Path: ...!weretis.net!feeder8.news.weretis.net!pasdenom.info!from-devjntp Message-ID: JNTP-Route: nemoweb.net JNTP-DataType: Article Subject: Re: the notion of relativity of simultaneity References: <3_55BPOgqiL20L5rUo2xG_Vp8ZQ@jntp> Newsgroups: sci.physics.relativity JNTP-HashClient: bPXHkSU-nLolsihF0SQHgcy08IM JNTP-ThreadID: M03ir3sQnaKnoNUOGTo8wLgKNI8 JNTP-ReferenceUserID: 4@nemoweb.net JNTP-Uri: https://www.nemoweb.net/?DataID=srE_IMbZF9dmXPkUjOpbkdj7YJs@jntp User-Agent: Nemo/1.0 JNTP-OriginServer: nemoweb.net Date: Thu, 03 Oct 24 12:53:00 +0000 Organization: Nemoweb JNTP-Browser: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0 Injection-Info: nemoweb.net; posting-host="a35b2e278e711c9c4fc7978e11d905ef151e9900"; logging-data="2024-10-03T12:53:00Z/9046389"; posting-account="190@nemoweb.net"; mail-complaints-to="julien.arlandis@gmail.com" JNTP-ProtocolVersion: 0.21.1 JNTP-Server: PhpNemoServer/0.94.5 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-JNTP-JsonNewsGateway: 0.96 From: Python Bytes: 3400 Lines: 62 Le 03/10/2024 à 14:49, Richard Hachel a écrit : > Le 03/10/2024 à 09:09, Thomas Heger a écrit : >> >> The comoving hyperplane (comoving with the observer) is usually called >> 'hyperplane of the present. > > Absolument. > >> This is so, because a spacetime diagram uses only two dimensions for >> space and one for time, because in pseudo-3d it is not possible to >> depict more dimensions. > > Absolument. >> >> This 'hyperplane of the present' is therefore depicted as a sheet, but >> actually means a space. > > Absolument. >> >> This space is the space of all events, which could be conneted to the >> place called 'here and now' by the observer, > > Absolument. > > >> if he would use a >> hypothetical signal with infinite velocity. > > This is already the case. > > There is no need to imagine an infinite speed of information, because in this > case, for the direct observer who "sees" the information arriving, it IS live. > > >> >> This is, of course, not possible, hence only points are accessible, >> which are located upon the observers future light cone. > > The notion of hypercone of light no longer has any reason to exist, we should no > longer use this term which adds nothing, even if it is true that for an external > observer B the hyperplane of A is transformed into a hypercone for B in its > hyperplane. > >> But for definitions we do not need to care about such limitations and >> could regard as 'present', what is placed upon the hyperplane of the >> present (instead of the positions on the light cone). > > Absolument. > >> TH > > R.H. https://fr.wiktionary.org/wiki/asinus_asinum_fricat https://www.latin-is-simple.com/en/vocabulary/phrase/181/ the jackass rubs the jackass Used to describe 2 persons who are lavishing excessive praise on one another.