The Jasper weekly courier. [volume] (Jasper, Ind.) 1858-1922, 1910-04-08
DISTANCE or The STARS.
How Astronomers Set About the Tss.
Of Measuring Il.

TO" astronomers set About the Tss-
OF Measuring II.
With the exception of a hundred
stars at most, we know nothing OF
the distances Of the individual stars.
What i the cause of this state Of
things? 1t is owing 10 the fact that
We have two ewes that we are en-
abled not only 10 perceive the d.
rectlon IN which external objects
are situated, but to get an idea of
their distance. 10 localize them in
space. But this power is rather linn
tied. For distances exceeding some
hundreds Of yards il utterly fails.
The reason is that the distance be-
tween the eyes as compared with
the distance TO be eyaluated be-
comes too small. Instruments have
been devised by which the distance
between the eyes is, as il were. arti-
fcially increased. With a good in
strument of this sort distances OF
several miles may be evaluated. For
still greater distances we NAV inn
agine each eye replaced BY photo
graphic plate. Even this would be
quite sufficient for one of the heav-
enly bodies-viz, for the moon.
At one and the same moment let
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 the moon hanging in
space" and may eyaluate its dis
lance.
But for the sun and the nearest
planets, our neN neighbors in the
universe alter the moon, the diff
Guilty recommences.
The reason Is that any available
distance on the earth, taken as eve
distance. j rather small for the
purpose. However, owing to in
perseverance and skill of
several observers and by substitut-
nc the most refined measurement
Tor stereosSQp-e examination, as
ronomefssfifse succeeded in over
.oming the difficulty for the sun.
hink We may say that at present |
re know its distance 10 within a
hou.andth part Of its amount.
Knowing the suns distance, we get .
hat Of all the planets by a well
nown relation existing between the
lsaetary distances.
But now for the fixed stars.
hich must be hundreds of thou
lnds Of times farther removed than
le sun. There evidently can be no
1estion of any sufficient eve dis
lnce on our earth. Meanwhile our
lccess with the sun has provided
; with rev one distance. $1,000
mes greater than any possible eve
stance on the earth, for now that
e know the distance at which the
nth travels in its orbit around the
IN We can take the diameter Of its
bit as our eye distance. Photo
apis taken at period. six months
art Will represent the stellar
orld as seen from points the dis
nee BETWEEN which is already best
pressed in the time it would take :
,ht TO traverse it. The time would
about sixteen minutes.
However, even this distance. i'm 4
anse as ii is, is, on the whole. in
eqHste for obtaining a stereo-
'pic view Of the stars. 1t is only
quite exceptional cases that pho
graphs on a large' scale-that is,
tanned by the aid Of big tele-
'pes-show any stereoscopic ef-
t for fixed stars. BY accurate
'asurement of the photos we may
rhaps get somewhat beyond what \
can attain by simple stereoscopic
pection; but, as we said a mo-
mt ago, astronomers have not sue
,ded IN this way in determining
, distance of more than a hun
a starsTin all.-Scientiic Ameri-