axes be parallel.
When these two frames' origins meet in passing,
let an explosive event occur at some point along
these frames' positive x axes. In the context of
SR, this explosion will occur at the same frame
point in both frames, which means that Xa = Xb,
which means that we can simply call this point X
for both frames. Indeed, since this explosive event
left its mark in each frame, the observers in each
frame can easily check where the event occurred after
the fact by looking for the burn marks left behind,
and these marks will be at the same x location in
each frame.

Case closed.

Not so fast.

Same example, add a couple of observers: C in A's frame at -X, D in B's frame at +X. Now C sees the explosion at a different time than A & B, as well as D. This is because the times in each reference frame are different. Besides, even in your example A & B witness the X explosion occurring at different times because one of them sees the event before the other (since they are in relative motion, they will not be co-located at each others' origin).

This effect is called the relativity of simultaneity, because the only way to get everyone to agree on the timing of events is to have them share information about each other's reference frames. If this were not necessary, then we would have absolute simultaneity - which we don't.

Case closed.