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Groups > sci.physics.relativity > #433027

Re: Train gedanken - again.

From Thomas 'PointedEars' Lahn <PointedEars@web.de>
Newsgroups sci.physics.relativity
Subject Re: Train gedanken - again.
Date 2017-09-20 14:33 +0200
Organization PointedEars Software (PES)
Message-ID <5079786.DvuYhMxLoT@PointedEars.de> (permalink)
References <opr46v$jhn$1@dont-email.me> <ops8jj$1rqc$1@gioia.aioe.org> <2403458.mvXUDI8C0e@PointedEars.de> <opsod0$im2$1@gioia.aioe.org>

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HGW wrote:

> On 20/09/17 12:48, Thomas 'PointedEars' Lahn wrote:
>> HGW wrote:
>>> On 19/09/17 22:56, Paul B. Andersen wrote:
>>>> The observations:
>>>> - At some time, Paul passes Ralph.
>>>> - At some later time, Ralph sees the flashes
>>>>      from the lightening bolts simultaneously.
>>>> - At some time, Paul sees the flash from the front,
>>>>      and shortly later, he sees the flash from the aft end.
>>>> - Ralph finds that he is midway between the marks in the ground.
>>>
>>> According to SR:
>>> Since Paul is at the midpoint of the train and the flashes did not reach
>>> him simultaneously, the flashes were not absolutely simultaneous.
>>> Since Ralph is midway between the flashes and DOES see them
>>> simultaneously, the flashes WERE absolutely simultaneous.
>> That would be the case if the train, on which Ralph is located, were not
>> moving relative to the places of the flashes.
> 
> But your colleagues have insisted that the flashes have no 'places'.

First of all, they are not my colleagues.  Second, you have misunderstood 
them.

>>> Your observations assume the flashes were at rest with the ground and
>>> moved at c in that frame.
>> First of all, not the flashes are moving towards the observers,
>> but the light from the flashes.
> 
> Yes I have told everyone here about that.

But you have neglected to consider the simple, experimentally confirmed, 
fact that light does not propagate instantly, and that light “does not care” 
how an observer is moving.  That is, its speed is *finite* and *constant*.

It takes time before the light rays/pulses of the flashes from opposite 
directions reach the observers.

It takes *less* time if the observer moves towards the light,
*more* time if the observer moves away from the light.  

Because in the first case the observer is catching up with the light,
and in the second case the light has to catch up with him.

So an observer moving relative to the places from where the light 
rays/pulses originated *cannot* observe both at the same time.

While an observer at rest to those places must observe them at the same 
time.

When events are observed at the same time, they are said to be simultaneous.
But in this case, they are not observed at the same time by all observers.

That is the *relativity* of simultaneity.

