Groups > sci.physics.relativity > #431259

Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth)

From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Newsgroups	sci.physics.relativity
Subject	Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth)
Date	2017-09-06 00:33 +0200
Organization	PointedEars Software (PES)
Message-ID	<3092185.y6phYKYAJH@PointedEars.de> (permalink)
References	(3 earlier) <d8bf8058-4cfd-4f96-9d0d-ad7143f202cd@googlegroups.com> <8521498d-a6df-40c3-adee-59a130c5c6d6@googlegroups.com> <5074121.DvuYhMxLoT@PointedEars.de> <d6d0b67c-41ec-48f0-ae36-301c63becfc2@googlegroups.com> <1659765.tdWV9SEqCh@PointedEars.de>

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Thomas 'PointedEars' Lahn wrote:

> gehan.ameresekere@gmail.com wrote:
>> That is one view. Take for example a swinging pendulum. In low gravity it
>> will have a longer period of oscillation.
> 
> That depends on which observer you ask.  “In low gravity”, time also
> passes faster than “in high gravity” (gravitational time dilation).

I was curious if the effects could cancel, and since I have not gotten into 
the details of general relativity yet, I have looked it up:

<https://en.wikipedia.org/wiki/Gravitational_time_dilation>

<http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/gratim.html#c4>

<http://www.wolframalpha.com/input/?dataset=&i=gravitational+time+dilation&rawformassumption=%7B%22FS%22%7D+-%3E+%7B%7B%22TimeDilationGravitational%22,
+%22t%22%7D%7D&rawformassumption=%7B%22F%22,
+%22TimeDilationGravitational%22,
+%22to%22%7D+-%3E%221+year%22&rawformassumption=%7B%22F%22,
+%22TimeDilationGravitational%22,
+%22g%22%7D+-%3E%22g%22&rawformassumption=%7B%22F%22,
+%22TimeDilationGravitational%22,+%22r%22%7D+-%3E%2220+000+km%22>

It turns out that the gravitational time dilation on the surface of Earth 
compared to the terrestrial orbit is so small that one needs extra precision 
to even calculate it.  But a pendulum would not swing in orbit at all 
(unless it could bounce off from something) because it is in free fall.  
This clearly shows that the two things have nothing to do with each other.

It is a common fallacy (in fact, I now remember that I had already seen it 
from a crackpot in the German-speaking Usenet, and my rebuttal of it) to 
equate the swinging of a pendulum with the passage of time, because the 
pendulum is a mechanism that is designed for a *particular* gravitational 
acceleration/spacetime curvature.  A clock that probably would be less 
susceptible to such problems  would be a clock that uses a spring instead.  
Which I guess is one reason why *atomic* clocks have been used in the 
Hafele–Keating experiment, and are used aboard GPS/GNSS satellites, and not 
any kind of mechanic clocks.

-- 
PointedEars

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

Thread

Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-01 03:25 -0700
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Dirk Van de moortel <dirkvandemoortel@hotspam.not> - 2017-09-01 13:23 +0200
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) "Paul B. Andersen" <relativity@paulba.no> - 2017-09-01 14:15 +0200
    Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-01 06:09 -0700
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) rotchm <rotchm@gmail.com> - 2017-09-01 06:20 -0700
    Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-01 07:05 -0700
    Re: Interstellar Travel and time taken for the trip. (No time  dilation for the Earth) The Starmaker <starmaker@ix.netcom.com> - 2017-09-01 12:40 -0700
      Re: Interstellar Travel and time taken for the trip. (No time   dilation for the Earth) The Starmaker <starmaker@ix.netcom.com> - 2017-09-02 12:19 -0700
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Odd Bodkin <bodkinodd@gmail.com> - 2017-09-01 19:37 +0000
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-02 03:26 +0200
    Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) xxein1x1@gmail.com - 2017-09-02 22:34 -0700
      Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) xxein1x1@gmail.com - 2017-09-02 22:48 -0700
      Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-03 10:18 +0200
        Energy (was: Interstellar Travel and time taken for the trip. (No time dilation for the Earth)) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-03 15:52 +0200
          Re: Energy (was: Interstellar Travel and time taken for the trip. (No time dilation for the Earth)) Ethel Ocallaghan <unlgclo@awlwaac.ag> - 2017-09-03 13:56 +0000
            The problem of crackpots (was: Energy) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-03 17:32 +0200
    Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-03 18:43 -0700
      Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-03 18:55 -0700
        Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-03 19:03 -0700
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 08:22 +0200
            Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-04 23:32 -0700
            Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 04:11 -0700
              Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Gary Harnagel <hitlong@yahoo.com> - 2017-09-05 05:06 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-05 05:17 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Gary Harnagel <hitlong@yahoo.com> - 2017-09-05 05:26 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Istrátora Metiku <untw@nwpovu.un> - 2017-09-06 12:42 +0000
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:11 -0700
              Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 14:33 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 00:33 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:48 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Istrátora Metiku <untw@nwpovu.un> - 2017-09-06 13:03 +0000
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:46 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 13:04 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 05:05 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-06 05:25 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 02:10 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 20:40 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 13:15 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-07 05:42 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-07 21:56 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-07 21:58 -0700
        Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 07:57 +0200
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-04 23:19 -0700
            Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 03:38 -0700
              Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-05 04:52 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:08 -0700
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 03:58 -0700
            Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 14:22 +0200
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 14:03 +0200
        Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 08:26 +0200
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 04:12 -0700
      Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-04 06:42 +0200
        Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-04 05:35 -0700
          Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-04 21:49 +0200
            Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-04 19:35 -0700
              Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 07:41 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 03:53 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-05 14:15 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:17 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 12:44 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 05:19 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 15:34 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 08:53 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 18:02 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 21:02 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 11:31 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Erika Milling <kak@kiilwgil.lc> - 2017-09-07 15:46 +0000
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-07 21:44 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 16:01 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-06 07:11 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 08:57 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 09:01 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 02:25 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 20:49 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 11:42 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-07 01:23 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-07 02:01 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Odd Bodkin <bodkinodd@gmail.com> - 2017-09-06 12:56 -0500
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) mlwozniak@wp.pl - 2017-09-06 12:44 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-06 20:36 -0700
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-07 12:04 +0200
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Odd Bodkin <bodkinodd@gmail.com> - 2017-09-07 12:14 +0000
                Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2017-09-06 20:12 +0200
  Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) bigal95210@gmail.com - 2017-09-05 15:48 -0700
    Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) gehan.ameresekere@gmail.com - 2017-09-05 22:49 -0700
      Re: Interstellar Travel and time taken for the trip. (No time dilation for the Earth) "Dono," <sa_ge@comcast.net> - 2017-09-07 07:32 -0700

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