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Groups > sci.physics.relativity > #432886 > unrolled thread
| Started by | "Paul B. Andersen" <relativity@paulba.no> |
|---|---|
| First post | 2017-09-19 14:56 +0200 |
| Last post | 2017-09-24 06:48 -0700 |
| Articles | 20 on this page of 185 — 15 participants |
Back to article view | Back to sci.physics.relativity
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
Page 2 of 10 — ← Prev page 1 [2] 3 4 … 10 Next page →
| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-22 12:22 +1000 |
| Message-ID | <oq1s4j$tef$1@gioia.aioe.org> |
| In reply to | #433256 |
On 22/09/17 09:24, Thomas 'PointedEars' Lahn wrote:
> HGW wrote:
>
>> On 20/09/17 22:33, Thomas 'PointedEars' Lahn wrote:
>>> HGW wrote:
>>>>>> 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.
>>
>> That is obvious and it is also where you are completely missing the point.
>
> Not at all.
>
>> According to SR, the train observer is not moving relative to the flashes.
>
> Wrong.
Well if you are assuming the flashes strike the ground only then the whole aim of the experiment falls apart.
It becomes a trivial exercise and has nothing much to do with Einstein's RoS.
I don't think you understand SR at all.
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-27 15:28 +0200 |
| Message-ID | <753266808.0ifERbkFSE@PointedEars.de> |
| In reply to | #433272 |
HGW wrote: > On 22/09/17 09:24, Thomas 'PointedEars' Lahn wrote: >> HGW wrote: >>> According to SR, the train observer is not moving relative to the >>> flashes. >> Wrong. > > Well if you are assuming the flashes strike the ground only then the whole > aim of the experiment falls apart. Of course not. That the flashes strike the ground relative to which one observer is _not_ moving and the other (in the train) *is*, is the *key* *fact* of the experiment. > It becomes a trivial exercise and has nothing much to do with Einstein's > RoS. I don't think you understand SR at all. Pot calling the kettle black. PointedEars -- A neutron walks into a bar and inquires how much a drink costs. The bartender replies, "For you? No charge." (from: WolframAlpha)
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-27 15:40 +0200 |
| Message-ID | <4805231.Sb9uPGUboI@PointedEars.de> |
| In reply to | #434160 |
Thomas 'PointedEars' Lahn wrote: > HGW wrote: >> On 22/09/17 09:24, Thomas 'PointedEars' Lahn wrote: >>> HGW wrote: >>>> According to SR, the train observer is not moving relative to the >>>> flashes. >>> Wrong. >> Well if you are assuming the flashes strike the ground only then the >> whole aim of the experiment falls apart. > > Of course not. That the flashes strike the ground relative to which one > observer is _not_ moving and the other (in the train) *is*, is the *key* > *fact* of the experiment. It is probably better to be more precise here. “Flashes” are short for “flashes of lightning”; this is the visual phenomenon associated with the electromagnetic phenomenon of _lightning_. So actually not the flashes strike the ground, but the lightnings do. It should also be noted that the ground here is just an explanatory vehicle to provide for a more tangible frame of reference. The experiment works just as well with lightnings in air or with lightnings striking the train (assuming it is long enough, and it and the train observer survive the lightnings striking), or with flashlights or other light sources instead of flashes of lightning. It also works with an automobile or a bus instead of a train aso. That is why it is called a *thought* experiment: the *concepts* matter, not the details of the implementation. PointedEars -- Q: How many theoretical physicists specializing in general relativity does it take to change a light bulb? A: Two: one to hold the bulb and one to rotate the universe. (from: WolframAlpha)
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-29 09:20 +1000 |
| Message-ID | <oqk04f$ish$1@gioia.aioe.org> |
| In reply to | #434164 |
On 27/09/17 23:40, Thomas 'PointedEars' Lahn wrote:
> Thomas 'PointedEars' Lahn wrote:
>
>> HGW wrote:
> It is probably better to be more precise here. “Flashes” are short for
> “flashes of lightning”; this is the visual phenomenon associated with the
> electromagnetic phenomenon of _lightning_.
