[glurgh]

Well, for one thing a non-constant second seems like it would break just about all of physics in deeply unpleasant ways.

I think 'btilly is right - it's an unpleasantly difficult problem.

I suppose my point is 'it just happens to be unpleasantly hard problem' - given that a great number of specialists have put serious time in thinking about it trying to solve it, I have a very difficult time imagining that the solution (or satisfactory answer) is as simple as 'just blame astronomers'.

Having _two_ or more slightly different units that measure the base unit of time (which would be the case if we defined seconds in terms of (siderial? some other?)) year seems like a far greater potential source of cock-ups than just having a well-defined unit that might not quite, but more often than not, matches astronomical detail.

[lmm]

>I suppose my point is 'it just happens to be unpleasantly hard problem' - given that a great number of specialists have put serious time in thinking about it trying to solve it, I have a very difficult time imagining that the solution (or satisfactory answer) is as simple as 'just blame astronomers'.

As far as I can tell the proposal before the ITU (replace leap seconds with leap hours, with a view to abolishing leap hours once any incompatibilities with national laws have been resolved) solves all the problems quite nicely. I'm not entirely clear why they voted to defer a decision until 2015, but I'm not aware of any serious objections to the proposal.

[btilly]

I'm not aware of any serious objections to the proposal.

The only objections that I've ever heard about are astronomers who are annoyed that this piece of traditional authority is being taken from them. My obviously unsympathetic attitude is that they used to serve an important role, but their once critical role in precision timekeeping has been obsolete since the development of the atomic clock. It is time to recognize that.