The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1933-08-05
-Dietz on Science
EXPANSION OF
UNIVERSE HELD
IN LIMELICHT
One Astronomer Advances
More Cheering Theory
That Crash Is Remote.
BY DAVID DIETZ
Scripps- Howard Science Editor

the astronomical world during the
last year has been the expanding
universe. According TO Eddington
and Jeans. the universe is expanding
Ike a gigantic soap-bubble. The
structure. however. is more compl-
Gated than that of a soap-bubble.
II is not a sphere but what Edding-
ton calls a four dimenSional hyper
sphere"
There is not much use trying to
make picture Of a four dimen-
sional hypersphere, although Ed
dington says that by trying hard he
can get a faint mental picture Of
four dimensions.
According 10 Lemaitre, the ex-
panding universe which we see
around lis is the flying debris OF a
prlmeval explosion that took place
cons ago. Before that explosion. all
the matter Of the universe was con-
centrated in one gigantic, universal
atom.
Still another model Of the uni
verse is given by Tolman. He ar
rived at his by mixing the theory OF
relatively with the laws Of thermo-
dynamics and shaking the mixture
well.
The result is no exploded universe
doomed 10 expand until its energy
mas been completely dissipated. but
a universe which expands and con-
tracts like an accordion. There IL
more optimism in Tomans celestial
accordion. It plays notes of hope.
reassuring us that the doom in
herent in Eddington's four-dimen-
sional soap-bubble may not neces-
sarily be so.
Discover Red Shift
But while discussions OF the ex-
panding universe hold the center of
the stage, most of the work going
on now in astronomical observa-
tories Is concerned with much less
I ambitious fields. Even the Mt.
wilson Observatory, whose studies
OF the very distant spiral nebulae
have furnished most of the obserya-
tional proof needed for theories of
the expanding universe. is con-
cerned also with problems closer at
home.
DR.. Edwin P. Hubble and DR.. Mil
ton c. HumaSon have collected most
OF the evidence for the theory Of the
expanding universe, using a power
iul spectroScope in conjunction with
the lO0-inch telescope, the worlds
largest telescope. What they dis
4 covered was the famous red shift"
IN the spectrum of these nebulae.
which the theorists interpret TO
mean that the universe is expand
ing.
But DR.. Walter S. Adams. director
Of the observatory, has also been at
| taching a powerful Spectrograph to
the big telescope and turning it on
objects right in our own astronom-
ical back yard. studying the earths
brothers and sisters, the other PLAN
cts in the solar system.
Doubtful of Life on Mars
This work has led DR.. Adams to
the conclusion that there is much
less possibility of life on the planet
Mars than astronomers have been
inclined to think there was.
Another important task carried
out under DR.. Adams direction
has been the determination OF the
spectroscopic absolute magnitudes"
OF 1000 stars. This study is Of the
utmost value since it enables us TO
say with considerable accuracy the
distances of those 1000 stars from
the earth and so gives us additional
insight into the structure OF our
Milky Way or galaxy.
The distance of the nearer stars
can be measured by trigonometric
methods. The astronomer notes the
shift Of the nearer star against the
background Of distant stars.
This shift, due to the movement
OF the earth around the sun, is so
extremely small for even the near
est stars that 1t can be detected In
their case only with the most pre-
else instruments by the most skill
full observers.
Measure Stars Brightness
In 1914 DR.. Adams showed that
the spectrum Of star was a clew
to its absolute magnitude or true
brightness. More exactly, he showed
that the strength or weakness of
certain lines in the spectrum were
clew to the stars intrinsic bright
ness.
Now the apparent brightness OF a
star can be measured easily. There
fore, if We know, by Adams meth
cd, the true brightness, we can then
calculate its distance from a very
simple formula.
The method. when tried out on
the nearer stars. checked with the
distances obtained by trigonometric
/ measurements. and 50 astronomers
have felt safe in extending 1t 10 the
more distant stars. And as previous
" mentioned, DR.. Adams has lust
completed such measurements for
1000 stars.
The trigonometric method works
well only with stars within a radius
Of $50 light years A light year is
six trillion miles.
The dominion astrophysical OBJ
servatory in Canada has also been
engaged in determining the absolute
spectroscopic magnitude Of stars
with the result that today we have
more distances determined by the
spectroscopic method than by the
/ trigonometric one.