>
> So actually not the flashes strike the ground, but the lightnings do.
>
> It should also be noted that the ground here is just an explanatory vehicle
> to provide for a more tangible frame of reference. The experiment works
> just as well with lightnings in air or with lightnings striking the train
> (assuming it is long enough, and it and the train observer survive the
> lightnings striking), or with flashlights or other light sources instead of
> flashes of lightning. It also works with an automobile or a bus instead of
> a train aso.
>
> That is why it is called a *thought* experiment: the *concepts* matter, not
> the details of the implementation.
I call it a bloody stupid thought experiment. It is designed to be deceptive.
> PointedEars
>
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-29 08:49 +0200 |
| Message-ID | <c7359d5f-85e7-3551-4d09-e7349b640d3e@PointedEars.de> |
| In reply to | #434384 |
HGW wrote: > On 27/09/17 23:40, Thomas 'PointedEars' Lahn wrote: >> That is why it is called a *thought* experiment: the *concepts* matter, not >> the details of the implementation. > > I call it a bloody stupid thought experiment. It is designed to be deceptive. You have a closed mindset, so that assessment is unsurprising. -- PointedEars Twitter: @PointedEars2 Please do not cc me. / Bitte keine Kopien per E-Mail.
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| From | Odd Bodkin <bodkinodd@gmail.com> |
|---|---|
| Date | 2017-09-29 12:08 +0000 |
| Message-ID | <oqld4p$m93$2@gioia.aioe.org> |
| In reply to | #434384 |
HGW <HW@home.net> wrote: > On 27/09/17 23:40, Thomas 'PointedEars' Lahn wrote: >> Thomas 'PointedEars' Lahn wrote: >> >>> HGW wrote: > >> It is probably better to be more precise here. “Flashes” are short for >> “flashes of lightning”; this is the visual phenomenon associated with the >> electromagnetic phenomenon of _lightning_. >> >> So actually not the flashes strike the ground, but the lightnings do. >> >> It should also be noted that the ground here is just an explanatory vehicle >> to provide for a more tangible frame of reference. The experiment works >> just as well with lightnings in air or with lightnings striking the train >> (assuming it is long enough, and it and the train observer survive the >> lightnings striking), or with flashlights or other light sources instead of >> flashes of lightning. It also works with an automobile or a bus instead of >> a train aso. >> >> That is why it is called a *thought* experiment: the *concepts* matter, not >> the details of the implementation. I’m amused by people who, when they get confused about simple things, blame their confusion on poor explications. > > I call it a bloody stupid thought experiment. It is designed to be deceptive. > >> PointedEars >> > > -- Odd Bodkin -- maker of fine toys, tools, tables
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| From | mlwozniak@wp.pl |
|---|---|
| Date | 2017-09-29 05:59 -0700 |
| Message-ID | <d999d8e6-e099-481b-9448-1d87f24afaa7@googlegroups.com> |
| In reply to | #434450 |
W dniu piątek, 29 września 2017 14:09:01 UTC+2 użytkownik Odd Bodkin napisał: > HGW <HW@home.net> wrote: > > On 27/09/17 23:40, Thomas 'PointedEars' Lahn wrote: > >> Thomas 'PointedEars' Lahn wrote: > >> > >>> HGW wrote: > > > >> It is probably better to be more precise here. “Flashes” are short for > >> “flashes of lightning”; this is the visual phenomenon associated with the > >> electromagnetic phenomenon of _lightning_. > >> > >> So actually not the flashes strike the ground, but the lightnings do. > >> > >> It should also be noted that the ground here is just an explanatory vehicle > >> to provide for a more tangible frame of reference. The experiment works > >> just as well with lightnings in air or with lightnings striking the train > >> (assuming it is long enough, and it and the train observer survive the > >> lightnings striking), or with flashlights or other light sources instead of > >> flashes of lightning. It also works with an automobile or a bus instead of > >> a train aso. > >> > >> That is why it is called a *thought* experiment: the *concepts* matter, not > >> the details of the implementation. > > I’m amused by people who, when they get confused about simple things, blame > their confusion on poor explications. You have to be very amused by yourself.
