[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 
: seconds.

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.

Warner




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