On Jan 8, 2006, at 6:41 PM, Tom Van Baak wrote:
am not sure I like the idea that eventually my car, traffic lights, airlines, television, and my thermostat will have to be reliably tied to the IERS in order to function properly.
This is a general issue with the increasingly tight coupling between any number of networked systems. Certainly not unique to timekeeping. On the other hand, rarely should any system (certainly not a safety critical application) depend on a clock that must remain tightly slaved to *any* external signal. Consider what evolutionary path technology would have to take such that significant numbers of traffic lights and thermostats would ever require direct contact with the IERS. It's easy to speculate about pathological engineering practices - A requires access to B, immediately and always, perfect and inviable. But real designs result from real requirements.
What if some killer app 40 years hence requires 100 ms or 1 ms time accuracy.
Don't think "accuracy" is the word you want. The short answer to your question is that all the time wonks would celebrate their newfound employability.
Do we still want UTC leap seconds when it will infect ten billion devices?
Perhaps you meant "affect"? :-) What we want and what we need are two different things. And as is currently true, those devices aren't required to use UTC unless they need UTC.
the current scheme does not scale well into the future;
No, it does not - but there are two caveats: 1) the current scheme (also known as an "international standard") is good for several hundred years 2) no other scheme scales better
either a technological future (way too many devices affected by unscheduled time steps) or an astronomical future (way too many leap seconds a year).
As I pointed out close to five years ago, the ultimate long term remediation will likely involve redefining the length of the second: http://iraf.noao.edu/~seaman/leap Nothing over the years of intervening discussions has given me cause to change my opinion. Rob