Re: NO positive leap second will be introduced at the end of December 2006

JRS: In article <UoqdnQP8SM4i8SPZnZ2dnUVZ_qydnZ2d@xxxxxxx>, dated Wed,
19 Jul 2006 13:32:40 remote, seen in news:sci.astro.amateur, Richard
F.L.R.Snashall <rflrs@xxxxxxxxxxxxx> posted :
oriel36 wrote:
Tell people why a 86 400 leap second correction is needed every 4 years
and what happens to that quarter day each year in respect to the annual
orbit of the Earth.

Because it's easier than adding a leap minute
every day except every 72nd.


I don't think that oriel36 understands that Leap Years deal with the
(substantially constant) non-integer part of the ratio between the
Earth's orbital and rotational periods, while Leap Seconds deal with the
(slightly-varying) discrepancy between 86400 seconds SI and the period
of the Earth's rotation with respect to the Sun's position.

There is (it is said) a historical justification for the use of the word
"Leap" in respect of Leap Years; it is probably a pity that the same
word was used for an entirely different adjustment involving seconds.

A Leap Minute every 73 days is one part in 1440*73 ~ 1 in 1E5
Leap Years are 0.2425 parts in 365.2425 ~ 1 in 1500
A Leap Second every year would be one part in about 31E6

So I don't see why you want a Leap Minute every 73 days.

--
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