Philosophy Discussion Forums

Steve3007 wrote:...If you've studied this subject in the depth required to overturn it at a very high level, then you are already very, very well aware of all this to a much greater extent than I, who does not have such ambitions, right?

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Steve3007 wrote:OK. Fair enough. Which parts [of [physics] do you regard as the relevant ones?

David Cooper wrote:Any parts relevant to any phenomenon that I'm exploring. If there's an area I'm not sure about, I do the necessary research, and if all I can find are pages of mathematical squiggles with a lack of explanation in ordinary language to go with it, I can ask for help in interpreting them at a science forum, though that's rarely necessary.

What "mathematical squiggles" are you referring to exactly? The mathematics of vector calculus? The Heaviside formulation of Maxwell's Equations? The tensor calculus used in General Relativity? Or just all algebra?

There is a hierarchy of required understanding in every subject, including physics. To simply learn a bit about the foundations of it, you study it to school level. To get a general, qualitative sense of the interesting concepts involved at higher levels than the foundations you perhaps read a popular account of the subject aimed at a lay-audience. To teach it, you study it to at least a level higher than the students you are teaching. I know from personal experience of having studied physics to degree level and taught it (and Maths and General Science) in high school, that to teach up to GCSE level you need at least 'A' level yourself. To teach to 'A' level you need at least first (bachelors) degree level. To teach undergraduates you need post-graduate experience. Finally, at the top of that hierarchy, way above the level of lowly former school teachers like myself, there is the depth of understanding required to confidently proclaim paradigm shifts in the subject - to be able to precisely demonstrate to other specialists in the subject where they've gone wrong, having understood precisely what those specialists have said.

With many, many comments here and elsewhere you have declared yourself to be at the top of that hierarchy. So when I ask you something like this:

Steve3007 wrote:In the above, by "those" and "they" I assume you mean Maxwell's Equations. Just to be clear about what you did when you "picked them apart": Which terms in Maxwell's equations are the distance terms? How were they measured by Faraday and other experimental physicists?

or this:

Steve3007 wrote:Please could you describe how the fact that the wave solution of Maxwell's equations yields a value of 'c' for the electromagnetic waves described in those equations works in the context of Lorentz Ether Theory.

I am eagerly expecting to learn something from someone who has much more depth of understanding and insight into the subject than I do (as a mere former-teacher with a, now, very rusty and old education in the subject). But, so far, nothing. You won't show me the depth of your knowledge. Instead, you appear to me to show muddle over, for example, what it means for a statement to be logically self-contradictory. You give a good impression of someone who isn't actually at the point in that hierarchy that they claim to be. That's why I keep asking questions to try to give you a chance to show that impression to be wrong.

David Cooper wrote:Maxwell's Equations are not a part of physics that I know enough about to use them, so I rely on other people showing me what they do with them. I've followed the trail in the past far enough to find distance terms which were being loaded with rest-frame values, ...

That's like an English Literature research post-grad saying that they've heard of a guy called Shakespeare but never read him themselves (and regard Shakespearean language as a bunch of squiggles). You can't just pick the thin thread through the subject that you think is going to lead you as quickly as possible to the conclusion you want. That leads you very, very likely not to have fully understood the arguments of those you seek to overturn. As I've said, to build the roof you first need the foundations.

What do you mean "being loaded with rest-frame values"? Walk me though some of the early experiments in electricity and magnetism, which led ultimately to the various equations that were brought together by Maxwell (and simplified by Heaviside), and show me what you mean in that context.

...and I have every confidence that the same thing will always be the case in these situations. There is also the difficulty that if you do feed in measurements in based on other frames, the equations themselves may be too simple to be able to apply to them - you may need more complex versions to handle this, while Maxwell's versions are simpler because they rest on the luck of the fact that relativity always works as a shortcut. I've been led to believe that Poincaré woked on fixing this, but I've never seen the details. So, the way forward for this part of the argument depends on you showing me how you apply numbers to these equations to get a speed of light relative to the apparatus. If you can't do that without using distance terms, then it won't prove anything. You shouldn't expect it to prove anything though, because if it showed that the speed of light relative to an object is always c in all directions, it would prove that 1=2 and we'd have to throw out all our maths.

(Bold added by me for emphasis.)

I can try to put some oil on my rusty knowledge and teach you some physics. But I shouldn't be doing that. You, as the paradigm-overturner, should be teaching me. The way forward is for you, the one with the extraordinary insight and the extraordinary claims, to be providing the extraordinary evidence to demonstrate those claims.

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After those general comments, just a little bit about the more specific things you've said for now:

Steve3007 wrote:But since nobody has said 2=1, you can't be talking literally.

David Cooper wrote:I'm talking absolutely literally...

That is very surprising because if you are, then you are wrong. Prove me wrong in saying that by quoting the mathematical expression, used in an accepted law of physics, which amounts to "2=1".

...The rival claims of different frames can only be valid and equally valid if we throw out the rule that 2 cannot be equal to 1. The claims generated by different frames don't merely say that 2=1, but that every number is equal to every other number. That's what the contradictions tell you if you decide to tolerate them instead or rejecting them.

Remember what I said earlier about language?

viewtopic.php?p=319102#p319102

If a statement in mathematical language does not contain an expression that is logically equivalent to "2=1" then, if you correctly render that statement into English, it still doesn't. Same as if the languages were French and English. If you think it does, then something has got lost in translation.

Your statements, about what reference frames "claim", are badly worded. And bad wording using imprecise definitions leads to mis-translation. As I've already said, reference frames don't claim anything. Observations/measurements are made by observers who use reference frames to quantify them. The results of those measurements are quantitative. They are represented mathematically. The rules of mathematical logic are applied in the form of an argument - that's where the application of reason comes in. This logic links different observations together in a pattern.

If observer A and B are both carrying clocks and observer A says "I count the ticks of B's clock coming more slowly than I count the ticks of mine" and if B says "I count the ticks of A's clock coming more slowly than I count the ticks of mine" there is no contradiction. Neither of them is wrong unless they've made a mistake in their observations. Nobody has said "2=1". If you think differently then you have to show me how, in terms of something that can be observed.

Describe to me an observation that shows one or both of them to have said something contradictory. It's when you do this that you start to have to think carefully about something like this famous "twin paradox".

David Cooper wrote: ↑September 8th, 2018, 5:29 pm It's your experiment, so you should be able to pin down your own angles for it and go through the maths without needing my help.

You would think, yes, but your help was appreciated. The 63.4 figure is the correct angle. I am stupidly doing the arccos instead of the arctan to get the angle. So all my mirror angles are incorrect.

