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From: "Paul.B.Andersen" <relativity@paulba.no>
Newsgroups: sci.physics.relativity
Subject: Re: Relativistic aberration
Date: Sat, 3 Aug 2024 19:44:14 +0200
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Den 02.08.2024 22:51, skrev Richard Hachel:
> Le 02/08/2024 à 21:49, "Paul.B.Andersen" a écrit :

>>> Den 01.08.2024 13:39, skrev Richard Hachel:
>>>>
>>>> The event that occurred at the supernova located 
>>>> at 15,000 ly has just been recorded by the Earth observer.
>>>> He notes E = (x, y, z, To, t)
>>>> Let x = 12000, y = 9000, z = 0, To = -15000, t = 0.
>>>> This is how I write in Hachel notation.

>> 
>> It isn't so different from what astronomers use.
>> 
>> The position of the star is given as two angles and a distance.
>> The angles are Right ascension (RA) and Declination(DEC).
>> The former is equivalent to longitude and the latter to latitude.
>> The distance is given in Parsecs or light years.
>> It is of course a trivial matter to convert these three coordinates
>> to a Cartesian  frame of reference.
>> 
>> Your system have the transit time of the light from the star
>> as a fourth coordinate, which is redundant because it is given
>> by the distance.
>> I didn't fail to notice that your √(x² + y² + z²) = -To⋅c.
>> So you could remove the To from your system.

> 
> What I would like physicists to understand because it is doubly 
> important, for the beauty of the thing, and then for the scientific 
> truth of the equations that will result from it, is the notion of 
> universal anisochrony, and the fact that what we believe to be an 
> absolute present time, does not exist.
> That it is only a mental idea, a complete abstraction, an empty shell.
> I think it is not nice to teach children this ridiculous idea that they 
> do not have innately, because THEY, they intuitively know the thing 
> without being mistaken, and do not say that what they see in the sky 
> does not exist or no longer exists, and that it belongs to the past, and 
> that perhaps, stars that they see no longer exist.
> Philosophically, theologically, artistically it is not BEAUTIFUL.
> And worse, scientifically, it is false.
> Now, it is preferable, you are right, to use To, which is however an 
> abstract structure, but which places all the observers in a certain 
> coherence that anisochrony does not allow for all the observers at the 
> same time.
> But it must be specified that it is a useful abstraction.
> This is why it is necessary to note, I think (x,y,z,To,t) for any event 
> perceived in the sky.
> t being the moment when the observer perceives the event, but ALSO the 
> moment when it actually occurs, in perfect simultaneity with the observer.
> Be careful, this effect is not reciprocal; because if it is true that 
> everything I observe in the sky is part of my present moment, of my 
> perfect simultaneity of existence, the reverse is not true. My current 
> existence does not exist for the whole of the observable sky and 
> according to the distance of the stars, it will only exist for them in t 
> = 2x / c. My present is in their future. If I send them a signal, they 
> will receive it instantly in their frame of reference, but this instant 
> is for ME at t=2x/c.
> This geometry is very simple to understand, and if it is not understood, 
> it only comes from a kind of intellectual reluctance to change our own 
> notion of present time.
> 
> R.H.

Does all this nonsensical babble change the fact that when the
distance to the star we see in the telescope is 15000 light years,
then the light we see left the star 15000 years ago?

-- 
Paul

https://paulba.no/