[LEAPSECS] Leap smear and Big Ben

[Tom Van Baak]

I'm not sure if this came up on the list before, but it's a good
leap second story for those who haven't heard it before.

A leap second is fine if you have a digital clock or computer
time-stamp that can show the extraordinary ":59:60" moment.
But analog clocks cannot do this because their hands display
time (hours minutes, seconds) as angles rather than digits.
It's all ordinary; extraordinary is not physically possible here.

Some people say that analog clocks don't matter, because they
are all "so inaccurate" that leap seconds are lost in the noise.
Not always true. The solution for an analog clock is, of course,
a leap smear. And the most wonderful example I know of is not
from Markus or even Google, but from Big Ben. See:

    New Year to arrive a tick later
    http://news.bbc.co.uk/2/hi/7797818.stm

To implement a leap second they add coin (yes, time is money).
Each penny changes rate by about "2/5 second per day", which
is about 5 ppm. Now, I've glanced at:
http://en.wikipedia.org/wiki/Penny_(British_pre-decimal_coin)
but perhaps one of our UK members can tell us the exact mass
of a pre-decimal penny and so tell us the rate change of Big
Ben per £ or per kg. Which will tell us how many kg-seconds
or £-hours is takes to implement one leap second in Big Ben.

/tvb
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