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Article #16157Re: Why sound needs a medium to travel and light not?
From: Pentcho Valev
Date: Mon, 19 May 2008 23:13
Date: Mon, 19 May 2008 23:13
56 lines
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4453 bytes
On May 19, 9:14 pm, Sanny <softta...@hotmail.com> wrote: > > > Why sound needs a medium to travel and light not? > > > Why kites need a medium to travel and bullets not? > > Good Analogy !!! > > Because Kites uses Aerodynamics to fly in air. It uses Air Lift to > rise high. Bullets travel using the Kinetic Energy possesed by it. > > Does Light has a Kinetic Energy that make it fly without the need of > any Medium? > > Bye > Sanny A very clever apostle of Einstein's, Banesh Hoffmann, could be useful: http://www.amazon.com/Relativity-Its-Roots-Banesh-Hoffmann/dp/0486406768 "Relativity and Its Roots" by Banesh Hoffmann, Chapter 5. (I do not have the text in English so I am giving it in French) Banesh Hoffmann, "La relativite, histoire d'une grande idee", Pour la Science, Paris, 1999, p. 112: "De plus, si l'on admet que la lumiere est constituee de particules, comme Einstein l'avait suggere dans son premier article, 13 semaines plus tot, le second principe parait absurde: une pierre jetee d'un train qui roule tres vite fait bien plus de degats que si on la jette d'un train a l'arret. Or, d'apres Einstein, la vitesse d'une certaine particule ne serait pas independante du mouvement du corps qui l'emet! Si nous considerons que la lumiere est composee de particules qui obeissent aux lois de Newton, ces particules se conformeront a la relativite newtonienne. Dans ce cas, il n'est pas necessaire de recourir a la contraction des longueurs, au temps local ou a la transformation de Lorentz pour expliquer l'echec de l'experience de Michelson-Morley. Einstein, comme nous l'avons vu, resista cependant a la tentation d'expliquer ces echecs a l'aide des idees newtoniennes, simples et familieres. Il introduisit son second postulat, plus ou moins evident lorsqu'on pensait en termes d'ondes dans l'ether." Translation from French: "Moreover, if one admits that light consists of particles, as Einstein had suggested in his first paper, 13 weeks earlier, the second principle seems absurd: a stone thrown from a fast- moving train causes much more damage than one thrown from a train at rest. Now, according to Einstein, the speed of a particle would not be independent of the state of motion of the emitting body! If we consider light as composed of particles that obey Newton's laws, those particles would conform to Newtonian relativity. In this case, it is not necessary to resort to length contration, local time and Lorentz transformations in explaining the negative result of the Michelson- Morley experiment. Einstein however, as we have seen, resisted the temptation to explain the negative result in terms of Newton's ideas, simple and familiar. He introduced his second postulate, more or less evident as one thinks in terms of waves in aether." Pentcho Valev pvalev@yahoo.com
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X-Google-Thread: 10b271,b00109c6511c30a6 X-Google-Thread: 113e84,b00109c6511c30a6 X-Google-Thread: fdc67,b00109c6511c30a6 X-Google-Thread: 10f545,b00109c6511c30a6 X-Google-Thread: fa4c1,c6becc1db29a0c2,start X-Google-Attributes: gid10b271,gid113e84,gidfdc67,gid10f545,gidfa4c1,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII Path: arc1-ca.pugleaf.net!g2news1.google.com!postnews.google.com!x35g2000hsb.googlegroups.com!not-for-mail From: Pentcho Valev <pvalev@yahoo.com> Newsgroups: sci.physics,alt.philosophy,alt.astronomy,sci.physics.relativity,fr.sci.physique Subject: Re: Why sound needs a medium to travel and light not? Date: Mon, 19 May 2008 16:13:54 -0700 (PDT) Organization: http://groups.google.com Lines: 56 Message-ID: <ae3e954f-f254-447c-a794-4b7951ec217f@x35g2000hsb.googlegroups.com> References: <530768f6-eba8-4a2a-a210-34b0c2a0057a@p25g2000pri.googlegroups.com> <4831CB59.C0A094AE@hate.spam.net> <8147cbec-0f84-4527-9921-326b2a98fd91@u12g2000prd.googlegroups.com> NNTP-Posting-Host: 89.3.109.60 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1211238834 18451 127.0.0.1 (19 May 2008 23:13:54 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Mon, 19 May 2008 23:13:54 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: x35g2000hsb.googlegroups.com; posting-host=89.3.109.60; posting-account=Lz-LbgoAAABPDavKeW-eYeobwLHD_cvQ User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1),gzip(gfe),gzip(gfe)