[LEAPSECS] comments on DRR TF.460-6

Robert Seaman seaman at noao.edu
Tue Sep 21 14:02:43 EDT 2010

Tony Finch wrote:

> Are there any requirements for mean solar time other than astronomy and celectial navigation?

Has anybody associated with the ITU crusade looked? Failing to look is not equivalent to performing a careful inventory.

Astronomy is not just a quirky avocation (that happens to deal with the most fundamental questions of all), but a commercial enterprise. Have the various makers of professional and amateur telescopes and software been contacted? Of planetaria? Of sundials for that matter?

There are requirements and then there are mere statements of fact. The calendar counts days. The clock divides them up. "Day" is a concept tied to the sun.

Navigation is an activity critical to the world economy. The assumption appears to be that GPS has completely and utterly replaced all else. Is this true? What about back-up systems? What about implicit assumptions buried in the architecture of the manifold systems on, say, airliners and cargo ships? UTC has been an approximation to UT since its inception. Universal Time as a concept is explicitly derived from Greenwich Mean Time. Perhaps there are no UTC gotchas hidden in the millions of lines of code and vast numbers of procedures comprising the modern world's many transportation systems. Shouldn't somebody look before we redefine a basic component of the system?

Several of us here were deeply involved in our organization's and community's Y2K remediation activities. Nothing similar has occurred related to this naive, unnecessary, and unimaginative campaign. The risks are unknown. Claiming there aren't any risks because you can't think of any off the top of your head is woefully reckless.


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