Bell's spaceship to spaceship thread catastrophe

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Re: Bell's spaceship to spaceship thread catastrophe

by crawler » Mon Apr 06, 2020 2:28 am

allynh wrote:
Sun Apr 05, 2020 6:03 pm
Yes.Thank you.I've had to put up with this nonsense since the 1970s, starting in high school.
Bell's spaceship paradox is just as ridiculous as the Ladder paradox. Ladder paradox https://en.wikipedia.org/wiki/Ladder_paradox

My obvious question in high school was:- How do you open and close the barn doors fast enough without vaporizing the barn.
I talked about "paradox" in a post I did for my Caltech: The Mechanical Universe thread.
Paradox Lost https://thunderbolts.info/forum3/phpBB3 ... 1512#p1023
"Paradox" is useful to get you started building experiments, but if you still have a "paradox" when you are done, then you did something wrong.

BTW, I'm still trying to finish reading Einstein's War. I got sidetracked with all that is going on. From what I've read so far, Einstein simply abandoned actual experiments to focus only on the fantasy of his "thought experiments".
The way i think of it a paradox is due to ignorance of the (perfectly ok) theory. A bad theory results in a contradiction. STR & GTR don't have paradoxes they have contradictions.
A typical contradiction might be due to say there being more than one answer to a question.
And the typical Einsteinian answer is that its ok to have more than one answer.

The wiki ladder contradiction stuff is wrong. They invoke the Lorentz factor for LC. But Lorentz relativity involves a physical contraction due to the aetherwind, plus a coordinate contraction due to the aetherwind, a double dose of contraction (of the ladder), ie needing the application of gamma^2. Einstein's STR had just one dose of contraction, a coordinate contraction.

The barn question would work better if u had the Sun overhead & the question involved whether the ladder would be in complete shadow or would a bit always be in Sunlight. No doors needed.

Does that book mention that Mrs E did most of the work? And that E stole his photoelectric stuff from Lenard?

Re: Bell's spaceship to spaceship thread catastrophe

by crawler » Mon Apr 06, 2020 1:53 am

JP Michael wrote:
Sun Apr 05, 2020 8:00 am
Sorry to ask the obvious, but how was the string not obliterated by the exhaust of rocket B? Is it magical string impervious to damage by fire? In which case, why would it break for length contraction if the rocket exhaust can't even break it?

I still don't understand how talking about two hypothetical spaceships connected by a 'delicate string' even matters? Surely this problem only exists in the minds of physicists and has no bearing on reality, where one would never actually have two rockets connected by a 'delicate string' accelerating in frame S at the same speed for however indeterminate amount of time for observer A to watch what might happen.
I did see comments re the thread being burnt by the rocket, or stretching due to acceleration.
STR & GTR have zero reality anyhow.
But i think that it is an interesting question, even though impossible, & it highlights differences tween every kind of relativity (at least re length contraction).
It reminds me of the question re if thousands of satellites orbited Earth one behind the other joined by 1 km threads forming a ring around Earth & if the threads were pulled tight would the threads form a straight line or a curve.
Apparently Einsteinians must say that an orbit is a curve (due to the bending of spacetime) & so too must the thread form a curve. Silly.

Re: Bell's spaceship to spaceship thread catastrophe

by allynh » Sun Apr 05, 2020 6:03 pm

Yes.

Thank you.

I've had to put up with this nonsense since the 1970s, starting in high school.

Bell's spaceship paradox is just as ridiculous as the Ladder paradox.

Ladder paradox
https://en.wikipedia.org/wiki/Ladder_paradox

My obvious question in high school was:

- How do you open and close the barn doors fast enough without vaporizing the barn.

I talked about "paradox" in a post I did for my Caltech: The Mechanical Universe thread.

Paradox Lost
https://thunderbolts.info/forum3/phpBB3 ... 1512#p1023

"Paradox" is useful to get you started building experiments, but if you still have a "paradox" when you are done, then you did something wrong.

BTW, I'm still trying to finish reading Einstein's War. I got sidetracked with all that is going on. From what I've read so far, Einstein simply abandoned actual experiments to focus only on the fantasy of his "thought experiments".

Re: Bell's spaceship to spaceship thread catastrophe

by JP Michael » Sun Apr 05, 2020 8:00 am

Sorry to ask the obvious, but how was the string not obliterated by the exhaust of rocket B? Is it magical string impervious to damage by fire? In which case, why would it break for length contraction if the rocket exhaust can't even break it?

