On Mon, Jun 15, 2009 at 11:33 AM, erik quanstrom<[email protected]> wrote:
> i ran astro -k a 3 times, a few minutes apart
> on the same machine.  the results are suprising
>
> The sun sets at 20:47:50 EDT
> The sun sets at 20:47:49 EDT
> The sun sets at 20:47:43 EDT
>
> Comet rises at 23:02:57 EDT
> Comet rises at 23:03:06 EDT
> Comet rises at 23:03:02 EDT
>
> can anyone explain why i don't
> get the same answer?

from ken:

astro "events" are found by a binary
search (in time) on a "crossing" of
the position of objects. for an event
like "rise", "set", "twilight", the event is
very vague because of atmospheric
bending. in those cases, the binary search
is stopped before the precision of the
printing (1 sec). binary searches are
started from the time that the command was
executed. thus the time found for
the crossing will vary.

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