Homepage
Login
Profile
BookClubs
dmBox
Read this ebook for free! No credit card needed, absolutely nothing to pay.
Words: 21098 in 10 pages
This is an ebook sharing website. You can read the uploaded ebooks for free here. No credit cards needed, nothing to pay. If you want to own a digital copy of the ebook, or want to read offline with your favorite ebook-reader, then you can choose to buy and download the ebook.
Poor pussy comes at break of day, And wakes me up to make me play; But I am such a sleepy head, That I'd much rather stay in bed!
OUR OWN STAR.
"As we have already," began the Professor, "had a talk about the stars in general, let us this morning give a little attention to our own particular star."
"Is there a star that we can call our own?" asked May, with unusual animation. "How nice! I wonder if it can be the one I saw from our front window last evening, that looked so bright and beautiful?"
"I am sure it was not," said the Professor, "if you saw it in the evening."
"Is it hard to see our star, then?" she said.
"How big is the sun?" asked Joe.
"You can get the clearest idea of its size by a comparison. The earth is 7920 miles in diameter, that is, as measured right through the centre. Now suppose it to be only one inch, or about as large as a plum or a half-grown peach; then we would have to regard the sun as three yards in diameter, so that if it were in this room it would reach from the floor to the ceiling."
"How do they find out the distance of the sun?" asked Joe.
"Why," said Gus, "that sounds just like what Bob Stebbins said the other day in school. He has a big silver watch that he is mighty fond of hauling out of his pocket before everybody. A caterpillar came crawling through the door, and went right toward the teacher's desk at the other end of the room. 'Now,' said Bob, 'if that fellow will only keep straight ahead, I can tell how long the room is.' So out came the watch, and Bob wrote down the time and how many inches the caterpillar travelled in a minute. But just then Sally Smith came across his track with her long dress, and swept him to Jericho. We boys all laughed out; Sally blushed and got angry; and the teacher kept us in after school."
"Astronomers have the same kind of troubles," said the Professor. "They incur great labor and expense to take some particular observation that is possible only once in a number of years, and then for only a few minutes. And after their instruments are all carefully set up, and their calculations made, the clouds spread over the sky, and hide everything they wish to see. People, too, are very apt to laugh at their disappointment.
"There would, however, be no science of astronomy if those who pursued it were discouraged by common difficulties. To explain the heavenly bodies they sometimes try to make little systems or images of the sun and the planets; but they are never able to show the sizes and distances correctly. If they were to begin by making the sun one inch in diameter, then the earth would have to be three yards off, and as small as a grain of dust; some of the planets would have to be across the street, and others away beyond the opposite houses. So when you look at these little solar systems, as they are called, you must remember that the sizes and distances are all wrong.
Free books android app tbrJar TBR JAR Read Free books online gutenberg
(0)More posts by @FreeBooks
