The Hawaiian gazette., 1910-05-06
Natures Mysteries
Los Angeles Times.

One is divided in mind whether to
head this article as above or to call it
Man S Colossal Ignorance. According
to the best scientific opinion IL is not
less than 10000 years since man, ra.
tiOnal being, using artieulate speech
and thinking in syllogisms, appeared
upon the earth.
Before sunrise these mornings watch.
ers are scanning the eastern skies for
glimpse of the famous HALEY Is
comet, which returns to visit us after
a period of seventy-five years. It is
more than half century since a nota-
BILE planet appeared in our skies here
tofore, and when Donati's great light
famed for nights through the western
sky covering half hemisphere in 1858,
it was even then an object of terror to
a great many people even in our own
enlightened country.
We know too much about comets to
imagine that they are providential por-
tents. Since Halley's time we have
learned good many of their laws and
understand some little thing about
comets. We know, for example, that
they circulate around the sun passing
through our solar system in an orbit
either in the form of an ellipse or of
parabola. Those that travel in a
parabola come rushing down the skies
and swing around our sun, to pass out
on its other side far into space and
never to return. Our planetary system
all travels around. the sun in orbits
which are elliptical, but the cometie
ellipses are much fatter than those of
the earth or the other planets. The
one in the sky now takes seventy-fve
years to make its circuit around the
sun. The ellipse has two fixed central
points instead of the one center of a
perfect circle, and these are called the
fOci of the ellipse. The cometic orbit
has one focus very close to the sun and
the other far away in space. The
movement of the comet is not uniform
in its pace throughout the whole of its
course. The farther from the sun the
slower its progress, and as this diapha-
nous body rushes down the sky sunward
its pace is accelerated until it whirls
around the center of our system at a
speed that defes the Imagination of
man to conceive of what it is. This is
in exact conformity to the law of the
planets, including our own earth, which
at its apogee goes slowly and accele
rates its pace as it approaches its peri.
gee. The reason for this is to nicely
balance the centrifugal and centripetal
forces, for if the earth moved as slow
ly at its perigee as at its apogee, il
would be drawn into the sun and de
stroyed, whereas if it moved as rapidly
at its apogee as at its perigee, it would
fly off into space aud be lost in a DIFF
ferent way, perishing form cold in the
one case as it would from heat in the
other.
We do not even know what a comet
is composed Of Its tenuity, its lack OF
substantially, is one of the greatest
Ipuzzles about it. This one in the sky
now at some near day will pass direct
ly between our earth and the sun, but
it will not cast any more shadow thar
the atmosphere of our earth. The sun
light will CLEAN not only through its
tail, but through the nucleus of the
comet. As it comes down the skies
toward us, at first there is no tail to
the comet, but as it approaches the
sun this buds out as if it were some
great bird from the unknown thai
sprouted and grew its tail feathers.