From the June 25, 1932, issue

ARTIFICIAL LIGHTNING FLASHED AT 10 MILLION VOLTS

The most powerful manmade lightning is flashing across the cover of this week’s Science News Letter from new equipment in the Pittsfield laboratories of the General Electric Co., which has twice the capacity of any preceding apparatus of its kind.

This is a discharge through a 15-foot space of 50,000 amperes at 10,000,000 volts. The voltage is capable of projecting an arc at a distance of 60 feet. F.W. Peek Jr. was in charge of the development of the new equipment.

Just what can be done with the 10-million-volt discharge nobody knows yet. It is to be used in connection with research on natural lightning, the effects of which it can approximate more closely than has hitherto been possible. Whether or not this high voltage will produce cosmic rays or split the atom, as scientists have predicted, Mr. Peek said that only time will tell.

Yet powerful as the new apparatus is, its discharge represents real lightning in only a fractional way. The voltage of a natural lightning discharge, Mr. Peek stated, is 100 million, or 10 times that of his best artificial “thunderbolt.”

SLOW ELECTRONS MAKE POSSIBLE “POLAR LIGHT” IN LABORATORY

Very slow electrons bent by the action of a magnetized sphere produce “laboratory auroras” in an apparatus devised by Dr. Alexandre Dauvillier, professor at the Ecole Supérieure d’Electricité of Paris. Dr. Dauvillier is a member of the French “polar year” expedition and will spend the coming winter at Scoresby Sound, on the Greenland coast, to obtain final proof of the continuity of the aurora lights right around the polar regions. To this end he will cooperate with the polar expeditions sent by other nations who take part in the “polar year” program.

The apparatus in which the aurora can be observed consists of a hollow sphere of aluminum, representing Earth; within it there is a slightly smaller iron sphere, also hollow and partly surrounded by conducting wire, so that it can be magnetized to give a magnetic field similar to that of Earth. The whole apparatus is enclosed in a large glass bulb, the air pressure in which is reduced to one-millionth of an atmosphere to correspond to the conditions in the upper atmosphere, where the aurora takes place. The sphere can be rotated around its axis, or the axis can be rotated, showing the daily and annual variations.

SUN MAY BE CHANGING ITS SPEED OF ROTATION

For many years astronomers have known that the sun varies in light over an 11-year period, as the sunspots wax and wane. The suggestion that it also varies in the speed of its rotation, but in a period of about 30 years, has been made in a report to the Royal Astronomical Society by John Evershed, following researches made in his private observatory in Surrey.

Dr. Evershed’s study is concerned with the sun’s equator, where the speed of the surface is about a mile and a quarter, or 2 kilometers, a second. His observations were made by photographing the edge of the sun with the spectroscope. By measuring the shift of the dark lines that appear in such photographs, the motion toward or away from Earth can be determined.

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