Dunham Joins Expedition to Alaska Studying Direction of Cosmic Rays--Results Will Determine Nature of Their Origin

J. L. Dunham '25, instructor in physics, will take part in one of the expeditions beings sent to all parts of the world this summer to study cosmic rays under the general direction of professor Compton of the University of Chicago.

According to Dunham, the research being done has no immediate utilitarian aim, and is being carried on solely in the interests of pure science. Cosmic rays are believed to be in the category with X-rays and light rays, but of considerably greater frequency and shorter wave length. "Ordinary light will penetrate glass and a few thin substances. X-rays are more penetrating, and will go through a few millimeters of lead. In contrast to both these, cosmic rays are able to pass through two feet of lead.

"The rays were first discovered when it was found that air could not be made into a perfect electrical insulator by purification. Inasmuch as pure air is a non-conductor of electricity unless ionized, it was found that a hitherto unknown agency accomplished that ionization with increasing intensity as the altitude above sea level was increased. It was concluded, therefore, that the electrifying agency originated outside the Earth; it was accordingly determined to ascertain the nature of the so called cosmic rays, and one of the first essentials to be determined in their study is their origin.

"The present research is concerned with verifying the findings of other scientists in Germany and the United States that cosmic rays approach the Earth from all directions and in practically equal intensity. If the rays make themselves more apparent in one part of the globe than in another, their direction will be ascertained, and much light will be thrown upon the question of whether or not the rays emanate from particular stars or simply from the infinite depths of space."