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-28 09:22 +1000 |
| Message-ID | <oqhbra$53h$1@gioia.aioe.org> |
| In reply to | #434160 |
On 27/09/17 23:28, Thomas 'PointedEars' Lahn wrote:
> HGW wrote:
>
>> On 22/09/17 09:24, Thomas 'PointedEars' Lahn wrote:
>>> HGW wrote:
>>>> According to SR, the train observer is not moving relative to the
>>>> flashes.
>>> Wrong.
>>
>> Well if you are assuming the flashes strike the ground only then the whole
>> aim of the experiment falls apart.
>
> Of course not. That the flashes strike the ground relative to which one
> observer is _not_ moving and the other (in the train) *is*, is the *key*
> *fact* of the experiment.
Gawd! You haven't a clue. That would just give it a trivial ballistic or aether explanation. The flashes leave marks on
both train and track. It can be assumed that light from the flashes leaves each pair of marks at the same instants. That
being so and since light speed is supposed to be source independent and isotropic according to the silly theory of
Einstein, it must reach either both or neither centrally located observers simultaneously, since neither the train nor
track frame has any superiority of the other with regard to the speeds of the flashes. If one observer receives the
flashes simultaneously and the other does not, then it clearly shows that the assumptions of SR are wrong.
>> It becomes a trivial exercise and has nothing much to do with Einstein's
>> RoS. I don't think you understand SR at all.
>
> Pot calling the kettle black.
www.scisite.info/ros.html
> PointedEars, Pinhead
>
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-28 03:08 +0200 |
| Message-ID | <4386936.0VBMTVartN@PointedEars.de> |
| In reply to | #434187 |
HGW wrote: > On 27/09/17 23:28, Thomas 'PointedEars' Lahn wrote: >> HGW wrote: >>> On 22/09/17 09:24, Thomas 'PointedEars' Lahn wrote: >>>> HGW wrote: >>>>> According to SR, the train observer is not moving relative to the >>>>> flashes. >>>> Wrong. >>> Well if you are assuming the flashes strike the ground only then the >>> whole aim of the experiment falls apart. >> >> Of course not. That the flashes strike the ground relative to which one >> observer is _not_ moving and the other (in the train) *is*, is the *key* >> *fact* of the experiment. > > Gawd! You haven't a clue. Pot, kettle, black. > That would just give it a trivial ballistic or aether explanation. No, it would not. > The flashes leave marks on both train and track. […] The lightnings would, but that is *completely* *irrelevant* as we are considering the flashes from the lightnings, not the marks they make. AISB, whether the lightnings actually strike the ground is irrelevant. Red herring. PointedEars -- Q: Why is electricity so dangerous? A: It doesn't conduct itself. (from: WolframAlpha)
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| From | gehan.ameresekere@gmail.com |
|---|---|
| Date | 2017-09-27 20:30 -0700 |
| Message-ID | <b63a0d30-8960-413e-a669-2083471c893e@googlegroups.com> |
| In reply to | #434187 |
On Thursday, September 28, 2017 at 4:52:22 AM UTC+5:30, HGW wrote: . > > Gawd! You haven't a clue. That would just give it a trivial ballistic or aether explanation. The flashes leave marks on > both train and track. It can be assumed that light from the flashes leaves ... HGW, for the train observer, where is the source of the photons from the flash located, at what distance from the train observer at the point of the flashes emission? Flash1 Flash2 A-------------------TRAINOBSERVER------------------B Can you answer this simple question?