There are many ways you could be aligning the experiment with the direction of travel, so I picked a convenient speed for you and decided to have the hall perpendicular to that. That means you shine the laser in the direction of travel, it hits a mirror, it travels to the far end of the hall and back, then hits the mirror and returns to the laser, but it misses it because your mirror is rotating, so it's deflected a little to the side of the laser.

It is a square prism, so it actually is intended to hit the mirror on the other side, reflecting the beam away from the laser. Sure, it hits both mirrors on return, but it's the defection of the one continuing east that is getting measured. The setup, coupled with the tachometer on the mirror acts as a clock measuring duration of the north/south out and back trip. The defection allows one to compute how much time elapsed without using a fancy atomic clock. We would have needed a clock that could take two nanosecond measurements, and we had nothing like that.

When the wave front of the laser light hits the mirror, one end of it touches first, and the positions where subsequent parts of it contact the mirror are made further away in the direction of travel, thereby changing the effective angle of the mirror to 15 degrees from the direction of travel - it takes a long time for the light to catch the mirror because the mirror is moving at 0.86c, so that's why the effective angle is so different from the physical one.

OK, got you. You are computing the angle that a stationary mirror would need to be to defect the light in the same direction. I hadn't computed that. You get a different effect since the wavelength of the light changes when reflected from the moving mirror, as opposed to a stationary mirror at this virtual angle.

When the light returns to the angled mirror, it approaches it at 30 degrees to the direction of travel of the apparatus, but the wave front hits the top first and then hits progressively lower parts of it, but in such a manner as to make the effective angle of the mirror 85 degrees (if we ignore the rotation of the mirror), so this sends the light back to the laser.

and also to target opposite the laser.

Add in the rotation of the laser and the beam will miss the laser, but I'll leave it to you to do the maths to work out how far it will miss by.

I just assumed I had a clock at that point. The elapsed time can be computed from the RPM, the deflection, and the distance from the mirror to the far wall. There are more complications in the moving frame. The target is closer, but receding. The light travels nearly 4 times the distance to reach that target on the wall, and yes, hits the same spot in any frame.

Other things to consider are that the frequency of the light has halved (if the apparatus is really moving at 0.86c) because the functionality of the laser has been slowed, but your clocks have slowed to match, and so have you, so it all looks normal.

I didn't work in the frequency, which changes anyway each time a mirror is hit. I cared about where the beam hits and not so much that it was objectively a different color.

If instead we move the setup at .866c north, in the direction of the length of the hall. The hall is now 150m long, and light takes 3.73 usec to catch up with the receding mirror and .27 usec to get back which is exactly 4 usec. The dilated clock would still read 2 usec, same figure it reads when it all stands still. But we have no clock, all we have is the return-mirror, which if it spinning slowly, sits at an angle of 120 deg. and deflects the photons forward at 30 deg. (vs 90 deg if we're stationary) at the paper on the side of the hall.

Your mirror angles are again wrong,

Indeed they are. The beam angles are OK at least.

but if you've understood why I gave the numbers I did before, they still apply here - you are pointing the laser in a direction perpendicular to the direction of travel, but the light leaving it is travelling at 60 degrees to that direction due to aberration - for the light to move through the laser at c, it has to move at 30 degrees to the direction of travel of the apparatus.

Yes, the beam is perpendicular while the photons are moving at 30 degrees. If you diagram the path of one photon and the actual position of the mirror when it hits, it actually appears to come from behind the mirror, which actually moves up and hits the photon like a ping pong paddle, deflecting it to straight north with a higher frequency.

If you draw that on paper it looks impossible, because the light looks as if it will hit the wrong side of the mirror but if you draw in the wave fronts, you'll see that the mirror is moving faster than them in the direction of travel of the apparatus, so it overtakes them in that direction rather than them catching it.

Hey, you said the same thing. Yes. It seems funny to have a scenario where the mirror moves along that axis faster than the photon does.

Relativity guarantees that the light will hit the same end point every time, and if you want to claim that it confirms the speed of travel that you used for your measurements, then you've just confirmed that the apparatus is moving at 0.14c relative to the light in its direction of travel.

Yes, it is. I don't disagree with that. Simple subtraction would have given the same result, without all the complicated angles and stuff. Light has a velocity of considerably more than c relative to the apparatus when the light returns, in that frame where the apparatus is moving like that.

It "confirms" the assumption that was made at the start, and it does that regardless of which assumption you make, which means that it confirms nothing of the kind and merely confirms the fact that there is a phenomenon of relativity.

It confirms the premise of relativity, not the predictions that result from that premise. I think that was all I was wanting to confirm. Early experiments assumed a fixed speed relative to the aether regardless of frame. Those experiments failed when a moving apparatus did not measure a longer time for light to make such a round trip.

If you are attempting to measure the speed of light relative to the apparatus,

I wasn't. That speed is actually a relative velocity (or delta-V, there isn't really a name for relative speed in physics) is frame dependent and completely variable (depending on the variable velocity of light) even within one given frame where the object is not stationary, so there is no one speed of light relative to any moving object, not even in the preferred frame. The constant c refers to the velocity of light itself in whatever frame.

If we go back to how this part of the argument began, it was because I said this: "Whenever you try to measure the speed of light you get the same value for it if you assume that you are stationary. If you assume you are moving, you measure values other than c for the speed of light relative to you."

OK, I see what you meant. Yes, you get other values for delta-v then. Delta-v is not what c is. What was experimentally discovered was the fixed speed of light in any frame, regardless of whether the measuring apparatus was stationary or not. This miscommunication (you were talking about velocity, or more specifically, delta velocity, but saying speed) would have been cleared up many posts ago if you would have known the difference and used the terms consistently. Delta-V is simply computed by subtracting the velocities of the two things in question. That doesn't work with speed, so you rarely hear about a term like Delta-speed.

My point was that if you use measurements that are based on you being stationary, you get back an answer that asserts that the speed of light relative to the apparatus is c, whereas if you use measurements based on some other assumption, you get back an answer that asserts that the speed of light relative to the apparatus is >c and < c in some directions.

I see what you trying to convey now, but light is not moving at any other speed than c. Sure the apparatus is also moving, so the difference between the two might be > c or < c. I've said that in other posts, especially the ones about the Sagnac effect.

You then replied with: "This is completely wrong. They initially assumed that they were moving and were surprised at the measurement not changing when 'moving with or against the wind' so to speak. How do you go about measuring light speed that requires assuming one is stationary? I've done it myself. Crude, but accurate to a digit at least. It took a laser, power drill, tachometer, and a piece of paper on the wall. All the components had the same relative velocity as each other, but not assumed stationary. Other early measurements used components that were moving relative to each other, so by definition could not have assumed a stationary measurement." In that, you deny that you assumed the apparatus to be stationary, but you used measurements that were based on the apparatus being stationary. I know that you didn't do it using measurements based on the apparatus moving, because you didn't know how to calculate the mirror angles correctly.

