The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1929-09-07
SCIENCE
by DAVID DIETZ-
scripps- Howard Science Editor
These Perfect RGinbo1Cs,'
Whose Scientific Name Is
Spectra, Reveal the Secrets
of the UniUerse to Us.

Scripps- Howard Science Editor
NEW discoveries made with the
/ y aid of the spectroscope occu-
pied much of the time of the ses-
sions here last week of the Ameri-
can Astronomical Society. For the
spectroscope is a child's toy which
has graduated into the worlds
greatest detective.
Every child has played with a
little glass prism and been amused
by its ability to split sunlight into
tiny rainbow of colors. That abil-
ity of the prism has made 1t one OF
the most useful objects in the world.
The spectroscope is just a series
of prisms combined with a telescope
to form very perfect rainbows. If
you prefer you may call them by
their scientific name, which is
spectra
These spectra give away the Sc
cretS of the universe. From them
the astronomer can tell what a star
is made Of, what its temperature is,
conditions in the star such as pres
sure and electrical state, whether
the star is moving toward the earth
or away from it, and how fast, and
many other important facts.
1t gives us even more detailed
information about our own sun and
in addition. is useful in studying
other problems.
Has the planet Mars an atmos-
ptere? What are comets tails made
of? We must turn to the spectre
scope for the answer to these and
many other mysteries.
n
XXTHEN a rainbow or spectrum is
w formed very carefully with the
aid of a spectroscope, it is found to
be crossed with a whole series Of
little black lines.
These little black lines tell the
secrets.
If we go into the physical labora-
tory and place little sodium in a
gas fame and then examine the
light with a spectroscope, we always
find a certain combination of lines
in the spectrum.
Consequently, when we find this
same combination in the spectrum
of the sun or a star, we know sodium
is present. Other combinations of
lines are the signatures" of hydro
gen. iron, copper, oxygen, and so on.
Moreover, these lines change with
temperature, pressure, electrical
condition and other factors. AS a
result, they tell us about all these
things in distant star or the sun.
An interesting bit of scientific his
tory is the story of helium, now used
in place of hydrogen in ZeppelinS
because it is non-eXplosive.
Sir Norman Lockyer, British
scientist, first discovered a combina-
ton of lines III the spectrum of the
sun for which no equivalent could
be found on earth.
He named the unknown element
helium, from the Greek nameyof the
sun-god
Subsequently, another British SCI
enlist discovered slight traces Of
heliun in our atmosphere. Within
the last few years, large amounts of
! the gas have been found in Texas
gas wells and it now possesses great
Importance for the airship industry.
n
LONE of the most important uses
~ OF the spectroscope is it's ability
to measure motion. This is lead
ing to important knowledge of the
movements Of the stars, and in time
may throw important light on the
structure and origin of the galaxy Of
stars.
In time, it even may help solve the
problem of the size and nature Of
| the whole universe.
Every one has noticed that when
a railroad train is approaching, the
sound of the whistle seems to be
rising. This is because the APP
proach of the train crowds the sound
waves upon each other.
Consequently more of them reach
our ears to the second than would
otherwise, and the pitch of the
whistle seems to go up.
When the train is receding from
us, just the opposite happens. FeWer
sound waves reach our ears to the
s~cond and the pitch Of the whistle
drops.
| The same thing is true Of stars.
When a star is approaching us, more
light waves to the second reach us
than should. AS a result Of this, the
lines in the spectrum are displaced
toward the violet end Of the spec
trum.
When the star is going in the OPP
posite direction, the lines are dis
placed toward the red end The
speed of a star can be calculated
from the amount of displacement.
In time, it is hoped that statistical
studies Of star motions will yield
important facts upon which a better
knowledge Of the structure of the
universe can be based.