Читать книгу Star-land: Being Talks With Young People About the Wonders of the Heavens онлайн

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We have spoken of the heat of the sun, how hot he is; of the distance of the sun, how far he is; and now we must say a little about the size of the sun; and also about his shape. It is plain that the sun is round, that it has the shape of a ball. We are sure of this because, though a plate is circular, yet, if it were placed so that we only saw it edgeways from a distance, it would not appear to be round. The sun is always rotating, and as it always seems to be a circle, we are therefore certain that the true shape of the sun must be globular, and not merely circular like a flat plate.

In the middle of the day, when the sun is high in the heavens, it is impossible for us to form a notion of the size of the sun. People will form very different estimates as to his apparent bigness. Some will say he looks as large as a dinner plate, but such statements are meaningless, unless we say where the plate is to be held. If it be near the eye, of course the plate may hide the sun, and, for that matter, everything else also. If the plate were about a hundred feet away, then it would often hide the sun. If the plate were more than a hundred feet distant, then it could not hide the sun entirely, and the further the plate, the smaller it would seem.