To: WSFA members <WSFAlist at KeithLynch.net>
From: "Keith F. Lynch" <kfl at KeithLynch.net>
Subject: [WSFA] An end to leap seconds
Date: Wed,  1 Apr 2015 22:40:40 -0400 (EDT)
Reply-To: WSFA members <WSFAlist at KeithLynch.net>

The International Earth Rotation and Reference Systems Service (IERS)
has been in charge of leap seconds since 1988.  Leap seconds are
necessary because of the tidal slowing of the Earth's rotation.  A
constant second is as necessary to our system of units as a constant
kilogram and a constant meter.  But it's also essential that the time
of day remain synchronized with the Earth's rotation.

Leap seconds are an ugly kludge that nobody is really happy with.
The differences between TAI time, UT0 time, UT1 time, and UTC time
complicates timekeeping, software, astronomy, and navigation.  And
the problem will only grow worse.  See the discussion on Wikipedia.

Today the IERS voted to petition the United Nations to require all
tidal power stations to be run in reverse.  The stations will pump
water in when the tide would have been low, and will pump it out when
it would have been high.  This will cause the Earth's rotation to
gradually speed up, back to its historic value of 86400 atomic seconds
per mean solar day.  (The atomic second was based on the length of the
mean solar day in the year 1900.)  This will consume energy, rather
than producing it, but the benefit is considered to be worth the cost.

This also has the benefit of keeping the Moon from drifting further
away, which would have changed the length of the month and thrown
lunar calendars out of kilter.  And which would have eventually caused
an end to total solar eclipses, once the Moon's angular size became
less than the Sun's.

It also has the benefit of spurring development of alternative energy
sources, since plenty of energy will be needed to run the tidal power
stations in reverse.  Especially since it will probably be necessary
to build additional tidal power stations.

The petition was co-signed by the Catholic Church (which wants to keep
Easter on the correct date), various prominent rabbis, the leaders of
the Sunni and Shi'ite Islamic sects, Exxon/Mobil, and OPEC.