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Discussion of precise time and frequency measurement

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Re: [time-nuts] FW: Bulletin C number 30

M
mikes@flatsurface.com
Tue, Jul 5, 2005 8:44 PM

At 03:15 PM 7/5/2005, Warner Losh wrote...

UTC was intended to be a civil time.  It was thought that it would be
best if it followed astronomical time.  Maybe that fundamental thought
is just wrong.

No, it isn't. Since much law is based upon specific reference to solar time, UTC (with leap seconds) is exactly appropriate for civil purposes. In the US, for instance, legal time "shall be based on the mean solar time of the [varies by time zone] degree of longitude west from Greenwich". 15 USC Sec. 261.

Should civil time (which is effectively linked to UTC) be separated from solar time, there will be significant costs and ambiguities introduced legally.

There would be significant costs also users in the astronomical and celestial navigation realms. The US Government states: "The mariner is constantly tempted to rely solely on electronic systems. But electronic navigation systems are always subject to failure, and the professional mariner must never forget that the safety of his ship and crew may depend on skills that differ little from those practiced generations ago. Proficiency in conventional piloting and celestial navigation remains essential." The US Navy, in fact, still requires shipboard competency in celestial navigation.

At 03:15 PM 7/5/2005, Warner Losh wrote... >UTC was intended to be a civil time. It was thought that it would be >best if it followed astronomical time. Maybe that fundamental thought >is just wrong. No, it isn't. Since much law is based upon specific reference to solar time, UTC (with leap seconds) is exactly appropriate for civil purposes. In the US, for instance, legal time "shall be based on the mean solar time of the [varies by time zone] degree of longitude west from Greenwich". 15 USC Sec. 261. Should civil time (which is effectively linked to UTC) be separated from solar time, there will be significant costs and ambiguities introduced legally. There would be significant costs also users in the astronomical and celestial navigation realms. The US Government states: "The mariner is constantly tempted to rely solely on electronic systems. But electronic navigation systems are always subject to failure, and the professional mariner must never forget that the safety of his ship and crew may depend on skills that differ little from those practiced generations ago. Proficiency in conventional piloting and celestial navigation remains essential." The US Navy, in fact, still requires shipboard competency in celestial navigation.
BH
Bill Hawkins
Tue, Jul 5, 2005 10:25 PM

Mike S said,

"No, it isn't."

This reminded me of something I saw in Monty Python's "All
the Words" Volume 2 called "The Argument Clinic." John
Cleese is Mr Vibrating, of the clinic.

...
Man - Look this isn't an argument.
Mr Vibrating - Yes it is.
Man - No it isn't, it's just contradiction.
Mr Vibrating - No it isn't.
Man - Yes it is.
Mr Vibrating - It is not.
Man - It is. You just contradicted me.
Mr Vibrating - No I didn't.
Man - Ooh, you did!
Mr Vibrating - No, no, no, no, no.
Man - You did, just then.
Mr Vibrating - No, nonsense!
Man - Oh, look this is futile.
Mr Vibrating - No it isn't.
...

Yours for less,
Bill Hawkins

Mike S said, "No, it isn't." This reminded me of something I saw in Monty Python's "All the Words" Volume 2 called "The Argument Clinic." John Cleese is Mr Vibrating, of the clinic. ... Man - Look this isn't an argument. Mr Vibrating - Yes it is. Man - No it isn't, it's just contradiction. Mr Vibrating - No it isn't. Man - Yes it is. Mr Vibrating - It is not. Man - It is. You just contradicted me. Mr Vibrating - No I didn't. Man - Ooh, you did! Mr Vibrating - No, no, no, no, no. Man - You did, just then. Mr Vibrating - No, nonsense! Man - Oh, look this is futile. Mr Vibrating - No it isn't. ... Yours for less, Bill Hawkins