[LEAPSECS] nails in the coffin of mean solar time

[Rob Seaman]

> A notable difference between these versions and previous ones is  

> that the CGPM's UTC shall be interpreted by the Secretary of the  

> Navy as well as NIST.


So the final determination of the policy issue (yea or nay on leap  
seconds) shall be whether the US military industrial complex believes  
there are more risks in continuing leap seconds (tested over 35  
years) or in a boundless DUT1 (never tested, heretofore negligible  
for many applications).  Presumably a Y2K-like inventory of DOD  
systems, embedded and otherwise, is called for.  Since implicit  
timekeeping requirements would be made explicit in the deferred-leap  
world, all DOD systems are potentially affected.

On the other hand, one can be confident the final determination of  
the actual timekeeping issue (whether civil time ultimately is  
reconfirmed as a flavor of mean solar time) will be decided by the  
actual requirements placed on our civilization's many  
instrumentalities by the fact that we live on a rotating planet in  
orbit about a star that illuminates our days.

My assertion that there are many such requirements to be revealed may  
yet prove wrong - although confidence in this result would only build  
over decades.  But then, the implicit - and therefore completely  
unsubstantiated - assertion of the "leap second die, Die, DIE!" crowd  
that not a single human activity - outside of astronomy and  
traditional sextant navigation - could possibly depend on mean solar  
time may itself also prove wrong.  That the requirements and budgets  
of astronomers and TSNs are considered unworthy of any consideration  
also seems unfortunate.

Note that even the opponents of "leap scheduling with a granularity  
of one second" acknowledge that these embargoed leap seconds must be  
released with a granularity no larger than one hour.  Nobody is  
recommending getting rid of leap seconds, rather merely placing them  
in a "lock box" for the benefit of our grandchildren's grandchildren  
several hundred years hence.

In any event, one can reject the pertinence of brain-dead computing  
standards such as POSIX to either decision.  One way or another  
software architects will have to design library interfaces that model  
the actual behavior of the physical world, and applications  
programmers will no longer be able to rely on naive thinking about  
timekeeping issues.

Rob Seaman
National Optical Astronomy Observatory

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