-- 
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

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Thread

Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-19 14:56 +0200
  Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-19 06:00 -0700
  Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:48 +0000
    Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:53 +0000
      Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-19 08:05 -0700
        Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 09:09 -0700
          Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-19 09:35 -0700
            Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 10:45 -0700
        Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 22:01 +0000
          Re: Train gedanken - again. Julio Di Egidio <julio@diegidio.name> - 2017-09-20 07:30 -0700
            Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-20 20:00 +0000
  Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-19 07:55 -0700
    Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-19 14:58 +0000
  Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-20 09:18 +1000
    Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-20 04:48 +0200
      Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-20 13:47 +1000
        Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-20 14:33 +0200
          Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:05 +1000
            Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-20 16:07 -0700
            Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:24 +0200
              Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:22 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:28 +0200
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:40 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-29 09:20 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-29 08:49 +0200
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-29 12:08 +0000
                Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-29 05:59 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:22 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:08 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 20:30 -0700
        Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-20 20:42 +0000
          Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:39 +1000
            Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-21 02:18 +0000
              Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:25 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:37 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:34 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 13:30 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 06:44 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-10-10 00:24 +0200
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 03:02 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 06:50 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 22:23 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 10:08 +1000
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-23 04:09 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-23 13:32 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 09:02 +1000
                Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 06:31 -0700
                Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-23 19:37 -0700
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 07:26 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 16:44 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 08:03 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 17:35 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:26 +1000
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 17:36 -0700
                Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-24 18:24 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 07:34 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:49 +1000
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 07:56 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-25 00:00 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:47 +0200
                Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-25 00:47 -0700
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 23:53 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 19:53 +1000
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-25 02:58 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:54 +0200
                Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:15 +1000
                Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-25 10:19 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:56 +0200
                Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:11 +1000
                Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 14:43 -0700
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 01:26 -0700
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 02:06 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-27 08:39 +1000
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:52 +0200
                Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 03:18 +1000
                Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-25 10:21 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-25 13:19 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:48 +1000
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 08:31 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-24 17:46 +0200
                Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-24 09:30 -0700
                Re: Train gedanken - again. Paparios <mrios@ing.puc.cl> - 2017-09-24 08:04 -0700
                Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-24 08:24 -0700
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-23 14:11 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 08:53 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 02:31 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 16:39 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 12:34 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:30 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-24 22:32 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 09:41 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-25 02:51 +0000
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 15:51 +1000
                Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-25 12:48 +0000
    Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 11:13 +0200
      Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 02:31 -0700
        Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 02:34 -0700
          Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 03:25 -0700
  Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-19 22:40 -0700
    Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 08:08 +0200
      Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:46 +1000
    Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 08:33 +0200
      Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-20 00:04 -0700
      Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 00:34 -0700
        Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-20 00:42 -0700
          Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 10:54 +0200
            Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 08:49 +1000
              Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-20 15:59 -0700
              Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 01:54 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 12:43 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-22 12:56 +0200
                Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-22 11:04 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:36 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 01:38 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-27 20:00 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:06 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:30 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:04 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 20:36 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 07:21 +0200
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-26 21:57 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 20:57 -0700
                Re: Train gedanken - again. "Dono," <sa_ge@comcast.net> - 2017-09-26 21:00 -0700
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 15:24 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 17:39 -0700
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 02:52 +0200
        Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-20 10:48 +0200
    Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 15:13 +0200
  Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-20 20:19 +0200
    Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-20 20:02 +0000
    Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:10 +1000
      Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 12:46 +0200
  Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-20 13:14 -0700
    Re: Train gedanken - again. mitchrae3323@gmail.com - 2017-09-20 13:27 -0700
    Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-21 09:29 +1000
    Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 14:03 +0200
      Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-21 05:19 -0700
      Re: Train gedanken - again. Kos Etrakis <uar@ksskkwi.ck> - 2017-09-21 12:42 +0000
      Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-21 07:24 -0700
        Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-21 22:16 +0200
          Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:51 +1000
            Re: Train gedanken - again. Odd Bodkin <bodkinodd@gmail.com> - 2017-09-22 03:02 +0000
              Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-21 20:18 -0700
          Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 20:39 -0700
            Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-21 20:42 -0700
            Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 07:49 +0200
              Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-21 23:51 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 09:04 +0200
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 09:08 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-22 00:27 -0700
                Re: Train gedanken - again. Poutnik <poutnik@privacy.net> - 2017-09-22 11:52 +0200
                Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-22 04:05 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:46 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:26 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:31 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:01 +0200
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-27 20:22 -0700
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 12:00 +0200
            Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 14:08 +0200
              Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:41 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-27 12:28 +0200
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-28 09:32 +1000
                Re: Train gedanken - again. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-28 03:02 +0200
          Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-22 07:03 -0700
            Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 19:55 +0200
              Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 07:42 +1000
              Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-23 06:55 -0700
                Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-24 11:17 +0200
      Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-22 08:30 +1000
        Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-22 13:52 +0200
          Re: Train gedanken - again. mlwozniak@wp.pl - 2017-09-22 05:34 -0700
          Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-23 08:05 +1000
            Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-23 15:38 +0200
              Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-24 09:12 +1000
                Re: Train gedanken - again. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2017-09-23 16:17 -0700
                Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-24 11:03 +0200
                Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 07:11 -0700
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-24 07:38 -0700
                Re: Train gedanken - again. HGW <HW@home.net> - 2017-09-25 08:43 +1000
                Re: Train gedanken - again. "Paul B. Andersen" <relativity@paulba.no> - 2017-09-25 14:38 +0200
                Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 07:15 -0700
                Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-25 07:38 -0700
                Re: Train gedanken - again. "HGW, DSc." <HG@....> - 2017-09-26 04:20 +1000
                Re: Train gedanken - again. gehan.ameresekere@gmail.com - 2017-09-26 01:23 -0700
              Re: Train gedanken - again. kenseto <setoken@att.net> - 2017-09-24 06:48 -0700

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