I was measuring the speed of light, not the delta-V of light. The former is frame independent. I did not use the mirror angles to compute the beam trajectories. You notice I got all the lengths correct despite my trig (wrong button) mistake on the mirror angles. Those angles were not used to compute anything else since there were simpler methods to compute the light path than the more complicated trig needed for light striking a moving mirror.

You did exactly what you're denying you did - your measurements were based on the apparatus being stationary. You've now attempted to do it by applying measurements for a different frame to assume that the apparatus is moving, but your angles are wrong, so you've still never done the job correctly.

I never used the mirror angles to compute the end result, as evidenced by the fact that I got the light angles correct. I also didn't use the fact that the light changes frequency with each defection, or worry about how far away the laser was from the first mirror.

Yes, I assumed SR (not GR) to do my computations, as did you when you were computing mirror angles. The early experiments assumed otherwise since there was no such theory. Those experiments predicted different results, which falsified their expectations of measuring a non-constant delta-V when the apparatus was moving. They very much assumed they were moving because they knew without a doubt that they were.

However, you also lost track of how this thread within the thread began and the fact that you reacted with "This is completely wrong" to something that was completely right

Let's look then at what I said was completely wrong, around post 60.

Halc wrote:

Whenever you try to measure the speed of light you get the same value for it if you assume that you are stationary.
If you assume you are moving, you measure values other than c for the speed of light relative to you

This is completely wrong.

You say two things here. The first line is talking about measuring the speed of light, and it is very much a constant in any frame, and thus does not need to assume the experiment is stationary to yield a correct value. That's what was demonstrated with all the arithmetic above. That statement was wrong because of the statement of the requirement of assuming that we are stationary.

The second line specifies something else apparently, that I didn't see because of the poor wording. The incorrect terminology (speed of light relative to X) means in the frame of X, even if X is moving. This is a mode you have frequently used in this thread, talking say about the frame of Earth even though Earth is not stationary.
What you apparently meant to express is that in a frame where X is moving the relative velocity (or delta-V) between X and light with a specific velocity is a value whose magnitude might be other than c. That statement would not contradict any theory. I had to say all that, because light doesn't have a specific velocity so you have to pick one. 'Magnitude' is necessary because that's how you translate velocity to a speed value. 'might be' was necessary since I could select a velocity for my light that happens to differ from the velocity of X by a magnitude of exactly c. Relative velocity with X is probably different, but light speed (the speed at which it is moving) is still c in this scenario.

David Cooper wrote: ↑September 8th, 2018, 5:57 pm This is nonsense. SR says that through a material with a >1 refractive index, light moves at less than c in any reference frame including the frame of the material. Sagnac effect does not ever contradict that.

Refractive issues have nothing to do with this.

Agree. Much simpler to consider the ideal scenario.

The whole thing can be done using a mirror-lined hollow cable where the light is slowed minimally by occasional reflections, and we can easily use speeds of rotation that lead to substantial differences in the time taken for the light to go one way round the circuit (from emitter/detector to emitter/detector) in one direction than the other.

Yes, this has been verified. That's what the Sagnac effect is. You act surprised by it. The light goes further one way than in the other, so the long way takes more time. Relativity does not predict otherwise, as you have asserted.

When we analyse the thought experiment that I set out there, we then find that the light sent clockwise round the ring (which is rotating anticlockwise) will return to the emitter/detector before the light that was sent out in the anticlockwise direction. This demonstrates that the speed of the clockwise light relative to the material of the ring that it was passing while it was passing it was higher than the speed of the anticlockwise light relative to the same material (on the same basis).

In the frame of the disk, yes, this is true. The material is not stationary.

(and you need to picture this being done on a sector by sector basis rather than losing the key finding by averaging it for the whole trip)

Here is where your argument goes to pieces. You're using a different frame here than the one above, and worse, using a whole series of different frames. You're playing invalid maths games now.

It is crucial that the effect isn't lost by playing games with the maths: I'm talking about speed of light relative to ring material local to where the light is, so we divide the ring into lots of sectors and consider only the speed of light relative to the material of each sector while it's passing through that sector and not relative to that sector while it's passing through other sectors.

This statement makes no reference to a frame, so I presume you mean that each little sector has light moving at c in the frame where the material is stationary.

By doing this, we can show that there must be some material in the ring which is being passed by the clockwise light at speeds >c relative to that material. It is mathematically impossible for this not to be the case.

Mathematics are not shown I see. This is exactly the invalid mathematics games you said it was crucial not to play. You have parted company with mathematics!

This means that there must exist frames which misrepresent reality by asserting that light moves in all directions relative to that material at c because we know that some of the material of the ring cannot conform to that requirement.

This means you are doing the mathematics incorrectly. You are mixing frames without doing the conversions.

Well, you need to tell me how you haven't parted company with mathematics if you reject my claim. I provide a list of questions in that thread which people refuse to answer, with one exception who provided wrong answers which showed that he had parted company with mathematics.

I didn't read very far. I found your first post and discovered that you assert that SR and LET make the same predictions, but that only one of them predicts the Sagnac effect. That's a contradiction right there. So I jumped on it since this is the first empirlcal claim (instead of a metaphysical claim) that you've made. SR would indeed be invalid if it didn't predict the effect. I went no further in the thread.

So I found this in post 54:

Here's the crucial thought experiment (backed by experiment through Sagnac and MGP):-

A ring of fibre-optic cable rotates anticlockwise. Light is emitted from an observer who moves with part of the cable. He sends a flash of blue light off anticlockwise through the cable and he simultaneously sends a flash of red light off clockwise. The red flash returns to him first (from the opposite side to the one he sent it out on), and then the blue flash returns to him the other way. He has observed the red flash return to him first, and every other observer in any other frame has made the same observation.

Now for the questions (the answers provided are for non-Minkowski Spacetime):-

I am presuming that axis of the disk is stationary in the absolute frame, which is perhaps what you mean by this non-Minkowski Spacetime qualification. It is the only clue you give to the reference frame being used. Almost all the questions are ambiguous without that.
Futhermore, when you say "speed of light relative to the material", I presume you mean the magnitude of the relative velocity between the cable and the light beams, in the frame of the axis of the disk.

(A) Did the red light pass through all the material of the ring of cable more quickly than the blue light?
Answer: yes.

(B) Is the cable the same length in both directions round it?
Answer: yes.

(C) Does the red light pass through that material at a higher speed relative to it than the blue light does?
Answer: yes.

(D) Does the red light pass through that material at a speed higher than c relative to it?
Answer: yes.

(E) Is there material in the ring which has the property that light passes it at >c in some directions relative to it?
Answer: yes.

