Re: [SR] Dismaying intellectual desert?

Den 04.04.2024 02:08, skrev Richard Hachel:

Le 03/04/2024 à 23:12, Maciej Wozniak a écrit :

W dniu 03.04.2024 o 22:26, Paul B. Andersen pisze:
>

Yes, we know that no speed of massive objects or particles
can exceed c. So what?

The following seems to be a response to my statement above.

 The notion of simultaneity being defined by the coincident existence of all events occurring
at the same time ; or again, being characterized by the set of all physical phenomena
taking place at the same time; we should be able, at least considering all the components
fixed being in a given inertial system, to speak of absolute simultaneity, of synchronization
cosmic, or common calendar -- these terms then being likely to acquire real significance
physical tion -- if we could, without it varying, transpose the universal simultaneity specific to a
particular observer to all the other inertial observers present in this same frame of reference.
    It would be enough to find any signal, or any action, by which a body A could
interact instantly with a body B, that is to say by means of information propagating infinitely
quickly, so that this notion of absolute simultaneity can be experimentally proven.
    We could then say that the action induced by body A was instantly transmitted to body B, or
that the action produced by body A was carried out at the same time as its detection by body B, and that it
exists, de facto, between A and B, a sort of reciprocal and absolute simultaneity.
     We could also imagine a round trip signal carried out over the distance separating A from B, and carried out at
means of infinitely rapid information, such that the departure and return times of
information is simultaneous. It would easily come to mind that if the two watches A and B are
well tuned, the notion of general coexistence of the things of the universe in perfect simultaneity would be
thus demonstrated.
     However, this proof does not exist.

What's your point with using so many words to state
the bleeding obvious?
Of course there is no such thing as "absolute simultaneity".

     We know that a body can act on another body at a distance, for example in the form of a wave.
electromagnetic, in the form of a mechanical shock transmitted along a rigid rod, or under the
form of a gravitational interaction, but we have never found a signal that is infinitely fast,
or remote action that is instantaneous. It rather seems, in fact, that there exists, in nature, a kind
impassable speed limit, which we will find in any Galilean reference frame considered, and which will
extend to all particles and all properties of physics.

So you confirm my statement quoted above above.
But you never addressed what you claimed was impossible
in my posting.
Try again?
03.04.2024 Paul.B.Andersen wrote:

Den 02.04.2024 15:25, skrev Richard Hachel:

Le 02/04/2024 à 14:48, "Paul B. Andersen" a écrit :

>
Let's stay in the real world.
>
The only objects moving at "relativistic speeds" we
can visually observe, are astronomical objects, like
the matter in the jets from some galaxies (from their
central black hole).
>
The only motion we can visually observe, is transverse motion.
>
So if the jet is coming right at us, we will see the matter
at exactly the same point at the centre of the galaxy, the apparent speed of the matter is zero.
>
But when it is approaching you at an angle, you can measure the
angular velocity, and when the distance is known, you can calculate
the apparent transverse velocity, which indeed may be higher than c.

>
No. It's impossible.

 There are _many_ "superluminal" jets where the matter in
the jet appear to have a speed faster than c.
>

Please explain why you wrote:  "No. It's impossible."
--
Paul
https://paulba.no/