[LEAPSECS] Time-of-day

Poul-Henning Kamp phk at phk.freebsd.dk
Mon Mar 7 11:33:49 EST 2011


In message <FAE132D8-A554-44AF-8FED-D7DEFA7DE08C at noao.edu>, Rob Seaman writes:


>What is "time-of-day" if not "time-of-synodic-day"? What is it that clocks

> are simulating?


Clocks do simulating anything, there is nothing for them to simulate.

Just because our units of time have a history related to astronomy
does not mean that the connection must for ever remain.

The meter is no longer related to the geometry of the earth, nor is
it defined using a particular stick of metal.

Significant expenditures and very interesting research is going on,
in order to similarly liberate the kilogram from the unreliable
lump of metal currently encapsulating it.

The goal of all metrology, is to use fundamental concepts that
allows measurements to be reliably reproduced anywhere, any time,
independently.

Seconds have been liberated from their earthly toil, and there is
absolutely no reason to confuse them with earth rotatation angle
anymore: Ever since Harrisson we have been able to keep time
without telescopes.

Like the stick were and the lump will be, telescopes should be
eliminated from the metrology of timekeeping because their role
as approximations are not only no longer necessary, it is an
undesirable source of uncertainty and unpredictability.

Time is no longer astronomy, live with it.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.


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