[guest4091]

David c.#76

The house example is only intended to show all observers aren't required to have the same perception or point of view, even without motion.
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and with such a model you get event-meshing failures unless you go to a block universe model,

 
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There are no such things as 'event-meshing failures' (your invention).
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Stop pretending that SR makes no such claims. SR claims that there is no aether, and in doing so it ceases to be a mere theory of perceptions.

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I don't have to pretend. All experiments to detect any effect of an ether have failed. Einstein called it superfluous and developed SR without it, yielding the same coordinate transformations as developed by Lorentz.
If you understand perception, then you know the brain is a complex process which behaves according to rules of physics, specifically chemistry. That is also 'reality'. Medical science can monitor this activity and 'map' certain areas to a corresponding activity. It's not just inanimate clocks that run slow when moving fast, but also biological clocks.
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one-way speed of light is always c relative to any object it passes

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SR does not state that. It does state "the measured speed of light relative to an inertial frame is c. In #72  the relative speed of light was overlaid in the A frame to show the round trip time (2.31) would be the same.
If U and A had the same perception about everything, why have transformations?
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No - it's plain contradiction. If its true that light passes A at c relative to A and that it also passes B at c relative to B while A and B are moving relative to each other along the same line, you must have light overtaking itself as it travels between A and B because it's moving faster than itself.

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Your interpretation is flawed. You are not compensating for time dilation and length contraction for both A and B. Those motion induced effects alter perception.

[David Cooper]

The house example is only intended to show all observers aren't required to have the same perception or point of view, even without motion.

Fine, but their perceptions must all map to the same reality. With relativity, the different perceptions can map to many alternative potential realities, only one of which will be the actual reality.

There are no such things as 'event-meshing failures' (your invention).

Event-meshing failures are an automatic consequence of SR - it isn't any invention of mine (other than the name), but a discovery. If you run a relativity simulation in which the only time allowed in the model is the time of the time dimension, you necessarily get event-meshing failures, and to deny that is to deny mathematics. It is shocking that the SR experts didn't already have their own name for this. I've written a simulation that demonstrates this in action and I've asked anyone who rejects what it shows to produce or point to any simulation of relativity that runs SR by its own rules without producing the same event-meshing failures, but none have been able to do so (because it is mathematically impossible to do so). All they have are simulations that cheat by bringing in an external (Newtonian) time to govern the unfolding of events, which means they're actually running LET with an aether and are dishonestly passing it off as SR.

I don't have to pretend. All experiments to detect any effect of an ether have failed. Einstein called it superfluous and developed SR without it, yielding the same coordinate transformations as developed by Lorentz.

You've just done it right there: the bit about the ether being superfluous. It isn't - it's vital, and MGP shows that it exists.
 

It's not just inanimate clocks that run slow when moving fast, but also biological clocks.

Who are you trying to correct here? LET says exactly that.

SR does not state that. It does state "the measured speed of light relative to an inertial frame is c.

Great, so if it doesn't assert that the one-way speed of light relative to any object is always c and can't be greater than that, you should be stamping down on the people who claim that it is always c, but you never do that, and armies of SR pushers are systematically miseducating the public with the same claims.

If U and A had the same perception about everything, why have transformations?

The transformations switch between different potential realities. Every time you use one, you are changing the asserted speed of light relative to the content of the system in some directions.

Your interpretation is flawed. You are not compensating for time dilation and length contraction for both A and B. Those motion induced effects alter perception.

It isn't flawed at all - you're just trying to have your cake and eat it again by switching from one potential reality to another while refusing to recognise that only one underlying reality is the real one.

Again though, what we're seeing is a game of avoidance, not just from you, but from everyone else here. What is your answer to the R>B vs. R=B issue? I've given you a clear experiment that resolves the whole issue by showing that the one-way speed of light relative to an object is >c in one direction and <c in the opposite direction. No one here other than me has had the courage to state an answer to that really simple little question, so what's holding them back?

Here's a list of little questions which everyone should be able to provide yes/no answers to without significant hesitation:-

Q1: If we have an observer X co-moving with S0 throughout, does he see the pulse of red light pass him more often than the blue light? (The correct answer is yes, and it is also yes for all observers - they see the red light pulse passing him more often than the blue one.)

