[LEAPSECS] Lets get REAL about time.

Rob Seaman seaman at noao.edu
Tue Jan 24 18:37:15 EST 2012


We should offer a prize when a new talking point is raised that hasn't appeared here before. I don't remember this one :-)

Very interesting. What about the other hands? The watch on my wrist is of the stepping, not sweeping, kind. But the other hands appear to move at a continuous pace. Implementing a leap second by this analysis would require the minute and hour hands to execute a less dramatic version of the flick maneuver (or a lien on the requirement and just accept the tiny angular display error).

For the non-astronomers here, note that the middle of the night can be the worst possible time to implement the little dance Steve describes.

Rob
--
On Jan 24, 2012, at 4:01 PM, Mark Calabretta wrote:


>

> On Tue 2012/01/24 07:18:36 -0800, Steve Allen wrote

> in a message to: Leap Second Discussion List <leapsecs at leapsecond.com>

>

>> The ones with WWVB

>> receivers in them do a little dance every night when nobody is

>> watching and the signal is strong, and that dance looks a lot

>> like the handling of a leap second.

>

> There are two basic types of analogue clock display. One where the

> second hand steps around the dial from second to second (thus

> disawowing sub-second timekeeping), and the other where it moves

> smoothly and continuously. It is interesting to contemplate how a

> leap second would appear on each were it to be implemented.

>

> In the former, on reaching 60, the second hand would stay there for 2

> seconds thus making it impossible to track time during a leap second.

>

> In the latter, the second hand would move continuously past 60 to 01

> second and immediately flick back to 60, thus making it possible to

> reckon time during a leap second.

>

> Regards, Mark




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