[LEAPSECS] drawing the battle lines

[Warner Losh]

On Mar 20, 2013, at 11:46 PM, Rob Seaman wrote:


> On Mar 20, 2013, at 8:28 PM, Joseph Gwinn <joegwinn at comcast.net> wrote:

> 

>> True enough, but beside my point.  The relationship between UTC and UT1 

>> is piecewise linear between leap seconds, so there are steps in the 

>> first derivative at the joints between lines,and steps in zeroth and 

>> first derivatives at the leap seconds.

> 

> Ignoring the perpetual refrain about leap seconds being merely a representational issue, Kevin's question was about point 9 of the CCTF recommendation, which is an assertion about UT1 itself.  Saying UT1 is unacceptable as a time scale is like saying John Harrison's descendants should refund the longitude prize.  Many quantities can serve as timelike independent variables.


Our notion of what constitutes a time scale has evolved over time. When John Harrison won the prize, this was the best we could do. We can do better now.

Nobody is saying that Darwin's On The Origin of the Species should be recalled because some of the details of the Theory of Evolution have been corrected and refined by science in the intervening years.

But it occurred to me that beside the point.

I think the real reason that UT1 shouldn't be considered a time scale is that it is based on not an imperfect realization of a fixed length second, but rather an imperfect realization of a variable (measured by oscillations of a fixed frequency) length second.

Warner