[LEAPSECS] honest-to-god copper

[M. Warner Losh]

In message: <20100607173442.GA25119 at ucolick.org>
            Steve Allen <sla at ucolick.org> writes:

: In the Manhattan project plutonium was copper, and copper was

: honest-to-god copper.

: 

: In the Java JSR-310 "Date and Time API"

: https://jsr-310.dev.java.net/userguide.html

: we see this:

: 

: 	Time scales

: 

: 	The Instant class operates on a time-line model that doesn't

: 	exist in reality.  Specifically it assumes that leap-seconds

: 	do not exist, and that there are always 60 seconds in a

: 	minute.

: 

: 	These simplifications are useful because most applications do

: 	not take into account the existence of leap seconds.  If your

: 	application needs to takeinto account leap seconds then an

: 	alternate class is needed.  The TimeScaleInstant class

: 	represents an instant in time measured againsta specific

: 	TimeScale.  The supplied scales include TAI and True-UTC.

: 

: "True-UTC", as opposed to just plain "UTC".  Just plain "UTC" is not

: the entity defined by ITU-R TF.460, but a (dare I use the word)

: proliferated time scale, something new created by them.


Sounds a lot like "true facts" vs "good facts" from 1985.  "True
facts" were facts that were, in fact correct.  "Good facts" are facts
that are useful, but might not actually be, in fact, correct.

Warner