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Article #6356Re: Viewing space station from ground...not
From: Martin Brown
Date: Tue, 01 May 2001 07:56
Date: Tue, 01 May 2001 07:56
33 lines
2463 bytes
2463 bytes
Will Simmons wrote:
> In article <3AE59064.E7BE1599@mindspring.com>,
> John Beaderstadt <beady@mindspring.com> wrote:
>
> [SNIP]
> > There's a
> >variable and irregular two to four minute discrepancy between the atomic
> >clock(s)
> >and the time as supplied by the phone company.
??? Surely you mean seconds ??? And even that is way OTT.
> Agreed, as I just discovered upon checking my phone company against the
> Naval Clock. But why ? Is it just the difficulty of starting (and stopping)
> those taped announcements ? Or something more fundamental ?
What ??? The UK manages to keep them well in sync at least to a small fraction
of a second. They can't control residual switching delays inside the BT network
but that is all.
The exception is with digital radio broadcasting where there can be a noticable
and variable up to a couple of seconds transmission packet switch delay in
their output. (And internet streaming where the delay behind real time can be
as much as 5 minutes).
A nice history of speaking telephone clocks is at:
http://www.sigtel.com/tel_hist_tim.html
Regards,
Martin Brown
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 113975,f669e6a693ddd682 X-Google-Attributes: gid113975,public X-Google-Thread: 10a148,f669e6a693ddd682 X-Google-Attributes: gid10a148,public X-Google-Thread: 101049,f669e6a693ddd682 X-Google-Attributes: gid101049,public X-Google-ArrivalTime: 2001-05-01 00:56:42 PST Path: arc1-ca.pugleaf.net!newsfeed.google.com!newsfeed.stanford.edu!skynet.be!newsfeeds.belnet.be!news.belnet.be!afrodite.telenet-ops.be!not-for-mail Message-ID: <3AEE5E08.ABC0D6CF@pandora.be> From: Martin Brown <martin.brown@pandora.be> Reply-To: martin.brown@pandora.be Organization: Nezumi X-Mailer: Mozilla 4.74 [en] (Win95; U) X-Accept-Language: en-GB,en-US,nl MIME-Version: 1.0 Newsgroups: sci.space.shuttle,sci.astro.amateur,dc.general Subject: Re: Viewing space station from ground...not References: <slrn9eao68.rb8.packer@clark.net> <3AE56C23.BE0E921D@videotron.ca> <3AE59064.E7BE1599@mindspring.com> <B713656C9668233951@ppp0b012.std.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 34 Date: Tue, 01 May 2001 07:56:41 GMT NNTP-Posting-Host: 195.130.146.146 X-Complaints-To: abuse@pandora.be X-Trace: afrodite.telenet-ops.be 988703801 195.130.146.146 (Tue, 01 May 2001 09:56:41 MET DST) NNTP-Posting-Date: Tue, 01 May 2001 09:56:41 MET DST