(F) If a frame of reference asserts that the speed of light relative to such material with that property is c in all directions, is it misrepresenting reality?
Answer: yes.

So, do you disagree with any of my answers?

I don't actually. But no theory asserts that in a frame where an object is moving, the velocity of a beam of light relative to that object has a magnitude that is c in all directions, so you've not begun to question any known theory.

The red beam goes part way around the circle, and the blue beam goes more than a full way around. Of course the red gets there first. Even Newtonian mechanics predicted that much. Relativity only comes into play with rotation rates so high that the exact difference between the two timings begins to diverge from the Newtonian prediction.

David Cooper wrote: ↑September 8th, 2018, 6:04 pm

Halc wrote: ↑September 7th, 2018, 12:51 pmDavid, SR does not forbid light passing through a material at delta-V (difference between material moving one way and light moving at sub-lightspeed in the other) > c. In your favorite absolute frame for instance, light coming from 'in the wind' passes through Earth's atmosphere at > c since Earth's speed is greater than air's refractive index slows it down. In Earth's frame, that light's speed is sub-c. In no frame is it > c.

When I'm talking about light moving at >c relative to an object, I mean relative speeds higher than the unslowed c that light moves at through empty space with no medium slowing it other than the fabric of space (which limits it to c). That doesn't mean that light ever moves faster than c, but that its relative speed to other things can be substantially higher, and it reaches 2c when we're giving its relative speed to light that's moving in the opposite direction.

Yes. SR doesn't forbid that. It doesn't have to be light. Two rocks can have a delta-V far greater than c in a frame where they're moving fast in opposite directions.

I do disagree.

First a quick note about the concept of "limits" as the basis of differential and integral calculus.

The phrase "in the limit that..." is often used in physics. A limit is a mathematical concept. When integrating an arbitrary function, one way to do it is to chop it into small sections and assume each small section is approximately linear. This is a method of numerical integration. It's a method that is used in a lot of computer simulations. David implicitly used it in the gravity/tides simulation code to which he posted a link. To increase the accuracy of the method, we reduce the size of each section. We can arbitrarily reduce that size. In other words, for any section size it's always possible to make it even smaller. As the section size tends towards zero so the accuracy of the approximation to the function tends to 100%. So we say: in the limit of an infinitesimally small section we approach the original function.

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This was to Halc about the Sagnac effect, and related effects:

David Cooper wrote:I haven't directly asked you the questions, but I'm going to ask you the most important one now. Does the light moving clockwise round the ring move faster relative to the material of the ring that it's passing (while passing close to it) than the light moving anticlockwise round the ring does? (And bear in mind that we're dealing with light not slowed by a medium other than the fabric of space.)

I'd like to say something about this myself.

OK, so how are we going to answer this question? Well, movement is defined as the change in position of an object or particle, with respect to time, relative to some other object or particle. Average speed is defined as delta distance / delta time. So average speed in a straight line is fairly simple. Average speed over a non-linear path is found by integrating over that path. And that brings us back to the concept of limits.

To answer a question about how something moves we have to observe it, from some chosen vantage point, at position X₁ at time T₁ and at position X₂ at time T₂. That gives us the average speed, between those two points, as observed from some other position (vantage point) which we could call X₃. We can simplify things by making X₃ = X₁ or X₂.

If we want to get the average speed over a smaller distance we can pick values for X₁ and X₂ that are closer together. We can keep bringing them arbitrarily closer together. i.e. for any given distance we can always think of a shorter distance. In the limit of an infinitesimally small distance between X₁ and X₂ we have the instantaneous speed. Note how limits work here (see above). Note the important distinction between the concept of "zero" and "infinitesimally small" or "arbitrarily close together". And note how this leads to the concept of instantaneous local speed.

So, to measure the local instantaneous speed of light at a point along that ring we can imagine placing two detectors an arbitrarily small distance apart, synchronizing their clocks, and recording the time at which they detect light hitting them. If we do that, at any point on the ring, we measure a local instantaneous speed of 'c' in both directions (on the basis that, as David said, we can assume a refractive index of 1 for the ring, or a series of mirrors in a vacuum, or perhaps a cylindrical mirror.)

But if we place detectors (with synchronized clocks) at the point on the ring from which the light was emitted, and if those detectors are stationary WRT the rotating ring, we find that the pulse which arrives from a direction indicating that it traveled in the same direction as the ring's rotation arrives after the pulse travelling from the other direction. But if we were to measure the instantaneous speeds of those two pulses, using the method previously described, we'd measure them both to be travelling at the same speed. Same on any part of the ring, including this one. This is a real device that is actually successfully used to measure rotation speeds. So these are real, reproducible results. The local, instantaneous speed of the light, in both directions, at any point on the ring, measured in a reference frame that is moving with the ring, is the same. But if you stop measuring local, instantaneous speed, move your two detectors (with their associated clocks) a finite distance apart and move them further and further apart, you deviate further and further from the concept of local, instantaneous speed. Your two detectors are no longer co-moving. The reference frames in which they are each stationary are no longer the same.


(Note: WRT means "with respect to")

David Cooper wrote: ↑September 8th, 2018, 9:21 pm But I will say now that if you're synchronising two adjacent clocks that are adjacent and not in exactly the same place, you will rely on signals moving between them.

Then they're not in the same place. If you intend to be picky, then the two clocks would need to be idea clocks with point locations, at the same point. No real clock is at one point. The applications that utilize Sagnac effect (like interial guidance) use one device to compare both signals, not separate synced devices.

I was agreeing, but what do you mean by 'comoving with'. Comoving is a property, not a relation, so I don't know how I might be comoving with another object.

If two objects are co-moving, each is co-moving with the other.

Why no just say they're each comoving? The relation is not necessary to convey that.

You mix different interpretations and find them contradictory.

I compare the claims of different frames and rule them to be incompatible because to accept them as compatible is to accept that 1=2.

You are comparing claims of different interpretations and proving the interpretations are not compatible. In particular, you mix Minkowski geometry of the universe with non-Minkowski, and find claims made by each to result in this 2=1. If you want to demonstrate the inconsistency of the Minkowski model, don't have non-Minkowski as one of your premises.

Your quiz in your webpage starts right out with a premise of non-Minkowski model of reality, which is fine, but then the remaining questions presume a Minkowski interpretation of reality and SR to draw contradictions. That is mixing models..

Looking at something from different angles and creating different images of them does not generate contradictions.

You are arguing otherwise.

Your rigor falls totally apart when you mix the two views. It is OK to only accept the one view, but you cannot assert it when disproving an alternative.

A contradiction's a contradiction. I'm not mixing up anything, but am simply applying reason in the strict way that it demands to be applied.

Consider just for a moment that I am correct about your mixing two different views. I really tire of these repetitive posts where you give the same repetitive answers and don't actually address the point I am trying to make here.

