The System of the Universe

On Tuesday, June 28th, Mr. I. L. Thomsen, of the Dominion Observatory, addressed the Mathematical and Physical Society on the "System of the Universe."

Mr. Thomsen pointed out that, while 100 years have passed since Sir John Herschel completed the survey of the heavens on which our modern views are still largely based, it is only in the let ten or twenty years that there has been any clear idea of the relative size and distance of the various types of heavenly body.

The methods used in determining the size and distance of such objects was hen clearly explained, special attention being paid to the globular clusters, and the Cepheid variables. The story of the work of Kapteyn, Shapley, Stebbins, Plaskett, and others, which had finally given us a clear picture of our Galaxy, is a fascinating one. Latest measures indicate that our Galaxy is a lens-shaped object some 97,000 light years in diameter, and from 3000 to 6000 light years in thickness.

For a long time our own Galaxy appeared to be the largest of such systems, but photometric observation on the Andromeda Nebuia, and the discovery of the Interstellar Calcium Cloud has caused us to somewhat modify our views.

Reference was also made to the recession of the distant nebulae—the so-called "Expanding Universe"—and it was pointed out that there were more theories regarding this than the number of observations would seem to merit. An interesting discussion followed the lecture, which was illustrated throughout with a fine series of well-selected lantern slides.

—G.A.E.

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The Glee Club proposes to hold a Community Sing in the Gym, on Wednesday, July 13th. Be sure and come along!