[David Cooper]

What you're failing to get is that the universe has to do something specific to coordinate the unfolding of events,

This is your personal interpretation, no currently accepted theory requires this. Is this part of a predestination world?

I don't know what you mean by "predestination world", but the unfolding of events has to be coordinated, meaning that it must be in run in some systematic manner. With the "twins paradox", for example, if the clock with the travelling twin is supposed to tick more slowly on one leg of a journey than the stay-at-home twin's clock and again tick more slowly on the second leg, that can't just happen by magic - it has to be controlled by something. Likewise, if it ticks more quickly on the first leg and more slowly on the second let, that likewise must be coordinated by something. Any theory which doesn't have a mechanism of some kind for this is left relying on magic to do this vital job. If you don't like the idea of clocks running slow, then we have to use a different SR model and replace the idea of clocks ticking faster or slower with clocks taking shortcuts into the future, or shorter shortcuts, or less short shortcuts, etc., but again this needs a system to control which paths are shortcuts over which other paths. There is always an issue of this kind with any SR model you choose to use, unless you go for the eternal static block universe model in which there is no movement at all and all the apparent causality written through it is fake.

and it can't have clock A ticking faster than clock B while at the same time having clock B ticking faster than clock A. If it does one of those, it cannot be doing both.

Then you truly don't understand SR based on your replies. The relativistic expressions are the classical expressions modified by the effects of time dilation for both mutual observers, and are therefore reciprocal or symmetrical.

No - you're the one who doesn't understand SR because you still can't see it's defects (the contradictions that are generated from it), and you've failed to see how each of the range of different incompatible models which pose as SR suffer from a fatal flaw, while Einsteinists pretend they have a single viable model. They don't - they point to a Lorentz-invariant model to remove the contradictions, then point to a Lorentz-variant model to allow causality to act.

A observes the B-clock moving past at v, and B observes the A-clock moving past at v, i.e. both in the same initial conditions, so why shouldn't each see the same clock behavior.

That is not under dispute, so why are you bringing it up? It shows that you haven't managed to follow the argument.

Each observer perceives a changed frequency of the other clock, increase or decrease, depending on approaching or receding, but perception (look up the word) is reality confined to the mind. The A and B clock rates have not changed.

Again that is beside the point. What we're interested in is the control mechanism by which a clock might tick more quickly or slowly than another, or by which it might take a shorter or longer path into the future.

In addition, time does not cause anything, that's why it's recorded AFTER the event occurs.

Time and the progress of causation go hand in hand together. A process is a series of steps in which earlier steps come before later steps and later steps come after previous steps. Look at the words used there: earlier, before, later, after - these are time words being used to describe an unfolding process of cause-and-effect events. We can run long strings of cause-and-effect processes inside our rockets as we run the "twins paradox" experiment, thereby showing that time must unfold for all those events in the same way as the processes unfold. Time and process are tightly coupled, to the point of being inseparable.

With no teleportation, you could communicate with the primed frame via light, and find its  description of events is different, the same sequence of events happen but with different times and locations.
Ten people in a circle around a house, with cameras. Each picture is a different perspective of the house, since no two people can be in the same location. Each picture is a real and valid representation of the one house.

Yes, you can do all of that and tie all the action to a single frame of reference with everything making sense, and you can choose any frame you like. If you do it with two different frames, both of them will make sense, but they will account for what's happened in ways that contradict each other because they set different different one-way speeds of light across objects. [Note that "different different" is not a mistake.]

The events you described are all humanly directed, planned and executed and dependent on consistent behavior of the elements of the universal, i.e. the 'laws'. Animal and plant life depend on the genetic programs and the 'laws', The remaining inanimate matter depends only on  the 'laws'. At this level there is no evidence of coordination or purpose beyond the 'laws'. There is randomness like thermal energy and quantum probabilities, which are welcome, by providing diversity vs monotony. Imagine if all mountains looked the same, and all lakes were the same, etc.

Wherever there is cause and effect, the cause has to run before the effect. You can't generate the effect first and then generate the cause (and no one suggests that you can), but you also can't generate the effect and cause at the same step in the process. When you fire a gun and the bullet smashes a glass plate, leading to a fragment of the plate embedding itself in an apple, the trigger of the gun was not pulled at the same step in the process as the shard of glass hits the apple. There is a chain of events which have an order with each causing or affecting the one that follows it. The process has to be coordinated, and time is necessarily dragged into that coordination and locked to it.

They come directly out of the idea that time never runs slow on any path (because time can't really run slower on one path than any other unless you have a preferred frame)

You believe in a universal independent  time, where SR requires a subjective time..

What I believe is irrelevant to my attempts to run SR models. The point is to run the model by its own rules, and if it doesn't function under its own rules, it's a broken theory. I have in such cases shown how you can get modified versions of such broken models to function by adding things to them that are not part of the original model, but pure SR is represented by model 0 (the eternal static block universe) in which there is zero functionality and causation cannot be real, and model 2 where infinite numbers of contradictions are generated and where events happen and unhappen as you change frame.

In a real world experiment, muons moving in a storage ring at .999c experienced time dilation compared to muons at rest in the lab. The results;
1. an example of the 'twin' scenario, an aging difference,
2. confirmation of the 'clock hypothesis', the tick rate depends on speed and not on acceleration (10^19 g in the storage ring).
3. no event meshing issues, both batches of muons were always present in the lab.

What's the point of all that? 1 and 2 are inevitable both with SR and LET, and with 3, of course you won't get event-meshing failures in the real universe or be able to sustain a memory of them if you do see any, either because the real universe has mechanisms to coordinate the unfolding of events so that event-meshing failures don't happen, or (much less likely) because they do happen and did occur in the lab until history was rewritten a moment later and they disappeared along with all records of the initial failure.

See if you can find any physicists who think that relativity can't be simulated.

I didn't say it can't. A pilot can practice flying in a simulator, but he doesn't go anywhere.

My point is that they all think it can be simulated, so my challenge to them (and anyone else who thinks they can hack it) is to show how. Model 0 "works", but you have to create the eternal block first under different physics, and if you do that, it's the physics of the construction phase that counts, because the imagined subsequent physics of the fossilised block is entirely superfluous. Model 2 "works", but it allows events to happen, then unhappen and rehappen repeatedly as the frame is changed, and the real universe cannot be allowed to do that.

I have never seen this issue mentioned anywhere, and why I questioned its origin.

The fact that you've never seen it mentioned anywhere shows that very few people have ever bothered to push SR hard enough to see where it breaks. The existence of the eternal static 4D block universe model shows though that some SR experts have explored SR further than others in order to get rid of the contradictions, but they've then failed to recognise that they've killed off all possible role for causality. It's when you try to generate the block that you find event-meshing failures, and of course they don't want to discuss that problem because they don't want their fig leaf to fall off.

[David Cooper]

Time and the progress of causation go hand in hand together. A process is a series of steps in which earlier steps come before later steps and later steps come after previous steps. Look at the words used there: earlier, before, later, after - these are time words being used to describe an unfolding process of cause-and-effect events. We can run long strings of cause-and-effect processes inside our rockets as we run the "twins paradox" experiment, thereby showing that time must unfold for all those events in the same way as the processes unfold. Time and process are tightly coupled, to the point of being inseparable.

