[LEAPSECS] h2g2

[M. Warner Losh]

In message: <67EFEC27-33C2-4D35-A48F-F7BE2ED7D846 at pipe.nl>
            Nero Imhard <nimh at pipe.nl> writes:

: 

: On 2010-09-03, at 15:56, p at 2038bug.com wrote:

: 

: >> on the SAME time.  Nobody cares here that solar time and civil time

: >> are 43 minutes off. 

: > 

: > *I* care 

: 

: Warner seems to be missing (or ignoring?) the point.

: 

: The difference doesn't matter, the fact that the difference is constant does.


I'm asking these question: Why does it matter so much?  What does
keeping things in sync buy you that merely measuring the difference
and knowing that number doesn't?  Why must UTC be used as the method
to synchronize "noon and the sun is approx overhead" when we have wide
timezones that already do that function?  Does the cost of
synchronizing to UTC exceed the benefits from synchronizing there and
not at a different, easier to change level?  Given the changes in how
time is used, propagated, etc, in the last 20, 50 or 100 years, does
it make sense to reevaluate things?

We've undergone a fairy radical paradigm shift in how time is used and
consumed in the past 20 years.  Doesn't it make sense to reevaluate
the system to make sure those items that used to be no big deal but
have become big cost items still fit the needs of the majority of the
users?  Time was when there were hundreds of different fields that
relied on having good time to know where they were (navigators,
surveyors, etc), but with GPS eliminating those users of UTC, do we
have enough of a community of |DUT1| < 1s to justify the costs to the
rest of the world, or is it time that this crowd shoulder the costs of
the raw data they need?

Those are the questions I'm asking...

Oh, and with Daylight Savings Time, the difference isn't even constant
anymore.  And why does MEAN solar time matter more than ACTUAL solar
time?  And what flavor of MEAN solar time is best?  What does solar
time mean on mars, the moon, etc?

Warner