Q2: Does observer X measure the ring as having the same length in both directions from S0 round the ring and back to S0? (The correct answer is yes, and it is also yes for all other observers.)

Q3: Given that the red light returns faster than the blue light each time, should observer X conclude that the red light has passed through the sectors of the ring at a higher average speed relative to them (while it's passing through them) than the blue light? (The correct answer is yes: he should respect mathematics and conclude that R>B.)

Q4: If we have an observer Y next to the rotating ring such that X is with him initially, but then X goes round with the ring next to sector S0 and eventually returns to Y at a moment when the pulses of red and blue light happen to arrive there simultaneously, should observer Y also conclude that the red light has passed through the sectors of the ring at a higher average speed relative to them (while it's passing through them) than the blue light? (The correct answer is yes: he too should respect mathematics and conclude that R>B.)

Q5: Do all observers have a perception which should lead them to conclude that R>B? (The correct answer is yes - all possible observers recognise that the red light has travelled through the 100 sectors at a higher speed relative to them on average than the blue light, assuming that they respect mathematics.)

Anyone who is incapable of answering these questions should ask themselves what's stopping them other than their determination to stick to their existing beliefs instead of adapting to reality.

[guest4091]

David C.;

blue lines are light paths, light gray are dimensions
Ann is the ref frame. Ben is moving at .6c in the +x direction as he passes Ann.
Ann sends a light signal from the origin in the +x direction as Ben passes.
Ann observes Ben moving at .6/sec and observes* a light signal moving at 1.0/sec.
Ann does not observe anything moving at .4/sec, but concludes the distance s  separating Ben and the signal is expanding at a rate of .4/sec.

Ben has a rod pointing in the x direction, with a mirror m at the far end. The rod s  measures 1 light unit in length. (nano, micro, ..., sec). Ben sends a signal from the origin to m. Ben detects the return at Bt=2.0, due to time dilation and length contraction, indicated in red. Ben calculates light speed as x'/t'=1/1=c. Ben does not observe anything moving at .4/sec.

Moving forward in time from At=0, the space between the near end of the rod and the photon expands at a rate of (1-.6)=.4.
Moving forward in time from At=2.0, the space between the near end of the rod and the photon contracts at a rate of (1+.6)=1.6. 

These cases are about closing speeds, i.e. not speeds of physical objects, but the rate of change for a relationship.

* records the events R and D via additional light from those events, and the assumption that light moves in straight lines between those events, and any needed calculations.

closing speed.gif (4.96 kB . 441x613 - viewed 1803 times)

[David Cooper]

David C.;

blue lines are light paths, light gray are dimensions...

Lovely, but why spend so much time on something we already agree on? You know that LET produces the same accounts of events to document the same perceptions. Where we differ is that you deny the role of the absolute frame, and you have to tolerate contradictions as a consequence of that denial (though you've been programmed to be blind to those contradictions through miseducation). If Ann is really stationary, her account represents reality while Ben's account is a distorted view of events. If Ben is really stationary, his account represents reality while Ann's account is a distorted view of events. If neither are stationary, both their accounts are distorted views of events.

My experiment, which you are still failing to address, demonstrates that there is a difference in the actual speed of light relative to the material of the ring in opposite directions as it travels through the sectors. The closing speed (seeing as you understand that term) between the red light and the material of a sector it's about to travel through next must on occasions be greater than c - we just can't pin down where in the ring this applies, so we can't identify the absolute frame from this. However, we can tell that there must be an absolute frame, because we clearly must have one at any location where the speed of light is greater than c in one direction relative to the ring material there and less than c in the opposite direction relative to that same material, and that absolute frame would necessarily have that material moving through it rather than being at rest there - to place material at rest there, it would have to be decelerated until the speed of light relative to it is c in both (or more accurately, all) directions.