I'm now going to expand on that. Imagine a light clock where a light pulse is sent from one end to the other, then it's detected at the far end and its frequency is measured. A pulse of light is then send back the other way with a new light frequency based both on the frequency of the received light pulse and a random number generated by running a complex program (which can take some genuinely random values as inputs - there are plenty of ways of doing this). Back at the first end of the light clock, the same thing is done there when that light pulse arrives, so each light pulse has a new light frequency which is calculated just before it is sent out and which cannot be predicted in advance. This provides us with a long chain of cause-and-effect steps which have to run through in series and which cannot be run simultaneously. All clocks used in any thought experiment like the "twins paradox" can be of this type, so we can always tie time very tightly to cause-and-effect processes - time and process both run, and they run in sync with each other. [Note that the generation of the next random number can be done just after the latest pulse of light is sent out, so there is no significant delay in calculating the next frequency of light to use after receiving a pulse - it will always make the final adjustment using the same number of computer clock cycles, leading to perfect spacings between the light clock's ticks. We can also make the calculations so intensive though that they only just complete each time as the next light pulse is received. Another thing we could do is add clear directionality into the process to make sure it can only be run forwards and not backwards, so we could have events where objects like china plates are smashed and a randomly-selected fragment is weighed each time to generate a number to feed into the computation, then all the fragments are ground into dust.]

Einsteinists like to play games with time, making out that it doesn't run, or that it behaves in weird ways that mean people have to throw out all they thought they knew about time and start again, but the games are just obfuscation. They confuse people until they simply give up trying to understand what time is and instead conform to the required beliefs imposed on them in order to avoid being labelled as stupid. Fortunately though, there is a way to understand time more clearly if you look instead at process. With our special light clocks (as described in the previous paragraph), we now have long cause-and-effect chains made up of steps where each step clearly must happen before the next, and we can compare the rates of these steps for different clocks. It's already easy to see that process and time are almost the same thing, but what we're doing with our special light clocks involves unpredictable behaviour of a kind you don't normally see with a clock (because the frequency of the light used for the pulses cannot be predicted in advance). We have complex process ticking on different paths at different relative rates. We therefore no longer need to discuss time, but can discuss everything in relation to process instead. While people are able to get away with all manner of obfuscating waffle about time, that kind of tactic simply won't work with process.

So, in generating the future from the past, a universe (or simulation of a universe) has to coordinate all the processes running on different paths. With the "twins paradox", we can have a final step that occurs at the moment of reunion of the twins where we take the frequency of light of the latest light pulses generated by their clocks and use them to produce a new value. We can't produce that new value unless we have access to the latest value from each of the clocks. If you fail to coordinate the action on different paths, what happens if you're ready to process that step but one of the players hasn't arrived yet (as the process on his/her path hasn't reached the required step to make the next step possible)? More steps need to have been processed on one path than the other if they are to be at the right point for the final shared step to be processed, and there should be no long delay for one path while the other catches up with its processing - they should both run straight on into that final step without either of them being switched into any kind of wait state. The only way to do the coordination and avoid any such waiting is by using a preferred frame mechanism. Without that, you will have event meshing failures where the final step cannot be made because one of the players is late in getting there. Remember that the universe itself doesn't know that the twins are supposed to meet up there, so it can't know if anything is late in arriving at a Spacetime location - it must just barge straight on with processing whatever is there. We could have another player who turns up and prevents the twins from being united, and we won't know what actually happens there until it all happens, so how can there be an option for the universe to wait if it doesn't know if any latecomers are on the way? With a preferred-frame mechanism it's easy - anything that can turn up at a Spacetime location must arrive there together with everything else that can reach that location, and then they can all interact without any delay. Without that mechanism, things will simply arrive when they arrive, so there can be changing action at a single location in Spacetime. The first thing that happens there is that only one player has turned up, so the final step can't happen and something different happens instead. Then that has to be undone and replaced when the other twin arrives and the final step is performed. But then that is undone as a third player turns up and prevents the twins meeting up. That is event-meshing failure, and it can't be avoided unless you have a systematic way of coordinating the unfolding of action on different paths. Those on the SR side who have never worked out how to simulate relativity with a computer program are not in a position to claim expertise in this subject - they simply don't understand the problem. Those who have worked out how to simulate it but who have relied on a preferred-frame mechanism are also not in a position to claim that SR works without a preferred frame. I don't care what qualifications they might have - if they can't show how to simulate SR under SR's own rules alone, their qualifications are inadequate for them to claim expertise in this subject. (Note that simulations of "events" in a ready-made eternal static block universe don't hack it either because they have killed causation - they need to account for the full generation of the block in past to future order, running through all the processes in the order of causation and coordinating the action properly.)

[GoC (OP)]

Everything is in the present it does not matter about our view. There is no such thing as time travel because time is the energy of motion as it relates to c.

David

You need to consider the issue of clocks ticking the same rate equidistant from the center of gravity and how it relates to the view of contraction. You are ignoring the issue in order to maintain physical contraction. The rotation of the Earth around the sun seems not to affect the tick rate of clocks on the Earth. So locally light has its own zero point return position in space for timing. Rotating Earth with the rotation around the sun and against the rotation around the sun has no affect on tick rate for timing. Now let's look at the MMX in that light (no pun intended).
North and south directions we only have Simultaneity of Relativity for distance so the timing and distance are exactly the same in either direction. Now the East and West directions are slightly different for distance measurements. But it is an affect of light being independent of the source that measured a different distance in each direction. It can be measured as (c+v) and (c-v) but this has nothing to do with the speed of light not being constant.

You are merely measuring the light distance not the physical distance through space. Lets take a distance of light and say it is 20ns shorter in the East to West direction which is about 20 feet for light. Now we go back and find it to be 20ns longer which is regaining the 20 feet we lost. There is just an offset in the East and West direction because light returns to the same position it left. Light can only count distance on Earth and not space. So locally light distance is the same when measuring the two way distance for light in any direction for the same energy use. Unlike the positions in space that do not return to the same position by energy use. So clocks on earth tick at the same rate in two way cycles which is what we use for timing.

You can maintain your understanding of physical contracting solids with velocity but it is based on incorrect use of data. Your understanding is in between SR and GR same as Einstein's was until he understood GR equidistance from the center of gravity and tick rates. It affects timing distances vs. energy use. It might be different in space between galaxies. Apparently gravity rotates with Galaxies similar to suns and planets.

[guest4091]

David Cooper

With the "twins paradox", for example, if the clock with the travelling twin is supposed to tick more slowly on one leg of a journey than the stay-at-home twin's clock and again tick more slowly on the second leg, that can't just happen by magic - it has to be controlled by something.

