The Princeton union. [volume] (Princeton, Minn.) 1876-1976, 1913-09-11
"A NATURAL Riddle.
Attraction of Gravitation Is a
Mystery to Science.
IT CONTROLS THE. UNIVERSE.

Vet That Wonderful Force That Di-
reefs and Regulates Moons, Planets,
Suns and Stars Without Visible
Means Of Connection IL lnexplicabie.
The mystery of mysteries in science
is the attraction of gravitation-that
very force of nature that is the most
familiar to US all. It seems strange
that the most familiar thing in the
world should be at the same time the
most inexplicable, but so it is.
In order to see clearly wherein the
mystery consists, let US first consider
what gravitation appears to be. 1t is
gravitation that gives the property Of
weight to all bodies II there were no
gravitation we could float like thistle
downs and infinitely better than this
tledowns, for they, too, are finally
brought down by gravitation.
1t is gravitation that brings a can
non ball eventually to the earth, no
matter how swiftly it may be project
ed. The faster it starts the farther it
will go, but during every second of its
fight it drops the same distance YER
tically toward the earth, whether the
speed impaired to it by the powder is
500 or 5000 feet per second. Gravita-
ton acts on moving body exactly as
we'll as on one at rest.
p It is gravitation that curbs the mo-
ton Of the moon and keeps it in an
orbit Of which the earth is the active
focus
So, too. it is gravitation that gov
ems the earth in it's motion around the
sun. preventing it from flying away
into boundless space. Astronomy shows
that gravitation acts between all the
plants and all the stars and controls
their motions with respect to one an
other.
Now, this mysterious force appears to
be an attraction, as if there were elias
tic cords connecting all the bodies in
space and tending to draw them to-
gether. But space, as far as our senses
can detect, is empty. There are no
elastic cords and no physical connec-
tons whatever between astronomical
bodies or between a flying stone or
cannon ball and the earth. How, then,
can there be an attraction: In order
that body may be attracted or drawn
there must be something to draw it.
Gravitation does the trick. but CON-
pletely hides from us the mechanism
through which it acts. We can discov-
er no mechanism at ALL
When an unfortunate aeroplanist
drops from his machine at height OF
thousand feet he begins at once to
fall toward the earth as if it were pull
ing him. But how can it pull if it
has nothing to pull with? You may
think at first sight that it is the air
which acts as an intermediary, but
that is not so. because the earth and
the moon "pull' upon one another with
force equal to the strength of steel
cable 500 miles in diameter But there
is no air and no other tangible thing in
the open space. 100000 miles across.
that gaps between the moon and the
earth.
Then. gravitation exerts the same
force at every instant. No matter how
fast the falling aeronaut may be de-
scending at any moment. gravitatiOn
will keep on adding speed as if he had
just started. Designating the slight
retardation produced by the resistance
of the air. he will fall sixteen feet in
the first second. forty-eight feet in the
second second. eighty feet in the third
second. gaining thirtytwo feet in his
velocity during every second after the
first.
From a height of 1000 feet he will
come down in about eight seconds. and
will strike the ground with velocity
Of about 256 feet per second. From 8
height of 10000 feet he would fall in
about twenty-five seconds and would
strike with velocity of 400 feet per
second.
The same kind of calculation can
be applied to the gravitation between
the earth and the moon. If the moon
were not in motion across the direc-
ton of the earth's ''pull' it would fall
to the earth in about 116 hours
Now, to return to the mystery. how
is this force exerted? Is it really
pull as it seems. to be? The answer
to which science is tending is that in
stead Of being pull, gravitation is
push; in other words, that the falling
aeronaut is pushed toward the ground
and the moon is pushed toward the
earth.
On the face of it one might think
that nothing was gained by this
theory. because it seems as impossible
that push should be exerted without
tangible connection as a pull. But
the clew Is found in the supposed prop
critics of that invisible. intangible. all
pervading medium called the ether.
This, to be sure. is explaining. one
mystery by another, for we know
nothing about the ether except that
it conveys the waves Of light and cleo
tricity: but. at any rate. it affords
conceivable explanation of gravitation,