The experiment (MGP, in this case), and the measurements are king: they give us numbers that tell us that R is greater than c and that c is greater than B, and we are duty bound as physicists to accept those facts rather than rejecting mathematics in a desperate attempt to cling to a dead theory. SR is in conflict with this experiment and is thereby invalidated, whereas LET is in full agreement with it. What should good, honest physicists do in such a situation? How should we judge these things? Do we judge the evidence and the argument, or do we ignore all that and just blindly follow a clergy? Should we judge by the qualifications of the person presenting the evidence (who in this case always claims to have none at all in order to avoid being followed on the basis of any kind of authority, although you really should wonder if he's hiding something when he has well-known mathematicians as uncles and a grandfather who hobnobbed with Gödel and Einstein), or should you go by the evidence itself? The correct answer is that you should always go by the evidence and argument and never be swayed by the identity of the person presenting it.

[Bill S]

I've not been following this thread, so this might well have been seen already.

https://medium.com/the-physics-arxiv-blog/the-one-way-speed-of-light-fcc5f05c5e44

If not, it might be of interest.

[jeffreyH (OP)]

How fast is the origin of a spacetime diagram moving?

[PmbPhy]

Stop pretending that SR makes no such claims. SR claims that there is no aether,

That is an invalid assertion. SR only states that an ether plays no role in the speed of light. Einstein surely never meant to claim there was no either because in a speech he gave in Berlin on Jan.27th 1921 he wrote and presented lecture entitled Sidelights of relativity[/i] in which he said

More careful reflection teaches us, however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether; only we must give up ascribing a definite
state of motion to it, i.e. we must by abstraction take from it the last mechanical characteristic which Lorentz had still left it. We shall see later that this point of view, the conceivability of which I shall at once endeavour to make more intelligible by a somewhat halting comparison, is justified by the results of the general theory of relativity.

This lecture can be found online by just Googling the title.

[David Cooper]

I've not been following this thread, so this might well have been seen already.

https://medium.com/the-physics-arxiv-blog/the-one-way-speed-of-light-fcc5f05c5e44

If not, it might be of interest.

It's a typical example of people making assumptions and failing to understand why their experiment can't determine the one-way speed of light relative to the apparatus:-

"So Ahmed and co’s method is important. These guys create two identical pulses of light and send them in opposite directions along the same length. If there is any difference in the speed of these pulses, that ought to be detectable by photodiodes at each end of the experiment."

Any difference should not be detectable unless you synchronise your clocks on the basis that the apparatus is moving through space - the answers you get depend entirely on that synchronisation, and the standard way to synchronise them necessarily does so in such a way that builds in an assumption that the apparatus is at rest, so it's no surprise when the answers come back to "confirm" that.

[David Cooper]

Stop pretending that SR makes no such claims. SR claims that there is no aether,

That is an invalid assertion.

That is possible, depending on which of Einstein's claims you consider to be part of SR and which you exclude from it because they aren't in particular papers. You yourself know that if you try to lay down the law about what SR is (on the basis of Einstein's papers) to the clergy on a certain physics forum that you can be banned for telling them what Einstein actually said SR is.

SR only states that an ether plays no role in the speed of light.

Isn't that bad enough? It's the aether (fabric of space) that imposes the speed limit on light. To deny that it has this role is to fly in the face of its crucial rule in actual relativity; a role which is exposed starkly by MGP.

What are your answers to my questions Q1 to Q5 (and to Q0: is R>B)? Do you have the courage to provide them? (I can't blame you if you don't want to say though, because you're more open to abuse by the clergy than the others here due to your position as an actual physicist, so you have a cast-iron excuse for staying silent.)

[jeffreyH (OP)]

How fast is the origin of a spacetime diagram moving?

I suppose no one has an answer to this.

[David Cooper]

How fast is the origin of a spacetime diagram moving?

I suppose no one has an answer to this.

It's always "at rest" in the chosen frame. The thing it's representing (if it maps to something real) may or may not be at rest in the actual universe.

[jeffreyH (OP)]

How fast is the origin of a spacetime diagram moving?

I suppose no one has an answer to this.

It's always "at rest" in the chosen frame. The thing it's representing (if it maps to something real) may or may not be at rest in the actual universe.

So define one spacetime diagram for the inertial frame and another for a frame in relative motion and see how it relates light between the two.

[David Cooper]

So define one spacetime diagram for the inertial frame and another for a frame in relative motion and see how it relates light between the two.