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SR gives an explanation in terms of basic physics. It's a motion induced phenomenon in combination with a constant and independent light speed. The process of 'ticking' slows when the clock moves past an observer. If you understand how the light clock works, you should know this. Couple this with altered perception (chemical processes slowing)  which prevents the observer from detecting his slow clock, and you have time dilation. As for the reuniting, that's coordinated by the anauts moving with the correct velocity, i.e. under human control.

If you do it with two different frames, both of them will make sense, but they will account for what's happened in ways that contradict each other because they set different different one-way speeds of light across objects.

_____
In your example of anauts A and B separating at speed v, each will observe the other clock ticking slower than their own. That is a contradiction only if considered simultaneously. It's not A and B, it's A or B. Each can assume a pseudo rest frame with the other moving and see the doppler effect. You don't even need two drawings, just swap pilots.
Light has a constant propagation speed c in SR. It is always measured as c in all frames.

Wherever there is cause and effect, the cause has to run before the effect. You can't generate the effect first and then generate the cause (and no one suggests that you can), but you also can't generate the effect and cause at the same step in the process. When you fire a gun and the bullet smashes a glass plate, leading to a fragment of the plate embedding itself in an apple, the trigger of the gun was not pulled at the same step in the process as the shard of glass hits the apple. There is a chain of events which have an order with each causing or affecting the one that follows it. The process has to be coordinated, and time is necessarily dragged into that coordination and locked to it

------
That's common knowledge even for people not interested in science. The indefinite causal chain is not always true, specifically when human choice is involved. You keep using examples of events planned and executed via human control, which answers your own question. If the person firing the gun misses the plate, the chain of causality ends That element was under human control, not time. I don't object to the idea of an objective 'time', it just hasn't been discovered yet.

I do reject any type of block universe, so no point in referring to it.

[David Cooper]

Everything is in the present it does not matter about our view.

The past is not present.

There is no such thing as time travel because time is the energy of motion as it relates to c.

There is time travel into the future - it's impossible not to travel that way with time.

You need to consider the issue of clocks ticking the same rate equidistant from the center of gravity and how it relates to the view of contraction. You are ignoring the issue in order to maintain physical contraction.

What issue am I ignoring? If they're moving, they're contracted regardless of how far they are from anything.

The rotation of the Earth around the sun seems not to affect the tick rate of clocks on the Earth.

How would you know? While the ticking rate changes, your inability to notice it changing hides the change.

So locally light has its own zero point return position in space for timing. Rotating Earth with the rotation around the sun and against the rotation around the sun has no affect on tick rate for timing.

How can you tell? If the galaxy's moving at relativistic speed, which it could be, then clocks on the Earth will be running slow one way and a bit less slow the other way.

Now let's look at the MMX in that light (no pun intended).
North and south directions we only have Simultaneity of Relativity for distance so the timing and distance are exactly the same in either direction. Now the East and West directions are slightly different for distance measurements. But it is an affect of light being independent of the source that measured a different distance in each direction. It can be measured as (c+v) and (c-v) but this has nothing to do with the speed of light not being constant.

The MMX uses such short arms that you needn't bother to think about the Earth rotating. You can simply take the MMX apparatus to be moving on a straight line because it will behave just like a copy of itself that is moving in a straight line (at a tangent to the Earth). The arm aligned with that straight line will have to contract.

You are merely measuring the light distance not the physical distance through space. Lets take a distance of light and say it is 20ns shorter in the East to West direction which is about 20 feet for light. Now we go back and find it to be 20ns longer which is regaining the 20 feet we lost. There is just an offset in the East and West direction because light returns to the same position it left. Light can only count distance on Earth and not space. So locally light distance is the same when measuring the two way distance for light in any direction for the same energy use. Unlike the positions in space that do not return to the same position by energy use. So clocks on earth tick at the same rate in two way cycles which is what we use for timing.

I don't know how tangled your thinking is on this, but if you send the MMX apparatus along a tangent to the Earth, the arm aligned with that path will be length-contracted all the way as it follows that path, and when it passes an MMX fixed to the Earth's surface that is co-moving with it for a moment, it will behave identically to it. The only significant complication is that the speed of light will be lower as the MMX apparatus following the tangent gets deeper into the Earth's gravity well, so it will function more slowly.

You can maintain your understanding of physical contracting solids with velocity but it is based on incorrect use of data.

Without length-contraction, particle accelerators could accelerate things to speeds greater than c. It's relativistic mass that prevents that happening, and relativistic mass drives length-contraction.

Your understanding is in between SR and GR same as Einstein's was until he understood GR equidistance from the center of gravity and tick rates.

I don't think so. Bringing gravity into things doesn't stop length-contraction happening. It just provides another mechanism for slowing clocks which is additional to the speed of movement mechanism.

[David Cooper]

SR gives an explanation in terms of basic physics. It's a motion induced phenomenon in combination with a constant and independent light speed. The process of 'ticking' slows when the clock moves past an observer. If you understand how the light clock works, you should know this. Couple this with altered perception (chemical processes slowing)  which prevents the observer from detecting his slow clock, and you have time dilation.

And that's a preferred-frame mechanism. If a simulation runs using a preferred frame, it is not running SR. If the universe runs using a preferred frame, it is not running SR either.

As for the reuniting, that's coordinated by the anauts moving with the correct velocity, i.e. under human control.

If you are running a Spacetime model which doesn't slow time on any path compared with any other path, there will be event-meshing failures where things that expect to meet up don't. To avoid such failures, the unfolding of events has to be coordinated carefully for different paths using a mechanism of some kind other than magic such that some clocks tick slower than others. SR provides no mechanism for this and therefore leaves that task to magic.

In your example of anauts A and B separating at speed v, each will observe the other clock ticking slower than their own. That is a contradiction only if considered simultaneously. It's not A and B, it's A or B. Each can assume a pseudo rest frame with the other moving and see the doppler effect. You don't even need two drawings, just swap pilots.

The universe can only do one thing - it cannot speed up the ticking of a clock while at the same time slowing it down. Can you not understand the difference between saying that clock A might be ticking more slowly or might be ticking more quickly than clock B, and saying that clock A is both ticking more slowly and ticking more quickly than clock B? The first claim is reasonable, but the second one is irrational. The accounts generated by using one frame of reference are one theory of what happened, and the accounts generated by a different frame comprise a different theory of events, and these two theories cannot both be true. That is why SR gets pushed into the eternal block model where these contradictions finally disappear (but where causality is lost in the process, or, to be more accurate, lost in the lack of process).

Light has a constant propagation speed c in SR. It is always measured as c in all frames.

And every change of frame changes the speed of light in different directions through all the other frames.

That's common knowledge even for people not interested in science.

Indeed, but you need to understand its importance here. The first important thing about it is that there are processes that must be run, killing the static block model because it fails to account for its construction, but it also puts severe constraints on how a simulation must be done so that it doesn't do anything the real universe can't do. The universe is not allowed to process later events in a chain of causation before earlier ones - it must process them all in order, and once those events have been processed, they must not be unprocessed. That means that if you jump ahead with the calculations to simulate the reunion of the twins, you can't know what the final value will be for the frequencies of light of the light pulses in their clocks because you've failed to process all the events that allow you to determine that. By putting these clear chains of causation which can't be predicted without running through the whole process, I force people to see that they can't just jump ahead - they have to run the processes on all paths properly and stop cheating. They need to coordinate the processing of those different paths too, and when they're forced to do this, they are unable to hide any cheating - the fact they're using a preferred frame becomes impossible for them to ignore and they have to stop fooling themselves.

