News
Garber Announces Advisory Committee for Harvard Law School Dean Search
News
First Harvard Prize Book in Kosovo Established by Harvard Alumni
News
Ryan Murdock ’25 Remembered as Dedicated Advocate and Caring Friend
News
Harvard Faculty Appeal Temporary Suspensions From Widener Library
News
Man Who Managed Clients for High-End Cambridge Brothel Network Pleads Guilty
Reports on the most extensive and distant groping into space ever undertaken, the project of Dr. Harlow Shapley of he Harvard Observatory, were one of the most noteworthy features of the forty-third meeting of the American Astronomical Society at Harvard held at the Harvard Observatory from December 30 to January 2.
The theory advanced by Dr. Shapley at the meeting deals with the distances in the universe and fixes these relative distances larger than ever before, almost beyond the conception of the human mind. The Harvard director has previously overthrown the accepted Kapteyn theory and has now elaborated on his own theory which replaced it.
The astronomical society meets annually at one of the observatories of America to discuss to accomplishments of the past year. The last time that Harvard was the host was during the Christmas period in 1921. It is the largest society of its king in existence, having a membership list of approximately 400, most of whom are professional astronomers. The president, Ernest W. Brown of Yale University, has been devoting most of his time during the last several years to the study of the motion of the moon.
Group Visits General Electric
The highspots of the meeting this year including sessions for the reading of papers on Monday and Tuesday by various astronomers who have been engaged in research along certain lines. On Tuesday afternoon, a tea was held in the Whitin Observatory at Wellesley at the invitation of Professor and Mrs. Duncan. On the same evening, there was a New Year's party given by Mr. and Mrs. Shapley at the Harvard Observatory, at which time there was a presentation of "Pinafore" by the members of the observatory staff.
The meeting was concluded by a visit to the General Electric plant in West Lynn to see the work being performed there in the making of fused quartz mirrors, an innovation in the manufacture of telescopes. A constant problem in astronomy is how to make bigger and better mirrors for the telescopes. Glass, which has long been used for the smaller mirrors, is almost out of the question for a really large project. The reason for this is that the surface curvature of these reflectors must be correct down to a fraction somewhere between a quarter to a half millionth of an inch.
Huge Reflector Being Made
The General Electric plant has at present undertaken to furnish the California Institute of Technology with a fused quartz reflector for a 200 inch telescope. That means that this mirror will be about 17 feet in diameter and about three feet thick.
The obstacles seem almost insurmountable, but many have been solved, and those that remain very likely will be in time. The difficulty of fusing quartz for so large a mirror at the great temperature required, the problem of supplying heat for such an undertaking, and the ultimate question of how to mount such a heavy thing without having it bend and distort the curvature--all these are as yet not definitely solved, but they will soon be considered.
Important Papers Read
The most important part of the meeting was the reading of the papers, of which there were perhaps there or four outstanding ones. J. W. Fecker made a report on the work done to date on the 70 inch disk cast by the Bureau of Standards in Washington. This has been an object of interest to all astronomers since 1921 when work was first started. After five failures, they have at last succeeded in making a start which seems likely to be successful.
Frederick Slocum announced the results of a rather extraordinary undertaking in which he has been engaged since 1921; his report was on the probability of a clear sky for the 1932 total eclipse of the sun. The path of totality of this eclipse has been accurately plotted, and Slocum has been receiving reports yearly as to weather conditions along this path for a period of about two weeks on either side of the date on which the eclipse is to take place. This preliminary report showed the chances to be about even, and he named several towns along the course of the eclipse which were most likely to see blue sky on that day.
Shapley Report Important
The climax of the whole proceedings lay in the joint reports of Professor Lundmark and Dr. Shapley. In general the reports of these men revolutionized previous conceptions of the extent of the universe.
The first conception of the universe was a geocentric one, and in the sixteenth century Copernicus made the first great step in astronomical research by overturning this old theory in favor of a heliocentric one which held that the earth and the planets went around the sun. In 1902, a man named Kapteyn put forth the theory that the sun was the center of things and that the stars were scattered about it. This Kapteyn Universe, as it was called, was in good standing till 1917 when Dr. Shapley found that we were not the center of things after all.
The first step in his discovery came when by examination of the globular clusters he discovered that the stars about us extended much farther into space than we had previously thought, and that most of the farthest of them were on one side of us. This led him to believe that we were not the center of the universe, but that we were, on the contrary, off center, and that the Milky Way was so full of stars because we were looking through the center. So the Shapley system, or the galactic system, as it is called, held that we were one of countless stars which go to form a system much in the shape of a giant millstone. Determining the thickest part of the Milky Way, Dr. Shapley then determined that the star Sagiltarins was the approximate center of this galactic system, and that we on earth are travelling around Sagittarius at the rate of 120 miles per second.
Astronomical Distances Increased
Dr. Shapley's most recent research has been concerned with variable stars in the large Magellanic cloud. This cloud seems to be another system rather like the one in which we are whirled about Sagittarius. Dr. Shapley has found, by examination of the Cepheids variables in this cloud that the light from certain ones waxes and wanes, the period which the change in brightness takes having a direct relation, through the average brightness, to the distance of the Cepheids from us. In this way he has calculated that the large Magellanic cloud is 86,000 light years away from us, a light year being the distance that a ray of light travels in a year at the rate of 186,000 miles per second. In the Kapteyn Universe, it was held that there was no star over 35,000 light years away.
Professor Lundmark in his paper told of his exploration among the spiral nebulae which are at a distance of 500,000 to 150,000,000 light years from the earth. Although these nepulae are smaller in themselves by much than our own galactic system, nevertheless they seem to come in groups of thousands or so, and Lundmark has advanced the important theory that each group of these comprises a separate system such as ours.
Limit Beyond Human Mind
Both these papers, Shapley's and Lundmark's, are of vast importance in a reorganization of our idea of the extent of space, fixing a limit of which is as yet beyond human comprehension, according to Lundmark, who reports that the spiral nebulae which he has been examining are by no means the farthest objects from earth in the universe.
Dr. Harian T. Stetson, director of the Perkins Observatory at Ohto Wesleyan University, for which the mirror is being cast at the Bureau of Standards, discussed land-tides similar in origin to the tides of the ocean. That the earth's crust actually shifts as a result of the gravitational pull of the moon on the earth is the theory advanced by Dr. Stetson.
Want to keep up with breaking news? Subscribe to our email newsletter.