Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: "Paul.B.Andersen" <relativity@paulba.no>
Newsgroups: sci.physics.relativity
Subject: Re: Langevin and Doppler effects...
Date: Thu, 12 Sep 2024 20:42:20 +0200
Organization: A noiseless patient Spider
Lines: 85
Message-ID: <vbvcjc$cgt2$1@dont-email.me>
References: <b5WDgbOwGmhfWpul72-1Pn3t5Ac@jntp> <vbfjlm$u3q4$1@dont-email.me>
 <SAXJTofwl9xPuF-NvQ223-8qgJw@jntp> <vbi8m5$1g3ev$1@dont-email.me>
 <Eag-OoGcu7t-d4OJd2q3_6J1q20@jntp> <vbnc2p$2gbmb$1@dont-email.me>
 <jEi5WPq6DnATz7TRmH6TC_JPzs4@jntp> <vbstto$3plaj$1@dont-email.me>
 <t-t_JsOy5bgtQXkYHDKY0O6cMKg@jntp> <vbus6g$9mj2$1@dont-email.me>
 <zgxExgejF-Xu8AwQyyLOskMYAL0@jntp>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Thu, 12 Sep 2024 20:40:45 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="c28d4363dc3658698d800a4fb665f9ae";
	logging-data="410530"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18WxJAa7R0Fmnsb/3TabPSV"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:OSmOxdiMXW9uNTWjYIQQwTXC1KU=
In-Reply-To: <zgxExgejF-Xu8AwQyyLOskMYAL0@jntp>
Content-Language: en-GB
Bytes: 5184

Den 12.09.2024 16:41, skrev Richard Hachel:
> Le 12/09/2024 à 16:00, "Paul.B.Andersen" a écrit :
>>
>> I have shown you Terrence's, speed, position and proper time
>> measured in Stella's rest frame, as a function of Stella's time.
>> 
>> It is quite simple:
>> 
>> During Stella's time 0y -> 9y, Stella is inertial and so is her frame.
>> MEASURED IN STELLA'S FRAME, Terrence is moving away at the speed 0.8c, his clock runs slow by 1/γ, and his position is x = 0.8c⋅t_Stella'
>> So when Stella's clock show 9h, t_Terrence = 5.4y and x = 7.2 ly
>> 
>> During Stella's time 9y -> 9y + 24h, Stella is accelerating towards
>> Terrence, so Stella's frame is an accelerated frame.
>> MEASURED IN STELLA'S ACCELERATED FRAME, Terrence will move away
>> from Stella at high speed, and his clock will run thousands of times
>> faster than Stella's.
>> So when Stella's clock shows 9h 12h, t_Terrence = 15y and x = 12ly
>> When Stella's clock shows 9h 24h, t_Terrence = 24.6y 25.6h
>> and x = 7.2ly + 19.2lh
>> 
>> During Stella's time 9y 24h - 18y, Stella is inertial and so is her  frame.
>> MEASURED IN STELLA'S FRAME, Terrence is moving away at the speed 0.8c, his clock runs slow by 1/γ, and his position is
>> x = 7.2ly + 19.2lh + 0.8c⋅t_Stella'
>> 
>> At Stella-s time 18y + 24h Terrence is back.
>> 
>> What is it that you don't understand?

This is how Doctor Richard Hachel understands the above:

Or should I say:
This is how Doctor Richard Hachel doesn't understand the above?

> Physicists don't realize that they are practicing artificially.
> The frame of reference that they attribute to Stella is firstly not the real one. It's not hers, but the frame of reference of a comoving observer placed very far away and observing things transversally.

So Stella's rest frame is not the real one, and it isn't hers,
but the frame of a distant comoving observer who is observing
things transversely.

> This is the first problem, but the second will be worse. For the return, we are forced to do the same thing, but here, it's no longer like with Terrence where M1=M2.
> 
> In Stella's frame of reference, M1 is imaginarily infinitely far from M2. We "jump" from frame of reference, which is neither pretty nor credible. We then "jump" from clocks. And all this is nothing more than a vulgar patch-up to "be even more right".

Ooops. You lost me there!

> 
> If we finally wanted to understand things (but we don't want to),
> we would realize that a frame of reference can only be attributed, in relativity, to a single observer.

So Terrence can't have a speed and position in Stella's rest frame?

> 
> This observer is at point O of the frame of reference.
> 
> In Stella's problem; Stella is NOT in her correct relativistic place, and we are forced to apply non-existent subterfuges (time-gap) to validate the passage from M1 (go) to M2 (return) while ideally these two points are infinitely far away in their respective space-time. We "jump" frames of reference.

And because Stella is NOT in her correct relativistic place, we are 
forced to apply non-existing subterfuges to validate the passage between 
two points which are infinitely far away.

As always, you express yourself crystal clear, Richard. Well done!

> 
> I don't practice like that at all.
> 
> I always stay in Stella's frame of reference, WITH Stella as center and origin. So she NEVER jumps frames of reference. She is always in her frame of reference and at point O.

So Stella's rest frame is not the real one, and it isn't hers,
but the frame of a distant comoving observer who is observing
things transversely.
But YOU always stay in Stella's frame of reference with Stella as
centre of origin.

---------------------

I think it is enough now.


-- 
Paul

https://paulba.no/