I still don't understand how talking about two hypothetical spaceships connected by a 'delicate string' even matters? Surely this problem only exists in the minds of physicists and has no bearing on reality, where one would never actually have two rockets connected by a 'delicate string' accelerating in frame S at the same speed for however indeterminate amount of time for observer A to watch what might happen.

Re: Bell's spaceship to spaceship thread catastrophe

by crawler » Sun Apr 05, 2020 2:50 am

What would aetherists say about that there thread?
What would (aetherists) Voigt & Larmor & Lorentz & Poincare say? I reckon that they would all say NO. I think that Voigt would be a NO-1. He would quickly accept that there is a contraction of the coordinates (ie a contraction of the center to center distance tween spaceships), & after some more thinking he would accept that the spaceships would themselves contract, but probably not due to any physical electromagnetic reasons, but due to a coordinate transformation effect (according to a stationary observer), & that the gap would contract, & that the thread would contract, all in equal measure. And he would then quickly change the subject, or perhaps he would walk away mumbling & scratching his head. But Larmor Lorentz & Poincare would be a NO-2.

NO-2. As for NO-1, but they would say that the contraction of the spaceships & thread is a physical effect, not a coordinate effect.

YES-6. I need to include this to cover the possibility that Larmor or Lorentz or Poincare after some clear thinking eventually realize that their theory gives a double dose of contraction, ie a physical contraction (of spaceships & thread)(ataso) on top of a coordinate contraction (ataso), in which case the thread breaks.

What would aetherist Janossy say? https://en.wikipedia.org/wiki/Lajos_J%C3%A1nossy
L Janossy -- Book -- 1972 – The theory of relativity based on physical reality. I haven’t read his book ($150) but judging by comments i reckon that Janossy might be a neoLorentzian, ie believing in a free-range aether blowing throo our solar system. If anyone can find some more info on his ideas i would appreciate knowing. I might try an inter-library loan. Ok here is what a neoLorentzian would say.

YES-7. The spaceships & thread physically contract & the thread breaks, because the faster the aetherwind blowing through the spaceships then the greater the contraction. The distance tween centers of the contracting spaceships doesn't change, but the gap gets wider (ataso).

NO-3. Alternatively the thread doesn't break, if the aetherwind is initially from behind. Because during acceleration that aether tailwind slows & the spaceships & thread dilate (ataso), & the gap contracts. Then gradually the tailwind becomes a headwind & eventually the headwind results in the thread breaking (in accordance with YES-7).

So that’s the neoLorentzian aetherist explanation. There are no clock synchronisation complications. No coordinate transforms needed. No spacetime needed. Not the slightest smell of any possible paradox or catastrophe. However me myself i don’t exactly agree with this neoLorentz explanation, i have issues with the Lorentz factor, but that is another story.

Bell's spaceship to spaceship thread catastrophe

by crawler » Sun Apr 05, 2020 1:17 am

Wiki -- Bell's Spaceship Paradox. https://en.wikipedia.org/wiki/Bell%27s_ ... ip_paradox
Bell – 1976 – How to teach special relativity. https://danielhoek.com/wp-content/uploa ... tivity.pdf

Does the thread tween two accelerating Einsteinian spaceships break? Some Einsteinians say yes & some no. There are 5 kinds of YESers.
YES-1 – Contraction of the spaceships. Here the two spaceships contract (according to a stationary observer) & the gap lengthens (ataso).
YES-2 – Contraction of the thread. Here the gap stays the same (ataso) but the thread contracts (ataso).
YES-3 – A combination of YES-1 & 2.
YES-4 – Loss of clock synchrony. Here two spaceships have differing accelerations because the STR requires that their synchronous clocks must lose synchrony (ataso) as their frame gradually changes (even though the two spaceships at all times share the same frame(s)). The trailing spaceship falls further behind (ataso), & the gap widens.
YES-5 –A combination of YES-1 & 2 & 4.

NO-1. I think that there is only one kind of NOer. Einstein said that objects don’t contract, but that spacetime contracts (& with it objects contract)(ataso). This means that Einsteinian contraction cant break the thread, hencely Einstein would disagree with YES-1 & 2 & 3. But what about YES-4. I can tell u that Einstein would disagree with YES-4. Its like this. A loss of synchrony (ataso) would be in accord with STR if the two clocks were continuously kept in synchrony (using Einstein's light signal method) during acceleration. But that aint what happens. The clocks were synchronised whilst at rest – in which case they will remain in synchrony for ever (if no rotation etc).

Anyhow Einsteinians cant agree on their Einsteinian krapp. And if they could agree it would still be krapp. Their Thread Catastrophe is equal to their Twins Catastrophe. A paradox can be eliminated by eliminating ignorance. A catastrophe can be eliminated by changing the theory.

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