Path: ...!2.eu.feeder.erje.net!feeder.erje.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Thomas Heger Newsgroups: sci.physics.relativity Subject: Re: Sync two clocks Date: Fri, 23 Aug 2024 08:32:55 +0200 Lines: 50 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: individual.net Uh97FD4azEoXNh7saPq0SAymLVNScuqsUYcRpctHL95X7dAF8x Cancel-Lock: sha1:BbqBhfvH4ZhW6iv+JcppIzgtZm4= sha256:GAYbAP4USjvqDeUbONP5TrXVlr9tCHZl5iljgy+so+I= User-Agent: Mozilla Thunderbird Content-Language: de-DE In-Reply-To: Bytes: 2881 Am Donnerstag000022, 22.08.2024 um 13:11 schrieb Python: .... >>> >>> Richard, read your watch NOW. Write down the time nn:nn:nn. >>> The time nn:nn:nn is a proper time (read off a clock), it is >>> invariant, not depending on frame of reference. >>> >>> Nobody can have another opinion of what time YOU read of YOUR watch. >>> >>> How is it possible to fail to understand this? >>> >>> If we have two stationary clocks in an inertial frame, >>>   and clock A shows tA = t1 when it emits light, >>>   and clock B shows tB = t1 + td when the light hits it, >>>   and clock A shows tA'= t1 + 2⋅td when it is hit by the reflected >>> light, >>> >>> then tA, tB, tA', t1 and td are all proper times which are frame >>> independent (invariants) and "the same for all". >>> >>>   tB − tA = t'A − tB = td >>> >>> The transit time td is a frame independent invariant and >>> the same in both directions, which means that the clocks according >>> to Einstein's _definition_ are synchronous in the inertial frame. >> >> >> You introduced t_d or 'transit time' (aka 'delay'), while Einstein >> didn't use any of these terms. > > But he write down two equations that implies directly that a delay > is taken into account. The equation on page 3 COULD be interpeted as calculation of the delay. But Einstein wrote, that would be the definition of the speed of light. I would miss the word 'delay' in this context (or something similar). Also the remainder of this paper does not mention delay neither. So: where have YOU found any use of delay or transit time in this paper? I 'combed' the text very carefully and could not find any statement, which eventually would match this discription. .... TH