If you don't think that's happening though, just go to a physics forum and watch your perfectly reasonable posts being deleted until you get banned

Or alternatively you could actually consider the replies you get instead of assuming up front that it is a conspiracy of inconsistency. Clearly you know I'm wrong so you're not even considering that I have a point.

The 4D version of SR generates contradictions in the same way as its 3D equivalent - modes 2 and 3 can both represent 3D or 4D universes.

Well, they do if you assert them both at the same time, yes.

LET's very clear - it's a 3D model which runs under Newtonian time.

Give a reference to that please. The wiki doesn't say it. Maybe somewhere else does. It does not run under Newtonian time since that model predicts a different light speed measurement when you're not stationary. That one has been empirically falsified.

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Only because [the chess example] leaves room for confusion when the task's so big that most people can't get their head around it.

The concepts don't require one to visualize all members of the set at once any more than the concept of integers is less understandable becuase nobody has printed the entire list. Considering of a select state and the states that immediately relate to it are enough.

I think you should care about whether it exists or not.

I do. My opinion is different than yours most likely. I have my logic for choosing my answer, but it is no proof, so I don't assert it.

But it has temporal properties fairly identical to the structure that is our own universe.

It is timeless, but time and causality do come into play when the positions are actualised and stop just being potentials.

Not needed. The events have the same relationship without that: A being the immediate prior state to B.

So here you go with your pet assertion again.

You asserted that causation is at play in a static set of things which don't actually exist in any real form until they've been actualised through a running process with real things representing them, and even then they only exist in the way that patterns and shapes exist.

I found the model to be similar. I bolded the part I never asserted. In particular, I made no ontological assertions about anything. Yes, it exists in the way that patterns and shapes exist, but I left that agnostic. I don't know the ontological status of such things.

They are part of a set of abstract things which play by different rules, so it isn't valid to equate the two kinds of things.

It is a valid model if the model of our universe plays by similar rules, which is a static set of things with indeterminate ontological state except for the Minkowski addition that different states have equal ontological status. It doesn't specify that status, but just that they're all the same. The set of chess states is exactly like that. There is no ontological difference between one state and another one, despite the fact that I've left that status unspecified.

The states are very much ordered, and I never suggested that any of the states had 'been done'. Each state has a causal relationship (but not a determined relationship) with the prior state, just like today's relationship with yesterday. That's the non-flowing way of defining causality. It doesn't make sense to you because you are mixing in a different interpretation of causality, the same mistake you make when finding contradictions in SR.

Your model of reality has an error in it where you're counting things that don't exist as things that exist. This comes from the dodgy rules of a particular set of rules for handling sets where defining a set of things can be asserted to bring something into existence even though nothing real exists in the set.

Most proponents of the 4D interpretations consider the structure to be actual, so since a lot of your post focuses on your bias that somebody else's view cannot be actual,

I didn't rule it out entirely - I only ruled out SR. A 4D theory similar to SR could be viable, but it goes against the metaphysical dogma tied to SR.

Umm... What do you think is the assertion of the interpretation you say is contradictory???? What dogma are you talking about? I thought I understood your argument. Are you trying to disprove a 3D interpretation of SR? I thought that's the model you're pushing. A 3D model has an objective frame, and only events simultaneous with a preferred moment are real. Your mode-3 in the simulation depicts a 3D interpretation of SR. The other two modes depict no interpretation that I know of, but the diagram above the simulation is a reasonable depiction of the 4D model.

There is no possibility of real causation in that model.

This presumes a definition of causation from a different interpretation. I don't care if you disagree with the model you don't like, but bringing in definitions from different models just proves that the models are not compatible. You apparently are not even aware that you are doing this. Maybe you should drop the SR claim and just push your presentist claims with the begging argument that a block model says it is also yesterday, therefore it is wrong. 2=1 and all that.

I won't accept any model with fake causation in it

Didn't ask you to accept it. I'm asking you to demonstrate inconsistency with itself, including what you label as fake causation. It is quite fallacious to put the 'fake' label on a part that doesn't match your opinion.

To summarize, here are my answers to David Cooper's questions about the Sagnac effect:

(A) Did the red light pass through all the material of the ring of cable more quickly than the blue light?

Yes.

(B) Is the cable the same length in both directions round it?

Yes.

(C) Does the red light pass through that material at a higher speed relative to it than the blue light does?

No. Unlike for question A, we are now no longer talking about the time taken for the light to pass through the whole ring of material. We're talking about the instantaneous speed at an arbitrarily small point on the ring. This speed being instantaneous, it can be measured WRT an inertial reference frame that is instantaneously at rest WRT the non-inertial reference frame that is at rest WRT this point on the ring. Therefore the instantaneously, locally measured speed of light is equal in both directions. But this inertial reference frame is not instantaneously at rest WRT any other points on the ring. It is not instantaneously at rest WRT the current position of the other pulse of light.

(D) Does the red light pass through that material at a speed higher than c relative to it?

No. See answer to C. If the local instantaneous speed of the red light were measured, as described earlier, it would be found to be c.

(E) Is there material in the ring which has the property that light passes it at >c in some directions relative to it?

No. The local instantaneous speed of light is c in both directions.

(F) If a frame of reference asserts that the speed of light relative to such material with that property is c in all directions, is it misrepresenting reality?

Frames of reference don't talk. Measurements are made using them as a reference (hence the name). Measurements made in inertial frames of reference find that the local instantaneous speed of light is c in all directions.


Footnote: The Michelson-Morley experiments can be considered to be experiments carried out on a relatively small object (the Earth) travelling around on the relatively large ring of a Sagnac Effect experiment (the Earth's orbit around the Sun). Considered in this way, those experiments, to a pretty high precision, carry out the measurement of instantaneous light speed at a point on the ring that I described earlier. They demonstrate my answer to questions C, D and E. They show that the near-instantaneous speed of light is measured as C in both directions.

Steve3007 wrote: ↑September 9th, 2018, 4:26 amWhat "mathematical squiggles" are you referring to exactly? The mathematics of vector calculus? The Heaviside formulation of Maxwell's Equations? The tensor calculus used in General Relativity? Or just all algebra?

Nothing to do with the discussion here - I was simply making the point that if I need to know something, I research it, and if the information is impenetrable, I find people who can make sense of it. Many pages on Wikipedia are dominated by squiggles with insufficient explanation to make sense of them in any reasonable length of time, and usually I'm only looking for one little bit of information which may be in there somewhere, but it isn't easy to find it.

With many, many comments here and elsewhere you have declared yourself to be at the top of that hierarchy.