The indefinite causal chain is not always true, specifically when human choice is involved. You keep using examples of events planned and executed via human control, which answers your own question. If the person firing the gun misses the plate, the chain of causality ends That element was under human control, not time. I don't object to the idea of an objective 'time', it just hasn't been discovered yet.

There is always a chain of causation. If something is moving, it's arrival in a new location is caused by it leaving its previous location, whereas if it isn't moving, it's continuing to be in the same location is caused by it not moving out of that location. What I'm doing though is making the chains of causation more clear so that they can't be ignored by people who want to simulate relativity. There are rules which they should not be allowed to break, and this forces them to stay within the rules. The cosmologist I mention on my page claimed that his bit of maths was a simulation, but it was just calculations that lead to the drawing of a Spacetime diagram without addressing the issue of process (or progression/unfolding of events). By adding these special light clocks where using a complex process to keep changing the frequency of the light in the light pulses (this doesn't change the time taken for a tick), I can ban him from jumping ahead to calculate the reunion point and think he's done the job - he now has to run the entire process for both paths instead, and he has to coordinate the relative rates at which the processing is done, or by introducing new physics to specify when and why the processing should halt and wait for other paths to catch up.

I do reject any type of block universe, so no point in referring to it.

I have to refer to it - it's the only kind of model that can remove the preferred frame from its mechanism, but at the cost that it can never be generated and it renders all causation a fiction.

[GoC (OP)]

The past is not present

Past is just motions from the past. Future is just motions that will happen. We travel in the present. Not the past and not the future. The entire universe travels in the present. There is no time travel!!!

 

There is time travel into the future - it's impossible not to travel that way with time.

That's a man made concept you are using to claim SR is incorrect. We only travel in the present with the motion of the present changing. You are using time travel issues that are not part of reality.

What issue am I ignoring? If they're moving, they're contracted regardless of how far they are from anything

No on Earth we have an offset for the two way measurement of light. That is not contraction.

How would you know? While the ticking rate changes, your inability to notice it changing hides the change.

No with our measurement techniques we know all clocks tick at the same rate regardless of the rotation around the sun by direction of the spin of the Earth. The gravitational energy position we reside in may affect the overall tick rates of our clocks but on Earth they all tick at the same rate equidistant from the center of gravity.

 

How can you tell? If the galaxy's moving at relativistic speed, which it could be, then clocks on the Earth will be running slow one way and a bit less slow the other way.

Because it is an observed fact all clocks tick the same at sea level.

The MMX uses such short arms that you needn't bother to think about the Earth rotating. You can simply take the MMX apparatus to be moving on a straight line because it will behave just like a copy of itself that is moving in a straight line (at a tangent to the Earth). The arm aligned with that straight line will have to contract.

Anytime some one says you needn't bother to think they are not in a position to learn. You cannot take it to be going in a straight line. The energy usage is different for a straight line in space because clocks tick at the same rate on the Earth at sea level. GR controlled tick rate is a different animal.

I don't know how tangled your thinking is on this, but if you send the MMX apparatus along a tangent to the Earth, the arm aligned with that path will be length-contracted all the way as it follows that path, and when it passes an MMX fixed to the Earth's surface that is co-moving with it for a moment, it will behave identically to it. The only significant complication is that the speed of light will be lower as the MMX apparatus following the tangent gets deeper into the Earth's gravity well, so it will function more slowly.

No it will not. Movement beyond the threshold of Earths gravitational influence as a tangent has a different affect than the curve of sea level.

Without length-contraction, particle accelerators could accelerate things to speeds greater than c. It's relativistic mass that prevents that happening, and relativistic mass drives length-contraction.

Particle accelerators can not get mass to go faster than c because c is the fundamental energy of motion. The only way to move faster than c is when mass accelerates faster than the speed of light and creates a BH.

I don't think so. Bringing gravity into things doesn't stop length-contraction happening. It just provides another mechanism for slowing clocks which is additional to the speed of movement mechanism.

All of this is based on believing clocks do not tick at the same rate at sea level. There is an offset in the two way speed of light measurement. That is not contraction. The offset can be measured with atomic clocks.

[guest4091]

David Cooper #425
You're in denial, even when reading the answers.

[David Cooper]

There is time travel into the future - it's impossible not to travel that way with time.

That's a man made concept you are using to claim SR is incorrect. We only travel in the present with the motion of the present changing. You are using time travel issues that are not part of reality.

I'm not using that to claim SR is incorrect - I don't see any dispute between me and SR on this point, although there may be a dispute there between different SR fans.

What issue am I ignoring? If they're moving, they're contracted regardless of how far they are from anything

No on Earth we have an offset for the two way measurement of light. That is not contraction.

I have no idea what you're on about. What's the offset got to do with the price of fish, and who said whatever it is is a contradiction? You seem to have found some deeply unsound way to fool yourself into thinking you've eliminated length-contraction at the Earth's surface due to the rotation of the Earth, but that doesn't work, as you should realise if you picture the MMX apparatus moving along a tangent to the Earth such that it is co-moving for a moment with another set of MMX apparatus sitting there on the Earth's surface. They both have to function the same way if the speed of light in both is the same, and if it isn't the same, you've made superluminal communication possible. I don't have time to create more interactive diagrams to show you this, so you'll just have to wait until AGI can do that job for you.

The rotation of the Earth around the sun seems not to affect the tick rate of clocks on the Earth.

How would you know? While the ticking rate changes, your inability to notice it changing hides the change.

No with our measurement techniques we know all clocks tick at the same rate regardless of the rotation around the sun by direction of the spin of the Earth. The gravitational energy position we reside in may affect the overall tick rates of our clocks but on Earth they all tick at the same rate equidistant from the center of gravity.

As the Earth moves round the sun, its speed of travel through space will vary, leading to all those clocks slowing down and speeding up repeatedly. The same thing applies to the rotation of the Earth where again clocks can speed up and slow down in their movement through space, so they are not all ticking at the same rate unless you're going by the long term average.

How can you tell? If the galaxy's moving at relativistic speed, which it could be, then clocks on the Earth will be running slow one way and a bit less slow the other way.

Because it is an observed fact all clocks tick the same at sea level.

This is hopeless - you're just missing the point every time.

The MMX uses such short arms that you needn't bother to think about the Earth rotating. You can simply take the MMX apparatus to be moving on a straight line because it will behave just like a copy of itself that is moving in a straight line (at a tangent to the Earth). The arm aligned with that straight line will have to contract.

Anytime some one says you needn't bother to think they are not in a position to learn.

There's a massive difference between telling someone they "don't need to think" and telling them that they "don't need to think about x" (where "think about x" means "bring x into the calculations where it will have no impact of any significance").

