Evening star., 1954-08-20
Rodio Telescope Built
In Nearby Maryland
Will Record Collisions
Of Fur-Distunt GuIuxies
By Thomas R. Henry

vi EUE-0tStuHV 6OIuAleS
By Thomos R. Henry
A fiat 90-acre Maryland pasture has
been converted into titantic "eye" of
the earth for observing hitherto un-
fathomed depths of creation.
Construction of great radio tele-
scope. largest in the New World and
in the northern hemisphere, was an
nounced today by DIR. Vannevar Bush,
president of the Carnegie Institution
Of Washington.
It is designed to detect radiation
from the heavens with wave length
Of approximately II meters-far inside
the radio wave range-which comes
primarily from clouds Of electron-
stripped gas. enormously hot and
crashing through space ct speeds ap-
preaching 1000 miles a second. The
instrument set up by Carnegie astrono-
mers at Seneca, Md, about 20 miles
from Washington, is modelled after the
so-called Mills Cross" built by the
pioneer radio astronomer DR.. Y. B.
Mills in Australia, but it involves sew
eral advanced features.
VNGW 1K0CtACG0s
During the past 10 years. DR.. Bush
explained in his announcement. radio
astronomers have tended to shift their
interests, and the design OF their in
struments, to pick UP shorter wave
lengths. This enables them to detect
and locate more precisely "hot spots"
in the universe, or radio stars. but
with finer details there is some danger
of losing the complete picture. The new
Carnegie telescope is a return to an
earlier technique which gives broader
outlook.
1t will be used primarily, DR.. Bush
said, for study Of the distribution Of
ionized gases, chiefly hydrogen, with
its outer electron stripped off, both in
the 100-billion star Milky Way galaxy.
in which the sun and its planets can
be considered an average star, and in
the outer galaxies of similar dimensions
millions Of light years across chasms
of nearly empty space. The primary
interest. however. will be in this galaxy.
The 14-meter radio waves picked up
by the Seneca telescope" can be con-
sidered as light to which both the
human eye and Photographic plates
are insensitive. It is light which will
pass through thick obscuring clouds
from recesses of the galaxy which can
be seen by no other means. A major
objective will be to determine the dis
tribution Of the hot ionized gas, which
in turn is bound to bring new concep-
tions of the shape and structure Of
creation which hitherto have been de-
duced only from what could be seen
or photographed.
CassiOpeia Radiation.
Said DR.. Bush: "A typical source of
radiation in our galaxy occurs In the
constellation of Cassiopeia over thou
sand light years (the space covered by
light moving at approximately 186.000
miles second in a year, distant. Until
the advent of radio astronomy this
source was completely overlooked by
astronomers. It consists of thin clouds
of gas in violent motion. No one knows
why these hot clouds are capable of
radiating such tremendous quantities
Of radio noise. It is hoped that through
observations with the new antenna the
mechanism causing the radiation can
be discovered"
Preliminary tests have been made
with the new telescope" It was able
to pick up without difhculty two crashes
Of galaxies both previously reported
from other observatories There may
be many other such titanic collisions
in the universe. What happens essen
TALLY is that one aggregation of hun
dred billion stars strikes head-on an
other aggregation of similar size. In
6iyi6ual stars Spnarotad nv distances
of light years, probably seldom smash
into each other and those that do add
very little to the total picture 1t is the
gas atoms and molecules between the
stars that crash together, with the
resulting output of radio waves.
How 1t Works.
The new "earth's eye" consists Of
1913 dipoles arranged along two diago-
nails of the 90-acre field. A dipole is a
simple two-wire antenna, such as often
is used for a television set. Each line
of dipoles is 2.040 feet long, and each
dipole is connected to a central point
by branched feeder system.
The EYE" DR.. Bush said, can be
directed to any point in the northern
sky. Thus it can accomplish for this
hemisphere what Is accomplished for
the southern hemisphere by the Aus
tralian installation.
The apparatus was designed by Drs.
Harry w. Wells and Bernard F. Burke
of the Carnegie staff, with the advice
of DR.. F. Graham Smith of Cambridge
University, England, where another
large radio telescope has been set up.