Halc wrote: ↑September 18th, 2018, 8:14 amOK, from the page showing how SR needs to be 'twisted' to predict the Sagnac effect: http://www.conspiracyoflight.com/Sagnac ... ndRel.html
On the other hand, the observer at A who is rotating with the disk has observed that the source and detector are stationary from his perspective, as are the paths, so he can only conclude (assuming no foreknowledge that he is rotating) that the light has actually travelled at two different velocities around the disk, being C+v and C-v. Who is right? Well, the problem is this – from the point of view of special relativity, there are no preferred frames of reference, there are only relative frames of reference, so we can’t argue that frame B is better than frame A without defeating the underlying premise of the theory.
The guy rotating with the disk very much knows he is rotating, even without foreknowledge. The spinning bucket bit above event points this out, but the author conveniently forgets this here.
You misinterpreted what he said about the guy at the centre of the bucket. He said "the cause of the concavity may not be obvious, particularly if the rotation is slow and his view of the surroundings is blocked". In the same way, if the rotation of the disk is slow, the guy going round with it may not notice the rotation, just as a hermit in a cave does not feel any rotation.
The next problem is the way he repeatedly uses language in a particular way where he talks about the speed of light not always being c, but what he means by that is its speed relative to something and not its speed through space - it's a bad wording, but he uses it consistently and you have to apply the right transformation to it each time to turn it into a form that makes more sense to you.
The last sentence in that quote is blatantly invalid physics. It is an embarassment to the author to twist things like that.
He appears to be treating frame A as an inertial frame on the basis that the guy thinks he isn't rotating and will treat it as an inertial frame. The rotation will be so slow that he's hardly moved at all, but a difference in the times taken for the light round the circuit will still show up. I agree with you that he's wrong there. I'll have to contact him and see if he's capable of correcting such errors. I've only read some parts of his site relating to the way LET correctly predicts the results of experiments and I've paid less attention to the places where he attacks SR where he's more likely to slip up - those parts don't interest me greatly because I don't need any more ammo for that.
It seems to be the same strawman techniques that you have been pushing, even if you've not asserted that particular error. Case in point where you insist on a flowing time model when considering a model without it:
and by all three other modes if you imagine them building the block as they go.
Halc wrote:That is not Minkowski spacetime.
Absolutely identical geometry.
But absolutely different metaphysics.
I haven't used any strawman techniques. Every time you've accused me of that, I've shown you that you're wrong. Same again here - you haven't shown the full context because you haven't gone back far enough to collect it. I was discussing the mode zero models which aren't directly shown on my page about relativity, and they aren't shown because they're static and impractical to draw using JavaScript and HTML - I can move dots (punctuation) representing planets around the screen, but can't draw lines with it unless they're made of chars such as "/", and that doesn't allow much variety of angles. (Attempts to make lines from lots of punctuation dots slow programs to a crawl.) I told you that the mode zero models would be the same shape as the one that would be built by running any of the three modes of the simulation if they built a lasting block behind them as they go. At no point did I intend you to take from that that the blocks were functionally identical. It should have been clear to you that they wouldn't be, because there is ongoing flow through some of them even once the blocks are complete. Mode 1 generates a block with an added Newtonian time which enables events to change over Newtonian time at individual Spacetime locations (and I've told you that before), so that model contains two kinds of time. The mode zero blocks don't contain that Newtonian time, but the geometry is identical. The mode 2 and 3 blocks might also be different, but it's hard to pin down how - they are really just fossils with imaginary physics being attributed to their content, but the mode zero models aren't greatly different other than in origin (by lacking one and relying on magic instead). Anyway - when I told you how to generate the shape of a mode zero block from one of the three time-running modes, I never told you to take anything other than the shape along for the ride - you made that decision for yourself, and now you're trying to label your error as mine.
For those who don't want to wade through the older thread:-
There are fourteen models that I've set out, and they're divided into four sets.
Set zero contains two models, one of which is a 3D block universe (which could arguably be the original version of SR), and the other's a 4D Minkowski model (used commonly for both SR and GR). These models contain the past, present and future all in one go as a static eternal block which has never been generated in order of causation because time in that model doesn't run/flow.
The other three sets each contain four models which are either 3D or 4D, while each of those options comes in block and non-block versions. The non-block versions run time without building a lasting block behind them (so the past doesn't exist any more), and the block versions are similar but build a lasting block universe behind the construction front which preserve the entire past. With all the block versions here, they are generated in order of causation rather than just existing by magic as complete blocks that were never anything less than complete.
Set 1 models run events in such a way that no clocks run slow - all clocks tick at the only rate they're allowed to tick at, and that's one second per second. There is no mechanism allowed in these models to make clocks on any paths run slower than they do on other paths.
Set 2 models run events in a way that allows each frame's time to govern the time of every other frame such that all clocks not at rest in a frame are made to tick slower than the ones that are at rest in that frame. These models have no absolute frame.
Set 3 models run events in a way that allows one frame's time to govern the time of every other frame such that all clocks not at rest in that frame are made to tick slower than the ones that are at rest. These models have an absolute frame, and the 3D non-block model in set 3 is the LET model (Lorentz Ether Theory).
