[time-nuts] On Setting the Astronomical Time
M. Warner Losh
imp at bsdimp.com
Sun Jun 10 14:44:10 EDT 2007
In message: <20070610173720.211CEBE20 at ip-64-139-1-69.sjc.megapath.net>
Hal Murray <hmurray at megapathdsl.net> writes:
: > Is there some way to get TT to better than a tenth of a second, or is
: > the earth just too sloppy of a time keeper?
: My guess...
: The earth is sloppy on this scale. If it wasn't, we could predict leap
UT1 is a smoothed function, not an instantaneous one, since it factors
out seasonal variation that's in UT2. NIST doesn't publish DUT1 more
accurately than milliseconds with a +/- 5ms caveat. So +/- 100ms is
"only" 20x worse than data published at nist.
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