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Re: The overpass

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Tom Roberts alle ore 16:06:41 del 13/08/2017 ha scritto:
>> On the overpass C the head A of the train AB encounters the head N of the 
>> train MN traveling in the opposite direction:
>> -------------M------->N------------------------
>> ----------------------C---------------------->x
>> ----------------------A<-------B---------------
>> 
>> Since the two trains have the same length and speed, in the land reference 
>> also the tail B of the train AB encounters the queue M of the train MN on 
>> the same overpass C:
>> ----------------------M------->N---------------
>> ----------------------C---------------------->x
>> -------------A<-------B------------------------
>> 
>> At that point, from the tail of both trains a bomb destroys the flyover but 
>> the trains are now gone and so they are safe.
>
> OK. That describes the physical situation. ALL reference frames will agree 
> that A and N reach C simultaneously, and all frames agree that B and N reach 
> C simultaneously, and the overpass is destroyed after both train are gone.
>
> Simultaneous happenings that occur at a single event in spacetime are 
> simultaneous in all frames. Here there are two separate events: A and N reach 
> C, and M and B reach C -- these two events have timelike separation and 
> therefore their order is independent of frame.
>
> It is only for spacelike-separated events that their order is frame 
> dependent. There are no such events here.
>
> Tom Roberts

Ok, grazie, bye

Luigi Fortunati

-- 
Luigi Fortunati

Credere e' piu' facile che pensare
Believing is easier than thinking

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The overpass LuigiFortunati <fortunati.luigi@gmail.com> - 2017-08-13 09:51 +0200
  Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-13 15:53 +0200
    Re: The overpass Luigi Fortunati <fortunati.luigi@gmail.com> - 2017-08-13 19:13 +0200
      Re: The overpass The Starmaker <starmaker@ix.netcom.com> - 2017-08-13 11:02 -0700
  Re: The overpass Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-13 09:06 -0500
    Re: The overpass Luigi Fortunati <fortunati.luigi@gmail.com> - 2017-08-13 19:07 +0200
    Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-13 19:40 +0200
      Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-13 21:32 +0200
        Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-13 21:45 +0200
          Re: The overpass Prudence Oppenheimer <phow@innfldo.sp> - 2017-08-13 21:32 +0000
            Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-14 00:34 +0200
      Re: The overpass Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-13 23:03 -0500
        Re: The overpass Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-08-14 15:52 +0200
          Re: The overpass Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-14 15:21 -0500
            Re: The overpass Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-14 16:43 -0500
    Re: The overpass "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2017-08-13 17:14 -0700
      Re: The overpass Tom Roberts <tjroberts137@sbcglobal.net> - 2017-08-13 23:04 -0500
        Re: The overpass "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2017-08-14 19:55 -0700

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