At no point have I claimed to be at the top in Physics, or anywhere near it. I've come into this as an outsider to check a theory to see if it stands up to scrutiny, and anyone who wants to do this is fully entitled to do so even if they don't have my background in applied reasoning (which I obtained through my work in AGI system development). The job is simply to apply reason and maths systematically to the theory being tested and to try to run the model by its own rules, and the reason and maths should be applied in the same precise manner as an AGI system would apply them. I have done that and found the model to be broken. It's possible to become an expert in Russian prepositions and case endings without knowing any Russian verbs, and someone with that expertise who doesn't know the language beyond that can still know the rules better than many native Russian speakers. You cannot break my argument by finding some area of physics that I don't know as well as someone who has a degree in physics.

In the above, by "those" and "they" I assume you mean Maxwell's Equations. Just to be clear about what you did when you "picked them apart": Which terms in Maxwell's equations are the distance terms? How were they measured by Faraday and other experimental physicists?

It's your job to tell me - you're the one who asserted, assuming I remember correctly (it's too time-consuming to hunt back to make sure), that Maxwell's Equations demonstrate that the speed of light relative to the apparatus is always c. If that's the case, you need to show how that comes out of those equations because I can't see any way that it could do so. I've told you why I think it won't work to help you test your claim (if you made that claim). And if you didn't make such a claim, then this entire issue is an unnecessary diversion of no consequence.

I am eagerly expecting to learn something from someone who has much more depth of understanding and insight into the subject than I do (as a mere former-teacher with a, now, very rusty and old education in the subject). But, so far, nothing.

The discussion is specifically about relativity and an argument (proof) that SR doesn't work. The argument doesn't depend on Maxwell's Equations, but I'm open to the possibility that you might be able to do something interesting with them which would destroy mathematics. It isn't my job to do that for you.

You won't show me the depth of your knowledge. Instead, you appear to me to show muddle over, for example, what it means for a statement to be logically self-contradictory.

Any muddle over that is at your end. I can show you contradictions, but I can't make you see them as contradictions if you're determined not to see them for what they are.

You give a good impression of someone who isn't actually at the point in that hierarchy that they claim to be. That's why I keep asking questions to try to give you a chance to show that impression to be wrong.

Your task here is to test the argument. My abilities are irrelevant to that - the argument either breaks or it doesn't, and the same applies to any other such argument whether it's put together by a leading scientist or a village idiot.

That's like an English Literature research post-grad saying that they've heard of a guy called Shakespeare but never read him themselves (and regard Shakespearean language as a bunch of squiggles).

Maxwell's Equations have no involvement in my argument - you brought them into this, and it's your job to do something with them to make them relevant.

You can't just pick the thin thread through the subject that you think is going to lead you as quickly as possible to the conclusion you want. That leads you very, very likely not to have fully understood the arguments of those you seek to overturn. As I've said, to build the roof you first need the foundations.

I have collected all the knowledge necessary for the argument. Not knowing irrelevant things is not an issue.

What do you mean "being loaded with rest-frame values"? Walk me though some of the early experiments in electricity and magnetism, which led ultimately to the various equations that were brought together by Maxwell (and simplified by Heaviside), and show me what you mean in that context.

I need you to show me what you're doing with the equations so that I can see what you're doing to get any values that represent a distance. If you're measuring the distance between two parts of the apparatus with a ruler, for example, you are almost certainly treating the rest frame of the apparatus as the frame of reference for your measurement, and that is programming in the assumption that the apparatus is stationary right at the outset, thereby making it no surprise if the assertion that light is moving at c relative to the apparatus in all directions is spat back out again at the end.

I can try to put some oil on my rusty knowledge and teach you some physics. But I shouldn't be doing that.

On this point, you absolutely should be doing it because you made a claim which you need to back up. It wasn't my claim and it has nothing to do with my argument - I don't know what trick you're using for your claim, so I can't unpick it for you unless you show me what you've done with the equations. And if you didn't make the claim that I think you made (because you may merely have meant that the constant c pops out of it), then this whole issue is irrelevant.

You, as the paradigm-overturner, should be teaching me. The way forward is for you, the one with the extraordinary insight and the extraordinary claims, to be providing the extraordinary evidence to demonstrate those claims.

It's my job to defend my argument and your job to defend yours, and to set it out in sufficient detail to make it possible to attack it.

That is very surprising because if you are, then you are wrong. Prove me wrong in saying that by quoting the mathematical expression, used in an accepted law of physics, which amounts to "2=1".

The 2=1 comes out of the claims that there is no absolute frame of reference and that all frames are equally valid, as you've been told repeatedly. All frames contradict each other in the claims they generate, and if you are to tolerate those contracictions, you are accepting that 2=1 (and that every number is equal to every other number).

Remember what I said earlier about language?

viewtopic.php?p=319102#p319102

If a statement in mathematical language does not contain an expression that is logically equivalent to "2=1" then, if you correctly render that statement into English, it still doesn't. Same as if the languages were French and English. If you think it does, then something has got lost in translation.

The claim that all frames are equally valid is part of the mathematics. If you don't accept that claim as part of SR, then it's being taught wrongly practically everywhere because that assertion is locked firmly to it along with the denial of an absolute frame.

Your statements, about what reference frames "claim", are badly worded.

My statements about that are very well worded, spelling out clearly how the rules work.

As I've already said, reference frames don't claim anything.

And I've made it clear that they absolutely do. You can claim that they don't, but the claims that are generated for them are necessary consequences of the way they work. If you're picturing a frame with a mouth and a speech bubble with one of these claims in it, then of course that isn't a reality, but the claims that I'm talking about are unavoidable and they contradict the claims generated by using other frames as a base.

Observations/measurements are made by observers who use reference frames to quantify them.

When you make measurements using a frame, you do so using precise rules, and a frame A measurement of the speed of light relative to object B in the direction that object B is moving through frame A will not be c. When you switch to frame B and make measurements of the speed of light relative to object B there, you will get the value c in all directions. The results contradict, so if one frame has given the true speed of light relative to object B, the other frame has not. That is all there is to it. There is no trick that you can use to get around this other than the standard one of passing off frame B measurements as frame A measurements while denying the actual frame A measurements - that is what is typically done, and it flies in the face of mathematics. My thought experiment with the ring is designed to help deprogram people who have been taught to apply that mathematically-illegal move.

Out of interest, do you apply that illegal move (passing off a frame B measurement as a frame A measurement) and consider it valid? If not, you should be capable of seeing the contradiction. And if you do see the contradiction that comes out of not recognising that all frames are equally valid, that logically forces you reject the mode 2 version of SR.

If observer A and B are both carrying clocks and observer A says "I count the ticks of B's clock coming more slowly than I count the ticks of mine" and if B says "I count the ticks of A's clock coming more slowly than I count the ticks of mine" there is no contradiction. Neither of them is wrong unless they've made a mistake in their observations. Nobody has said "2=1". If you think differently then you have to show me how, in terms of something that can be observed.

