Re: Alternatives
@Martin it's already decoupled, although they need to be somehow synchronized because you need (and will always need) to be able to perform conversion between the two. What you call Astronomical Time is actually Atomic Time, called TAI and what you call Earth Time is various timezones, all relative to UTC. Leap second is just one possible synchronization mechanism when one wants to keep the conversion between TAI and UTC simple. It is possible to imagine different mechanisms.
As for base-60 , well you do not have to use it. Everyone knows that counting number of seconds from midnight UTC of 1st January 1970 is perfectly accessible and universally accepted measure of time. Right?
Biting the hand that feeds IT
