Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-08-03
Novel Plan DEVISED to Measure the
Milky Way
WITH THE ORBIT Of TWIN STARS
The Idea of a Famous Local
Astronomer.
WOULD TAKE MANY YEARS

millions of suns encircling the solar sys-
tem--has just been devised by Dr. T. J. J.
See, astronomer of the naval observatory.
Such an enterprise has hitherto been ut
terly beyond the hope or anticipation of
science. The mind cannot conceive Of
measuring feat more tremendous. unless 1t
be the stalking OF Of the boundaries Of the
very universe itself. Yesterday 1 asked
DR.. See to describe his methods for this
stupendous undertaking, in such words as
any layman might readily comprehend.
Heretofore said he. ''the distance be-
tween the earth and sun has been accepted
as the yardstick with which. to measure
how far away the stars are from us. Now
this yardstick becomes too small for accu-
rate measurement when these distances
become immense. The prospects are that
1t will never grow larger. because the
earths orbit does not seem to be changing
When the stars reach beyond 3,50O,0OO
times the distance of the sun II becomes
impossible to use even this great unit Of
measurement with any telescope Of the
world. A luminous rod long enough to
reach from here to the sun, and, therefore,
81, SOC, 600 miles from point to point, If
poised III the heavens at the above dis
tance would look in the greatest tele-
scope just as long as one of your hairs
placed $50 feet distant would appear wide.
Orbits of Distant SIMS to BE Used.
Il propose to substitute a measuring rod,
which can be seen as far off as the stars
themselves are visible. This will be the orbit
or path of one Of the twin stars of the Milky
Way itself. II the orbit of this double
star is sufficiently big to be seen In our
telescopes and If the motion Of the star on
this orbit is sufficiently rapid to be detect
ed by the shifting lines which it causes
in our spectroscopes. it will become pos
sible to measure it's distance. Having
learned how big the stars orbit appears it
will be easy matter to figure out how
far away the star itself is.
I'VE will first observe with our great
telescopes the revolution of one of these
double suns. We will next attack spectre
scopes to our telescopes and observe it's
motion toward or from the earth. The tele-
scope alone. you understand. would give
only the apparent path. If 1T were direct
ed at an orbit turned exactly edgewise to
the earth it would show the star simply
moving up and down or back and forth
along straight line. Thus the spectre
scope gives the material for determining
how large the orbit Is. The Spectroscope
would give it in miles or kilometers. We
would use this distance as a base line. Hav-
ing thus measured the distance of certain
stars composing its fabric it will be pos
sible to measure the great arch of the
THE spectroscope takes the light from
any star, throws il through a prism and
places it upon screen in the form of
rainbow band. If the star contains iron.
magnesium. sodium, carbon, hydrogen, etc,
these elements will appear in this rainbow
band as lines, in the yellow, green or red
parts as the case may be. The astrono-
ner takes iron, magnesium, ETC., into his
laboratory, and by means of a powerful
electric arc he produces from them an
other rainbow band which shows their con-
dition while at rest on earth. By ccmpar-
ing the band from the star and that from
the elements Of the laboratory he can tell
whether the star is moving toward or from
the earth. With the spectroscope you can
thus penetrate as deep into the heavens as
you can see the orbits OF the stars in mo-
ton.
Fifty QuadrilliOns Miles Back.
Il estimate that the nearer portion Of
the general body of the Milky Way is
something over 5000 900 600 600 900 miles
from US and it requires the light about a
thousand years TO travel from this part
to our eyes. II we can imagine that this
nearest portion is inhabited and that it's
people have telescopes looking down upon
us, they would view the earth as it APP
peared about the time of the death of AL
fred the Great / estimate that the farth-
est portions of the Milky Way are about
ten times as far, or more than 50,oO0,0O0,-
OOO,O0UOoO miles from and that il there
are eyes there capable OF seeing our world,
it appears to them as it was 10000 years
ago, or before the beginning Of human his
tory. . =
LAS the Milky Way is now known to as
tronomers it Is composed of about LOG,
600 stars. 1t is an endless band, deep not
Nat, the brighter portion running from the
constellation Of the Swan. through the
Lyre. Eagle, Scorpion and Sag4ttarius, in
the south. where Jupiter and Saturn now
appear. l am speaking Of what we
see these summer nights, when the moon
Is set. But IN winter, when the sun has
-to rr6ul f.vp y.,,-
It's other side. we will see the other side Of
the heavens at night. = L E.se
These 1O0,O00,0O0 stars of the Milky Way
are mostly gigantic suns. The distance be-
tween them is of the same order of mag
nitude as that which separates us from
the star Alpha Centauri, removed from us
215,oO times farther than our sun. They
are not all single stars, but are occasion
ally composed of two associated stars, very
close together and revolving under the law
or gray1tation. In other words. they are
held together by mutual attraction.
AS all stars are self-iuninous suns,
these systems are gigantic double suns,
moving about one another somewhat as
the moon reyoiyes about the earth. Both
move about the common center of gravity,
an invisible point between them where,
theoretically. body would be suspended
In space. without falling upon one or the
other. -.
Ten Thousnnd Twin Stars Discovered.
discovered UP to date Only forty or fifty
Of their orbits have been accurately COM
puted Some Of them move about on their
orbits once in ten years. One OF the com
ponent stars Of Epsilon sLyrae seems to
complete its circuit oily once In SOC years.
In about forty the two csmponents are so
close together that they, cannot be sepa-.
rated by any telescope on earth. But the
spectroscOpe reveals That they are double
by certain displa cements.1tn the lines on
the band which ] described. These lines
show that there must bei In these single
points OF light stars going from us and
toward US at the same time. Prof. Camp
bell OF the Lick obsef1 atory. California.
has. with the spectroscope. recently dis
covered thirty-fOur but Nof forty double
stars invisible through the telescope. In
examining the motions of the spectral lines
OF $50 stars scattered promiscu0nsiy
throughout the heayehs he found that the
spectroscope revealed one out OF nine to-
be double. All telesc8pess Of the world had
revealed these as single stars
This unexpected discovery has opened
to astronomers an iGnmshse field for flu
ture exploration. 1t 'fs the most important
contribution to astronomy In the past
quarter century. It's importance consists
In showing us that those double stars
which We see with our telescopes are not
All which exist In fact, we can conclude
from Prof. Campbeil's work that one-ninth
or possibly one-sixth. as he thinks. OF ali
stars are double. There has lately been
deyised method OF proving beyond q