On Sat, Jan 14, 2006 at 02:09:20AM -0700, Rob Seaman wrote:
> On Jan 13, 2006, at 12:46 AM, John Cowan wrote:
> In the end, it will be impossible to maintain the notion that a solar
> day is 24h of 60m of 60s each: we wind up, IIRC, with the solar day
> and lunar month both at about 47 current solar days.
>
> There's a lot of difference between what happens over a billion years
> and a million years. Length of day increases only about 20s per million
> years. Should we be here to care in a million years, only a 1/4 of 1/10
> of
> one percent tweak to the length of the "civil second" would suffice to
> allow
> our Babylonian clock paradigm to continue in use.
Of course, since there is a future time of equilibrium (though a long
time off...), the "quadratic" nature of the accumulation of leap
seconds will also stop at some point, and eventually we won't need
them any more. I hope the 47 day calculation takes the solar tidal
influences into effect, and that the moon has to overcome that.
It makes me wonder when the maximum rate of change in length of day
will come? Not that we need to plan for events that far in the future
- just some fun astronomy....
Neal McBurnett
http://bcn.boulder.co.us/~neal/
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Received on Tue Jan 17 2006 - 16:00:36 PST