Tony Finch dot at dotat.at wrote
No that is not correct, or at least it's nowhere near as simple as that. The atomic second was matched to the second of ephemeris time, and that was based on Newcomb's tables of the sun, which in effect used the average length of the second from the 1800s. http://ucolick.org/~sla/leapsecs/dutc.html
Last fall we held a meeting to consider how UTC might be changed and what the implications of leaps seconds were. The proceedings fill 400 pages of a book. For the sound bite version (only 3 pictures) of leap seconds http://www.ucolick.org/~sla/leapsecs/amsci.html For a view of the international legal mess caused by leap seconds http://www.ucolick.org/~sla/leapsecs/epochtime.html For a blow-by-blow review of the international bureaucratic regulatory situation for leap seconds see http://www.ucolick.org/~sla/leapsecs/onlinebib.html For a worked example that could alleviate the disagreement between POSIX and leap seconds, and which might break the international stalemate http://www.ucolick.org/~sla/leapsecs/right+gps.html In there are also links to those 400 pages of the book, but I suggest that this forum is not the best place to rehash this information. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m