[LEAPSECS] Leap seconds, precision time, and technical progress

[Michael Deckers]

    On 2010-12-26 17:33, Dave Finkleman wrote:


>  Technology advances to exploit our ability to realize and measure time

>  precisely increases.  Use of spectrum with frequency, time, and code

>  division multiplexing is an example.  I realize that the time scale of

>  such applications need not have a uniform epoch in the distant past or

>  be tied to astronomical phenomena.  Perhaps you can think of better

>  examples that do.

>

>  Therefore, it is broadly important that precise time accrual be

>  synchronized and coordinated.  Astronomical phenomena are the most

>  fundamental vehicles for synchronization.  They belong to no one.  No

>  one can control them.


    I think this is a good argument _against_ the current
    definition of UTC.

    "Precise time accrual" is achieved today by integrating
    stable clock frequencies, not by astronomical observations.

    The astronomical phenomenon that is used for determining
    the phase of UTC is the rotation of the Earth, and this
    is no longer one of the "fundamental vehicles" for
    synchronization because it is (currently) neither
    constant nor predictable to a sufficient degree.

    The quest for the redefinition of UTC is based right
    on this incoherence: the rate of UTC is a "fundamental
    vehicle for synchronization" and is used as such in
    innumerable applications, while the phase is erratic.
    The suspicion is that a less erratic phase would not
    hurt as many applications as the incoherence could.

    Michael Deckers.