It relates it by changing the asserted speed of light relative to the two such that if one of them happens to show reality properly, the other shows a warped version where the asserted speed of light relative to the content is wrong (though you can never measure which is right or wrong from inside the universe).

Every time you change the frame of reference, you are producing a new theory of what the reality might be. (And if you use a non-inertial frame, you are mixing incompatible theories together in an unholy mess of contradiction.)

[David Cooper]

There's still a complete lack of people who are prepared to answer the simple questions I asked. Perhaps it's so clear that the answers have to be "yes" that they don't feel the need to do so. Assuming that this is the case, allow me to spell out the consequences of R>B in another way.

If R>B, there must be some parts of the ring where the speed of light relative to the material of the sectors it's passing through is greater in one direction than the opposite direction. If we now draw a tangent to the ring passing through such a point (or a straight line passing through that point along the direction in which that material is actually moving - the whole ring could be moving along, so this line isn't guaranteed to be a tangent to the ring), we can imagine an object Z moving along that line, temporarily co-moving with the material of the sector in question. The speed of light relative to Object Z in one direction along that line must also be greater than it is in the opposite direction - if this was not the case, we would have to have light moving at different speeds in the same direction on the same path, perhaps with one lot of light being visible to the ring material and magically hidden from Z, while the other lot would be visible to Z and magically hidden from the ring material, but we shouldn't be looking for magical theories like that.

If you want to deny that the speed of light relative to Z is different in these opposite directions, then you are forced to deny that the chosen point on the ring is in that situation too, which would mean that we've chosen the wrong point on the ring, but we can go through every point of the ring in turn and apply the same process to each of them in turn, and at least half of them must qualify as locations where the speed of light is different in opposite directions relative to the local ring material. If we deny that the speed of light relative to Z is different in opposite directions along the line in every case, we are left with no points on the ring where the speed of light can be different in opposite directions relative to the material of the sector it's passing through, but the result of that is that we must bury our heads in the sand and deny the result of the MGP (and the Sagnac) experiment. Serious physicists should not be doing this - they are duty bound to accept the results of these experiments and the consequences.

What is most interesting about all this though is that we have something directly equivalent to a religious belief in science - it is a case where programming (or systematic brainwashing by people who actively teach that LET is wrong) overrides people's ability to see even the most obvious contradictions. If you want to assert that the speed of light relative to Z in all directions must be c in every case, you are actually changing the frame of reference to do so, and in doing so you are changing the asserted speed of light relative to each object in order to pretend that it is equal to c in all directions. Whenever you do that though, you effectively assert that it is no longer c in all directions relative to some other objects which aren't co-moving with z, although you are banned from recognising that you are making this hidden assertion. You have been taught to keep changing the speed of light relative to an object until it's c in all directions (without understanding that that's what you're doing when you change frame), and then when you find other objects that don't conform to that because they're moving through the current frame of reference, you play the same game again with those - you use as many different frames of reference as necessary to assert that the speed of light relative to all objects is c in all directions, but these different frames of reference simply aren't compatible with each other - they are rival theories which each assert a different speed of light relative to the speed of light of other frames. If you try to apply two or more of them at once, this equates to an unspoken assertion that light moves along the same paths at different speeds (which again you are banned from recognising).

It may be that my analysis of MGP is your last hope of being deprogrammed of the SR mind virus that has blocked your ability to recognise contradictions. Here we have a clear case where we can measure the track round the ring by putting down measuring sticks all the way round it and verifying that it's the same length in both directions. We can time the light circuits relative to X (who moves with sector zero at all times) from any perspective with all observers confirming that the red light does indeed pass the material of all 100 sectors more times than the blue light, and they are forced (assuming they are rational) to conclude that the red light passes that material at a higher average speed relative to it (while it's passing it). This means that there must be some sectors where at some points in time the speed of light passing through them is moving at greater than c relative to them in one direction and less than c in the opposite direction. As soon as we accept that this is the case, we should be able to see that there must be an absolute frame to support this difference in the speed of light relative to the material content of space because frame Z manifestly cannot be a true representation of reality if Z (which is at rest in frame Z) doesn't have light moving relative to it at c in all directions, and if you want to rule out that Z as having that property, you are forcing other Zs to have that property instead.