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| From | Odd Bodkin <bodkinodd@gmail.com> |
|---|---|
| Date | 2017-09-20 20:42 +0000 |
| Message-ID | <opujrp$1pml$2@gioia.aioe.org> |
| In reply to | #432980 |
HGW <HW@home.net> 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'. Like Seto, you can't read. The flashes have places. They have no duration. > >> But it is, and so he is: he >> is moving away from the place of the one flash and towards the place of the >> other, and so he is moving away from the light of the former and towards the >> light of the latter. > > You have assumed the flashes are at rest with the ground. > >> (Use a fixed-width Unicode font to read the following.) >> >> t₀: ☇ R ☇ Flashes strike >> ☇ P ☇ Flashes strike >> >> t₁: → R ← Ralph has not seen either flash yet >> → P ← Paul has not seen either flash yet >> >> t₂: → R ← Ralph has not seen either flash yet >> → P ← Paul has not seen either flash yet >> >> t₃: → R← Ralph has just seen the front flash >> → P ← Paul has not seen either flash yet >> >> t₄: → ← R Ralph has already seen the front flash, >> but not the rear flash yet >> →P← Front and rear flash are simultaneous for Paul >> >> t₅: ← → R Ralph has already seen the front flash, >> but not the rear flash yet >> ←P→ Paul has seen both flashes already >> >> t₆: ← → R Ralph has already seen the front flash, >> but not the rear flash yet >> ← P → Paul has seen both flashes already >> >> t₇: ← → R Ralph has already seen the front flash, >> but not the rear flash yet >> ← P → Paul has seen both flashes already >> >> t₈: ← →R Ralph finally sees the rear flash >> ← P → Paul has seen both flashes already >> >> (It’s so very simple, isn’t it?) > > Simple to a simpleton....Ken is far smarter than any dingleberry here > even though he is silly enough to believe in an > aether. > >>> .... so your experiment is impossible. >> >> No, your logic is flawed. > > Your logic doesn't exist. > >>> 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. > >> Second, the speed of light is the same in all frames of reference. >> Experimentally confirmed. > > Your stupidity confirmed...as Ken so wisely pointed out. > > If the speed from both ends of the train is c in the train frame then > Paul, who is at the centre, MUST receive them > simultaneously. > > End of RoS...End of Einstein! > > > > -- Odd Bodkin -- maker of fine toys, tools, tables
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-21 08:39 +1000 |
| Message-ID | <opuqnf$54d$1@gioia.aioe.org> |
| In reply to | #433092 |
On 21/09/17 06:42, Odd Bodkin wrote:
> HGW <HW@home.net> wrote:
>>>
>>> That would be the case if the train, on which Ralph is located, were not
>>> moving relative to the places of the flashes.
>>
>> But your colleagues have insisted that the flashes have no 'places'.
>
> Like Seto, you can't read. The flashes have places. They have no duration.
So now you are changing your tune, eh, Bodkin?
Since the flashes have 'places', those places also have velocities, eh? It matters not that they have no duration.
End of RoS...End of Einstein!
--
HGW
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| From | Odd Bodkin <bodkinodd@gmail.com> |
|---|---|
| Date | 2017-09-21 02:18 +0000 |
| Message-ID | <opv7hl$kpr$1@gioia.aioe.org> |
| In reply to | #433107 |
HGW <HW@home.net> wrote: > On 21/09/17 06:42, Odd Bodkin wrote: >> HGW <HW@home.net> wrote: > >>>> >>>> That would be the case if the train, on which Ralph is located, were not >>>> moving relative to the places of the flashes. >>> >>> But your colleagues have insisted that the flashes have no 'places'. >> >> Like Seto, you can't read. The flashes have places. They have no duration. > > So now you are changing your tune, eh, Bodkin? Nope > Since the flashes have 'places', those places also have velocities, eh? Nope. Having a place isn’t enough. You have to have duration to have velocity. Duh. > It matters not that they have no duration. > > End of RoS...End of Einstein! > > > -- Odd Bodkin -- maker of fine toys, tools, tables
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-22 08:25 +1000 |
| Message-ID | <oq1e84$b9k$1@gioia.aioe.org> |
| In reply to | #433125 |
On 21/09/17 12:18, Odd Bodkin wrote:
> HGW <HW@home.net> wrote:
>> On 21/09/17 06:42, Odd Bodkin wrote:
>>> HGW <HW@home.net> wrote:
>>
>>>>>
>>>>> 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'.
