Omaha daily bee., 1912-10-20
is THE sun GETTING COLD?

Ii The Sun GETIlNG WLDi
Astronomers Striving to Solve the
Important Solar Problems.
PREPARATIONS FOR THE TEST
Instruments to Determine Heat
Radiation and the Size of Old
sOI-Explanations of
Experts.
With two instruments by means of
which scientists hope to take astronom-
ical observations with greater accuracy
than has yet been possible, preparations
are being made in southern California
to discover whether or not the sun is get
ting cold. A new forty-foot vertical tele-
scope is being erected on top of the
Smithsonian Institutions observatory
Oh Mount Wilson, and through it as
tronomers will seek to find out whether
A'ShV hoFo DCch ally hppl l6CidDi6 u6CTedS6
in the size of the sun. And a new
thermometric instrument, more finely
constructed than any in present use
will be called into service to measure
the suns actual heat, Both these pro-
cesses are needed in ascertaining
Although the possible cooling Of the
sun is question in which scientists
are greatly interested, astronomers are
quick to explain that their inquiries
have no practical significance what
ever The sun may be cooling off, it
may be getting smaller, it may have
| solidified at the center, it may be
throwing off great deal less heat
than any previous records have shown
But all this can make no possible diff
ference to the earth and its inhabit-
ants; 1t cannot execise the slightest in
fluence upon our climatic conditions;
we shall continue to live through
scorching summers and summers of
rain, and scorching summers again till
| geologic ages have come and gone. And
probably, in the course of 9008O00 or
100000 years, the sun will have become
quite cool and dead, and the earth will
grow frigid too.
The whole thing Is merely in the
| line Of scientific investigation" said Dr.
Jacoby Rutherfurd, professor of astron-
omy at Columbia, "and it is by no
means a new experiment Men have
/ been working for years in measuring the
heat of the sun and the proportion of
its radio-energy that reaches the earth
1t has been assumed, as a result of ex-
pertinent and theoretic calculation, that
the sun will one day begin-or has al
ready begun-to lose, very gradually, it's
heat. There is already on observatory
! in Algeria where highly perfected in
struments for measuring the suns rays
are in constant use. These instruments
that are to be used under DR.. Abbot's
direction in California are simply plan
lied as finer and more minute, able to
take more accurate measurements, and
so to record slight differences. Whether
not the sun Is cooling in any part,
the same amount of heat reaches us.
''The forty-foot tower referred to in
the dispatches from Pasadena" Prot.
Jacoby went on, lis not tower at
all, but an immense telescope. 1t diff
| fers from most other telescopes in that
| 1t is quite vertical. 1t is furnished to
! register the size of the sun by what We
call angular measurements.
Prot. Jacoby picked up pencil and
drew a circle on a piece of paper. From
each side of the circle he drew a tangent
and extended them until they met at a
point where he marked cross.
"Now this cross, he expiainef rs let
| us say, a man on the earth. The circle
is the sun, The lines are imaginary lines
| from the man on the earth 10 the sun.
The angular measurements are taken So,
he drew a line from one tangent to the
other, near the point where they met.
Now this line in this triangle is the
angular measurement" he ad6ed. IF
the sun is changing in size, that line must
change with ii. 1t is that line that we
measure with the telescope. We believe
that the sun is growing constantly
smaller But so very slow is the decrease
in its size, as compared ID its entire
radius, that we have never been able to
| perceive the slightest difference. We
may not be able to for many years.
"This decrease in size is closely con-
nected with the throwing off OF heat
from the sum-" Prof. Jacoby continued.
Scientists have known for many years
that the prodigious amunt Of heat which
the sun throws off would have caused it
to cool, probably long ago, il the heat
supply had been in some way replenished.
There have been several more or less in
genious explanations for this replenish-
ment Of heat The most plausible, and
the one generally accepted at the present
time, is the theory Of contraction, which
was offered by the famous German phys
icist, Helmholtz little more than fifty
years ago. Helmholtz's theory is that
the sun contracts slightly but constantly;
its molecules are drawn by gravitation
closer together, and this impact produces
heat again, through the transformation
of the energy of motion.
'He estimated that the average CON
traction in. the radius of the sun each
year was about $50 feet. But the suns
radius is estimated to be 4S3, go miles. and
the sun is s2,Ss7.0 600 miles away: SO we
have never been able to perceive this con-
traction with any instrumental means We
have had al hand. Helmholtz calculated,
in fact, that this shrinking process might
go on about 5000 years before II became
perceptible!
''The actual heat of the sun is measured