[time-nuts] Re: UTC - A Cautionary Tale
seaman at noao.edu
Sat Jul 16 12:32:41 EDT 2005
> Hopefully not too many people will be hurt trying to convince you.
Amen. And hopefully any resulting lawsuits will assign blame and
damages where they belong - with the financial backers and managers
and designers of systems that failed to implement the appropriate
international standard. If a house burns down because a 110v
appliance is plugged into a 220v line, whose fault is it?
Why are you so convinced that there couldn't possibly be negative
ramifications associated with the unexamined assumptions underlying
the distinction between time-of-day and interval time? Or simply
with the unwarranted assumption that one single timescale applies in
all cases? Claiming that "leap seconds are bad, we'll be safer
without them" doesn't make it so. Some systems will fail when DUT1 >
1s. Others will fail when their conceptual model of a timescale
based on time-of-day collapses. Still others will come in conflict
with systems that they must interoperate with that make the opposite
naive assumption, whatever it is. Planes navigating via TAI versus
planes navigating via UTn, for instance. Control software for
nuclear reactors whose build conditions are violated because some of
the modules were timestamped before the great clock change of 2007
and others afterwards. Who knows what unchallenged assumptions will
fail when they are later challenged by the real world facts of a
secularly diverging DUT1? I certainly don't - but neither do
supporters of this dangerous proposal. This is why a standards
process should be open and inclusive. This is why decisions
shouldn't be left to narrow special interests.
The issue isn't with picking TAI on the one hand or UTn on the other
- or even with continuing to support the rather elegant compromise of
UTC that neatly conveys *both* interval time and time-of-day. The
issue is really that there are also many other timescales that are
appropriate for various purposes - see http://tycho.usno.navy.mil/
systime.html. Why are we not building systems that accurately convey
the full richness of time? Why are we not even discussing that
possibility, but rather simply seeking to pretend that one single
timescale fits all purposes?
>> "Mandrake, do you recall what Clemenceau once said about war?"
>> "No, I don't think I do, sir, no."
>> "He said war was too important to be left to the generals. When he
>> said that, 50 years ago, he might have been right. But today, war
>> is too important to be left to politicians. They have neither the
>> time, the training, nor the inclination for strategic thought. I
>> can no longer sit back and allow Communist infiltration, Communist
>> indoctrination, Communist subversion and the international
>> Communist conspiracy to sap and impurify all of our precious
>> bodily fluids."
Time is too important to be left to the Time Lords.
National Optical Astronomy Observatory
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