Okolona messenger. (Okolona, Miss.) 1900-current, 1903-12-30

subject in general way, is that the sun, with the
earth and his other planets, is flying through the
universe, from point in the South toward point
in the North, with speed OF about SOO'OOO'OOO
miles per year.
The object now is to ascertain as nearly as posi-
BILE the exact situation of the point toward which
we are moving, and the exact velOeit Of our fight.
The ultimate fate OF our globe may be involved in
this and at any rate it is an inquiry Of immense in
tellectual interest
That the spectrOscope (whose business is simply
to aAalyze light and spread out it's component cOOrs
at I'll e same time revealing certain significant gaps
betWeenst the light waves which apper as black
linesi thOslOred band Of the spectrum) should be
able to tell MS anything about the motion Of the
earth seems at first sight uttCrly incredible. Indeed
the fact is one Of the most surprising known tC
science.
Yet, thesmannerA In which the ssactrOscope does
this is really very simple.
When the light of a star is passed through a spec
troscope it is spread out into 3 coOred band, in
which the red waves at one end and theN violet
waves at the other end, while the orange, yellow,
green blue and indigo waves are arranged in regu
lar order between Them. The reason these cOlOrs
thus separated is because the waves OF light belong
ing to them vary in length aud in quickness OF vi.
bratiOn. The red waves are the longest and slow.
est the violet waves are the shortest aud the quick
est In passing through the spectrOScOpe the long
slow waves are less deViated from straight course
consequence is that after they have ali passed they
appear arranged in a each color standing by it.
self, bat gradu lily blending at its border into it,
next neighbOr.
In addition to the cOlOrs, as already remarked
the spectrOscope shows certain gaps in the array
light waves which appear as thin black lines in tbs
spectrum. These lines serve landmarks to de
termine the exact position In the spectrum Of par
tcular wave lengths Of light
Nov, starting with these facts let us try to SCI
what the speCtrOscOpe can tell about the motion o
the earth. Suppose we begin With a star that liei
directly ahead Of u.s. that is to y right in the patti
which the earth is pursuing. Evidently that stal
will be drawing nearer, and the effect must be x
cause the waves Of light that come from it to enter
our eyes more rapidly than they would otherwise
do. They are, so to speak, crowded together il
consequence Of the 1rth's motion toward them, anC
the speetrOscOpe shows the result Of this CrOwdine
by shifting Of the black lines toward the violet, O
short and quick wave end Of the spectrum. By ths
amount Of shifting we can calculate the speed with
which the earth and star are approaching one en-
other.
Then, take e star which lies bshind the earth ID
its path. Evidently the light waves from the star
because we are flying away from them, viii not en-
ter oar eyes as rapidly as they would otherwise
DO. Tney viii be drawn out longer, and vill seen
to vibrate slower and again the speCtrOsc0pe shows
the consequence BY shifting Of tie black lines 10
ward the red, I. O., the long and slow wave end o.
the speCtrumsyE
Finally, take q star which lies on to the side o.
the earth's path. Evidently as We speed along w
are neither approaching receedng iron that stal
Cat least not drecty) and The result is hat its light
waves are not interierred with either In their lengt
or the apidIty Of ther arrival ct eyes, and ths
spectrOscOpe shows that the lines on the spectrum
Of such star ere not changed ct all In position