You cannot take it to be going in a straight line. The energy usage is different for a straight line in space because clocks tick at the same rate on the Earth at sea level. GR controlled tick rate is a different animal.

You can and must take it to be going in a straight line because the deviation off the straight line is utterly insignificant. You cannot allow light to travel at different speeds in the two co-moving sets of MMX apparatus unless you're happy to allow superluminal communication. The photons in the two sets must keep exact pace with each other and the length-contraction on the set following the tangent must be matched by the length-contraction on the set sitting on the Earth's surface.

I don't know how tangled your thinking is on this, but if you send the MMX apparatus along a tangent to the Earth, the arm aligned with that path will be length-contracted all the way as it follows that path, and when it passes an MMX fixed to the Earth's surface that is co-moving with it for a moment, it will behave identically to it. The only significant complication is that the speed of light will be lower as the MMX apparatus following the tangent gets deeper into the Earth's gravity well, so it will function more slowly.

No it will not. Movement beyond the threshold of Earths gravitational influence as a tangent has a different affect than the curve of sea level.

You do realise, I hope, that I'm talking about a tangent to the Earth that brings the MMX following a straight line right down to the surface such that the two sets of apparatus are in the same place and moving in the same direction? What exactly is it that you imagine light does at the Earth's surface that can eliminate length-contraction from the MMX in this situation? Bear in mind that it takes light longer to complete a circuit eastwards than westwards, so it doesn't appear to be doing anything in any way exotic enough to eliminate the need for length-contraction to produce the null result.

All of this is based on believing clocks do not tick at the same rate at sea level.

I don't know how you imagine that has anything to do with it. Your thinking is really messed up.

There is an offset in the two way speed of light measurement. That is not contraction. The offset can be measured with atomic clocks.

I refer you to my reply above (starting with "You do realise..." - if you're going to get anywhere, you need to think about that issue. There are times in the MMX when the light must be going further one way than the other in order to complete the round trip, and that cannot be done at the same speed on the path aligned with the direction of travel of the apparatus as on the perpendicular path. Until you understand that, you'll just continue to do some weird kind of voodoo instead of physics.

[David Cooper]

David Cooper #425
You're in denial, even when reading the answers.

In denial of what? I've shown that the SR model doesn't function adequately and you just tell me I'm in denial as if that magically fixes it! Show me how SR can function in a relativity simulation, and when you realise it's impossible to do that, explain how the universe can run SR when it's impossible to simulate it. The simulations use a preferred frame, and the universe must likewise use a preferred frame unless it runs on some special kind of magic that can't be simulated. You're the one who's in denial here, and so are all the others who think the same way because they've spent a century making a ludicrous assertion that they can't back up - they claim the SR model is functional, and yet it cannot function without running on a preferred frame, which means the only functional models they have are NOT SR (with the one exception of the eternal static block universe model which renders real causation impossible, replacing it with the mere illusion of causality).

Let me remind you:-

(1) A valid simulation (and the universe) must process (or make happen) events in order of causation, never jumping ahead and then jumping back again to fill in gaps.

(2) A valid simulation (and the universe) must not unprocess (or make unhappen) events once they have been done [which means the frame changes of mode 2 are banned as they cause events to unhappen].

(3) A valid simulation (and the universe) must coordinate the action on different paths in such a way as to avoid event-meshing failures [which are banned in SR], so it must impose rules on the relative rates to run the clock events (ticks) to ensure that all players arrive at Spacetime locations together such that the computation process for each path can run directly into the next shared step of the process without the processing of any of those paths being halted to allow the others to catch up.

The standard way to do the coordination is to use a preferred frame (either directly or under a pile of obfuscation), but that is not allowed in SR, so I want to see how SR handles this without a preferred frame and without bringing in any other mechanisms not specified for SR. I already know that this task is an impossible one, but they repeatedly claim they can do it while being completely incapable of showing how. All they can produce are simulations where they cheat by breaking the rules.

You (and I'm addressing all the SR preachers and their massive congregation of followers) have a duty to show your model functioning somewhere: you need to show that it allows causality to be real (by providing laws of physics that allow the generation of the future out of the past rather than using a magical, eternal block universe which was never constructed) and you need to to show that it does not depend on a preferred frame. Where is your demonstration of this? Where do you show off this functional SR model to the world? This is so important that you must actually have one somewhere if your theory is genuinely viable in some way. We're talking about physics here, so you should not be behaving like a church that refuses to show the world its impossible deity.

[GoC (OP)]

The preferred frame is c. Not because it is at rest but because it is a limit that all SR is based. c=0 time on your clock. Which is a valid frame? All frames are equally valid which actually means no frame is valid. Light is not instantaneous but the present is instantaneous in a sense. Your simulations only account for the differences in time and not distance measurements. In SR both cycle timing and distances change together. You measure the speed of light in a vacuum the same in every frame. When your timing slows your measuring stick expands in SR. You are only looking at timing. You need to understand the full affect. Lets say Gods Eye is instantaneous not using light or measuring stick. There would be no need for relativity or simultaneity of relativity. In SR the Gamma term is the increase in distance of your measuring stick to match the change in timing. Try that in your simulations.

[guest4091]

David Cooper #429
SR experiments are performed in the real world, they are not simulations. The results agree with the theory. Whenever the results are presented as a response to your questions, you deny/ignore them by repeating this fantasy notion about coordination and event meshing issues, etc. How would you prove an event never happened? Sounds silly doesn't it?  Did you ever consider your models may have errors? 

[David Cooper]

The preferred frame is c.

c is not a frame. It's a speed.

Your simulations only account for the differences in time and not distance measurements.

When you change frame on the 3-mode interactive diagram, you see the distances changing - they wouldn't function correctly if they didn't work on both time and distances.

In SR both cycle timing and distances change together.

As happens in my diagram.

You measure the speed of light in a vacuum the same in every frame.

Correct, and that means that every time you change frame, you change the speed of light across all the objects in the simulation relative to them.

When your timing slows your measuring stick expands in SR. You are only looking at timing. You need to understand the full affect.

You need to look at what I'm doing and describe that accurately instead of accusing me of failing to do things I'm doing.

Lets say Gods Eye is instantaneous not using light or measuring stick. There would be no need for relativity or simultaneity of relativity.

With the God view, you see all the action in a frame simultaneously without any communication delays, but the communication delays are still there for the objects displayed and there is no removal of the need for relativity - it is simply a different way of "viewing" the action.

In SR the Gamma term is the increase in distance of your measuring stick to match the change in timing. Try that in your simulations.

What kind of warping do you want to introduce to my simulations that will keep them the same shape as they already are? They are the right shape and I'm not going to mash them up to fit the requirements of anything that doesn't match up to the real universe.

[David Cooper]

SR experiments are performed in the real world, they are not simulations. The results agree with the theory.

Experiments don't show the mechanism. We can't detect the mechanism because relativity prevents us from determining the one-way speed of light relative to us. The results of experiments are the same regardless of which frame is (or comes closest to being) the absolute one.

Whenever the results are presented as a response to your questions, you deny/ignore them by repeating this fantasy notion about coordination and event meshing issues, etc.

