Evening star., 1933-07-13
.C0SM|C RAY VIEWS
VARY AS TO ORIGIN
Important to Know Whether
Phenomena Are Photons
or Light Waves.
BY DIR. ARTHUR H. COMPTON,
Professor OF Physics at the University o
Chicago and 1927 Nobel Prize
Winner for Physics.

BY DIX. ARTHUR II. COMfI fION,
ProtessSr Of Physics at he a,.Y Ynsys5siy OF
Winner for Physics.
CHICAGO, July l3 (N.AN.A).-The
various views relative to the origin OF
the cosmic rays are based upon differ
ent presumptions regarding their ma
ture. Prof. Millikan interprets the cos
mic rays as resulting from the forma-
ton of heavy atoms in interstellar
space. assuming that the rays are pho
tons, or light waves.
DR.. Swami supposes they are high
speed electrons shot out from sun spots
and from similar disturbances on the
hotter stars Able Lemaitre believes that
the whole universe as we now know II
was started by q gigantic prlmeval eX-
plosion. which blew out into space not
only the stars and galaxies which we
gee about us. but also atoms and cleo
irons and photons and other minute
subatomic corpusclcs come OF which
after flying through space for billions
of wears. strike the earth as cosmic
rays
In order to select which, If any, OF
these views of the origin Of the rays
is correct, it Is important to know wnat
the rays are: Photons or light waves,
as Millikan says; electrons, with swami;
or a mixture of the various KINDS OF
rays, as Lemaitre supposes.
Information Source.
One source of information on TINS
point is measurements Of the rate OF
| increase of the strength OF the cosmlc
rays with altitude. If the rays are
irh 10
! the air in the ionization chamber should
reach a. maximum at about 10 miles
high. and then decrease for still higher
attitudes.
If the rays are electrons, the intensity
should continue to increase all the way
| to the top of the atmosphere. Actually
sounding balloon carrying lightly built
servers, can reach attitudes much
greater than those which will be at
tanned in the Picard flight from
Soldiers Field this month. The ngnt
recording instruments which these BAL
| looms carry are, however. much less pre-
else in the results they give than are
| the larger ioniZation chambers such as
will be carried in our gondola. .
Last Summer, DR.. Erich Regener OF
Germany made a record flight with a
sounding balloon carrying lightly-bullt
cosmic ray chamber, without an OBJ
f, server. to the unprecedented height OF
| II miles. On cur flight we should be
able to check with much greater pre-
| cision than he could attain the cosmic
ray intensities as high as 10 miles or
more. If our results agree with his
up to that altitude, 1t will give greater
confidence in the values obtained In
sounding balloons at still higher levels.
In another experiment we shall use
6Hy
q hundred pounds of lead dust. BY
comparing the cosmic rays recorded by
this meter with those measured by the
unshielded meter, we shall get valuable
information about the wav in which
these rays are absorbed. This will give
additional evidence regarding whether
the rays are electrons or photons. After
these measurements have been COM
pleted, the lead dust will be poured
out as ballast.
Directions Studied.
In a third experiment We shall OBJ
serve the direction in which the rays
are coming into the earth'S atmosphere.
| For this purpose we use an instrument
very similar to that which is on per-
| manent exhibit in the General Motors
Building at the Century of Progress. It
, consists of pair Of small tubes, inside
which are wires of high voltage.
If a cosmic ray passes through the
| tube it makes tiny spark jump across
the tube This spark is amplifled and
operates recording mechanism. This
device is so arranged that a record will
be made only if the ray goes simul-
i taneously through both tubes This
makes it possible to tell what direction
the rays come from.
1t is found that at sea level the rays
come much more strongly from straight
above than horizontally. Prof. Pic
cards observations last Summer, how
ever. indicated about equal intensities
in all directions at height of 10 miles
Using the more refined technique re-
sulting from his experience, We hope
to be able to tell whether there may be