The Jasper weekly courier. [volume] (Jasper, Ind.) 1858-1922, 1917-03-16
DISTANCE OF THE STARS.


OF measuring TX.
With the exception of hundred
vtArs at most, we know nothing of
The distances of the individual stars.
What Is the cause of this state of
things? 1t is owing to the fact that
we have two eyes that We are en-
sbled not only to perceive the di-
rection in which external objects
are Situated, but to get an idea of
their distance, to localize them in
space. But this power is rather linn
tied. For distances exceeding some
hundreds of yards it utterly fails.
The reason is that the distance be-
tween the eyes as compared with
the distance to be evaluated be-
comes too small. instruments have
been devised by which the distance
between the eyes is, as it were, arti-
nahIy increased. With a good in
stcrment of this, sort distances Of
several miles may be eva.uated. For
still greater distances we may inn
agins each eye replaced by photo
graphic plate. Even this would be
quite sufficient for one of the heay-
emily bodies-viz, for the moon.
At one and the same moment Jet
a photograph of the moon and the
surrounding stars be taken both at
the Cape observatory and at the
Royal observatory at Greenwich.
Placing the two photographs side by
side in the stereoscope, we shall
clearly see TIE moon changing in
space" ard may evaluate its dis
tapce.
But for The sun and the nearest
planets, our next neighbors in tho
universe alter the moon, the diff
Guilty recommenccs.
The rea son is that any available
distance on the earth, taken az eve
distance, is rather small for the
purpose. However, owing to in
credible pre- GRANGE and skill Of
several ob-4ryers and by substi.u 1T
Ing t. INST refined measurement
for stereoscopic examination, as
tronoraeIs hare succeeded IN over
coming the difficulty for the sun. l
think We may say that at present
we know its distance TO within q
thousandth part of its amount.
Knowing the suns distance, we get
that Of all the planets by a well
known relation existing between the
planetary 3srlnces.
But no for the fixed stars,
which must be hundreds of thou
sands o. times farther removed than
the sun. There evic antly can be no
question of any sufficient eve dis
tance on our earth. Meanwhile our
success with the sun has provided
Us with new one distance, $4,000
times greater than any possible eve
distance on the earth, for now that
We know the distance at which the
earth travels in its orbit around the
sun we can take the diameter of its
orbit as our eve distance. Photo
graphs taken at periods six months
apart will represent the stellar
world as seen from points the dis
tance between which Is already best
expressed in the time it would take
light to traverse it. The time would
be about sixteen minutes.
However, even this distance, i'm
mense as it is, IS on the whole, IN
adequate for obtaining a stereo-
scopic view of the stars. It is only
b quite exceptional ca that pho
tographs on a large scale-that is,
obtained by the aid Of big tele-
scopes-show any stereoscopic ef-
feet for fixed stars. By accurate
measurement of the photos we may
perhaps get somewhat bevond what
We can attain by simple ste. eoscopia
Inspection; but. a. we sa;d no.
ment ago, astronomers have not sue
ceeded i'm this wav in dc'erninips
the distane Of more than a hun
Tdred stars N All alI--Sc,entlIc AmcTis