What's the point of trying to use the results of experiments as a response when they shed no light on the issue in question? We already know that they are compatible with frame A being absolute and with frame B being absolute, because that's what everyone agrees happens with relativity.

The issue, which you still seem incapable of grasping, is that frame A cannot be the absolute frame if a different frame, frame B, is the absolute frame, and frame B can't be the absolute frame if frame A is. You can't have more than one absolute frame.

In frame A, the absolute frame, an object A that's at rest will have light move relative to it at c in all directions, while an object B which is moving through frame A has light moving relative to it at a range of speeds other than c at different angles (although at some angles it will still be c). If we change frame to frame B, we are changing the asserted speed of light relative to all the objects, so we now assert that light moves relative to object B in all directions at c, and that it now moves at a range of speeds other than c relative to object A. The frame B account is incompatible with the frame A account, and because frame A is the absolute frame, the frame B account is wrong - it is giving us the wrong speeds for light relative to the objects. The only complication is that with the real universe, we can't tell which frame is the absolute one, so the universe itself has to have one frame act as the absolute one - if it didn't, it would mean that light moves relative to object A at all speeds between 0 and 2c in any single direction at the same time.

How would you prove an event never happened? Sounds silly doesn't it?

If an event is unhappened, you aren't going to know that it's been unhappened, but a universe running physics that allows it to unhappen things as it changes the frame it's using to coordinate events is using much more complex physics than a universe which sticks to using a single frame for its mechanism.

Did you ever consider your models may have errors?

When I wrote them, of course, as it's easy to have bugs in a program, so I checked that they matched up to the Spacetime diagrams that cover the same events (they're a perfect fit), and I checked the maths of it repeatedly too. If they were wrong, one of the many "experts" in relativity (with the qualifications to prove it) would have found an error with them and would have taken great delight in pointing to it and tearing my argument to pieces - some of them have put a lot of time into it, but they've all drawn a blank. The diagrams are correct. There are only two SR models that run on SR's rules, and they behave exactly like my models of them. Model 0, the eternal static block universe model, is the only one that doesn't depend on a preferred frame, but fails to explain how the block can be generated to make the causation real - in trying to generate the block, extra rules would have to be brought in to coordinate the action, at which point you bring in Newtonian time and a preferred frame. Model 2 is the only other model that can be said to be pure SR, but it actually runs on a preferred frame and can only claim not to do so by changing frame continually to obfuscate its mechanism, thereby causing events to happen, unhappen and rehappen repeatedly. Another way of looking at it though would be to assert that it uses all frames at once as its mechanism, which means that all events have both happened and not happened yet, and that that is always their status no matter how long the universe has been going. That's again a much more complicated act to perform though than just doing the simplest thing, which is to use a preferred frame to govern the unfolding of events.

Go back up to the paragraph starting with "In frame A" and focus on understanding the issue. In frame A, light moves relative to object B at speeds other than c. It is only when we switch to frame B that light is asserted to be moving relative to object B at c in all directions, but such a change in what the light's doing relative to the objects should not be allowed. A change of frame is a major reworking of reality, producing a new description of what's happening that's a major distortion of the truth, telling lies about the amount of length-contraction that's applied to different objects and about the speed of light relative to them. That is shown up by mode 2 causing events to happen and unhappen as you change frame. The real universe cannot be doing that. The real universe must pick one frame to use for its mechanism and stick with it throughout.

[GoC (OP)]

The real universe must pick one frame to use for its mechanism and stick with it throughout.

Yes, the frame is c zero point energy. The timing in your modes are related to energy used vs. energy available. While you can measure energy available with a clock's tick rate there is nothing to measure energy used. So Einstein said all frames are equally valid. This also means no frame is valid because of relativity of simultaneity. Light speed is not infinite. If it were infinite we could not distinguish objects. Just like beyond 13.6 billion light years we cannot distinguish objects. This does not mean there is nothing beyond 13.6 billion light years distance.

[guest4091]

The issue, which you still seem incapable of grasping, is that frame A cannot be the absolute frame if a different frame, frame B, is the absolute frame, and frame B can't be the absolute frame if frame A is. You can't have more than one absolute frame.

SR does not claim frame A or any other frame is the absolute frame, that's the significance of the relativity principle which you don't seem to understand. Give us your explanation/mechanism of why moving clocks run slower.

[Le Repteux]

Look at his MMx simulation Phyti, it shows that light takes more time two ways if the interferometer is traveling than if it is not traveling, which is the same mechanism as the SR light clock's one.

[David Cooper]

SR does not claim frame A or any other frame is the absolute frame, that's the significance of the relativity principle which you don't seem to understand.

SR certainly doesn't claim there is one, but indeed it goes so far as to claim there isn't one. However, it depends on a preferred-frame mechanism for its functionality (unless it moves to the eternal static block universe model where the future had no opportunity to be generated out of the past), so it depends on there being an absolute frame whether it acknowledges the fact or not.

Why don't we take this right back to the very beginning to see if we can find out where it all went wrong for you. I want you to imagine that you know nothing about relativity at all and that you're a bright, open minded (but also suitably sceptical) child in a classroom who is completely new to physics. The teacher has a desk at the front of the room which is about 3.3 metres long and which is end-on to a window. He explains that light travels at a speed that allows it to go from one end of the desk to the other in ten nanoseconds. He produces two stopclocks which can count in nanoseconds and puts one at each end of the desk, then he attaches light detectors to the clocks (perhaps slave units designed for flash photography) so that the clocks can be stopped by flashes of light. He also has a flashgun from a camera which he's going to use to trigger them. He is able to start the clocks and synchronise them in some way, so they're both running and displaying the same time. He takes the flashgun to one end of the desk and aims it at the two detectors, then presses the button. There's a bright flash, and the clocks stop. One of them reads a value higher than the other by ten nanoseconds.

Now the teacher explains to the class that the Earth is moving, and so is the sun, and the galaxy, so can the speed of light really be the same in both directions along the desk relative to the desk? What if the desk is really moving through space at half the speed of light in the direction of the window such that light would take much longer to go from one end of the desk to the other in that direction and much less time to go the other way? Or what if the desk is really moving at 90% the speed of light? Well, he starts the clocks again from zero, but he has changed the mode they're running in such that they are now ticking more quickly than they were before. He also explains that he's changed the synchronisation so that one of them is ahead of the other, although it's too small a difference for you to see it. Now he repeats the experiment by setting off the flash from the same end as before. The result this time is a difference between the times of the clocks of seventy four nanoseconds.

He now explains to the class that he has measured the speed of light along the length of the bench twice. The first measurement claimed that light travels one desklength every ten nanoseconds. The second measurement claimed that light travels one desklength every 74 nanoseconds (in that direction). What he does next though is startling, because he tells the class that light travels the length of the desk in ten nanoseconds AND in 74 nanoseconds, AND in a millon years, AND in five nanoseconds. He tells them that light is moving the length of the table at all those different speeds at the same time and that his fiddling with the way the clocks are synchronised and the rates at which they tick is fully valid. Each method of synchronising the clocks is based on the idea that the desk could be moving at high speed through space, and each speed needs its own synchronisation.

