[David Cooper]

[There seems to be a history of David Cooper trying to discredit Relativity here.
No amount of evidence will convince you, you don't understand SR.

Sure - you must understand it better than me because you can't answer the questions I've put to you (and to others) even though I've provided all the answers to help you out. What I've just shown you is that the red light passes four times as much length of material in the same time as the blue light, and that means that the red light's speed relative to that material is four times that of the blue light relative to that material. You have no answer to that whatsoever, and SR has no magic formula to account for it either. For the average speeds of the red and blue light both to be c relative to the sectors they're passing through, you'd need some way to contract the length of the loop in one direction to half the measured length while doubling that same length in the other direction (negative length-contraction!), but the only known length contraction factor that can be applied here is the 0.8, and that's already been applied to the apparatus. So, all you can do is ignore the problem and pretend it isn't there. But at least you had a bit of a go at it and did eventually answer one question very reluctantly, so I congratulate you on that - you've done better than all the others on the SR side put together.

The imagined 'problems'...

How have you allowed yourself be blinded to the realities that I've placed before you? Do you deny that the light passes the sectors that it passes at a relative speed at all? What is that speed? This is really basic stuff, and it's absolutely shocking that no one from the SR camp (here and elsewhere ) is capable of taking it on. If it's c in both cases, then your numbers tell you that 1=4 (and that you're in conflict with mathematics). It's just applying bog-standard mathematics to the facts of bog-ordinary experiments and the production of clear conclusions driven by that maths. This shows though why so many leading mathematicians refuse point blank to comment on physics - they know that their maths is being misused in the most appalling ways, but they get a lot of grief if they dare to say so.

...made me wonder, why your site is named 'magic school'.

It's "Magic Schoolbook, and the explanation as to why is provided there. I hated school because it was just a children's prison where practically nothing was being taught. What I wanted was a special book that would teach me everything I was supposed to be learning at school so that I could get the hell on with it and never have to go back to that damned place ever again. I decided at five years old that I would write the book myself some day if no one else did it first - a book to liberate children from that idiotic school system that fails to teach and merely squanders childhood for nothing. But idiocy is hard to topple from power, as is clear everywhere you look - that's why the world's always been a hopeless mess in the way it's run. The only cure for that will come with AGI.

This is tiresome and boring, so I have projects to work on, which are more constructive.

I've shown you where SR fails, and your response is that you're bored. The truth is much simpler - you have no idea how to handle the argument because the argument is right. Just ask yourself why no one has been able to show that my numbers are wrong.

[David Cooper]

I don't normally respond to the same post twice, but this one's a special case.

There seems to be a history of David Cooper trying to discredit Relativity here.

There is, and the reason that I keep doing it is that certain people keep ignoring the faults with SR when I draw attention to them, never acknowledging them. "What contradictions?" they always say, even though the contradictions are manifest. The specific argument I've been using in this thread is aimed at making those contradictions even more obvious to those who have been systematically trained not to see them. This argument isn't even found on my relativity page because I'd always thought the contradictions were so obvious that there was no need to spell things out - most people new to the subject see them straight away because they haven't been brainwashed into being blind to them.

This is tiresome and boring, so I have projects to work on, which are more constructive.

I have important work that I could be getting on with too if the discussion wasn't dragged out by avoidance tactics? It's always tiresome and boring when a politician repeatedly fails to answer the questions they've been asked where they answer other questions instead which shed no light on the issue. Politicians do that because they're scoundrels. Scientists don't have the same need to avoid answering questions because they are honest pursuers of truth. So how should scientists deal with questions that are put to them? They should answer them directly. Here's how it ought to go (but never does) - I will post an imagined conversation between me (DC) and a scientist called Elf Mice (EM):-

DC: Is R>B?

EM: So; let's see if we can make R=B. If the red light passes through sector S0 at c relative to that sector, and at c relative to S1, and relative to S2, and S3, and so on all the way round the loop, and if the blue light passes through every sector at c relative to it too, then the time the red light takes to go through all the sectors eight times must be the same as the time the blue light takes to go through all the sectors eight times... unless the sectors are four times shorter in length when the red light goes through them than when the blue light does. That means, as you say, a length of stuff would need to be different for light passing it in different directions.

DC: And do you think that's possible?

EM: Assuming that light always passes everything at c, then no - the two lengths must match.

DC: is there absolutely no way that length contraction could be involved?