>>>
>>> Like Seto, you can't read. The flashes have places. They have no duration.
>>
>> So now you are changing your tune, eh, Bodkin?
>
> Nope
>
>> Since the flashes have 'places', those places also have velocities, eh?
>
> Nope. Having a place isn’t enough. You have to have duration to have
> velocity. Duh.
No event has zero duration. Places can be represented by coordinates which are certainly frame dependent and mobile.
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-22 01:37 +0200 |
| Message-ID | <4319783.GXAFRqVoOG@PointedEars.de> |
| In reply to | #433249 |
HGW wrote:
> On 21/09/17 12:18, Odd Bodkin wrote:
>> HGW <HW@home.net> wrote:
>>> Since the flashes have 'places', those places also have velocities, eh?
>> Nope. Having a place isn’t enough. You have to have duration to have
>> velocity. Duh.
>
> No event has zero duration.
On the contrary, an event e is defined as a position/point in spacetime:
at a specific location (spatial coordinates) at a specific time (temporal
coordinate). So the sizes of the spatial and temporal interval between the
“ends” of an event, so to speak, are *zero*:
t ^
:
:
: . e
:
:
:
---------------+--------------> x
:
:
:
:
:
:
:
> Places can be represented by coordinates which are certainly frame
> dependent and mobile.
That does not mean that a position has a non-zero width, breadth, or height.
In fact, it means exactly the opposite.
--
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-22 12:34 +1000 |
| Message-ID | <oq1sr8$u4h$1@gioia.aioe.org> |
| In reply to | #433257 |
On 22/09/17 09:37, Thomas 'PointedEars' Lahn wrote:
> HGW wrote:
>
>> On 21/09/17 12:18, Odd Bodkin wrote:
>>> HGW <HW@home.net> wrote:
>>>> Since the flashes have 'places', those places also have velocities, eh?
>>> Nope. Having a place isn’t enough. You have to have duration to have
>>> velocity. Duh.
>>
>> No event has zero duration.
>
> On the contrary, an event e is defined as a position/point in spacetime:
> at a specific location (spatial coordinates) at a specific time (temporal
> coordinate). So the sizes of the spatial and temporal interval between the
> “ends” of an event, so to speak, are *zero*:
Yes, in thought experiments that is true....but in any practical situation an event will occupy at least an
infinitesimal time interval, dt, which is long enough to assign a value of velocity dx/dt to the object associated with
the event at your point e below.
> t ^
> :
> :
> : . e (dx/dt)->
> :
> :
> :
> ---------------+--------------> x
> :
> :
> :
> :
> :
> :
> :
>
>> Places can be represented by coordinates which are certainly frame
>> dependent and mobile.
>
> That does not mean that a position has a non-zero width, breadth, or height.
> In fact, it means exactly the opposite.
All events are associated with objects that have positions and velocities in all frames.
In the case of the emission of light, its speed is c relative to the emitting object and therefore c + dx/dt relative to
the frame you have drawn above.
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-09-22 13:30 +0200 |
| Message-ID | <9212486.nUPlyArG6x@PointedEars.de> |
| In reply to | #433275 |
HGW wrote:
> On 22/09/17 09:37, Thomas 'PointedEars' Lahn wrote:
>> HGW wrote:
>>> On 21/09/17 12:18, Odd Bodkin wrote:
>>>> HGW <HW@home.net> wrote:
>>>>> Since the flashes have 'places', those places also have velocities,
>>>>> eh?
>>>> Nope. Having a place isn’t enough. You have to have duration to have
>>>> velocity. Duh.
>>>
>>> No event has zero duration.
>>
>> On the contrary, an event e is defined as a position/point in spacetime:
>> at a specific location (spatial coordinates) at a specific time (temporal
>> coordinate). So the sizes of the spatial and temporal interval between
>> the “ends” of an event, so to speak, are *zero*:
>
> Yes, in thought experiments that is true....
