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Article #666Re: HOW EINSTEIN USED MAXWELL
From: Androcles
Date: Fri, 02 Apr 2010 09:32
Date: Fri, 02 Apr 2010 09:32
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8935 bytes
"Sebastian Garth" <sebastiangarth@gmail.com> wrote in message news:1f98cc79-ec52-40be-a241-602ecb1a6286@g11g2000yqe.googlegroups.com... On Apr 1, 4:18 am, Pentcho Valev <pva...@yahoo.com> wrote: > According to Maxwell's theory, (1) the speed of light is independent > of the speed of the emitter but (2) it does depend on the speed of the > observer: > > http://www.pitt.edu/~jdnorton/papers/companion.doc > John Norton: "Einstein's second postulate, the light postulate, > asserts that "light is always propagated in empty space with a > definite velocity c which is independent of the state of motion of the > emitting body." Einstein gave no justification for this postulate in > the introduction to his paper. Its strongest justification came from > Maxwell's electrodynamics. That theory had identified light with waves > propagating in an electromagnetic field and concluded that just one > speed was possible for them in empty space, c = 300,000 km/sec, no > matter what the motion of the emitter." > > http://www.futura-sciences.com/fr/doc/t/physique/d/relativite-restrei... > "Les �quations de Maxwell pr�voyaient la propagation de la lumi�re � > la vitesse de 300.000 km/s par rapport � l'�ther. Or, si l'on cherche > � calculer la vitesse de la lumi�re par rapport � un r�f�rentiel qui > est lui-m�me mobile dans l'�ther, on observe que la lumi�re se propage > avec une vitesse diff�rente..." > > http://www.solidarity-us.org/node/58 > "Maxwell's theory of electricity and magnetism provides a successful > framework with which to study light. In this theory light is an > electromagnetic wave. Using Maxwell's equations one can compute the > speed of light. One finds that the speed of light is 300,000,000 > meters (186,000 miles) per second. The question arises: which inertial > observer is this speed of light relative to? As in the previous > paragraph, two inertial observers traveling relative to each other > should observe DIFFERENT SPEEDS FOR THE SAME LIGHT WAVE." > > In 1905 Einstein adopted the former assertion of Maxwell's theory (the > speed of light is independent of the speed of the emitter) and, by > applying the principle of relativity, inferred that the speed of light > is independent of the speed of the observer as well. > > Einstein could have adopted the latter assertion of Maxwell's theory > (the speed of light does depend on the speed of the observer). Then, > by applying the principle of relativity, he would have inferred that > the speed of light does depend on the speed of the emitter as well. > This would have been a return to Newton's emission theory of light: > > http://www.mfo.de/programme/schedule/2006/08c/OWR_2006_10.pdf > Jean Eisenstaedt: "At the end of the 18th century, a natural extension > of Newton's dynamics to light was developed but immediately forgotten. > A body of works completed the Principia with a relativistic optics of > moving bodies, the discovery of the Doppler-Fizeau effect some sixty > years before Doppler, and many other effects and ideas which represent > a fascinating preamble to Einstein relativities. It was simply > supposed that 'a body-light', as Newton named it, was subject to the > whole dynamics of the Principia in much the same way as were material > particles; thus it was subject to the Galilean relativity and its > velocity was supposed to be variable. Of course it was subject to the > short range 'refringent' force of the corpuscular theory of light -- > which is part of the Principia-- but also to the long range force of > gravitation which induces Newton's theory of gravitation. The fact > that the 'mass' of a corpuscle of light was not known did not > constitute a problem since it does not appear in the Newtonian (or > Einsteinian) equations of motion. It was precisely what John Michell > (1724-1793), Robert Blair (1748-1828), Johann G. von Soldner > (1776-1833) and Fran�ois Arago (1786-1853) were to do at the end of > the 18th century and the beginning the 19th century in the context of > Newton's dynamics. Actually this 'completed' Newtonian theory of light > and material corpuscle seems to have been implicitly accepted