The contradiction only appears if you assert that clock A is ticking more rapidly than clock B and that clock B is ticking more rapidly than clock A at the same time. If you accept that these two things can both happen at once, then you have accepted something akin to 2=1 (and by extension that 2=1 and that every number is equal to every other number). If you don't accept these two things can happen at the same time, then you have rejected the dogma that all frames are equally valid.

Describe to me an observation that shows one or both of them to have said something contradictory. It's when you do this that you start to have to think carefully about something like this famous "twin paradox".

The travelling twin (TT) sets off and the stay-at-home twin (ST) sees TT's clock slow down (after compensating for the Doppler effect which he knows to take into account). TT sees ST's clock appear to slow down in the same way, but he knows that ST didn't accelerate, so he might determine that his own clock must have speeded up. Either way though, these observations produce contradictions and both accounts cannot be correct (that ST's clock is now ticking faster than TT's clock and that TT's clock is now ticking faster than ST's clock at the same time). It's really straightforward stuff and I can't see why you have so much difficulty with it.

Halc wrote: ↑September 9th, 2018, 10:57 am

However, you also lost track of how this thread within the thread began and the fact that you reacted with "This is completely wrong" to something that was completely right

Let's look then at what I said was completely wrong, around post 60.

Halc wrote: This is completely wrong.

You say two things here. The first line is talking about measuring the speed of light, and it is very much a constant in any frame, and thus does not need to assume the experiment is stationary to yield a correct value. That's what was demonstrated with all the arithmetic above. That statement was wrong because of the statement of the requirement of assuming that we are stationary.

The context was based on the idea of trying to measure the speed of light relative to the apparatus. The "relative to you" part at the end of the second statement is a reminder of that, but it already applies to both statements and I only added it in as a reminder. Again though, as so often before, we end up arguing at cross purposes because we aren't taking ten times as long to produce legal documents.

The second line specifies something else apparently, that I didn't see because of the poor wording. The incorrect terminology (speed of light relative to X) means in the frame of X, even if X is moving. This is a mode you have frequently used in this thread, talking say about the frame of Earth even though Earth is not stationary.

If I say that X is moving, I'm clearly not using frame X for that statement, so if I talk about the speed of light relative to a moving object, I'm very clearly using some other frame, even if I'm moving with the object. I am also using wording that is fully acceptable in LET and which is used extensively by others, including physicists who speak to the public and have to avoid using jargon. I will continue to use wordings which the general reader will understand if they read this thread, and you are welcome to translate things into jargon if it helps specialists understand what's being said.

On the business of getting the mirror angles wrong, yes, you're right - you can get them wrong and still get the rest of it right, so I accept that you did test it for different frames (and thereby confirmed that relativity happens).

David Cooper wrote:Maxwell's Equations have no involvement in my argument - you brought them into this, and it's your job to do something with them to make them relevant.

The theories of Relativity and the LET brought them into this.

I have collected all the knowledge necessary for the argument.

That remains to be seen.

The 2=1 comes out of the claims that there is no absolute frame of reference and that all frames are equally valid, as you've been told repeatedly.

Please define the word "valid", as you understand it, in this context.

The claim that all frames are equally valid is part of the mathematics.

Please show me the part of the mathematics that contains this claim.

The contradiction only appears if you assert that clock A is ticking more rapidly than clock B and that clock B is ticking more rapidly than clock A at the same time.

That assertion is not made and the expression "at the same time", in the context of that sentence, is a misuse of language. This is an example of you mis-translating the Theory of Relativity, as I mentioned previously. You have therefore not collected all the knowledge necessary for the argument.

The travelling twin (TT) sets off and the stay-at-home twin (ST) sees TT's clock slow down (after compensating for the Doppler effect which he knows to take into account). TT sees ST's clock appear to slow down in the same way, but he knows that ST didn't accelerate, so he might determine that his own clock must have speeded up.

"He might determine that his own clock must have speeded up" relative to what? What precisely is meant, in this context, by the statement: "my own clock has speed up"?

Either way though, these observations produce contradictions and both accounts cannot be correct (that ST's clock is now ticking faster than TT's clock and that TT's clock is now ticking faster than ST's clock at the same time). It's really straightforward stuff and I can't see why you have so much difficulty with it.

The above is a mis-representation of the accounts of ST and TT, similar in form to your earlier mis-representation.

David Cooper wrote:At no point have I claimed to be at the top in Physics, or anywhere near it. I've come into this as an outsider to check a theory to see if it stands up to scrutiny, and anyone who wants to do this is fully entitled to do so...

Yes, everybody is absolutely entitled to do so. But when they want to scrutinize something that somebody else has said, the first step is to understand what it is that they have said! You repeatedly show that at the most basic level you have not done that. I keep telling you what it is that the theory says and you keep just changing it back to the same old incorrect form so that you can keep finding your contradictions. You appear to be repeatedly constructing and re-constructing a straw man and then triumphantly knocking it down again. I don't know why you would want to do that.

Halc wrote: ↑September 9th, 2018, 12:18 pmYes, this has been verified. That's what the Sagnac effect is. You act surprised by it. The light goes further one way than in the other, so the long way takes more time. Relativity does not predict otherwise, as you have asserted.

I'm not in the least bit surprised by it, and I never said that SR or any other kind of relativity predicts otherwise. The point that you should be focusing on is the speed of the light relative to the material of the ring that it's passing (when it's at the closest point of approach to each bit of that material).

(and you need to picture this being done on a sector by sector basis rather than losing the key finding by averaging it for the whole trip)

Here is where your argument goes to pieces. You're using a different frame here than the one above, and worse, using a whole series of different frames. You're playing invalid maths games now.

I'm using a single frame of reference, though the whole thing can be thought through from the perspective of any other frame with the same finding coming out of it in every case. The easiest frame to imagine to begin with is the one with the centre of the ring stationary in it while the disk rotates. The ring is divided into lots of sectors, but let's keep it down to 100 of them, and we can name them s0, s1, s2, etc. all the way up to s99. The emitter/detector is on the boundary between sector s0 and s99. That's how I described the experiment in the threads linked to on the other forum. I have the ring rotate anticlockwise (because I started off describing it as being set round the equator of the Earth and viewed it from over the north pole, while the sector numbers go up as you move eastward round the ring [faster than the ring is rotating]).

The point of introducing these sectors is simply to uncover something that would be hidden otherwise by averaging out the effect that we're trying to see. I want the speed of the clockwise light relative to the material of the ring as it's passing that material at close range and not when it's at the far side of the ring, so it's added up on a sector by sector basis. We have the speed of the clockwise light relative to the material of s99 while it's passing through s99, the speed of that light relative to s98 while it's passing through s98, etc. all the way round. This produces the finding that the speed of light relative to the material to the ring that it's passing while it's right next to it is higher clockwise than it is anticlockwise.

