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Re: Why the time kept at the ISS is UTC? And Einstein's time?

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On 09-Dec-24 2:29 am, rhertz wrote:
> The International Space Station (ISS) uses Coordinated Universal Time
> (UTC), also known as Greenwich Mean Time (GMT), as its standard time.
> UTC is the scientific standard of timekeeping for the world and is based
> on atomic clocks.
> 
> The ISS is a partnership between five space agencies from 15 countries.
> The station is continuously operated 24 hours a day, 7 days a week, 365
> days a year. Crews from the U.S., Russia, Japan, Canada, and Europe live
> and work on the ISS, which orbits Earth every 90 minutes.
> 
> The shuttles also had UTC clocks so that the astronauts could easily
> figure out what the "official" time aboard ISS was.
> 
> It's a compromise for the Americans and Russians. The crew day begins at
> about two in the morning in Houston and ends at about eleven at night in
> Moscow.
> 
> 
> So, for ISS, t = t'. Einstein's SR time is not even considered, even
> when there are several atomic clocks onboard.

For most practical purposes, the general relativity corrections to 
clocks on the ISS are irrelevant. Ordinary clocks are not even accurate 
enough for the corrections to be meaningful.

The corrections only matter when, well to pull an example out of thin 
air, you need to know exactly where satellites are and when signals were 
transmitted from them, so that you can calculate where you are on Earth 
based on the signals from several satellites.

Sylvia.

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Why the time kept at the ISS is UTC? And Einstein's time? hertz778@gmail.com (rhertz) - 2024-12-08 18:29 +0000
  Re: Why the time kept at the ISS is UTC? And Einstein's time? "Paul B. Andersen" <relativity@paulba.no> - 2024-12-11 14:41 +0100
    Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-11 15:09 +0100
    Re: Why the time kept at the ISS is UTC? And Einstein's time? nospam@de-ster.demon.nl (J. J. Lodder) - 2024-12-12 09:44 +0100
      Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-12 10:37 +0100
      Re: Why the time kept at the ISS is UTC? And Einstein's time? clzb93ynxj@att.net (LaurenceClarkCrossen) - 2024-12-12 18:00 +0000
        Re: Why the time kept at the ISS is UTC? And Einstein's time? "Paul B. Andersen" <relativity@paulba.no> - 2024-12-12 20:41 +0100
          Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-12 21:21 +0100
          Re: Why the time kept at the ISS is UTC? And Einstein's time? clzb93ynxj@att.net (LaurenceClarkCrossen) - 2024-12-12 21:28 +0000
          Re: Why the time kept at the ISS is UTC? And Einstein's time? clzb93ynxj@att.net (LaurenceClarkCrossen) - 2024-12-12 21:26 +0000
            Re: Why the time kept at the ISS is UTC? And Einstein's time? "Paul.B.Andersen" <relativity@paulba.no> - 2024-12-15 11:11 +0100
              Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-15 11:57 +0100
    Re: Why the time kept at the ISS is UTC? And Einstein's time? clzb93ynxj@att.net (LaurenceClarkCrossen) - 2024-12-12 17:56 +0000
      Re: Why the time kept at the ISS is UTC? And Einstein's time? "Paul B. Andersen" <relativity@paulba.no> - 2024-12-12 20:26 +0100
        Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-12 20:37 +0100
        Re: Why the time kept at the ISS is UTC? And Einstein's time? clzb93ynxj@att.net (LaurenceClarkCrossen) - 2024-12-12 21:17 +0000
          Re: Why the time kept at the ISS is UTC? And Einstein's time? "Paul B. Andersen" <relativity@paulba.no> - 2024-12-13 11:31 +0100
            Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-13 11:44 +0100
  Re: Why the time kept at the ISS is UTC? And Einstein's time? Sylvia Else <sylvia@email.invalid> - 2024-12-13 15:10 +0800
    Re: Why the time kept at the ISS is UTC? And Einstein's time? Maciej Wozniak <mlwozniak@wp.pl> - 2024-12-13 08:44 +0100

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