[LEAPSECS] tinkering with time ?

Rob Seaman seaman at noao.edu
Mon Jan 31 11:29:30 EST 2011

On Jan 31, 2011, at 8:59 AM, Poul-Henning Kamp wrote:

> In message <12988684-B911-481B-B557-90E55CD736A4 at noao.edu>, Rob Seaman writes:

>> On Jan 31, 2011, at 1:07 AM, Poul-Henning Kamp wrote:


>> Is there really a requirement to render the concept of "universal time" meaningless? Or is UTC merely collateral damage from an intellectually lazy campaign to "suppress TAI"?


> There is a desire to see computers work reliably together.

These are yes/no questions. Your non-response may be taken as equivalent to "no" and "I don't know".

It is likely that everybody on this list thinks "computers should work reliably". That this is our shared desire does not mean that this is what is principally motivating the ITU.

Time-keeping is broader than computing. Computers "working together" is broader than your (substantial) networking experience. "Reliably" is a very non-linear concept (see http://catless.ncl.ac.uk/risks). Physical reality has a way of inserting its own functional requirements.

The reality is that interval time and Earth Orientation time are two different things. My assertion is that civil timekeeping is a type of the latter, since day means "synodic day". The ITU asserts (basically) that "we can cheat for the next few hundred years". This position does not contradict my assertion. Proper engineering doesn't seek to bury the underlying issues.

With a wave of its goose quill pen, the ITU can create a new timescale and new dissemination infrastructure addressing whatever the underlying issues are with TAI. It need only call it something other than UTC. Meanwhile, they can just stop dealing with UTC. If need be they can arrange to transfer UTC to some other standards organization, but more likely they can just ignore UTC and start disseminating the new leap-less time scale.

Call it "TI" for "Temps ITU".

The ITU's non-response since 2003 to this position from the Torino meeting may be taken as equivalent to "No, there is no requirement to render the concept of universal time meaningless". If there were such a requirement they certainly could have explained the reasoning at any point since 2003.


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