[154456] in North American Network Operators' Group
Re: F-ckin Leap Seconds, how do they work?
daemon@ATHENA.MIT.EDU (valdis.kletnieks@vt.edu)
Wed Jul 4 17:03:18 2012
To: Brett Frankenberger <rbf+nanog@panix.com>
In-Reply-To: Your message of "Wed, 04 Jul 2012 12:44:40 -0500."
<20120704174439.GA2363@panix.com>
From: valdis.kletnieks@vt.edu
Date: Wed, 04 Jul 2012 17:02:02 -0400
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
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On Wed, 04 Jul 2012 12:44:40 -0500, Brett Frankenberger said:
> Leap Seconds and Leap Years are completely unrelated and solve two
> completely different problems.
>
> Leap Seconds exist to adjust time to match the Earth's actual rotation.
> They exist because the solar day is not exactly 24 hours.
>
> Leap Years exist to adjust time to match the Earth's actual revolution
> around the Sun. They exist because the that time period isn't exactly
> 365 days.
Actually, it's the same exact problem - an astronomical value isn't
exactly conformant to the civil value, and thus adjustments are needed.
And you missed the bigger point - that leap seconds aren't needed because the
earth is slowing any more than leap days are needed because the year is getting
longer. If an actual siderial day was a fixed unchanging 86400.005 seconds
long, you'd still need a leap second every 200 days. *SLOWING* would be
indicated by the "every 200 days" changing to "every 175" or "every 150".
For bonus points - at the current rate of slowing, in what year will the day be
of sufficient length that the current "rule of 400" for leap days requires changing?
You may assume that the orbital parameters of the Earth do not also change. :)
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