Evening star., 1955-02-23
Mun-Mude Diamonds
Open Vast Unknown
Processes Reveal Secrets
Cached Deep Into Earth
By Thomas R. Henry

Man-made diamonds are just O door
opener to vast unknown,
The first successful production Of real
diamonds in a laboratory, announced
the other day by the General Electric
Co., promises to be, per Sc, Of consid-
cradle practical importance to indus
try and perhaps, eventually. to the gem
market. But the real significance. 1t Is
emphasized by the company's physi-
cists, lies in the fact that an almost
hmitless new field of research has been
opened which probably will result in
hitherto unknown kinds Of matter
with properties unknown to science.
This field Is. that Of extremely high
pressures combined with extremely
high temperatures such as exist $50
miles below the earth's surface
pressures as high as is million pounds
to the square inch combined with
temperatures running from 1000 to
5000 degrees Fahrenheit.
Under somewhat similar conditions
diamonds were made originally by ma
ture. The diamond happens to be
quite stable substance which presum-
ably was not changed by the earth
upheavals which brought 1t to the sur
face in two or three parts of the earth.
Nobody knows what else exists at such
depths-material which loses its pc
culiar properties when accidentally
brought to the surface.
Change Under Pressure.
Diamonds, the physicists feel, even
tually may prove a quite insignificant
by-product of this research.
1t long has been known that prop
critics of elements change greatly under
high pressures. Their molecular ar
rangement, strength, electrical con-
ductivity, and many other factors
differ as the pressure is increased.
This is we'll illustrated, the physicists
say, by such substance as ice. There
are six known kinds of ice, all with
different properties. For example, ice
II. created by relatively high pressures,
takes about twice as long to melt as
ordinary ice. Iron and other metals
undergo somewhat similar changes. but
these differ for each element and can
not be predicted.
The theoretical requirements for
making diamonds demanded that con-
ditions deep in the earth be duplicated
in the laboratory. BY far the greater
part of the problem was concerned with
evolving such techniqueS-and it turns
out that the techniqueS themselves
are more important than the diamonds.
These, after ALL have a limited, al
though unquestionably important use.
1t might be said that science today
knows more about the physical condi-
tions in the distant universes than at
the center of this planet. There, it
can be calculated, pressures are as great
as 100 million pounds per square inch.
Nobody knows what the earth's core
is made of.
Once having started on the way, how
ever, the General Electric Co. physicists
are going further and further. without
any real hope of reaching the ultimate.
They have adopted new motto: ITO
He'll by 1860" They mean, of course,
that the goal is to reach pressure of
100 million pounds square inch.
Piston and Cylinder.
Practically all ultra high pressure
generators are based on the principle
of pushing a piston into a cylinder that
incloses the substance that is to be
subjected to the pressure The upper
limit of attainable pressures is set by
breakage of the cylinder or piston, and
not by the force available to push the
piston.
The main factor which limits maxi
mum pressures is the strength of ma
terials. The strongest steels, for ex-
ample have ultimate strengths of from
100000 to 100000 pounds per square
inch. Certain synthetic materials,
notably the cobalt-based carboloy, have
compreSsive strengths of the order Of
100000 pounds per square inch. Making
the walls Of vessel thicker contributes
very little, the General Electric physi-
cists say.
They started with special technique
originally devised at Harvard, which
resulted in chambers with a pressure
resistance of 735,000 pounds.
From this point on they were in
unknown territory but by various de-
vices they were able essentially to
double this previous maximum.
From this point on everything is
speculative but considerable progress
beyond is million pounds square inch
already Is in sight, say the General
Electric Co. phySicistS