Ed Davies says: > My 757/767 captain friend couldn't think of any actual Earth > rotation dependencies -
I commend you for continuing to press this discussion with folks outside the leap second loop. I suspect that many of the folks on this list, like I, were active in their organizations Y2K remediation efforts. The expense of Y2K was no only - or perhaps even mostly - contained in fixing bugs and testing the fixes. A large fraction of the expense was in the time and money needed to inventory every system that could even potentially require Y2K related changes. We have no business discussing a fundamental change to international time standards without performing a similar inventory. Not only is such an inventory needed before implementing a change - such an inventory is needed before designing the change. Before Y2K, highly competent members of our staff (equivalent in experience to your 7N7 captain) opined that there were likely no major Y2K remediation efforts that the observatory would have to undertake. It is indeed true that the Y2K inventory that I supervised on our major image processing package (used by most of the world's astronomers) only turned up a couple of dozen routines out of 10,000 or so that required changes. But those were key routines for many activities and an easy test (using the computer I'm currently typing this on) showed that our unremediated software was going to fail completely. Those two dozen routines required relatively simple bug fixes. There was also a new interface that we found prudent to write that now isolates all date conversions within the system. For this system, the characterization of the problem was by far the most expensive step. The expense of validating the correctness of the fixes was not far behind. Actually implementing the fixes was relatively easy - but note that Y2K really involved only bug fixes and very little system redesign. Another expense of Y2K was the revision of dependent standards. Several of the members of the astronomical software community who also subscribe to this list were active in the revision of the astronomical FITS data interchange standard to support Y2K related changes. This involved large numbers of individuals from many organizations in our community who each spent many weeks or months on this issue. The details were discussed for three or four years prior to 2000-1-1. Our efforts have yet to completely cease. And yet another expense of Y2K to the astronomical community was what I would say falls into the category of random surprising absurdities of legacy systems. The observatory scheduled a variety of activities to characterize the Y2K behavior of expensive, one-of-a-kind systems. The more recent systems were relatively well behaved and well understood. Typically the folks who designed those systems were still on staff to make the necessary fixes. But astronomy is not unique on relying on a wide range of legacy systems, some of whom are poorly documented and most of whom were long since orphaned by retired or departed staff. In short, two of our oldest telescopes were controlled by PDP's running forth (one of these still is) - and we discovered that those two telescopes were going to track the sky backwards after the millennium. Were they fixed in time? Yes. Was it easy? Relatively - if you ignore the fact that some very busy staff member had to relearn obsolete technologies purely for this purpose. It may well be that all of the world's interlocking technical, social, economic, commercial, religious, political, computational, and scientific systems are completely uncaring about civil time continuing to approximate time-of-day. It may well be that only a few obscure loonies like astronomers will have to change anything at all - and that the lives of millions of hardware and software engineers will be made easier for generations to come. It may be that there are NO other international standards that depend on the current assumptions of the UTC standard. It may be that there are NO de jure or de facto (UTC ~ GMT) dependencies in any jurisdiction on the planet. It may be that not a single religious sect anywhere on the globe will care about the secularization (pun intended) of the world's clocks. It may be that there will be not a single negative economic consequence. It may be that (other than astronomers and traditional sectant navigators) not a single operational procedure or technical software/hardware system will have to be changed. It may be that only a few publishers will have to update tables in almanacs and that they will view this as a way to sell more books. It may be that no legacy systems will have to be updated or retired. It may be that the world's programmers will either be able to ignore this change - or will view it as another full employment opportunity like Y2K. But shouldn't we fully inventory and characterize and test the various such named and unnamed systems BEFORE we decide to make a change? Rob Seaman National Optical Astronomy Observatory