at the > time. In such a Newtonian context, not only Soldner's calculation of > the deviation of light in a gravitational field was understood, but > also dark bodies (cousins of black holes). A natural (Galilean and > thus relativistic) optics of moving bodies was also developed which > easily explained aberration and implied as well the essence of what we > call today the Doppler effect. Moreover, at the same time the > structure of -- but also the questions raised by-- the Michelson > experiment was understood. Most of this corpus has long been > forgotten. The Michell-Blair-Arago effect, prior to Doppler's effect, > is entirely unknown to physicists and historians. As to the influence > of gravitation on light, the story was very superficially known but > had never been studied in any detail. Moreover, the existence of a > theory dealing with light, relativity and gravitation, embedded in > Newton's Principia was completely ignored by physicists and by > historians as well. But it was a simple and natural way to deal with > the question of light, relativity (and gravitation) in a Newtonian > context." > > http://ustl1.univ-lille1.fr/culture/publication/lna/detail/lna40/pgs/... > Jean Eisenstaedt: "M�me s'il �tait conscient de l'int�r�t de la > th�orie de l'�mission, Einstein n'a pas pris le chemin, totalement > oubli�, de Michell, de Blair, des Principia en somme. Le contexte de > d�couverte de la relativit� ignorera le XVIII�me si�cle et ses racines > historiques plongent au coeur du XIX�me si�cle. Arago, Fresnel, > Fizeau, Maxwell, Mascart, Michelson, Poincar�, Lorentz en furent les > principaux acteurs et l'optique ondulatoire le cadre dans lequel ces > questions sont pos�es. Pourtant, au plan des structures physiques, > l'optique relativiste des corps en mouvement de cette fin du XVIII�me > est infiniment plus int�ressante - et plus utile p�dagogiquement - que > le long cheminement qu'a impos� l'�ther." > > Pentcho Valev > pva...@yahoo.com Alright, let's just recap here. When an object is accelerated, we find that (relative to us) it occupies both less space (length contraction) *and* time (dialation). =============================================== Ok, let's just recap here. The time for the resting object is t and the time for the moving obbject is tau The length for the resting object is x' and the length for the moving object is xi. According to SR, tau = t * sqrt(1-v^2/c^2) Ref: http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img61.gif and sqrt(1- <anything>) is less than 1, so tau < t. xi = x'/ sqt(1-v^2/c^2) so xi > x. Why are you calling Einstein's length dilation a contraction? Why are you calling Einstein's time contraction a dialation? Are not able to read algebra? ============================================= Acceleration causes space-time curvature (relativistic effects) ============================================= Alright, let's just recap here. Fuckin' bullshit, you drooling cretin!
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X-Google-Thread: 10f545,e17dad18d26e7f0c X-Google-NewGroupId: yes X-Google-Thread: 10b271,e17dad18d26e7f0c X-Google-NewGroupId: yes X-Google-Thread: fa4c1,e17dad18d26e7f0c X-Google-NewGroupId: yes X-Google-Thread: 111645,e17dad18d26e7f0c X-Google-NewGroupId: yes X-Google-Attributes: gid41be78289e,gid54ac8f410d,gid2479375fed,gid237b8ad48,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII Path: arc1-ca.pugleaf.net!g2news2.google.com!news4.google.com!feeder.news-service.com!feeder.news-service.com!cyclone01.ams2.highwinds-media.com!news.highwinds-media.com!npeersf01.ams.highwinds-media.com!newsfe26.ams2.POSTED!7564ea0f!not-for-mail From: "Androcles" <Headmaster@Hogwarts.physics_x> Newsgroups: sci.physics.relativity,sci.physics,fr.sci.physique,fr.sci.astrophysique References: <1e43f6e3-a9d5-4f43-8c87-64ada4cc4f7d@r18g2000yqd.googlegroups.com> <1f98cc79-ec52-40be-a241-602ecb1a6286@g11g2000yqe.googlegroups.com> Subject: Re: HOW EINSTEIN USED MAXWELL Lines: 130 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Message-ID: <TQitn.748933$Dy7.309483@newsfe26.ams2> NNTP-Posting-Host: 82.34.70.125 X-Complaints-To: http://netreport.virginmedia.com X-Trace: newsfe26.ams2 1270200755 82.34.70.125 (Fri, 02 Apr 2010 09:32:35 UTC) NNTP-Posting-Date: Fri, 02 Apr 2010 09:32:35 UTC Organization: virginmedia.com Date: Fri, 2 Apr 2010 10:32:04 +0100