Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1919-09-04
Scientific Discussions
by Garrett P. Serviss


>ater iE order to enjoy Shakespeare.
SssSs~ag in his room, with the book in
his hand, he is independent of the
L>stor and the stage manager. This
EAme elemental power ,oI the imagina-
ton frees the mind from the limita-
tons of time, also. knowledge of his
tory would be impossible without it.
One reason why historians disagree
so much is because of the immense
share that imagination necessarily has
in their work. They can describe only
That they mentally visualize, but
Il =ntal as well as physical sight varies
Nth persons. If as lawyers know, two
,sctual witnesses of the same occur
renee never see it exactly alike, now
could we expect two persons to form
an imaginary picture Of an unwit-
messed scene or event in exactly the
same way?
However this is aside from what
l set out to write. The imagination
being free of time limitations and OF
space limitations likewise, we can
wander wherever we will in the uni
verse, and relieve its whole life, as tar
as we can get clues. We can, not only
go back through geological ages, and.
piecing together the bits of evidence
which the rocks afford, reconstruct the
most dramatically interesting scenes
which occurred on this earth millions
of years ago. but with the hints de-
rived from another line of evidence,
we can follow the earth in its amaZ-
ing adventures as chaser of the sun
we are carried 400,000,000 miles
per year toward the region where now
shines the star Vega, in the northern
sky. As far as measurements show
this motion of the earth, disregardlng
it's annual spiralling around the SUM-
which is merely an incident, follows
straight line IN space. PROBABLY the
real path is a very long curve, nut
for the present let us regard it as
straight.
Four hundred million miles seems
q vast distance. 1t is about -FOUR
and a third times the width of the
space between the earth and the sun.
Eut compared with remotcness of even
the nearest stars it is so slight that
10 ordinary observation this amount OF
change in the position of the earth
has no effect upon the apparent posi-
tions of those stars.
When we reckon star distances in
miles we have to use trillons instead
Of millions. "A trillion being million
millions. Thus Alpha Centauri is
about twenty-five trillion miles away
and Sirius about fifty trillions Vega
is probably two hundred trillion
miles distant Yet magnify the time
units enough and very different as
pect is put upon the matter. Thus,
while the 400 million miles traNcieu
northward by the earth in a year IS
not enough TO make any nouceapIe
difference in the brightness OF vega
during human lifetime or even IN
Il thousand years, yet II we use geo
logical time intervals an TINS -
changed
In million years the earth Will
travel twice as far as the distance
now separating it from the star vega
Then, if we disregard It's own move
mcnts in the meantime vega VIII "P-
pear to the inhahIta'ts OF the eart.'
IN the southern instead OF the north-
Urn sky, and the entire aspect OF the
starry heavens Will have heeh com
pletely changed. Not constellation
will be left rs it appears to-day
Now, in its past history the earth'
as member o. the sonar system
has traNersed even greater distances
than this. y moderate estimate OIL
the time elapsed since the first recoS'
ni2able stratitied rocks We're laid down
is 5O,0OO,oOO years. Multiply that by
41O.Uo0,0OO and you get 2O,uoo trilI!ons
o. miles as the distance travelled by
the earth since. let us say, the be-
ginning or the Siurlan period 4hat
amounts to about a thousand parsecs
tthe parsec is the Astronomical unit
OF the star distance measurement
and falls somewhat below moderate eS-
Inmates of the distance OF the nearer
party OF the MILKY way. 10 cross
the entire width OF the central space
within the Milky way the sonar sES-