We have lately advanced farther along the road of Pythagoras and Aristarchos, of Copernicus and Galileo, and we have perfected their methods to a high degree. Progress in astronomy and kindred sciences is nowadays made at a dizzying speed if measured with the standard of antiquity. Occasionally we hear a warning voice asking us to show more deference to a philosophy directly descending from the Platonic-Aristotelian. He who is at all familiar with the history of natural science will understand us when we answer: “We have had more than enough thereof.”
That non-naturalists sometimes have a peculiar conception of the present status of astronomy is well illustrated by the statement of one of our foremost theologians in a review of a popular astronomical work where he remarked that the astronomer of today had not advanced much beyond those of ancient time who also could forecast eclipses of the Sun. The predictions were then founded on the recurrences of eclipses after regular intervals much as the new Moons were foretold, with the difference only that the latter occur much more frequently.
Our knowledge of the stellar bodies at present and fifty or sixty years ago are a world apart and the same is true of the latter and that of antiquity. But we must not therefore forget that our brilliant star-science today is derived from men’s desire to measure time, and particularly from their need to foresee the food supply in coming days.
CHAPTER II
THE RIDDLE OF THE MILKY WAY
During dark but starlit nights, the gorgeous firmament is decorated with an irregular band of light that describes a winding path across the heavens. It continues also in the quarters hidden from our sight so that it may be said to surround the firmament like a girdle. This band, which is most luminous in the Northern Hemisphere, is called “The Milky Way.”[1] It forms an angle with the equator of about 60° and divides the firmament in two nearly equal parts—the northern, however, is slightly larger.
[1] The literal translation of the Swedish name is “The Wintry Way.”
The Milky Way, no less than other stellar phenomena, attracted the early attention of the people. The Dieri Tribe in Central Australia says that the Milky Way is the stream of heaven and the Mexicans consider it the source of all that is. Tradition endeavoured to explain its origin. Its milky appearance caused the Romans to call it “Via Lactea,” a name that is retained in translated form in most modern languages. This name is coupled with the legend of the Hercules-child, who sucked the breast of Juno and when it was pushed away by the incensed goddess, the milk was spread across the sky.
Nevertheless, the human race, until about two hundred years ago, had little conception of the extraordinary importance of the Milky Way. Anaxagoras and Democritos surmised, however, that it consists of a collection of exceedingly minute and densely clustered stars each of which has the nature of our Sun. Ptolemy described, nearly two thousand years ago, its position on the firmament and his observations are valid today as far as determinations with the naked eye suffice. When Galileo introduced the telescope, the conception of the Milky Way as made up of innumerable stars was verified. Not quite two hundred years ago Swedenborg, in his cosmological speculations, considered our solar system as a part of the Galaxy. Wright, Kant, and Lambert further amplified these theories.
The first important forward step was taken by the great William Herschel in his statistical researches. He demonstrated that the stars lie closer to each other the nearer the Milky Way they are located. This is mainly true about the small stars invisible to the naked eye while the more luminous ones are more evenly distributed over the heavens. In certain parts of the Milky Way the stars are over one hundred times more crowded than at its poles—that is, the points farthest removed from the Galaxy. Herschel’s investigations were continued and elaborated by Struve, and later by numerous other scientists.