Staunton vindicator. [volume] (Staunton, Va.) 1860-1896, 1891-05-08
THE VELOCITY OF LIGHT.

Speed That Is Too Great for the Average
Mind to Fully Comprehend.
Ii you could take all the people in the
world and set them cut in space mile
apart like mile posts along railroad, and
then at the farther end use all the dogs and
cats to extend the line of mile posts, you
would run far short of material to mark
the distance out to the earth's brother
planet, Neptune. Again, if you could use
all this material of men, women, children,
dogs and cats, and put them out SO that
they would be as far from one another as
Boston is from San Francisco, your line
wouldn't be half long enough to reach to
the nearest star.
On a clear night the average eye will
readily see stars as low as the sixth nagni-
tude Such shining beauty as Sirius
winks at you so archly that it seems al
most impossible that years are consumed
in the passage of its rays to the earth,
when we remember that light travels more
than 10000 miles in second Yes, if the
nearest of the beautiful twinklers should
be blotted out at this moment we should
still see it without the slightest change in
appearance two or three years after Chi
cago cleans up the debris of the Worlds
fair
DQU Ch Gil IL oUdI 81 away fto oliou EUCLID
nearly within touching distance when we
find that other stars, visible with the telc-
scope, are SO far away that, for all we
know, they may have been blotted out be
fore Cain and Abel were born. That is to
say, if one of those far distant orbs had
been utterly annihilated, as you would
snuff out a candle, when Adam and Eve
were enjoying themselves in the Garden of
ba rox- then cfaptinO toward tho
earth, notwithstanding the awful speed of
light, could not get here in time to meet
the closing of the Nineteenth century.
How do we know that light travels at
such wonderful speed? Up to about two
hundred and twenty-five years ago it was
supposed that rays of light from all the
celestial orbs passed instantly to the OBJ
servers eve. The old astronomers, in fact
never took thought of the matter at all.
They simply saw the sun and the stars,
but they never dreamed that the rays from
them had to journey millions, billions and
trillions of miles in getting to mundane
eyes 1t was the great fortune OF Danish
| astronomer to make the discovery that
| light, as well as sound or railway train,
requires given time to travel given dis
| lance
Roemer, the famous Dane alluded to,
was led to his discovery by observations OF
the eclipses Of Jupiters moons. He found
that there was difference of several min
utes in these eclipses, that they occurred
earlier when the earth was on the side of
the sun nearest to Jupiter and later when
| farthest away With this data as a start
/, ing point he soon found that the differ
| ence of apparent time resulted from the
| time required for light to travel across the
diameter of the earth's orbit, about one
hundred and eighty-two million miles.
This time proved to be about sixteen min
utes, and as half that would be the time
| from the earth to the sun the mystery was
solved.
The accuracy of this calculation has since
been verified by other methods, and all
authorities now agree that the velocity OF
light is not far from 1876, 600 miles second
It is difficult for the mind to grasp and
comprehend such speed. The swiftest ami
mated thing is undoubtedly the pigeon
which has been known to travel hundreds
of miles at the rate of fifty miles an hour
A little arithmetical exercise will show
that it would take a pigeon more than 2O(
years to cover the distance to the sun al
fifty miles an hour without stop, and tt
60 as far as Neptune it would take The
bird nearly thousand years.
When we want an illustration of speed
we often use the expression "swift as ;
cannon ball" But if you could fire can
non ball to the sun when you are colieg
freshman your hair would be sprinklet
with gray when the ball stopped, for yol
would be seventeen years older than whel
you fired the shot.-Philadelph Times.