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Groups > sci.physics.relativity > #476367
| From | benj <benj.fake@gmail.com> |
|---|---|
| Newsgroups | sci.physics.relativity |
| Subject | Re: Relative motion again |
| Date | 2018-11-05 21:45 -0500 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <prqv8l$159o$1@gioia.aioe.org> (permalink) |
| References | <5a7ad418-fc96-4c4c-b352-140904aeed03@googlegroups.com> <g4cbr4F5gouU1@mid.individual.net> |
On 11/5/2018 9:16 PM, Sylvia Else wrote: > On 6/11/2018 5:49 am, xip1415926@gmail.com wrote: >> Some guy walks out of a bar… >> >> Well, almost. >> >> Actually, two guys walk out of two bars, these guys being of about >> equal weight, mass = 150 lbs, and equal walking speed, 2 mph. They >> turn right and left on leaving doorways, thereby approaching each >> other on the sidewalk. >> >> Walker-A has speed a = 2 and walker-B has speed b = 2, speeds >> conveniently positive though of opposite directions. >> >> Relative motion of the walkers is convergence. Walkers A and B >> approach one another with speed v = a + b = 2 + 2 = 4. >> > > This is wrong. You are making the unfounded assumption that velocities > combine by addition, when they do not. The difference is negligible for > small velocities, but large when the magnitudes of the velocities > approach the speed of light. > > Sylvia. You are simply wrong Sylvia. By the principle of Galilean relativity, if the two guys walk out of the bar and approach each other it would not matter if both of them were traveling near the speed of light. To each other they would be traveling slow. But to an observer across the street things would appear quite different. And the reason would be retardation not relativity. Or do you believe as they approach the speed of light the sidewalk shortens?
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Relative motion again xip1415926@gmail.com - 2018-11-05 10:49 -0800
Re:Relative motion again Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-11-05 20:16 +0100
Re:Relative motion again Buck Dehner <uktea@yswdoiz.cp> - 2018-11-05 21:07 +0000
Re:Relative motion again Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-11-05 22:55 +0100
Re:Relative motion again Buck Dehner <uktea@yswdoiz.cp> - 2018-11-05 22:46 +0000
Re:Relative motion again Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-11-06 01:22 +0100
Re:Relative motion again Ntowicz Usarczyk <iswso@wioioksi.io> - 2018-11-06 20:27 +0000
Re: Relative motion again Sylvia Else <sylvia@email.invalid> - 2018-11-06 13:16 +1100
Re: Relative motion again benj <benj.fake@gmail.com> - 2018-11-05 21:45 -0500
Re: Relative motion again Sylvia Else <sylvia@email.invalid> - 2018-11-06 14:57 +1100
Re: Relative motion again xip1415926@gmail.com - 2018-11-05 19:58 -0800
Re: Relative motion again xip1415926@gmail.com - 2018-11-05 21:24 -0800
Re: Relative motion again Sylvia Else <sylvia@email.invalid> - 2018-11-06 18:10 +1100
Re: Relative motion again Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-11-06 09:21 +0100
Re: Relative motion again xip1415926@gmail.com - 2018-11-06 06:03 -0800
Re: Relative motion again Tom Roberts <tjroberts137@sbcglobal.net> - 2018-11-06 08:41 -0600
Re: Relative motion again Ntowicz Usarczyk <iswso@wioioksi.io> - 2018-11-06 20:32 +0000
Re: Relative motion again Tom Roberts <tjroberts137@sbcglobal.net> - 2018-11-06 20:39 -0600
Re: Relative motion again Ntowicz Usarczyk <iswso@wioioksi.io> - 2018-11-07 19:44 +0000
Re: Relative motion again Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-11-06 22:32 +0100
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