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From: Mikko <mikko.levanto@iki.fi>
Newsgroups: sci.physics.relativity
Subject: Re: What is "local time"?
Date: Fri, 18 Oct 2024 11:41:59 +0300
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On 2024-10-16 13:07:58 +0000, Richard Hachel said:

> Le 16/10/2024 à 11:03, Mikko a écrit :
>> On 2024-10-14 11:28:45 +0000, Richard Hachel said:
>> 
>>> What is "local time" in relativity?
>> 
>> The expression is usually not used in Relativity. In particular,
>> Einstein did not use it.
> 
> You may be right.
> For my part, I firmly believe that a lot of words or concepts should be 
> completely abandoned.

A lot of words and concepts are already abandoned.

> This will make many relativity lovers jump, I think, but I think it is 
> "necessary for the song" and that one day, we will have to go through 
> it.
> Example of words or concepts that are TOTALLY useless, even biased.
> "local time",

Not used.

> "relativity of simultaneity by change of reference frame",

Can be used as a reminder but does not mean much.

> "local present time",

Not used.

> "hypercone of present time",

Not used as "present time", if used, is usually defined as a hyperplane,
not a hypercone.

> "invariance of the space-time interval",

Space-time interval is invariant.

> "time-gap": we don't need all of this.

Does not exist except as a false impression from an approximation
so only rarely used.

-- 
Mikko