It's easier to understand these different sets of models if you can see them in action, so I wrote a simulation that can run in three different modes to illustrate the three sets of models that have a running time in them (mode zero is static, so it is not represented there directly). You can find that simulation about 3/8 of the way down my page about relativity:
http://www.magicschoolbook.com/science/relativity.html - scroll past the MMX diagrams near the top, on beyond the diagrams with little space-shuttles in them, and on down to the pair of Spacetime diagrams. The simulation is below them, but the Spacetime diagrams represent the same thought experiment, and the text underneath them explains what's going on in the simulation.
Einstein's original version of SR is arguably a set 2 3D non-block model, but it could also be a set 1 3D non-block model. It's often described in such a way as to be a hybrid of the two, but the two models are incompatible with each other as they run on different rules, so such a hybrid model is banned. The two models named here are also impossible models: the set 1 non-block models suffer from event-meshing failures which invalidate them; while the set 2 non-block models generate contradictions which invalidate them. Set 2 block models cannot be constructed rationally, so they are invalidated too, and that means that all the set 2 models are dead. No viable theory can use them.
Is there any model left that could be Einstein's original SR? Well, if it's set 3's 3D non-block model, then it's the same theory as LET and must take on the same metaphysics as LET, but Einstein was very clear that SR is not LET. Perhaps it could be the set 3 3D block model where the absolute frame becomes rather redundant, but that model needs to be constructed by LET, so it's superfluous. The only model that remains as a candidate is the set zero 3D block, and that's a block that was never generated in order of causation, so all the causality written through it is fake. It's an invalidated model. We can see from this that there is no viable model for Einstein's original version of SR.
What about the version that replaced it when Minkowski turned it into 4D? Well, we have seven models to look at for that. The Mode zero 4D block model involves a block that was never generated in order of causation, so all the causality written through it is fake. It's an invalidated model. This model is very much an SR and GR model, but it cannot be a viable description of reality due to the complete lack of a role for causality in it.
Set 1 has two 4D versions. The non-block one is invalidated by event-meshing failures. The block version could work though, because the event-meshing failures are deleted over time (Newtonian time) as events change at individual Spacetime locations. This model breaks the rules of SR and GR by having two kinds of time in it.
Set 2 has two 4D versions, but we've already established that all set 2 models are invalidated by their generation of contradictions, so they're out of the running.
Set 3 has two 4D models, but the block version is superfluous and can be ignored (due to its need to be built under the rules of the non-block version). The non-block version has an absolute frame, so it's not regarded as compatible with SR, but could arguably be compatible with GR if an absolute frame is acceptable there.
That's an overview of things, but it takes you straight to where this discussion will end: all SR models have been invalidated if we apply the normal rules of SR, but if you're prepared to make modifications to it, there are some options available to try to breathe some life into it. Even if you do that though, you're left with the far-fetched and highly contrived set 1 3D and 4D block models (with two kinds of time and with event-meshing failures during the construction phase), or you have set 3's 4D non-block model, but you then have to accept an absolute frame. That's your only other option, and it's by far the better one.
4D models are also extremely far-fetched though, and the thing that makes that clearest is this: in 4D models, light reduces all paths that it takes to zero length and covers them in zero time (by the "time" of the "time" dimension). There is no such thing as a speed of light in these models. When you run time in a 4D model, light has to spend a lot of time waiting without going anywhere - light coming to us from distant galaxies, for example, has spent over ten billion years travelling zero distance through the non-Euclidean geometry of Minkowski Spacetime to reach us, and if we're using a model with an absolute frame, that means it really has spent that length of time making that trip of zero length by the Newtonian time of the absolute frame (so again this model, the Set 3 4D one which is the last refuge of the most viable approximation of SR, has two kinds of time in it). That is where we actually stand once we've separated out all the models and tested them on their own merits instead of mixing incompatible ones together and asserting that they're viable, which is what the establishment typically does. The most consistent SR adherents go for the mode zero 4D block and stick to that rigorously, but that model lacks real causality, so they're in an extreme position, even if they're not cheating in any way beyond claiming that the fake causality is real. By the time you've looked at all the models carefully and examined the difficulties (and impossibilities) that apply to them, you should recognise that the most rational model of the lot is LET, and you should see that it wins with ease. That depends on you being rational though, and many people aren't.
Now, many people dispute points that I've made above and claim that they're wrong, but the points are correct and the people who claim otherwise are the ones who are wrong. I can demonstrate that all the points I've made are correct (or at least, the ones that the argument depends on - I can't guarantee that every statement I make in the course of a conversation in a long thread is correct, but the key ones that the argument rests on are right and have stood up to all attempts to break them over many years).
In the other thread, what happened was that I made various statements which people claimed were wrong, so I showed that the statements I'd made were right. It isn't clear whether any of them were eventually accepted, but perhaps that will show up in this thread, and if they still refuse to accept proven points, that's up to them, but I will show the stark reality of the extreme positions that they have to take up in order to oppose those points. Halc defended the set zero 4D block model by asserting that the causality in it can be real rather than fake, and he came up with an interesting argument to justify that which was based on sets of abstract things that don't actually exist and the causation that supposedly generates them from each other. Steve spent most of his time trying to make out that I didn't understand enough physics, imagining that parts of physics that have no role in my argument have a role in it on the basis that they're part of physics and that I don't appear to know them (even though I do, but merely describe them using different language because I speak the language of LET rather than SR). The third main participant didn't get involved much, but all his comments were based on the idea that I must be wrong because I'm attacking an establishment position and the establishment must be right.