[LEAPSECS] ITU-R SG7 to consider UTC on October 4

Rob Seaman seaman at noao.edu
Thu Aug 5 17:28:00 EDT 2010

On Aug 5, 2010, at 1:55 PM, M. Warner Losh wrote:

> ashtongj <ashtongj at comcast.net> writes:


>> McCarthy and Seidelmann, on page 17 of _TIME: From Earth Rotation

>> to Atomic Physics_ (2009) state "GMT is still used as the official

>> time scale of the United Kingdom and in some communication systems

>> as UTC."



> In one of these mailing lists, there was a debate about NASA using

> the term "GMT" when they really meant "UTC". There were many

> different references cited during that debate. One of them

> indicated that even in the UK there's not a clear distinction

> between GMT and UTC and often (but not always?) the terms are used

> interchangeably. UTC being viewed as just another way to realize

> GMT with some small, trivial error for the real pendants.

Precisely. (Or rather, approximately.) It will prove impossible to
untangle the historical identification of UTC as - well - a flavor of
actual Universal Time, which is to say a way of approximating GMT.

The simplest and most direct (and most likely to succeed) way to
achieve a goal of removing leap seconds from civil timekeeping would
be to advocate GPS timekeeping as the alternative. Civilians love
their GPS units.

Stop viewing this issue as a way to cleverly (that is to say, naively)
sneak through a putatively invisible change to every clock on the
planet. Rather, view it as a way to make timekeeping sexy and visible
and of significant economic interest. There is already a healthy GPS
industry in place that would be delighted to fill orders for new clocks.

Rob Seaman
National Optical Astronomy Observatory

More information about the LEAPSECS mailing list