[LEAPSECS] The Battle of Flodden Field

Rob Seaman seaman at noao.edu
Fri Jan 7 11:09:29 EST 2011

On Jan 7, 2011, at 7:57 AM, Poul-Henning Kamp wrote:

> In message <0A3268A1-4BBD-4B45-ABCA-04B9E1821BC6 at noao.edu>, Rob Seaman writes:


>> Put it this way. Diurnal periods are ubiquitous in our cultural norms and the technical systems underlying them.


> That is a value judgment which should be left to governments.

No, it is a patently obvious fact. You appear to think I am making a rhetorical argument (what is "rhetoric" in Danish?) - rather I am making an assertion of fact. As with all assertions it might be incorrect (but it isn't), but it isn't open to opinion polling by governments, the ITU, or anybody else.

1) of or pertaining to a day or each day; daily.

It also has a secondary meaning:

2) of or belonging to the daytime (opposed to nocturnal).

Examine the word nocturnal:
1) of or pertaining to the night (opposed to diurnal).

Are diurnal/nocturnal the only two options? Well no.

1) of, pertaining to, or resembling twilight; dim; indistinct.

Crepuscular animals are those that forage or are otherwise active at dawn or dusk.

I suspect there are adjectives in many other languages that more finely subdivide the days of our lives. It is not as simple as Jim Morrison (and you) suggest:

Day destroys the night
Night divides the day

There are gradations and nuances and subtleties that the ITU is attempting to ignore.

> Who are you to decide that working nightshifts is not according to our "cultural norms" ?

They certainly are. Who are you to infer that I was saying otherwise?

Nightshifts also occur at a frequency determined by the synodic length of day. This is the diurnal rate (meaning #1), whether or not we're talking about diurnal (meaning #2) or nocturnal or more nuanced activities such as described by the word "crepuscular".

A reason to choose to use an interval timescale such as TAI or GPS is to keep an even "atomic" frequency cadence to better than a fractional (SI) second level. Universal time on the other hand, currently including UTC, keeps our long-term cadence to an even synodic frequency of better than a fractional (solar) day level. These are two distinct master clocks that we are synchronizing in each case.

Factions at the ITU are making the assertion that this is somehow no longer necessary. I am saying they are incorrect. It is a question of fact, not opinion, which assertion is true.


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