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Date: Fri, 2 Aug 2024 22:07:59 +0200 Mime-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Relativistic aberration Newsgroups: sci.physics.relativity References: <QsysQnpetTSlB_zDsjAhnCKqnbg@jntp> <lgtntqFjg34U1@mid.individual.net> <17e7331a73814274$123023$505064$c2265aab@news.newsdemon.com> <v8cgia$1e4s9$1@dont-email.me> <O-L1WgU1eCsz14Wrc6D7tpNPV7s@jntp> <v8fkn6$23nee$1@dont-email.me> <FS7BRIsxO-_X20VxXPebSsjPIt4@jntp> <v8gpr4$2c66e$1@dont-email.me> <1r17YwSTuu_yFwJ8Mj7O-umZb_M@jntp> <v8jd83$2vsa3$1@dont-email.me> Content-Language: pl From: Maciej Wozniak <mlwozniak@wp.pl> In-Reply-To: <v8jd83$2vsa3$1@dont-email.me> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Lines: 94 Path: ...!news-out.netnews.com!s1-1.netnews.com!tr2.iad1.usenetexpress.com!feeder.usenetexpress.com!tr2.eu1.usenetexpress.com!news.newsdemon.com!not-for-mail Nntp-Posting-Date: Fri, 02 Aug 2024 20:07:59 +0000 X-Received-Bytes: 4417 Organization: NewsDemon - www.newsdemon.com X-Complaints-To: abuse@newsdemon.com Message-Id: <17e80233df90cd90$123033$505064$c2265aab@news.newsdemon.com> Bytes: 4761 W dniu 02.08.2024 o 21:49, Paul.B.Andersen pisze: > Den 01.08.2024 23:03, skrev Richard Hachel: >> Le 01/08/2024 à 22:05, "Paul.B.Andersen" a écrit : >>> Den 01.08.2024 13:39, skrev Richard Hachel: >>>> >>>> The event that occurred at the supernova located at 15,000 ly has >>>> just been recorded by the Earth observer. >>>> He notes E = (x, y, z, To, t) >>>> Let x = 12000, y = 9000, z = 0, To = -15000, t = 0. >>>> This is how I write in Hachel notation. >>> >>> A very stupid notation! >>> Giving the position of a star in Cartesian coordinates >>> would obviously include the distance to the star, and then >>> in addition giving the distance to the star in light years >>> or years is redundant. >>> >>> Astronomers give the position to the star as an angle >>> in a spherical coordinate system. The angle is given as >>> observed from the Sun. >>> The distance is given in parsecs (or ly) and will be determined >>> by parallax or other method. >>> >>> The Earth is orbiting the Sun, which will mean that >>> an observer on the Earth will see the direction to >>> the star varying during the year. The star will appear >>> to move along an ellipse with major axis 40.98 arcsecs. >>> The direction to the star observed from the Sun will be in >>> the centre of the ellipse. >>> >>> https://paulba.no/pdf/Stellar_aberration.pdf >>> >>>> >>>> An observer crosses the Earth at this moment at a few thousand >>>> kilometers, his speed is 0.8c (his rocket has very advanced >>>> technology, and he is heading on the Ox axis). >>> >>> Along the x-axis? >>> So his velocity is 37⁰ from the direction to the star. >>> >>>> >>>> It is clear, at the risk of being absurd, and of not having >>>> understood anything at all about the theory of relativity that the >>>> events will be simultaneous for the two observers who will be >>>> conjoined at this moment. >>>> >>>> Their watch will mark t = 0 (since they are triggered at this moment). >>>> >>>> We want to know what the coordinates of the supernova event will be >>>> in the new reference frame of the rocket, and what the commander >>>> will write on his on-board carent. >>> >>> Due to aberration he will see the supernova in a very >>> different direction than the person on Earth. >>> >>> https://paulba.no/pdf/AberrationDoppler.pdf >>> equation (19) >>> The rocket will see the supernova >>> an angle 12.7⁰ from the x-axis. >>> >>>> >>>> Let E'=(x,y,z,To,0) since not yet knowing the Poincaré-Lorentz >>>> transformations, we can only guess the other four coordinates. >>>> >>>> But you, Paul, who knows the TL and who knows a little about SR, can >>>> you give the five new coordinates in RH mode? >>> >>> The aberration above is from the LT. >>> It is obviously meaningless to transform the distance, >>> there is no way the rocket man can measure it. >>> It is measured by other means. >>> >>>> >>>> Don't be afraid to make mistakes, we are here to learn and >>>> understand, and even if you make a mistake, it will allow us to go >>>> further. >>>> >>>> If you don't make a mistake, it's because you have already >>>> understood this point perfectly. >>> >>> Did you have a point? >> >> We don't care. >> I give this notation because it is the best. > > It isn't so different from what astronomers use. > > The position of the star is given as two angles and a distance. Oh, your idiot guru has refuted these Euclidean prejudices a long time ago. Have you never heard of it, Paul, poor halfbrain?