Cosmic Connection by Carl Sagan Page B

surface of Mars–what could be more extravagant! However, it is only with the advent of reactive vehicles that a new and great era in astronomy will begin, the epoch of a careful study of the sky… The prime motive of my life is to do something useful for people… That is why I have interested myself in things that did not give me bread or strength. But I hope that my studies will, perhaps soon but perhaps in the distant future, yield society mountains of grain and limitless power.
    -K. E. Tsiolkovsky, 1912



10. On Teaching the First Grade
    A friend in the first grade asked me to come to talk to his class, which, he assured me, knew nothing about astronomy but was eager to learn. With the approval of his teacher, I arrived at his school in Mill Valley, California, armed with twenty or thirty color slides of astronomical objects–the Earth from space, the Moon, the planets, exploding stars, gaseous nebulae, galaxies, and the like–which I thought would amaze and intrigue and, perhaps to a certain extent, even educate.
    But before I began the slide show for these bright-eyed and cherubic little faces, I wanted to explain that there is a big difference between stating what science has discovered and describing how scientists found it all out. It is pretty easy to summarize the conclusions. It is hard to relate all the mistakes, false leads, ignored clues, dedication, hard work, and painful abandonment of earlier views that go into the initial discovery of something interesting.
    I began by saying, “Now you have all heard that the Earth is round. Everybody believes that the Earth is round. But why do we believe the Earth is round? Can any of you think of any evidence that the Earth is round?”
    For most of the history of mankind, it was reverently held that the Earth is flat–as is entirely obvious to anyone who has stood in a Nebraska cornfield around planting time. The concept of a flat Earth is still built into our language in such phrases as “the four corners of the Earth.” I thought I would stump my little firstgraders and then explain with what difficulty the sphericity of Earth had come into general human consciousness. But I had underestimated the first grade of Mill Valley.
    “Well,” asked a moppet in the sort of one-piece coverall worn by railroad engineers, “what about this business of a ship that’s sailing away from you, and the last thing you see is the master, or whatever it’s called, that holds up the sail? Doesn’t that mean that the ocean has to be curved?”
    “What about when there’s an ellipse of the Moon? That’s when the Sun is behind us and the shadow of the Earth is on the Moon, right? Well, I saw an ellipse . That shadow was round, it wasn’t straight. So the Earth has to be round.”
    “There’s better proof, much better proof,” offered another. “What about that old guy who sailed around the world–Majello? You can’t sail around the world if it isn’t round, right? And people today sail around the world and fly around the world all the time. How can you fly around the world if it isn’t round?”
    “Hey, listen, you kids, don’t you know there’s pictures of the Earth?” added a fourth. “Astronauts have been in space, they took pictures of the Earth; you can look at the pictures, the pictures are all round. You don’t have to use all these funny reasons. You can see that the Earth is round.”
    And then, as the coup de grâce , one pinafored little girl, recently taken on an outing to the San Francisco Museum of Science, casually inquired, “What about the Foucault pendulum experiment?”
    It was a very sobered lecturer who went on to describe the findings of modern astronomy. These children were not the offspring of professional astronomers or college teachers or physicians or the like. They were apparently ordinary firstgrade children. I very much hope–if they can survive twelve to twenty years of regimenting “education”–that they will hurry and