Humans—or as Quark, the Ferengi, in Deep Space 9 used to
say, hu‑mahns—are challenged in a three-dimensional world. It might just be
that we come from a four- or four-plus-dimensional region of the cosmos where
wishing is as good as going there, so who needs bothering with maps. It’s a
different story here. Two posts on this site are very popular. One, called
“Longitude,” is the all-time favorite; another, “The Astrolabe,” which deals
with Latitude, is tenth. One wonders why. Perhaps people are confused—and count
me in. I wrote those posts but occasionally a kind of baffled fog surrounds me.
I am temporarily unsure again. What is it, again, that longitude measures? I
think the lines run up and down. Does it measure north-south alignment. Wrong,
WRONG. But let us get there.
The “long” in longitude has obvious meaning. Something that
is long. The “lat” in latitude is less obvious. It comes from Latin and means
width. But we don’t measure the lat of a table or of a football field. Now the
maddening—and confusing—aspect of these terms is that in effect we use
longitude to measure width, latitude to measure height, both from fixed points
on the face of the globe.
Longitude measures distance from some fixed point to the
east and west. Call it Eastwestitude. Those lines are numbered from 0 to 180.
The zeroeth line runs through Greenwich, England north to south or the other
way about—which tells us who ran the last undisputed world empire. To the left and
right of that line, the Meridian, thus to west and east of it if your head is
north, your feet are south, the numbers increase at equal increments on both
sides until they meet again and merge in 180 exactly at the opposite point of
the globe from Greenwich.
Latitude measures distances from the Equator to the north
and south. Call it Northsouthitude. The Equator represents 0 Latitude. Numbers
above and below it both increase until they reach 90 at the two poles. Is there
some equivalent to Greenwich on the Equator the name of which everybody knows?
Yes and no. There is such a place, but virtually nobody knows it. It is Ciudad
Mitad del Mundo (Mid-World City) in Ecuador. I bring an aerial image of it here
from Wikipedia (link). Notice the yellow line faintly visible in the middle of the picture.
That’s the equator. In this town you can walk with your loved-one hand-in-hand,
one of you walking in the northern, the other in the southern hemisphere, and
your hands clasped in the mitad.
Now when it comes to mnemonics, the problems continue.
Eastwestitude is a pretty decent, straightforward description. But notice that
it lacks an O, the marker in lOngitude, to which it belongs. Similarly,
Northsouthitude is handy, but it lacks the A that might link it to lAtitude.
Gul darn it. Based on this I am sure that in some future time I’ll be struck
again by the lightning of confusion. Longitude will be there like some hovering
monster—and I won’t remember whether to go up or down or left to right. That’s
when blogs come in handy. Or should I speak of blags?
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