Evangeline I shall not miss
Though we wander the dim starry sheen,
On opposite sides of rivers so vast
That islands of worlds intervene.
But what is there in space? There is the great ceaseless force of
gravitation. Though the weakest of natural forces, yet when displayed
in world-masses its might is measureless by man's arithmetic. Tie an
apple or a stone to one end of a string, and taking the other end whirl
it around your finger, noting its pull. That depends on the weight of
the whirling ball, the length of the string, and the swiftness of the
whirl. The stone let loose from David's finger flies crashing into the
head of Goliath. But suppose the stone is eight thousand miles in
diameter, the string ninety-two million five hundred thousand miles
long, and the swiftness one thousand miles a minute, what needs be the
tensile strength of the string? If we covered the whole side of the
earth next the sun, from pole to pole and from side to side, with steel
wires attaching the earth to the sun, thus representing the tension of
gravitation, the wires would need to be so many that a mouse could not
run around among them.
There swings the moon above us. Its best service is not its light,
though lovers prize that highly. Its gravitative work is its best. It
lifts the sea and pours it into every river and fiord of the coast.
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