It is *always* true.
> but in any practical situation an event will occupy at least an
> infinitesimal time interval, dt, which is long enough to assign a value of
> velocity dx/dt to the object associated with the event at your point e
> below.
You are mixing up the colloquial meaning of “event” with the physical
meaning.
<https://en.wikipedia.org/wiki/Event>
In colloquial speech, people talk of “events”, such as an exhibition.
There is no doubt that a certain time passes between the opening and
the closing of the exhibition.
But that is _not_ what we mean when we use the word “event” in physics.
Instead, the location and time of the opening, and the location and time
of its closing, are *two* events:
<https://en.wikipedia.org/wiki/Event_(relativity)>
>> t ^
>> :
>> :
>> : . e (dx/dt)->
>> :
>> :
>> :
>> ---------------+--------------> x
>> :
>> :
>> :
>> :
>> :
>> :
>> :
Your *unmarked* *diddle* of my correct diagram makes it not even wrong.
Instead, we have, for the exhibition mentioned above, the following
spacetime diagram:
t ^
:
t₂ _:_ _ _ _ e₂ = (x₂, t₂)
: |
: |
t₁ _:_ _ _ _|
:. : e₁ = (x₁, t₁)
: :
--+-------:------> x
: x₁ = x₂
We call the path from e₁ to e₂ the *world line* (or “worldline”) of the
exhibition. The exhibition starts out at a specific location, a point in
space, at the spatial coordinate(s) where a line drawn from e₁ perpendicular
to the spatial axis/axes (here: x) intersect that/those axis/axes. It
begins at a specific time, at the temporal coordate where a line drawn from
the e₁ perpendicular to the temporal axis (here: t) intersects that axis.
The exhibition ends at a specific location, a point in space, at the spatial
coordinate(s) where a line drawn from e₂ perpendicular to the spatial
axis/axes (here: x) intersect that/those axis/axes. As this exhibition does
not move in that frame of reference, that is the same coordinate where it
started. It then ends at a specific time, at the temporal coordate where a
line drawn from the e₂ perpendicular to the temporal axis (here: t)
intersects that axis.
<https://en.wikipedia.org/wiki/Spacetime#Introduction>
dx/dt is something related to that that I might explain to you later,
after you have grasped those *basics*.
>>> Places can be represented by coordinates which are certainly frame
>>> dependent and mobile.
>>
>> That does not mean that a position has a non-zero width, breadth, or
>> height. In fact, it means exactly the opposite.
>
> All events are associated with objects that have positions and velocities
> in all frames.
Events *are* positions in spacetime; therefore, if one would define that,
their “velocity” in all frames is *zero*.
You are using the words, but you do not know what they mean; therefore you
are using them wrong, and the result of that is *word salad*: such a
meaningless nonsense that it is *not even wrong*.
--
PointedEars
FAQ: <http://PointedEars.de/faq> | <http://PointedEars.de/es-matrix>
<https://github.com/PointedEars> | <http://PointedEars.de/wsvn/>
Twitter: @PointedEars2 | Please do not cc me./Bitte keine Kopien per E-Mail.
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| From | HGW <HW@home.net> |
|---|---|
| Date | 2017-09-23 06:44 +1000 |
| Message-ID | <oq3snu$6qv$1@gioia.aioe.org> |
| In reply to | #433323 |
On 22/09/17 21:30, Thomas 'PointedEars' Lahn wrote:
> HGW wrote:
>>>> No event has zero duration.
>>>
>>> On the contrary, an event e is defined as a position/point in spacetime:
>>> at a specific location (spatial coordinates) at a specific time (temporal
>>> coordinate). So the sizes of the spatial and temporal interval between
>>> the “ends” of an event, so to speak, are *zero*:
>>
>> Yes, in thought experiments that is true....
>
> It is *always* true.
>
>> but in any practical situation an event will occupy at least an
>> infinitesimal time interval, dt, which is long enough to assign a value of
>> velocity dx/dt to the object associated with the event at your point e
>> below.