EM: Well, I'm not sure that you've entirely ruled that out, so let's look at it more closely. You say that you've already applied a length contraction factor of 0.8 because the loop of cable is going round the circuit at 0.6c, so if we're using the frame of reference in which Y is at rest, then that is indeed the only way that length contraction can apply here. If we use a different frame of reference though, what happens? Suppose we use the frame in which object Z is at rest... If we do this, the material in the lower part of the loop won't be contracted because it's at rest too in that frame.

DC: And the material in the top part of the loop?

EM: That will need to be much more strongly contracted.

DC: And that must affect the spacing between the pulleys. The rod length.

EM: Yes, I was just thinking that. We need to see if this R>B business applies for this frame too. The pulleys and rod must be moving to the left at 0.6c.

DC: Indeed, and more of the cable must be on the top part of the apparatus at any point in time than on the bottom part because it will bunch up with that stronger length contraction applying to it. The rod must still be telescoped to its shortened length, so this length contraction applying to it will further shrink it to 0.8 of that length.

EM: Right, and the contraction applying to the top part of the cable is worked out using relativistic velocity addition where we add 0.6c to 0.6c and then divide by 1 + 0.6x0.6, which gives us 0.88235c as the speed of movement of the sectors there.

DC: And that means a length contraction factor of 0.47059.

EM: I get that value too. But how do we apply these numbers...?

DC: Five laps for the light, but 8 or 2 laps of the material of the cable depending on the direction it goes round it.

EM: Ah yes - I see where you're going with that! The red light spends half its time passing material that's moving at 0.88c, and the other half of its time passing stationary material.

DC: No, that isn't right - the rod and pulleys are moving to the left, so the red light spends more time moving along the bottom part than the top and the blue light does the opposite.

EM: This is all devilishly complicated!

DC: That's why most people can't be bothered investigating this to check the facts. But before we go any further with the numbers, let's think a bit about that difference. The blue light spends most of its time travelling to the left through the top part where it's travelling at c past length-contracted material that's moving in the same direction at 0.88c, and it only spends a short time moving to the right along the bottom part where it's moving at c past material that's at rest and not contracted.

EM: Ah ha! So that light's spending most of its time passing length-contracted material, which means that it could in a way be shortening the course!

DC: Yes, but that's the blue light, and we'd want to lengthen the course for that if we're to find a get-out-of-jail-free card for SR. The red light spends very little time moving through the contracted material and spends the rest moving through material that's at rest, so on average it's spending less of its time on a contracted part of the course than the blue light.

EM: Which means this approach is futile.

DC: As it should be.

EM: I think I'll calculate those numbers anyway though, just to make sure they don't hold any surprises, and then I'll contact some of my colleagues to see if they have any ideas. Got to go for now though - I've got a machine doing an experiment here that'll blow up if I don't attend to it and flick a few switches.

DC: That's okay - nice talking to you, Mice Elf.

EM: Oh b***** it! Too late! Now see what you've gone and done by distracting me! I've just made a ruddy black hole, and it's eating my kitchen!

That's the way I expect a subject like this to be discussed - an honest exploration of the issues which tries to break an argument by taking it on instead of avoiding it, but I can't find anyone capable of holding such a co-operative conversation. All I get is, "You don't understand relativity", and yet I clearly understand it better than they do, not least because I actually implement it in software and can thereby check directly whether models really work when they apply their own rules instead of smuggling in other rules that aren't part of the model and pretending that a simulation of SR isn't just LET in disguise.

[Kris Kuitkowski]

Hi David,
I can see the topic of one way speed of light is still alive. If you recall our conversation about it, you insisted that length contraction of my rod (even moving at a very slow speed relative to the lasers) would falsify the results. I did not agree  but since done some thinking to make experiment more robust.
Instead of long rod lets have a solid square (each side length of the rod)  with small holes ABCD drilled close to each corner.  Let A'B'C'D'  be laser points aligned exactly with ABCD when stationary.
Similarly to our previous experiment let the square ABCD glide past lasers A'B'C'D'.
Since AB is perpendicular to the direction in which the square moves, there should be no length contraction of the distance AB regardless of the speed of the square. If there is a contraction of the distance AC (or BD), it should be relatively easy to measure it by measuring time of flight of a photon from A to B and comparing it with the time of flight from A to C.
Best regards,
Kris

[David Cooper]

I can see the topic of one way speed of light is still alive...

That doesn't belong in this thread, so you should either revive your old thread for this or start a new one in the same forum. Send a link to it in a PM to me if I don't respond to it within 24 hours. You can also delete your post from this thread (and I'll delete this reply).