[LEAPSECS] Tripping over the International Date Line

[John Cowan]

Rob Seaman scripsit:


> The class "Phileas Fogg" likely contains only Michael Palin (and

> entourage) in addition to Fogg (and Paspartou, of course) himself.


Lots of people used to take trips round the world: the traditional
route was London-Delhi-Bangkok-Hong Kong-New York-London, to
keep to (then) anglophone cities.  (Fogg's planned route was
London-Suez-Bombay-Calcutta-Hong Kong-Yokohama-San Francisco-New
York-London.)  A little googling shows that many people travel round
the world by air nowadays.

Zefram scripsit:


> It was getting round the world in less that 80*86400 seconds

> that saved the wager.  


In fact Fogg took only p79dt5m to circle the globe by London time (from
1872-10-02t20:45 to 1872-12-20t20:50), though by his own reckoning it was
p80dt5m.  He didn't discover his error until 1872-12-21t20:35 London time,
and didn't actually arrive back at his club until 1872-12-21t20:44:57.
(What drama, what tension, what epic scope compressed to those few
dry figures!)

Daniel R. Tobias scripsit:


> The reader is expected to believe that through all of this none of

> their party happened to notice that the date, as reckoned by [American]

> locals in the places they passed through, differed by one day from the

> date they believed it to be, despite managing to catch various trains

> and ships whose timetables depended on the actual date.


An excellent point, particularly about the ships.

Lewis Carroll set a puzzle depending on the Date Line in Knot 10 of
his book of puzzles, _A Tangled Tale_ (online at
http://etext.library.adelaide.edu.au/c/carroll/lewis/tangled/knot10.html ).
The Knot was first published in a monthly magazine in 1880 or 1881,
and asks the question:  If it's Wednesday-Thursday midnight in Britain,
it is Wednesday at all points west, and Thursday at all points east --
but somewhere they must meet, and where is that?

Carroll confesses in his "Answers" (see
http://etext.library.adelaide.edu.au/c/carroll/lewis/tangled/answers10.html )
that he does not know the answer:

	I must postpone, sine die, the geographical problem -- partly
	because I have not yet received the statistics I am hoping for,
	and partly because I am myself so entirely puzzled by it; and
	when an examiner is himself dimly hovering between a second
	class and a third, how is he to decide the position of others?

In any case, even after the Washington Conference of 1884 that nailed
down the de jure time zone system, the Date Line itself remained only
de facto, as it is to this day.

-- 
You know, you haven't stopped talking           John Cowan
since I came here. You must have been           http://www.ccil.org/~cowan
vaccinated with a phonograph needle.            cowan at ccil.org
        --Rufus T. Firefly