>
> You are mixing up the colloquial meaning of “event” with the physical
> meaning.
>
> <https://en.wikipedia.org/wiki/Event>
>
> In colloquial speech, people talk of “events”, such as an exhibition.
> There is no doubt that a certain time passes between the opening and
> the closing of the exhibition.
>
> But that is _not_ what we mean when we use the word “event” in physics.
> Instead, the location and time of the opening, and the location and time
> of its closing, are *two* events:
>
> <https://en.wikipedia.org/wiki/Event_(relativity)>
>
>>> t ^
>>> :
>>> :
>>> : . e (dx/dt)->
>>> :
>>> :
>>> :
>>> ---------------+--------------> x
>>> :
>>> :
>>> :
>>> :
>>> :
>>> :
>>> :
>
> Your *unmarked* *diddle* of my correct diagram makes it not even wrong.
>
> Instead, we have, for the exhibition mentioned above, the following
> spacetime diagram:
>
> t ^
> :
> t₂ _:_ _ _ _ e₂ = (x₂, t₂)
> : |
> : |
> t₁ _:_ _ _ _|
> :. : e₁ = (x₁, t₁)
> : :
> --+-------:------> x
> : x₁ = x₂
>
> We call the path from e₁ to e₂ the *world line* (or “worldline”) of the
> exhibition. The exhibition starts out at a specific location, a point in
> space, at the spatial coordinate(s) where a line drawn from e₁ perpendicular
> to the spatial axis/axes (here: x) intersect that/those axis/axes. It
> begins at a specific time, at the temporal coordate where a line drawn from
> the e₁ perpendicular to the temporal axis (here: t) intersects that axis.
>
> The exhibition ends at a specific location, a point in space, at the spatial
> coordinate(s) where a line drawn from e₂ perpendicular to the spatial
> axis/axes (here: x) intersect that/those axis/axes. As this exhibition does
> not move in that frame of reference, that is the same coordinate where it
> started. It then ends at a specific time, at the temporal coordate where a
> line drawn from the e₂ perpendicular to the temporal axis (here: t)
> intersects that axis.
>
> <https://en.wikipedia.org/wiki/Spacetime#Introduction>
>
> dx/dt is something related to that that I might explain to you later,
> after you have grasped those *basics*.
You haven't clue. An event has a speed....that of its associated object at the instant it occurs. Its coordinate
location has a frame dependent speed. You don't even understand what dx/dt means.
>>>> Places can be represented by coordinates which are certainly frame
>>>> dependent and mobile.
>>>
>>> That does not mean that a position has a non-zero width, breadth, or
>>> height. In fact, it means exactly the opposite.
>>
>> All events are associated with objects that have positions and velocities
>> in all frames.
>
> Events *are* positions in spacetime; therefore, if one would define that,
> their “velocity” in all frames is *zero*.
That is nonsense. dx/dt does not have to be zero just because dt is xero.
The location of the following instantaneous event e is at rest in the AB frame. It has dx/dt=v in O's frame.
A---------e-------B
O>v
> You are using the words, but you do not know what they mean; therefore you
> are using them wrong, and the result of that is *word salad*: such a
> meaningless nonsense that it is *not even wrong*.
Learn some basics please and stop trolling....
--
HGW
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| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Date | 2017-10-10 00:24 +0200 |
| Message-ID | <ff4c179a-c01e-3766-7386-64bcce573d8e@PointedEars.de> |
| In reply to | #433387 |
HGW wrote:
> On 22/09/17 21:30, Thomas 'PointedEars' Lahn wrote:
>> In colloquial speech, people talk of “events”, such as an exhibition.
>> There is no doubt that a certain time passes between the opening and
>> the closing of the exhibition.
>>
>> But that is _not_ what we mean when we use the word “event” in physics.
>> Instead, the location and time of the opening, and the location and time
>> of its closing, are *two* events:
>>
>> <https://en.wikipedia.org/wiki/Event_(relativity)>
You have not read that, yes?
