Advancement in Philadelphia

To Rosella Carroll, 14, test tubes and microscopes were the most fascinating things in the world. Studying science at Bethlehem Academy in Faribault, Minn., her grave, shining brown eyes seldom missed a trick. Rosella was pious, too, and she intended to enter the Catholic sisterhood. But she knew that in this day and age a nun could be a scientist, if she were smart as well as conscientious.

So at Rosary College in Illinois, she went on with her science studies. In 1930 she took her final vows as a member of the Dominican Sisters, became Sister Mary Jordan Carroll. Dr. George Sped Sperti, famed director of the Institutum Divi Thomae in Cincinnati, sent word that he had places for two able sisters on his research staff. Sister Mary Jordan Carroll went.

Dr. Sperti found Sister Mary Jordan Carroll a "brilliant student," quick-fingered and witty as well. She and Professor J. C. Fardon did an astute experiment on the eye colors of Drosophila melanogaster, the scientifically renowned fruit fly. They made spectroscopic analyses of the pigments, found there was only one basic, sepia-hued pigment which was present in varying amounts under the control of the genes. In 1938 Sister Mary Jordan Carroll's paper on this work attracted wide notice.

Lately Sister Mary Jordan Carroll, Professor Fardon and others at the Institutum have been investigating the respiration of cells. From yeast and animal tissue cells they were able to extract an oxidizing agent, which they call biodin, and which stimulates oxygen consumption. After precipitation as a white powder, biodin retains its powers, can be sent back to work to speed up the life fires of injured tissues. Last week, at the American Association for the Advancement of Science convention in Philadelphia, Sister Mary Jordan Carroll demonstrated biodin, with microscope and test tube. Naturally she attracted a good deal of attention.* Someone observed that she is very young to be so well-known in science. She is 33. "Why," she laughed, "I think that's awfully old!" Other highlights of the A. A. A. S. sessions which ended last week:

Three-Way Split. Most sensational leap of science in recent years is the splitting of the massive uranium atom, heaviest of the 92 standard elements, into nearly equal parts, with enormous returns of atomic energy (TIME, Feb. 6, 1939; May 27). Even physicists who turn up their noses at Buck Rogers talk had to admit that the practical harnessing of atomic power was now much nearer--though they still insist it is far off. When a slow-moving neutron hits the uranium atom's nucleus, the nucleus is constricted around the middle and finally splits, like an amoeba reproducing itself. But though the energy of the activating neutron is only a small fraction of one electron-volt, 200,000,000 electron-volts of energy are released. Last fortnight, Dr. Richard David Present of Purdue described a three-way split. If conditions, including the energy of the entering neutron, are right, two constrictions instead of one crease the atom, dividing it into nearly equal thirds. First one end breaks off, then the other. Total energy release: 220,000,000 volts, a gain of 10%.

Centrifuges. The three-way split will not put atomic power to work tomorrow. The only promising kind of uranium for neutron-splitting or "fission" is the isotope called U-235.-- This kind is scarce and extremely difficult to separate from the common isotope, 11-238. So far, not enough U-235 has been isolated to put in a fruit fly's eye. A Swedish scientist was beginning to speed up the process with gadgets called thermal diffusion tubes when the war stopped him. Another line of attack is with centrifuges -- whirling machines which work like cream separators.

No. 1 high-speed centrifuge man in the U. S. is Professor Jesse Wakefield Beams, of the University of Virginia, who has broken his own speed records again & again. Dr. Beams it was who invented the centrifuge rotor that floats on a cushion of the same air that drives it. Last fort night one of his graduate students, Lloyd E. MacHattie, turned up in Philadelphia to describe a new, again record-breaking Beams centrifuge whose rotor is eerily suspended in a vacuum by means of mag nets. It is driven by electrical induction (i.e., without wires). Apparently its speed is limited only by the strength of the steel balls used for rotors. Before they exploded, the investigators got up to more than 6,000,000 r.p.m., to rim speeds of 3,500 miles an hour. So far they have done little with this machine on separation of uranium isotopes. They are more interested in separating blood plasma from blood for storage and shipment to war-pounded Britain.

How Bats Fly. A doodad for ships sounding the ocean bottom is the echo-recorder, which shoots down supersonic waves (sound of higher pitch than the human ear can hear), gauges the depth by the time it takes the waves to bounce back to the surface. The same principle enables airplanes to keep a continuous record of their altitude. But, long before there were any ships, planes or men, bats invented the same system for blind flying. Able both to produce and to hear supersonic sounds, they utter a steady, staccato stream of supersonic squeaks, keep away from ob-tacles from which echoes bounce back. Thus they can fly through intricate mazes in the dark.

For about a century and a half scientists have known that blinded bats could fly without collisions, but that deafened bats could not. To get exact data on the bat technique, Biologists Robert Galambos and Donald Griffin collected specimens from caves in the Berkshires, put them through their paces in rooms hung with wires like a balloon barrage, with special supersonic recorders. In finding out what prevents bat crackups, the scientists did not mutilate the creatures, used blindfolds, ear plugs, mouth gags. Last week Galambos & Griffin reported that the pitch of the bat signal is around 50,000 vibrations a second.* Flying in free space, the bats utter about 25 cries a second. Near an obstacle the rate shoots up to 50.

Down to Earth. Many an astronomer believes that the glow of the aurora borealis ("northern lights") is due to bombardments of electric particles from the sun, which agitate atoms in the upper air to the glow point. For a long time the spectrum lines corresponding to the auroral colors were called "forbidden lines'' because they could not be reproduced in the laboratory. Last week Drs. Joseph Kaplan and S. M. Ruben of U. C. L. A. told how they brought the auroral colors down to earth. They put gas molecules in a tube, stirred them up with a high-frequency discharge, then snapped off the current with extreme suddenness. The brief afterglow of the gases they caught in a spectroscope. They found the colors to be not only those of excited oxygen and nitrogen, the most plentiful components of the air, but also of helium, which makes up only .0005% of the atmosphere and is exceeded in scarcity only by xenon. Conclusion: there is probably lots of helium in the upper atmosphere.

* For other news of women in science, see p. 54.* Isotopes: atoms of the same chemical element which have different atomic weights. * Highest frequency that humans can hear is about 20,000 a second. Middle C on the piano is 256 vibrations a second; each octave going up doubles the frequency.

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