[jeffreyH (OP)]

Spacetime diagrams have only 1 spacial dimension. They may be useful to compare separation over time but it would be better to have axes ct, x and y so that we can have the paths at least evolve on a plane.

[Le Repteux]

This is exactly why this is the best science forum. Is everyone taking this in? This is a very unique opportunity to learn. Don't waste it. No tuition fees!

I'm late, but what an interesting question Jeffrey. This is indeed by far the best forum on relativity, and it is so because Jeffrey is challenging it even if he doesn't say so and because David is there to replace him showing us how it works.  I think that the one way speed leads to a dead end for relativity, and that one day or another, it will be admitted. Meanwhile, I can again observe my theory on resistance being tested right before my naked eyes. I still have a question for those who think the one way speed of light can be measured to be c all the time though; who knows if I won't be luckier than David?

What's the use to know that the one way speed of light is always c if we never have to use it in real life?
 
No need for that data in the GPS for instance, and it works. As Einstein might have said, that data is superfluous, so why keep it? I do have to use a constant speed for c when I make my simulations with light though, but it is so only because the screen works as a medium where light can travel at c in any direction. These simulations are mathematically and logically right otherwise they wouldn't give the right numbers and they do, and they show very clearly that the one way speed of light is not the same in both directions for the light clock that moves across the screen. So what is easier? Let down the ether without which we could not make any simulation of reality, or let down the one way speed that we can use nowhere but in our minds? Can you feel my resistance? :0)

[guest4091]

David C #83;

If Ann is really stationary, her account represents reality while Ben's account is a distorted view of events.

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Red is based on what?
In the 'train' example, both observe the extended event 'object falls from passenger hand to floor', but some of the details vary for each. One reality, two descriptions. You aren't allowing for the changing position of the object due to relative motion, which results in different trajectories for the object. The trajectories are images/reality in the mind.
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My experiment, which you are still failing to address, demonstrates that there is a difference in the actual speed of light relative to the material of the ring in opposite directions as it travels through the sectors.

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My answer was:
A, moving with the ring, will meet the cw photon 1st, then the ccw photon 2nd.  A explains the time difference as due to the rotation, not a difference in light speed, i.e. different path lengths. These are shown with the aide of the mirror.
If light clocks were used in the H-K experiment, the same results would occur, due to rotation. Although an absolute frame with acceleration, it can be analyzed with SR.
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Q1: If we have an observer X co-moving with S0 throughout, does he see the pulse of red light pass him more often than the blue light? (The correct answer is yes, and it is also yes for all observers - they see the red light pulse passing him more often than the blue one.)

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[guest4091]

David C. #83;

You know that LET produces the same accounts of events to document the same perceptions.

Given a choice, LET or SR, I would choose SR since it doesn't require an ether, and light as particles doesn't require a medium.

[jeffreyH (OP)]

This is exactly why this is the best science forum. Is everyone taking this in? This is a very unique opportunity to learn. Don't waste it. No tuition fees!

I'm late, but what an interesting question Jeffrey. This is indeed by far the best forum on relativity, and it is so because Jeffrey is challenging it even if he doesn't say so and because David is there to replace him showing us how it works.  I think that the one way speed leads to a dead end for relativity, and that one day or another, it will be admitted. Meanwhile, I can again observe my theory on resistance being tested right before my naked eyes. I still have a question for those who think the one way speed of light can be measured to be c all the time though; who knows if I won't be luckier than David?

Hold on cowboy. Don't go putting words into my mouth or motives into my mind. Read what I actually post, not what you think I post

[alancalverd]

Here's another experimental idea. Consider the Doppler shift of received frequency

Δf = 2vf/(c - v)

So you can set up a laser, microwave transmitter, or radionuclide gamma source to provide a one-directional electromagnetic wave, and measure the Doppler shift between a fixed and a moving (e.g.oscillating) receiver. Now rotate the principal axis of the experiment around the receiver station, say from E-W to W-E,  and convince yourself that f and Δf remain the same, so c must be independent of direction.

Note that f varies between up and down - the Pound-Rebka experiment. The explanation depends on the constancy of c!