>> [explanation of what an event is *in physics*]
>> dx/dt is something related to that that I might explain to you later,
>> after you have grasped those *basics*.
>
> You haven't clue.
You cannot read – or write.
> An event has a speed....
If one wants to *define* the speed of an event, then it always has the speed
*zero*, yes. But that is a nonsensical definition, and nobody but
you uses it. Moreover, you are misusing it because you say that "speed"
would be anything *different* from zero.
>>>>> Places can be represented by coordinates which are certainly frame
>>>>> dependent and mobile.
>>>> That does not mean that a position has a non-zero width, breadth, or
>>>> height. In fact, it means exactly the opposite.
>>> All events are associated with objects that have positions and velocities
>>> in all frames.
>> Events *are* positions in spacetime; therefore, if one would define that,
>> their “velocity” in all frames is *zero*.
>
> That is nonsense. dx/dt does not have to be zero just because dt is xero.
Straw man. dx/dt is *definitely* zero if *dx* is zero. Still, such
considerations merely try to evade the fact that an event is *a point in
spacetime* which has *fixed* coordinates, and therefore it does not make
any sense to say that it has a size, a duration, or a speed.
> The location of the following instantaneous event e
^^^^^^^^^^^^^^^^^^^
Pseudo-scientific word salad. There is no such thing.
*Two or more* events can be simultaneous *in a frame of reference*; that is
the case if they have the same temporal coordinate or IOW they are all lying
on the same parallel to the spatial axis of that frame (that parallel is
then called a *line of simultaneity*). (As I have showed before, this does
not hold in another frame that is not co-moving with the first one;
therefore the concept of the *relativity* of simultaneity.)
c t ^
: e₃ = (x₃, t₃)
: /
t₃ +---. e₁ = (x₁, t₁)
: :`. /
t₁ +- -:- `.- - - - -. e₂ = (x₂, t₁)
:. : : :
: : : :
--+---+---+---------+---> x __
: x₃ x₁ x₂ |PE
Here, e₁ and e₂ are simultaneous events in the chosen rest frame. e₃ and
e₁, and e₃ and e₂, and _not_ simultaneous in that frame: e₃ happens *later*
than both e₁ and e₂, e₁ and e₂ happen *earlier* than e₃.
Also, while e₁ and e₂ happen *at the same time* (are simultaneous), they do
not happen at the same place (their spatial coordinates differ). For
example, e₁ and e₂ could be the simultaneous opening of the doors (by
different people) at different entries to the exhibition.
e₃ then could be an event that is unrelated to the exhibition. It could
also be related to the exhibition as it can be connected with e₁ by a
light-like worldline (the diagonal here); for example, it could be the event
that a news magazine learns about the opening of the exhibition and tweets
“The exhibition has opened!”, or something like that.
> Learn some basics please and stop trolling....
Pot, kettle, black.
--
PointedEars
Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.
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| From | Odd Bodkin <bodkinodd@gmail.com> |
|---|---|
| Date | 2017-09-22 03:02 +0000 |
| Message-ID | <oq1uf9$100l$2@gioia.aioe.org> |
| In reply to | #433249 |
HGW <HW@home.net> wrote: > On 21/09/17 12:18, Odd Bodkin wrote: >> HGW <HW@home.net> wrote: >>> On 21/09/17 06:42, Odd Bodkin wrote: >>>> HGW <HW@home.net> wrote: >>> >>>>>> >>>>>> 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'. >>>> >>>> Like Seto, you can't read. The flashes have places. They have no duration. >>> >>> So now you are changing your tune, eh, Bodkin? >> >> Nope >> >>> Since the flashes have 'places', those places also have velocities, eh? >> >> Nope. Having a place isn’t enough. You have to have duration to have >> velocity. Duh. > > No event has zero duration. Yes they do. That’s how a physics event is DEFINED. Read the books. >Places can be represented by coordinates which are certainly frame dependent and mobile. Places are not proxies for events. > > > > -- Odd Bodkin -- maker of fine toys, tools, tables
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