SHALL the Eye of the Universe suffer from ophthalmia? Shall the orb of celestial fire in the incorruptible heavens type of purity and perfection—noblest symbol of God—be stained and blackened with impurities? Such were the questions indignantly asked when it began to be whispered about that there are spots of darkness on the face of the sun.
Yet again what was thought impious and impossible proved true: and again it was demonstrated that the cherished opinions of thousands of years were not only erroneous, but were in flat contradiction to the truth. Not only were spots, which it was thought profane even to suspect, shown to be realities, but they have turned out to be the principal means of letting us into a knowledge—such knowledge as we have—of the solar constitution.
It is now upward of 250 years since the invention of the spy-glass led to the revelation of the solar spots, which has been variously attributed to Fabricius, Galileo, and Scheiner, the Jesuit astronomer. It is said of Scheiner, and it well illustrates the spirit of his age, that he dared not publish his discovery, and at first confided it to only a few of his most intimate pupils. After repeated observations that removed all doubt as to their existence, he consulted the provincial father of his order, who refused to believe in any thing of the kind; "For," said he, "has not Aristotle said that the sun is all over shining with light? I have several times," he sagely observed, "read my Aristotle all through from beginning to end, and I can assure you that he mentions not a syllable about it. Go, my son, make yourself easy, and take it for certain that what you suppose to be spots on the sun, are nothing but specks in your eyes or flaws in your glasses." Scheiner obeyed, admitting that his eyes must be in the wrong, and Aristotle in the right, for he lived in an age of credulous faith and blind authority. A doubting pupil of his, however, wrote to Galileo, who replied: "Scheiner's eyes are as good as need be; I have myself watched those spots for some time past."
Scheiner at first considered these dark specks to be minute planets travelling round the sun close to his surface, but Galileo more shrewdly concluded that they were part of the sun itself, perhaps floating scum or scoria, and he saw their importance in astronomy. For not only do they prove the revolution of the sun on its axis, but they afford the only means of ascertaining the time of that revolution, the position of the solar axis and its inclination to the earth's orbit. Galileo therefore watched the spots with an interest and assiduity so great that it finally cost him his eyesight.
- Edward Livingston Youmans (Wikisource contributor note)