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Everyone knows what a leap year is, but did you know there are also leap
seconds?
At least for now, because the leap seconds very existence was debated in Geneva
Yesterday:
with Britain, China and Canada fighting to keep it against the USA, Germany and
France.
Introduced globally 40 years ago, the leap second was designed to keep atomic
time
(used by computer systems) and astronomical or solar time (the Earths rotation)
in sync with each other.
Discrepancy
Atomic time, which GPS and telecommunications depend on,
is so accurate that it gains or loses no more than a second every million years.
However, astronomical time alters because of variations in the Earth rotation
and can be affected
by things like earthquakes. The leap second was needed to keep the two time
scales coordinated
so atomic time doesn't jump ahead of astronomical time, the International
Telecommunication
Union (ITU-R) explained to Yahoo! News.
In fact, a leap second has been added at irregular intervals “ a total of 24
times since
its introduction in 1972.
Without the leap second keeping time in check, it is predicted that the
difference between
atomic time and astronomical time will increase at a rate of approximately one
second per year “
meaning that in 550 years, the difference between atomic time and astronomical
time will be
about an hour, the International Bureau of Weights and Measures (BIPM) projects.
The decision
Thursday Radiotelecommunication Assembly saw delegates from member states
discuss the
elimination of the leap second and voting for or against the controversial
proposal.
A decision to remove the leap second completely would then need to be approved
at the
ITU-R World Radiocommunication Conference due to take place next week.
The next leap second is expected to be added at midnight on 30 June. However,
Thursday debate, which an ITU-R spokesperson described as very polarised could
see all that change.
Against the leap second
Countries like France, Italy, Germany and the USA are calling for an end to the
leap second
because telecommunications from GPS systems to mobile phone networks must be
manually
adjusted by a whole second to keep in sync with the change every year or two.
This adaptation of a second, critics argue, leaves systems open to the risk of
error.
If the leap second was abolished, time would be more standard.
The ITU-R, a United Nations agency, said in a statement:
The benefits of the change would be a continuous time scale available for all
the modern electronic navigation
and computerised systems to operate with and eliminate the need for specialised
ad hoc time systems.
For the leap second
Britain, China and Canada are opposed to the change because without that leap
second,
atomic and astronomical time will drift further apart, which would need to be
corrected by
adding a single leap second, minute or hour at an agreed point in time which
would be
even more technically challenging and costly.
Without leap seconds we will eventually lose the link between our perception of
time
and our own experiences of day and night, added the ITU-R spokeswoman
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