Date: Fri, 12 Jul 2024 12:00:04 +0200 Mime-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Approximately 300,000 km/s With Respect To What? Newsgroups: sci.physics.relativity References: <6690fd8f$0$8002$426a34cc@news.free.fr> Content-Language: pl From: Maciej Wozniak In-Reply-To: <6690fd8f$0$8002$426a34cc@news.free.fr> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Lines: 33 Path: ...!weretis.net!feeder9.news.weretis.net!panix!usenet.blueworldhosting.com!diablo1.usenet.blueworldhosting.com!tr2.iad1.usenetexpress.com!feeder.usenetexpress.com!tr2.eu1.usenetexpress.com!news.newsdemon.com!not-for-mail Nntp-Posting-Date: Fri, 12 Jul 2024 10:00:03 +0000 X-Received-Bytes: 2023 X-Complaints-To: abuse@newsdemon.com Organization: NewsDemon - www.newsdemon.com Message-Id: <17e16ed7633e53e3$36006$546728$c2565adb@news.newsdemon.com> Bytes: 2435 W dniu 12.07.2024 o 11:55, J. J. Lodder pisze: > Mikko wrote: > >> On 2024-07-11 19:58:02 +0000, amirjf nin said: >> >>> Approximately 300,000 km/s with respect to what? >> >> Whenever the speec of something is measured it is measured with respect >> to someting else. The report should make clear what is the reference that >> is considered stationary. Usually it is the instruments used in the >> measurement, and usually but not always they are at rest with restpect to >> Earth surface at the place of the measurement. > > You really need to have a look at what and how is actually measured, > instead of elaborating your own ideas of measurement. > > FYI, in the precision 'speed of light' measurements > that preceded the abolition of the meter in 1983 > physicists measured the frequency of a standing wave. > This is a proper measurement in a proper frame, > yielding an obviously dimensionless number. > (a world scalar of course, being the same in every proper frame.) > It does not involve something going from somewhere. > >> Sometimes numbers with units of speed are used for other purposes instead >> of speed, for example in E = mc?, where c has units of speed. In those cases >> the question need not be asked. > > Standard error: speed does not -have- a unit. Yeah - that's what The Shit is making to the brains of its victims.