The idea that the new synchronisation is valid for a high speed of travel for the desk makes sense, so that isn't the startling thing about the teacher's claim. Someone behind you speaks up, suggesting that light can only be moving at one speed along the desk. The teacher replies, "Well, there is actually a theory that asserts just that, and it fits all the facts perfectly, but we have a simpler theory which also fits all the facts which says that light's moving along the table at an infinite number of different speeds at the same time." Another heckler's voice is heard grumbling that it doesn't sound simpler. "Ah, but it is simpler," says the teacher, "because... Oh, I'm afraid I misspoke! When light's moving along the table at an infinite number of different speeds at the same time, we should simply state that it's moving along the desk in ten nanoseconds without worrying about how fast the desk might be moving, and that means we can always claim that it isn't moving at all and that we'll always be right. It means that light always travels at the same speed relative to all objects and that all the other speeds we record for any object can simply be ignored. Yes; that's what the simpler theory says!" He walks over to a cupboard in the corner of the room and by opening it reveals that it is actually a wardrobe full of clothes dangling from hangers, then he steps into it and calls, "Who's coming to Narnia with me!"

Should you follow him to Narnia? You stop to think. The measurement that he made where the clocks recorded it taking 74ns for the light to travel the length of the desk would be correct if the desk is moving at about 87% as fast as the light, and it really could be moving that fast through space. That second experiment measured the speed of light relative to the table and found it not to be the 10ns/desklength, but 74ns/dl. Someone in the class knows what the speed of light is supposed to be in km/s, so you get a calculator out and crunch the numbers. Yes - 10ns/dl matches up to the official speed of light. But 74ns/dl most certainly does not. The teacher carried out an experiment which measured the speed of light along the desk as 0.135c relative to the desk. At first he asked you to believe that light travels the length of the desk at all speeds between 0 and 2C at the same time, but then he changed his mind and asked you to ignore that and to believe instead that light always travels at c relative to the desk and doesn't travel at any other speed than c relative to anything.

"I don't want to fail my exams," says a boy at the front. He gets up and walks into the wardrobe. "If we have to say we believe this stuff to get through, I'll gladly say it!"

"I want a job at NASA," says the girl who was sitting next to him, so she follows him into the wardrobe.

A flock of baaing sheep then make their way to the wardrobe and they all pass through into Narnia. You are left with a few people who either don't care about physics or who object to what they're being asked to believe. What are you going to do? We can measure the speed of light relative to moving objects and get values which are clearly not c, so do these measurements not provide valid information? The measured value of 74ns/dl may be correct, and if it is correct, all the other speeds for light relative to the desk in that direction are necessarily wrong. If the teacher wants the speed of light to be c relative to the desk for all speeds of travel of the desk, he must be changing the speed of light through space in different directions to match any change in the speed of travel of the desk through space. But as soon as there are two desks moving relative to each other, his trick is broken - the speed of light across one of the desks will not be c relative to it in every direction, and you will be able to measure the difference. The teacher's favoured theory produces contradictions, while the "less simple" theory (which seems much simpler) doesn't.

As I said before, there's some weird psychology tied up in all this.

Give us your explanation/mechanism of why moving clocks run slower.

I refer you to my interactive MMX diagrams and the text around them. It has a fixed speed of light through a fabric of space (instead of having an undeclared [and denied] infinite number of such fabrics in order to provide an infinite number of speeds of light across all objects and maintaining all events in a state of happened and not-happened at all times).

[GoC (OP)]

SR certainly doesn't claim there is one, but indeed it goes so far as to claim there isn't one. However, it depends on a preferred-frame mechanism for its functionality (unless it moves to the eternal static block universe model where the future had no opportunity to be generated out of the past), so it depends on there being an absolute frame whether it acknowledges the fact or not.

That is a straw man argument. The two postulates make no such claim. In fact having a constant c is a claim for an absolute frame.

Why don't we take this right back to the very beginning to see if we can find out where it all went wrong for you. I want you to imagine that you know nothing about relativity at all and that you're a bright, open minded (but also suitably sceptical) child in a classroom who is completely new to physics. The teacher has a desk at the front of the room which is about 3.3 metres long and which is end-on to a window. He explains that light travels at a speed that allows it to go from one end of the desk to the other in ten nanoseconds. He produces two stopclocks which can count in nanoseconds and puts one at each end of the desk, then he attaches light detectors to the clocks (perhaps slave units designed for flash photography) so that the clocks can be stopped by flashes of light. He also has a flashgun from a camera which he's going to use to trigger them. He is able to start the clocks and synchronise them in some way, so they're both running and displaying the same time. He takes the flashgun to one end of the desk and aims it at the two detectors, then presses the button. There's a bright flash, and the clocks stop. One of them reads a value higher than the other by ten nanoseconds.

Good so far if the desk is about 10 feet long as you suggest.

Now the teacher explains to the class that the Earth is moving, and so is the sun, and the galaxy, so can the speed of light really be the same in both directions along the desk relative to the desk? What if the desk is really moving through space at half the speed of light in the direction of the window such that light would take much longer to go from one end of the desk to the other in that direction and much less time to go the other way? Or what if the desk is really moving at 90% the speed of light? Well, he starts the clocks again from zero, but he has changed the mode they're running in such that they are now ticking more quickly than they were before. He also explains that he's changed the synchronisation so that one of them is ahead of the other, although it's too small a difference for you to see it. Now he repeats the experiment by setting off the flash from the same end as before. The result this time is a difference between the times of the clocks of seventy four nanoseconds.

They would tick more slowly at 90% of the speed of light. If you change the tick rate of your clock you are no longer synchronized with relative rest for your clock. You do not get 74ns at 90% relative to rest. You measure the same 10ns because of your contraction and the slower tick rate by relativity (although I do not believe in physical contraction). The affect for one way vs. two way is different. Lets make your clock the same distance as your desk and measure the one way as a tick. Clocks are only timing measurements based on c. You cannot measure something if that something is part of the measurement. Timing using c and measuring c is included.

He now explains to the class that he has measured the speed of light along the length of the bench twice. The first measurement claimed that light travels one desklength every ten nanoseconds. The second measurement claimed that light travels one desklength every 74 nanoseconds (in that direction). What he does next though is startling, because he tells the class that light travels the length of the desk in ten nanoseconds AND in 74 nanoseconds, AND in a millon years, AND in five nanoseconds. He tells them that light is moving the length of the table at all those different speeds at the same time and that his fiddling with the way the clocks are synchronised and the rates at which they tick is fully valid. Each method of synchronising the clocks is based on the idea that the desk could be moving at high speed through space, and each speed needs its own synchronisation.

Nothing is valid for timing and view.

