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BEGINNINGS OF SCIENCE
1. Some Questions to Think About. — Did you ever wonder why water runs down hill and not upward ? Or why a kite flies, why trees shed their leaves, why plants produce seeds, why dew is formed, why milk sours, why yeast raises bread, why the moon grows and wanes, why the sun gives off heat? Did you ever wonder what fire, sound, light, and electricity are, why we have eclipses of the sun and the moon, what lightning is, how soil is formed, why grass is green, how we are nourished by our food ?
There seems to be no end to the questions you can ask yourself regarding the objects you see and what happens to them. So far as we know, men have always wondered about the earth and the sky; they seem always to have tried to find the reason for the many things that happen in this world of ours. To be sure, the answers they first gave would probably sound very foolish to us, but gradually men were able to give well-thought-out and common-sense answers to questions regarding nature; their answers are what we study in Science.
2. Old and New Answers. You have probably read about some of the strange ideas of men of past times. If you had asked, a few centuries ago, what causes an eclipse of the sun, you might have been told that a great beast or spirit moves across the sky and blots out the sun; afterwards men saw that an eclipse of the sun never occurs except at the time of “ new moon,” that is, when the moon is between the sun and the earth (cf. $ 92). So they decided that it is the moon, not a beast or spirit, that sometimes comes exactly between us and the sun.
We have all read how men made fun of Columbus because he believed that the earth is a sphere; the people of his day felt certain that if the earth were round, the people on the other side of it must be standing heads down. Since the days of Columbus we have become used to the idea that we are living on a great, round ball; we see that“ down toward the earth's center, while “up” means away from it; we are not afraid that we may become dizzy from standing topsy turvy, nor that the earth will in some way lose its grip upon us and let us drop off into space.
Franklin helped us to understand another mystery of nature: the lightning. No doubt many people thought him foolish, on that June day in 1752, to send up a kite (Fig. 1) when a thunderstorm was coming on. But men since that time have honored Franklin, because his experiment showed that lightning is only a great electric spark. So we might go on with stories of how common-sense ideas of nature grew up among men.
3. What is Science ? — Columbus and Franklin and other great discoverers and inventors were able to do big things for the world because they learned early to notice common things and to think clearly about them.