Re: Introduction of long term scheduling

2007-01-07 Thread Daniel R. Tobias
On 8 Jan 2007 at 0:15, Tony Finch wrote: How did you extend the UTC translation back past 1972 if the undelying clock followed TAI? I assume that beyond some point in the past you say that the clock times are a representation of UT. However TAI matched UT in 1958 and between then and 1972 you

Re: how to reset a clock

2007-01-04 Thread Daniel R. Tobias
On 4 Jan 2007 at 10:53, Peter Bunclark wrote: Indeed isn't this Rob's ship's chronometer? Captain's log, stardate 30620.1... http://en.wikipedia.org/wiki/Stardate -- == Dan == Dan's Mail Format Site: http://mailformat.dan.info/ Dan's Web Tips: http://webtips.dan.info/ Dan's Domain Site:

Re: A lurker surfaces

2007-01-02 Thread Daniel R. Tobias
On 2 Jan 2007 at 12:40, Warner Losh wrote: The interval math in UTC that's hard today would be significantly harder with rubber seconds. But it is just software, eh? In short, it is an interestingly naive idea that was tried in the 1960's and failed when there were only dozens of high

Re: Introduction of long term scheduling

2007-01-02 Thread Daniel R. Tobias
On 2 Jan 2007 at 19:40, Poul-Henning Kamp wrote: Has anybody calculated how much energy is required to change the Earths rotation fast enough to make this rule relevant ? Superman could do it. Or perhaps he could nudge the Earth's rotation just enough to make the length of a mean solar day

Re: A lurker surfaces

2007-01-02 Thread Daniel R. Tobias
On 2 Jan 2007 at 11:47, Ashley Yakeley wrote: The obvious solution is to transmit rubber time on a rubber frequency. Are rubber duckies involved? -- == Dan == Dan's Mail Format Site: http://mailformat.dan.info/ Dan's Web Tips: http://webtips.dan.info/ Dan's Domain Site:

Re: A lurker surfaces

2007-01-02 Thread Daniel R. Tobias
On 2 Jan 2007 at 11:56, Ashley Yakeley wrote: GPS is TAI. I'm not proposing abandoning TAI for those applications that need it. It's a few seconds off from TAI, isn't it? It was synchronized to UTC in 1980 (I think), but without subsequent leap seconds, so it's now different from both TAI and

Re: Mechanism to provide tai-utc.dat locally

2006-12-27 Thread Daniel R. Tobias
On 27 Dec 2006 at 20:57, John Cowan wrote: Very true. And adopting the Egyptian-Roman calendar redefined the concept of a month. Somehow civilization survived. Keeping months in sync with phases of the moon apparently turned out to be insufficiently important to civilization to require it as

Re: what time is it, legally?

2006-12-14 Thread Daniel R. Tobias
On 13 Dec 2006 at 21:43, Steve Allen wrote: http://gauss.gge.unb.ca/papers.pdf/gpsworld.january01.pdf One quibble with that article is that it gives the Global Positioning System as an example of how humanity has been obsessed with knowing what time it is. Actually, GPS arises from our

Re: Comparing Time Scales

2006-02-03 Thread Daniel R. Tobias
On 3 Feb 2006 at 15:37, James Maynard wrote: Thanks, guys, for your feedback. Here's another iteration. It would seem that PTP is actually counting from 1970-01-01 00:00:00 in TAI rather than UTC; the subsequent values of that scale reflect the full TAI-UTC offset, not just the part of it that

Re: Risks of change to UTC

2006-01-21 Thread Daniel R. Tobias
On 21 Jan 2006 at 10:11, M. Warner Losh wrote: I maintain that for human activity, there's no need for leap seconds at all. In each person's lifetime, the accumulated error is on the order of a few minutes. Over generations, the problems with noon drifting to 1pm can trivially be solved by

Re: Risks of change to UTC

2006-01-21 Thread Daniel R. Tobias
On 21 Jan 2006 at 15:15, M. Warner Losh wrote: For some perspective, we've been using UTC for only ~50 years and the gregorian calendar for only ~1500 years. I'd anticipate that something would need to be done about the slowing of the day well before 4300 years have passed. Actually, that's

Re: The real problem with leap seconds

2006-01-11 Thread Daniel R. Tobias
On 11 Jan 2006 at 0:08, Tim Shepard wrote: If humans spread out to other places besides the earth, an earth-centric time scale might begin to seem somewhat quaint. Distributing leap second information to a Mars colony seems kind of silly. As I recall, the NASA Mars missions are using

Re: interoperability

2006-01-08 Thread Daniel R. Tobias
On 8 Jan 2006 at 15:04, Tom Van Baak wrote: You cannot divide timekeeping, time dissemination, into neat stages. In the 1960s if ten labs were told to offset their phase or frequency it affected only a handful of people or systems. Today when IERS announces a leap second, millions of

Re: a system that fails spectacularly

2005-12-09 Thread Daniel R. Tobias
On 9 Dec 2005 at 10:42, David Harper wrote: On the other hand, the idea of ISO 9000 compliant Morris dancers is a very funny one. Presumably, they'd have to standardise the size of their pig's bladders. There's a Monty Python sketch just waiting to be written. I'm guessing that their level

Re: Comments on Civil Time decision tree

2005-09-26 Thread Daniel R. Tobias
On 26 Sep 2005 at 16:09, Poul-Henning Kamp wrote: Other more laid back parliaments like the Danish have not been able to find time to revisit the issue since 18xx and still use solar time at some more or less random coordinate. You mean like the U.S. Congress?

Time after Time

2005-01-22 Thread Daniel R. Tobias
I sure hope that the future of mankind's timekeeping systems doesn't get decided by an Internet flame war between contending groups of geeks... As I see it, the dispute comes from the fact that people want two different, irreconcilable types of time, time of day (earth/solar angle) and constant