On Jul 28, 2007, at 8:53 AM, Steve Allen wrote:
HR 2272, Title IV (NIST)
'Sec 2 (Metric system defined)
(4) Modifies the 1918 Calder Act which is 15 U.S.C. 264
and adds section
'(b) which defines UTC for the sake of the US.
The original 1918 Calder act specified "mean astronomical time".
Enforcement of that act was suspended within a couple of years
until sufficient chaos had been wrought that congress acted again.
When it was amended to standardize time zones and daylight savings
in 1966 congress had been informed that there was more than one
sort of mean time in astronomy, so the current text reads
"mean solar time".
To be a bit more explicit:
(B) by striking the second sentence←→ and the extra period after
it and inserting `Except as provided in section 3(a)←→ of the
Uniform Time Act of 1966 (15 U.S.C. 260a), the standard time of the
first zone←→ shall be Coordinated Universal Time retarded by 4
hours; that of←→ the second zone retarded by 5 hours; that of
the third zone retarded by 6 hours; that of the fourth zone
retarded by 7 hours; that of the fifth zone retarded 8 hours; that
of the sixth zone retarded by 9 hours; that of the seventh zone
retarded by 10 hours; that of the eighth zone retarded by 11 hours;
and that of the ninth zone shall be Coordinated Universal Time
advanced by 10 hours←→.'; and
(C←→) by adding at the end the following:←→
`(b) Coordinated Universal Time Defined←→- In this
section,←→`(1)←→ the term `Coordinated Universal Time←→'
a mathematics, science, or technology teacher at ←→means the
time scale maintained through the General Conference of Weights and
Measures and interpreted←→ or modified for←→`(2)←→ the
United States by the Secretary of Commerce←→ in coordination
with ←→the Secretary←→ of the Navy.'.←→
So the question devolves back to whether UTC will continue to express
mean solar time, but the skids have been greased.
My position remains that civil time by definition is an expression of
mean solar time. The calendar orders our days and the clock is a
division of the calendar. Cheating the clock must catch up with you.
This act, if passed, will tie UTC more firmly to civil time, and thus
one could argue, to mean solar time. Perhaps the intent behind this
maneuver is actually to head off the determination of the Torino
Colloquium in May 2003:
5. Potential Alternative to the Leap Second
During the roundtable discussion several alternative proposals
concerning the Leap Second were discussed. If a change were to be
made, one proposal seemed to be preferred. The essence of this
proposal is:
1. Any change should slowly evolve from the current UTC Standard
by transition to a uniform timescale,
2. The final timescale should have a new name to distinguish it
from Universal Time, since Universal Time is general understood to
Solar Time and the earth’s rotation. A new name suggested and
discussed was International Time, Temps International (TI).
3. A suggested date for inaugurating any change would be 2022, the
50TH anniversary of the UTC timescale. The date suggested was
remarked as being influenced by the beyond the lifetimes of
currently existing systems that would be expensive to change.
4. TI should be a continuous atomic time scale, without Leap
Seconds, that is synchronized with UTC at the time of transition.
5. UT1 information would continue to be made available under the
sole responsibility of the IERS.
By tying U.S. civil time directly to UTC, there would then be no room
for TI by this line of reasoning. I believe the suspect logic behind
this bill will ultimately be proven to be weaker than the Torino
consensus, however, whether or not an attempt is made to embargo leap
seconds into leap hours. A fresh start as TI would be infinitely
easier to carry off than trying to staunch all the broken
entanglements that would come with UTC.
My grandfather was a carpenter. One of his favored phrases was a
"lazy man's load" - that is, picking up more than you can safely
carry in an attempt to save a second trip. This bill (like so many
others) is a lazy man's load.
Rob Seaman
National Optical Astronomy Observatory
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