If we rotate the ring at a suitable speed, e.g. 0.6c, we can ensure that both lots of light return to the detector/emitter at the same moment after a few laps but with the clockwise light having passed all the material of the ring more times than the anticlockwise light. It has, on average, passed through the sectors of the ring at a higher speed relative to them than the anticlockwise light, and it has done so at a speed greater than c relative to them (on average). [The wording "on average" isn't actually necessary in this case where the centre of the ring is at rest in the frame we're using, but it is needed for other frames where the centre of the ring is moving through them.]

This statement makes no reference to a frame, so I presume you mean that each little sector has light moving at c in the frame where the material is stationary.

Yes - each sector is moving through the frame that we're using, and light always moves at c through this frame, as the rules demand.

By doing this, we can show that there must be some material in the ring which is being passed by the clockwise light at speeds >c relative to that material. It is mathematically impossible for this not to be the case.

Mathematics are not shown I see. This is exactly the invalid mathematics games you said it was crucial not to play. You have parted company with mathematics!

The mathematics is all there for you to extract and run through your head, and you can easily supply your own numbers to test it. I've suggested rotating the ring at 0.6c because it produces a convenient amount of length contraction for the ring - this speed contracts things to 0.8 of their rest length, so you'd need an extra 0.25 of ring material to complete the ring (which actually means it has to shrinks down in size once it's up to speed). After the ring has completed three rotations, both lots of light have done five laps by this point from the point of view of a stationary observer standing by the ring who is not rotating with it, but the clockwise light had passed through each sector eight times while the anticlockwise light has only passed through each sector twice. This means that the clockwise moving light has passed through the sectors of the ring at a speed four times higher relative to them than the anticlockwise light did. The speed of the clockwise light relative to those sectors while passing through them is 1.6c, while the speed of the anticlockwise light relative to those sectors while passing through them is 0.4c.

This means that there must exist frames which misrepresent reality by asserting that light moves in all directions relative to that material at c because we know that some of the material of the ring cannot conform to that requirement.

This means you are doing the mathematics incorrectly. You are mixing frames without doing the conversions.

How am I mixing frames when I'm using a single frame throughout? Try again.

I didn't read very far. I found your first post and discovered that you assert that SR and LET make the same predictions, but that only one of them predicts the Sagnac effect.

I made no such claim, so you must have read a meaning into something that wasn't there.

I went no further in the thread.

That explains a lot.

I am presuming that axis of the disk is stationary in the absolute frame, which is perhaps what you mean by this non-Minkowski Spacetime qualification. It is the only clue you give to the reference frame being used. Almost all the questions are ambiguous without that.

It applies to any frame, so you can pick whichever one you like. The reference to it not being Minkowski Spacetime is there simply because if you use that you're dealing with different models where light has no speed because it reduces all paths to zero length.

Futhermore, when you say "speed of light relative to the material", I presume you mean the magnitude of the relative velocity between the cable and the light beams, in the frame of the axis of the disk.

That sounds right.

So, do you disagree with any of my answers?

I don't actually. But no theory asserts that in a frame where an object is moving, the velocity of a beam of light relative to that object has a magnitude that is c in all directions, so you've not begun to question any known theory.

A 3D theory that asserts that all frames are equally valid necessarily generates claims from different frames that contradict each other. People typically assert that the speed of light relative to object A is c in all directions, and then they switch frame to assert that the speed of light relative to object B is c in all directions, and they insist on the frame B claim about the speed of light relative to object B being the correct one for frame A too while rejecting frame A's measurement for the speed of light relative to object B. They do this in order to deny the existence of contradictions, and they have been systematically taught to do this by people who teach relativity incorrectly. The contradictions are clear though: frame A and frame B produce different speeds for light relative to object B and their contradictory claims cannot both be true.

The red beam goes part way around the circle, and the blue beam goes more than a full way around. Of course the red gets there first. Even Newtonian mechanics predicted that much. Relativity only comes into play with rotation rates so high that the exact difference between the two timings begins to diverge from the Newtonian prediction.

Relativity isn't important with the experiment at all, unless you want to get into the length contraction issue. The point of the thought experiment is simply to show that some frames generate claims that misrepresent reality, and the aim is to try to deprogram brainwashed victims of bad education. Here we have an experiment which can be looked at from the perspective of any frame where it will always show that the speed of light relative to some of the material of the ring must be >c and <c in some directions, and switching frame doesn't eliminate this fact. Any frame that represents that material as having the speed of light relative to it as c in all directions is misrepresenting reality, and all the experiment does is prove that point: not all frames are equally valid, and by extension, only one frame can be giving a true account of reality.

I'm stopping here for tonight, but I'll jump ahead to deal with Steve's short post and return to earlier ones next time:-

Steve3007 wrote: ↑September 9th, 2018, 6:22 pmI keep telling you what it is that the theory says and you keep just changing it back to the same old incorrect form so that you can keep finding your contradictions. You appear to be repeatedly constructing and re-constructing a straw man and then triumphantly knocking it down again. I don't know why you would want to do that.

I'm attacking SR as it's presented, including the dogma that is firmly locked to it. If you don't want the dogma about there not being an absolute frame, that's a step in the right direction, but you're not speaking for the herd, and even if you were speaking for them, it is pointless to try to make SR agnostic on the issue because it generates contradictions if it doesn't have an absolute frame, and those invalidate that option. In rejecting the contradictions, it is forced to have an absolute frame. [Note though that this doesn't directly apply to all the SR models, but each model has to be looked at individually and be ruled in or out. Different ones are ruled out in different ways.]

David Cooper wrote:I'm attacking SR as it's presented...

Presented by whom? I learnt it as part of a general physics education from various textbooks and lectures. Your repeated mis-representations of Relativity do not match the sources of that education. If you're saying that it has also been mis-represented by other people as well as you, that doesn't really change anything.

OK. Talk to you later.

David Cooper wrote: ↑September 9th, 2018, 5:44 pm The context was based on the idea of trying to measure the speed of light relative to the apparatus.

I don't see how that can be done. You can't change the light in any way, so no mirrors or light tubes or anything. Any such thing would change the velocity of light, and thus alter this delta-speed you are seeking. There is no value that represents a generic speed of light relative to a moving object because the difference is not independent of velocity like light speed relative to a frame is. My amateur experiment with the mirrors had no speed of light relative to the apparatus since the value changed with every mirror used. It seems a pretty meaningless thing to want to measure, when a simple subtraction of known values, (not measured by the apparatus), would do.