The idea that the new synchronisation is valid for a high speed of travel for the desk makes sense, so that isn't the startling thing about the teacher's claim. Someone behind you speaks up, suggesting that light can only be moving at one speed along the desk. The teacher replies, "Well, there is actually a theory that asserts just that, and it fits all the facts perfectly, but we have a simpler theory which also fits all the facts which says that light's moving along the table at an infinite number of different speeds at the same time." Another heckler's voice is heard grumbling that it doesn't sound simpler. "Ah, but it is simpler," says the teacher, "because... Oh, I'm afraid I misspoke! When light's moving along the table at an infinite number of different speeds at the same time, we should simply state that it's moving along the desk in ten nanoseconds without worrying about how fast the desk might be moving, and that means we can always claim that it isn't moving at all and that we'll always be right. It means that light always travels at the same speed relative to all objects and that all the other speeds we record for any object can simply be ignored. Yes; that's what the simpler theory says!" He walks over to a cupboard in the corner of the room and by opening it reveals that it is actually a wardrobe full of clothes dangling from hangers, then he steps into it and calls, "Who's coming to Narnia with me!"

Relativity only says the speed of light is constant. How you measure timing is not valid. Measuring the same speed of light in every frame is a proof timing measurements fail and not that SR is incorrect. c is the absolute frame not a static block universe. c creates the present. Not the past and not the future. Only the present as motion for the energy of time.

Should you follow him to Narnia? You stop to think. The measurement that he made where the clocks recorded it taking 74ns for the light to travel the length of the desk would be correct if the desk is moving at about 87% as fast as the light, and it really could be moving that fast through space. That second experiment measured the speed of light relative to the table and found it not to be the 10ns/desklength, but 74ns/dl. Someone in the class knows what the speed of light is supposed to be in km/s, so you get a calculator out and crunch the numbers. Yes - 10ns/dl matches up to the official speed of light. But 74ns/dl most certainly does not. The teacher carried out an experiment which measured the speed of light along the desk as 0.135c relative to the desk. At first he asked you to believe that light travels the length of the desk at all speeds between 0 and 2C at the same time, but then he changed his mind and asked you to ignore that and to believe instead that light always travels at c relative to the desk and doesn't travel at any other speed than c relative to anything."I don't want to fail my exams," says a boy at the front. He gets up and walks into the wardrobe. "If we have to say we believe this stuff to get through, I'll gladly say it!"

It's c that is constant. You are making a straw man argument. Measuring and timing are not valid except for relative measuring from a frames point of view and only that frame. No view is valid!!!!! They are indirect measurements that change with velocity. Both time and distance.

A flock of baaing sheep then make their way to the wardrobe and they all pass through into Narnia. You are left with a few people who either don't care about physics or who object to what they're being asked to believe. What are you going to do? We can measure the speed of light relative to moving objects and get values which are clearly not c, so do these measurements not provide valid information? The measured value of 74ns/dl may be correct, and if it is correct, all the other speeds for light relative to the desk in that direction are necessarily wrong. If the teacher wants the speed of light to be c relative to the desk for all speeds of travel of the desk, he must be changing the speed of light through space in different directions to match any change in the speed of travel of the desk through space. But as soon as there are two desks moving relative to each other, his trick is broken - the speed of light across one of the desks will not be c relative to it in every direction, and you will be able to measure the difference. The teacher's favoured theory produces contradictions, while the "less simple" theory (which seems much simpler) doesn't.As I said before, there's some weird psychology tied up in all this

Yes there is a faith issue in relativity. It's an incomplete understanding of the masses that allows confusing points of view. I am sorry to say you have not completed your understanding until you resolve the paradoxes you claim. You are creating paradoxes that are not applicable. No view is valid and no measurement is valid but c is constant.

[David Cooper]

That is a straw man argument. The two postulates make no such claim. In fact having a constant c is a claim for an absolute frame.

A lot depends on your interpretation skills, though there's plenty of stuff out there written about SR to help you understand what its claims are.

"The speed of light in vacuum has the same value c in all inertial frames of reference."

Which means SR has no absolute frame, or rather that it has an infinite number of absolute frames which conflict with each other mechanistically.

They would tick more slowly at 90% of the speed of light.

No. I'm actually using 87% the speed of light (the 90% merely being one speed suggested by the teacher). When he set the clocks to tick faster, he set them to tick twice as quickly as normal. If we assume that the desk is stationary and call the frame in which it is stationary Frame A, we are going to set up a clock synchronisation and tick rate for Frame B which is a frame moving at 87%c relative to the desk. The Frame B view of the desk, once converted to the "God view", will show time running at half speed for the classroom, but the two clocks will be ticking at the same rate as Frame B's clocks in their analysis, so that's why we have the clocks ticking faster. The desk is moving through their "God view" analysis at 87%c with its action slowed to half rate, but the clocks appear unslowed because they're ticking twice as fast as any other clocks in the classroom. The synchronisation of these clocks means that they are displaying the same time as each other in that Frame B "God view" analysis. This is how we are able to perform a Frame B measurement of the amount of Frame B's time taken for light to go from one end of the desk to the other.

If you change the tick rate of your clock you are no longer synchronized with relative rest for your clock. You do not get 74ns at 90% relative to rest. You measure the same 10ns because of your contraction and the slower tick rate by relativity (although I do not believe in physical contraction).

Of course you get 74ns (at 87%c) - it's exactly the same value you would record for light overtaking a desk that's moving past you at 87%c when you consider yourself to be stationary and synchronise your clocks on that basis. All I've done is allow you to make a Frame B measurement of a desk that you're co-moving with while you (and the desk) are at rest in Frame A.

The affect for one way vs. two way is different. Lets make your clock the same distance as your desk and measure the one way as a tick. Clocks are only timing measurements based on c. You cannot measure something if that something is part of the measurement. Timing using c and measuring c is included.

I can't make sense of that word salad. All synchronisations should be equally valid in SR so long as if they map to possible frames, which means both measurements of the length of the desk should be equally valid in SR. The fact that they contradict each other is not my problem, but is simply a result of SR using the crude trick of changing the speed of light across an object whenever the frame of analysis changes.

It's c that is constant. You are making a straw man argument. Measuring and timing are not valid except for relative measuring from a frames point of view and only that frame. No view is valid!!!!! They are indirect measurements that change with velocity. Both time and distance.

You are not the ideal person to defend SR because you are such a long way from understanding what SR is and what it asserts. There is nothing "straw man" about what I'm showing you when I reveal the crude trick that SR is playing on people - every change of frame changes the speed of light across every object (relative to that object) and leads to many events unhappening.

Yes there is a faith issue in relativity. It's an incomplete understanding of the masses that allows confusing points of view. I am sorry to say you have not completed your understanding until you resolve the paradoxes you claim. You are creating paradoxes that are not applicable. No view is valid and no measurement is valid but c is constant.

The problem here is that you don't understand SR and are repeatedly misrepresenting it. Outside of a gravity well, c is constant, moving through space at a fixed speed. When two objects pass each other, light cannot be moving past both of them in all directions at c relative to both of them. SR makes out that it can, but it's claiming something impossible. If light is moving past object A at c in all directions relative to object A while object B is moving past object B, light cannot also be moving past object B in all directions at c relative to object B. As soon as someone is programmed to believe that it can be, they have been taken away from rationality to become citizens of Narnia.