Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1919-03-14
Some Of the Curiosities
of Father Time


Why Places Thousands of Miles
Apart May Have the Same Time of
Day IL One Is in the orthern and the
Other in the Southern Hemisphere.
by GARRTT p. sERvIss
''I have a bet with friend OF
mine," says a correspondent. "and
wish a bit of your advice. My
friend says that when it is daytime
here in New York, in Buenos Aires,
S A.. it is night time. And 1 say
Just the opposite. Now, would ike
to know who is right and why?
Great are the uses of confusion
of mind, if only there be earnestness
behind it, for then it may result in
strong grasp on the truth, when
it is cleared up. Living on glooe
which turns around a fixed axis has
always been a source of mental con-
fusion for its inhabitants Its ro-
tundity and it's axial rotation pro-
duce deceptions of the senses with
which even science finds 1t convent
ent to compromise.
In the case in hand, putting aside
the failure of the writer to say clear
ly what he means in his contradic-
tion of his friends erroneous opin-
ion, it is evident that there is con-
fusion in the mind of at least one
of the bettors concerning the effect
produced on the apparent position
of the sun by regarding 1T. at the
same moment, from opposite hemi-.
spheres OF the earth.
Itmakes an enormous difference
whether the hemispheres considered
are north and south, or east and
west. Buenos Aires lies about 75 1-3
90 latf Of
York, and only about 151a degrees
of longitude east of New York. The
former would correspond to over
five hours of time il it were a diff
ference of longitude, but being
difference of latitude it has no effect
on the time, although the two places
are in opposite hemispheres.
The other difference, viz. 10 is
degrees in latitude, has an effect
on the time amounting to little
more than one hour. Thus, night
begins and day dawns about an hour
earlier at Buenos Aires than at New
York. But If you could tip the axis
of the earth over so that the poles |
should lie on the equator, then what |
is now latitude would become longi- |
tude, and the clocks of New York |
and Buenos Aires would be about as |
far apart as those of New York and ;
London are at present, while, on J
the other hand, London and New !
York would differ in time less than |
three-quarters of an hour, and New |
York. Madrid, Naples. Constantinople. |
Bokhara and Pekin would differ only |
a few minutes from one another.
At the same time, it must not be
assumed that places opposite to each |
other-one in the Northern and the
l.
may not differ so widely in time tha.
midnight for one corresponds with !
midday for the other. The thing
10 look for is the difference in longi-
tude, which is measured east and
west, and not in latitude. which il
measured north and south. Thus
Alaska and the Cape of Good Hope
are twelve hours apart in time. not
because one lies far to the north
and the other far to the south of Il
the equator, but because they are on
opposite meridians of longitude.
Some persons have difficulty in
understanding the difference in the
time of day at different points on
the earth. a homely illustration may l
make the cause of the difference /
more evident. Take lamp to rep
resent the sun, and let your head /
stand for the earth. Suppose the
top of your head is the North Pole.
Let your nose be New York, and the
ocipital bone in the back of your
head Batavia in Java, which is OPP
posite to New York in longitude.
Let your right ear be Rome, which
is about 30 degrees or one-quarter
round the world east of New York,
and your left ear the Sandwich Is
lands. which are nearly quarter of
the way round toward the west.
Now. face the sun (the lamp. Then
1t will be noon at New York (your
nose), because the sun will there
be in the middle of the sky. But
what time will it be at batavia (the |
back of your head)? Evidently it will
there be midnight. Now spin round
right. Then it will be sunset on your
nose (say p. mo- noon at your lef
ear (Sandwich lslands), sunrise C
p. mo- at the back of your head
(Batavia), and midnight at your right
ear (Rome).
You perceive that all of these diff
ferent local dates occur at the same
moment of absolute time, but that
the hour indicated by local clocks
placed at the various points, differs
according to the locality, 6 a. m,
IL NJ, p. M, etc., occurring earlier
the farther round the place is in the
direction toward which you turn.
To illustrate the fact that two
places may be very far apart on the
earth, one in the Northern and the
other in the Southern Hemisphere. II
and yet both have the same time of |
day, take the center of the ton of |
your forehead to represent the north II
western corner of Greenland, and the II
point OF your chin to represent Cane |
Horn, while your nose is New York. |
Then as you turn round you will |
find that sunrise, sunset midnight |
and noon; each occurs simultaneous
ly at all three places, because those |
places lie on the same meridian, or
on line through the center of your
face which is at right angles to the
plane in which your head turns.