[LEAPSECS] graphical tools

[Rob Seaman]

I'm taken by the differences in presentation between Steve's figure:

	http://ucolick.org/~sla/leapsecs/amsci.pdf

and Tom's:

	http://www.leapsecond.com/pages/ut/ut-ani-v2.gif

Steve's is a depiction of scientific measurements.  Tom's is a cumulative engineering figure-of-merit.  Animated versus static, etc.

One aspect of Tom's is the choice of pivot.  It might prove interesting to rather locate the pivot on the right hand side, that is, as a retrospective tool toward a future engineering choice.  We're not about to actually redefine the SI-second at this point, but it is of perhaps more than historical interest to understand what sort of inferences could have been drawn (in 1972 by this data set, but similar logic could have been applied in 1958 or any other epoch) given 40 years of past data.

Steve's presentation has also had a chance to evolve through multiple iterations and has become more dense and presents more dimensions of information.  This same Edward Tufte style strategy could be applied to Tom's plot to represent scheduled leap seconds, etc.  (Call it "Ken Burns" mode since it's animated :-)

Rob