[LEAPSECS] WP7A status and Re: clinical evidence about time and sun

Rob Seaman seaman at noao.edu
Fri Dec 19 01:50:08 EST 2008

On Dec 18, 2008, at 9:45 PM, John Cowan wrote:

> Ah, but will Lunar civil time be mean solar time on Luna?

For many purposes, yes. The Apollo missions were planned to occur in
daylight, for instance. For other purposes, the factor of ~30
contrast between the lunar day and the innate human diurnal rhythms
would result in the natural use of a clock similar or identical to
mean solar time on Earth. One supposes the lunar synodic period would
be divided into 30 parts. It would be interesting to see whether the
Earth day or Lunar day would win out - that is, whether the synodic
period would be evenly divided by 30 to set a local clock rate, or
whether the Earth day (meaning the mean solar day on Earth, of course)
would trump being evenly divisible into the local day.

>> Ignore everything else we've ever discussed. The central issue with

>> several of us is that the meaning of the UTC standard should not be

>> changed. If a decision (ideally a calm, reasoned and publicly

>> transparent decision) is made to relayer civil timekeeping on a clock

>> without leap seconds, then don't call that clock "UTC".


> As you know, I support that.


>> How about calling it - say - GPS? The public already knows GPS,

>> already owns devices that speak it, and already regards it as a brand

>> name denoting high precision/accuracy timekeeping.


> I think the public associates GPS with location rather than time.

As an aside, I highly recommend Steven Pinker's "The Stuff of
Thought", which persuasively argues that the grammatical structures we
use to describe time are precisely the same as those used to describe
(and reason about) spatial information.

GPS is a very popular brand name that could certainly be used as a
component of a successful campaign to market a new concept of civil
timekeeping. Redefining UTC, on the other hand, will simply make what
is a somewhat obscure standard even more obscure.

> The World Series does seem an egregiously stupid name, though.

No - they simply ought to extend it to teams from Japan and the
Dominican Republic, etc.


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