African Expedition Looks for Sun Spots' Influence on Radio

Traveling all the way to Queenstown, South Africa to solve some of the riddles of the upper atmosphere, four members of the Physics Department will conduct some research on long-distance radio broadcasting.

To determine the causes for the recent disruption of broadcasting by sun spots, they will measure the density of the ionosphere, an atmosphere layer above the stratosphere, during the eclipse of the sun next October 1.

Leading the party is J. A. Pierce, supervisor of field activities in Communication Engineering, who is assisted by T. J. Keary, and Joseph T. deBettencourt '36 G.E.S.

Costly Apparatus

The party is preparing over $4,000 worth of equipment which will measure the ionosphere continuously from September 1, a month before the eclipse, to October 30, a month after it. Special apparatus will be used during the actual moments of the eclipse for recording the ionospheric changes.

Since the ionosphere reflects radio waves back to earth, the measurements will be carried out in roughly the same way that depth soundings are made to plot the ocean bottom: by sending up radio signals in the form of dots one ten-thousandth of a second long and recording the time it takes them to be coheed back to earth.

Special Insulated Car

Parked behind Cruft Laboratory is an old Packard with a completely insulated copper body. With the aid of this car the Physics Department has been measuring the ionosphere 24 hours a day since 1931.

Sunrise and sunset data have been carefully collected, but there is a need for complete ionospheric records corresponding to the sudden changes in the energy from the sun at the time of an eclipse.

Will Aid Transmission

Although they refuse to predict the results of this expedition, members say that it will probably and long distance broadcasting by enabling scientists to calculate ionospheric conditions more accurately and to choose radio frequencies accordingly.

In addition, this party help to discover the relationship between sun sports and radio transmission, may determine the atomic constitution of the ionosphere, and may enable long-distance television broadcasts, now impractical, to become a fact.