[ntp:questions] Re: no more leap seconds?
res at tuttle.usno.navy.mil
Wed Aug 10 20:05:02 UTC 2005
Moi, regarding your "IMHO" I must say your opinions are deservedly
humble. You lack a basic understanding of Earth rotation and lunar
tides, for a start. Regarding "critical systems"
and the need for precise time, keep in mind, in electronic navigation
time <==> position. One nanosecond = 1 foot. One second = 1 billion
feet, i.e., most of the way to the Moon. There are indeed critical
systems that require amazing time accuracy. Of the systems we can talk
about, FAA's WAAS is one. Imagine trying to land a plane via WAAS if
your coordinates are off by a few tens of meters! Dr. Klepczynski is a
former Naval Observatory Time Service Director and an FAA consultant,
and is extraordinarily informed.
GPS satellites do not "navigate on the stars". They do not navigate any
more than the Moon navigates.
The estimate of a need for a "leap hour" about the year 2600 is based
on current analysis of historical observations of the Earth's rotation.
This is found in the document USWP-7A/1 14 Jul 04 of the US Working
Party 7A, International Telecommunications Union (ITU). See my next
posting for more details. Rich Schmidt, Naval Observatory
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