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November 17, 1957 - Image 8

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The Geophysical Year
A REPORT ON ACTIVITY AT THE McMATH-HULBERT OBSERVATORY

By DAVID TARR
Daily Staff Writer
ONE CLEAR, warm night last
July people across the country
turned their eyes into the northern
heavens and were witness to one
of the best displays of northern
lights in years. Most of the observ-
ers were awed and surprised, but
just a generous hour's drive from
here a small group of scientists
knew the display was coming and
knew it had greater significance
than a mere evening's entertain-
ment.
Their foreknowledge of the event
came in a small group of buildings,
some 35 miles north of Detroit,
nested on the edge of a quiet
Michigan lake and curtained from
the casual observer by tall pines.
The buildings compose the Mc-
Math-Hulbert Observatory, an in-
stitution that has' grown from
small beginnings into a world-
renowned observatory. It is one
of the several observatories of the
University department of astron-
omy.
The McMath-Hulbert Observa-
tory currently is playing a major
role in the International Geo-
physical Year, a sort of large-scale
fact-finding expedition which be-
gan July 1 and will continue until
the end of 1958. .
Under the direction of Prof.
Robert R. McMath, the staff of the
observatory is part of a global
team of more than 5,000 scientists,
engineers and technicians from 56
nations taking part in the IGY
program of intense, direct obser-
vation of the earth and its atmos-
phere.
Some of the astronomers at the
observatory, which gained its fame
for studies of the sun, are seeking
a better understanding of solar-
flares, those great tongues of fire
on the sun that are believed to
have a marked effect on radio
communications and other earthly
phenomena - including northern
lights.
To understand the work of the
astronomers in the IGY program,
it would first be wise to make
several statements about the sun.

Detailed understanding of the
sun's behavior is lacking, but cer-
tain facts are well known and
generally accepted. Basically, the
sun is an enormous globe of hot
gas, more than 800,000 miles in
diameter.
Its surface temperature is in the
neighborhood of 11,000 degrees F.,
increasing steeply in the interior
to an estimated 35-45 million de-
grees F. at the center. Its gases are
so compressed that they become
many times denser than steel.
Necessarily, observations of the
sun are limited to its outer layers,
the solar atmosphere being trans-
parent only to a depth of a few
thousand miles. But the surface
is in a continual state of activity.
Great masses of gas, or "promi-
nences," may almost always be
seen projecting from the edge of
the sun. Frequently in rapid mo-
tion at speeds up to hundreds of
miles per second, they describe
sometimes straight and sometimes
curved trajectories while moving
into or away from the sun.
THIS continual activity is evi-
dent in sunspots or solar-
flares. Sunspots are phenomena
that become most numerous in
cycles of 11 years. This cycle,
which reaches a maximum this
year and next, was a major factor
in determining the time of the
IGY.
Although the origin and nature
of sunspots are still obscure, they
are known to have strong mag-
netic fields associated with them.
Scientists know also that sunspots
are regions about 2,000 degrees
cooler than the surrounding sur-
face of the sun.
Frequently local areas around
sunspots brighten up briefly and
tremendously. These so-called
"flares" or "eruptions" are the ob-
ject of intensive examination by
the observatory staff using solar
telescopes and other special equip-
ment.
"Solar flares are often associ-
ated with radio fadeouts and mag-
netic storms on the earth," ac-
cording to Prof. Helen W. Dodson,

who is directing the observatory's
work in the IGY.
Study of flares aids in predicting
disturbances in long distance com-
munication on the earth, a pro-
gram to which the observatory
contributed substantially during
World War II.
IT IS known that when a solar
flare occurs there is a great in-
crease in short wave radiation
from the sun. As a result, there
is likely to be a disturbance in the
"roof" of the earth's atmosphere,
known as the ionosphere, causing
a short-wave fadeout.
Flares may also eject high veloc-
ity atomic particles. The atomic
particles, because they, travel more
slowly than light, require from one
to four days to traverse the 93,000,-
009 miles to earth. If these par-
ticles reach the earth's atmos-
phere, they cause the series of
phenomena that are associated
with geomagnetic storms.
These storms are detected pri-
marily by variation in the pointing
of sensitive compass needles as a
result of strong electrical currents
induced on the surface of the
earth. In addition, there are often
displays of northern lights.
Although flares wreak havoc with
shortwave radio transmission of a
thousand miles or so, they do not
affect short-range communica-
tions, according to Prof. Orren
Mohler, assistant director of the
observatory. The best example, he
said, is television which, contrary
to popular belief, is not in the least
affected.
But there is another kind of
radio trouble that may arise from
solar flares, a trouble that Prof.
Dodson refers to as "a sudden
enhancement of atmospherics."
This means, for example, that a
radio turned to about 25 kilocycles
in northern United States might
experience an. increase in static
from thunderstorms as far away
as the tropics because of changes
in the ionosphere during the flare.
It is also true that some radio
receivers can detect radiation at
radio frequencies from distant

Under the direction of Prof. He
McMath-Hulbert Observatory is f
International Geophysical Year.'
Robert R. McMath is one of th
renowned institution.
stars and planets. During solar
flares, this "cosmic static" dimin-
ishes or fades because of increased
absorption in the earth's ionos-
phere at such times.
Special equipment has been in-
stalled at the observatory to
measure the amount of this cosmic
noise absorption.
The IGY national committee
has also sent an automatic-control
telescope that will take two pic-
tures per minute of the entire solar
disc showing when and where
flares occur, how bright they are
and how fast they disappear.

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len W. Dodson, the University's
playing an important role in the
The Observatory's director, Prof.
e three founders of the world-
These special instruments are
entirely supplementary to an al-
ready excellently equipped observ-
atory. How this observatory was
begun and has grown to the posi-
tion it holds today is as fascinat-
ing as the studies conducted there.
Until recent years progress in
solar physics was hampered by the
almost complete lack of accurate
measurements of the motions and
radiant energies associated with
solar phenomena. The McMath-
Hulbert Observatory has been de-
veloped around the desire to fill
this gap.
7tE story began in the late
1920's when three Detroiters,
Prof. McMath, then president of
Motor Metals Manufacturing Co.,
his father, Francis C. McMath, fi-
nancier and engineer, and Henry
S. Hulbert, one-time Wayne
County probate judge, began as
amateur astronomers to plan and
build the observatory that was to
pioneer in solar studies.
The observatory was founded in
the summer of 1930 with the con-
struction of a small dome housing
a ten and one-half inch telescope.
Research by the three men, as
they began to move off the ama-
teur level, led them to design their
own instruments where necessary
equipment was unavailable. In-
cluded was a specially designed
camera with the unusual name of
spectroheliokinematograph.
With this instrument motion-
picture photography was for the
first time applied successfully to
the sun. It immediately proved its
value as a powerful research tool,
winning international recognition
for the observatory.
Early work at the McMath-Hul-
bert Observatory consisted of mo-
tion pictures showing changes in
celestial objects, Some of the
earliest records show motion of
the satellites of Jupiter and the
changing shadow patterns on the
surface of the moon.
In 1931, the founders made a
gift of the observatory to the Uni-
versity and Robert McMath was
named director.
The original telescope dome now
houses a 24-inch reflector which
has been employed in motion-pic-
ture photography of the moon and
planets. In 1936, the 50-foot tower
telescope, was completed, providing
a specialized instrument of great
power and versatility for solar
studies.
Another special instrument in-
stalled in this tower in 1939 per-
(Continued on Next Pasms

441

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