Evening star., 1948-05-24
stors, Men and Atoms
Light HeIium Separated n
By Ohio Stute Scientists
Development May Be Important
Landmark in Nuclear Physics
By Thomas r. Henry

DeVelOpInSNI way OC 1HupOI tuHA
Landmark in Nuclear Physics
By Thomas r. Henry
Light heli,m, which weighs only three
fourths as much as ordinary helium with
which 1t is mixed In nature at ratio OF one
part in 100000, has been separated for the
first time by two Ohio State University
physicists working under q contract with thu
Once OF Naval Research. -.
This accomplishment of Drs. j. G. Darst
and H. l. johnson may become one OF the
landmarks Of the new physics Of the aton,io
nucleus comparable to the first separation
of light and heavy hydrogen at the Bureau,
of Standards about 20 years ago from which
have sprung some Of the major Developments
Of the age. trts'
This new helium promises to be a.sre.o
markable material in many ways. Drs Dafsts
and johnson have obtained = mixture very :
much richer in the rare isotope than y
helium in nature. They still have far to 60
before pure preparation is obtained although
there are rumors that this has been done
by q Government agency which Is not free
to reveal its accomplishments.
Helium Is Second -Lightest Element. $50
Helium. the sun gas, is the second-lightest
element in the atomic table. Its atom weighs
q uCLfe less ltan lOuT tlllcS as HuCA as ah
atom of hydrogen, lightest and simplest Of
the elements. In the enormous temperatures
of the interiors of the sun and stars hydro-.
gen atoms are built up into helium. the extra
weight turning into energy which Is respoil-,
sible for the most of the continuing solar
energy. If man ever learns to duplicate this
trick, probably impossible, the atomic bomb
would be q toy firecracker compared to the
pOtentialities that would ODen, N'
The new helium weighs only three times
rs much as hydrogen. The nucleus Of its
atom contains one less neutron. ~.
Ordinary helium, as 1t Is obtained from,
natural gas wells, is an inert gas. 1t will not
combine with any other element Thus 1t Ii
absolutely non-explosive under any circt1m-
stances. When this gas Is reduced to tenn
perature of ~ degrees above absolute zero
that is, about ass below zero centigradevt
changes into a liquid. This behaves generally
like any other liquid. popularity is that 1t
always is boiling violently under normal pres
sures as 1t struggles to regain Its gaseous
state. 49,. -
Liquid Flows Upward. 90 ,
But when the temperature Is dropped -
little lower to % degrees above absolute zere'
the boiling stops An extraordinary change
takes place. The liquid which results seems
to violate some of the best-established laws OF
physics. Among its properties Is that OF
flowing uphill. 1t will always flow against
temperature gradient from cold to warm. N
no longer has any viscosity, one of the prt-
mary properties of liquids. 1t will climb up
the walls of . glass tube and flow over the
sides.
Some irresistible force seems to impel It
to spread over any surface, regardless OF :
vttn
out OF glass tube like a fountain. One
of the most remarkable and potentially use
full changes is the loss of any resistance to
the passage of an electric current. 1t becomes
. super conductor. Through 1t an electric
current could be sent around the world with
no loss whatever. ..-.
The LIQUID continues to boil-or evaporate--
but it no longer seethes and bubbles. The
fact that it boils Is known only from the
fact that the amount present always dinlin-
Bhes.
Separation Held Big Accomplishment.
It has been believed for some time on tfleo-
retical grounds that some OF these remarkable
properties-especially that Of flowing uphill
are confined to liquefied helium and
would not be shown by the lighter heiium
3, the existence of which up to now has
been postulated only on theoretical grounds.
This difference IN behavior. however, was
suficient to enable Drs. Darst and johnson
to effect the partial separation In spite OF
extreme rarity Of the lighter isotope. Ex-
treme technical skill was necessary and, the
separation is regarded by officials OF the Once
of Naval Research as one of the major accom-
plishments to date of the Nays research pro-
gram in the pure sciences. ~
The preparation will be still further purified.
even If this has not already been done
elsewhere. The properties of pure helium
; liquid are purely conjectural. 1t Is ex7r
pected, however, to be very close to basio
form of matter in which particles behave like
protons and neutrons In an atomic nucleus
A curious property, it is pointed out, Is that
liquid helium will not freeze and become
solid at any temperature, even absolute zero
when all molecular motion stops, except under
enormous pressures.