On Jan 10, 2006, at 11:06 AM, Poul-Henning Kamp wrote:
Let me see if understood that right: In order to avoid computing problems and to get precise time, astronomers rely on a timescale without leapseconds, because the Earths rotation is too unstable a clock for their purposes.
Just like everybody else, astronomers rely on interval time when interval time is needed and rely on earth orientation "time" when earth orientation is needed. The particular irony is that these two purposes may be mistaken one for the other. In a technical arena, there is no more ambiguity here than in many other issues. Define the requirements for a particular project and crunch the numbers and design an experiment or apparatus that does what it needs to do. In a civil/business/international/legal historical context, one of the requirements (you will disagree, but please try to make your own case, not just blow holes in mine) is that only a single realization of timekeeping may be supported. Ambiguity and conflict are inevitable as a result. Our goal is to manage the balance between these appropriately. Rob