PREFACE
The course you are about to take—Atoms & Stars—presupposes no familiarity with science or mathematics. It flirts with mathematics and mathematical equations only briefly. Although it will acquaint you with a few basic physical and astronomical conceptions, doing so is not its main purpose. It tries, rather, to show you what science is and how scientists acquire new beliefs and explanations. It seeks to demonstrate the commonsense nature of science. It attempts to show that, despite the arcane language of some scientific fields and despite the aura of inaccessibility and mystery given to science by the popular media, its methods, goals, and main features can for the most part be understood by the layman. It seeks, besides, to arouse your curiosity about the world around you.
The first few articles we put together for this Reader begin with theoretical discussions of the scientific method, followed by a few historical episodes which illustrate this method.
We shall then move on to a brief review of some contemporary physical conceptions of reality. This part will tell you what material objects—like water, salt, and leaves of grass—are made of. It would tell you what you might be able to see if you possessed Alice in Wonderland's ability to become as small as small can be. Your senses can't detect remote galaxies or Jupiter's moons—you need a telescope to know that they even exist. Similarly, your senses can't tell you what substances like sticks and stones are made of. Since the Lilliputian land of the atom is invisible to us, we can only make some inferences on how it would look if we could become infinitely small. This course will tell you what some of these inferences are—what the community of physicists imagine simple objects like a gold earring and glass window to be made of. We shall then explore at some length how humanity's conceptions of the nature of heat have developed and changed over the centuries. We shall also try to describe some paths along which the lone discoverers who contributed to this picture traveled.
We then travel back to the ancient Greek World, the birthplace of rational inquiry and science. The Reader tries to capture the flavor of this bygone era through the lives and discoveries of a few prominent Greek intellectuals.
We then move on to a review of modern astronomy. Contemporary astronomical conceptions, e.g., of the solar system, the Milky Way, the origin of the universe, the birth and death of stars, are of fundamental importance to understanding humanity's place in nature. Why do we reject the time-honored belief that the sun revolves around the Earth? We depend on sunshine for survival, but how and why does the sun generate light? Will the sun shine forever? Will it one day become so hot as to destroy all life on Earth? Will it stop shining? What will happen to our descendants then? Can we colonize stars outside the solar system? Why is life as we know it impossible on the moon? Why is Mars freezing cold and Venus sizzling hot? If the Earth is gravitated to the sun, why doesn't it just fall into it? This part of Atoms & Stars will provide answers to these, and many other, fascinating questions.
But this course is not only concerned with contemporary conceptions of reality. We also want to know some of the reasons which lead scientists to believe in them, and the intellectual and psychological paths which led astronomical explorers to these conceptions. To demonstrate this frail and all-too-human aspect of astronomy, the Reader will highlight Johannes Kepler's discoveries of the laws which govern the motions of planets around the sun.
Learning is a radically different activity than watching TV news. To get anywhere, you must bring something of yourself into the process. One way of doing this is through actual experimentation. Such hands-on activities also give you a better appreciation for the methods and scientific ideas under consideration and they build your confidence as a science student. For these reasons, the course includes a few take-home experiments. We shall also try to put some flesh on our sometimes abstract discussions through occasional in-class demonstrations and films.
Besides curiosity, open-mindedness, and the ability to speak and read English, the course requires one additional attribute. This attribute can perhaps be captured through an anecdote. In his book the Elements, written in Alexandria some 23 centuries ago, Euclid put together much of the mathematical wisdom of the ancient world. King Ptolemy, legend tells us, came across the famous professor's treatise. Finding it either too difficult or too time consuming, he asked Euclid if there was a faster way of learning geometry than struggling through the Elements. To which Euclid replied: "there is no royal road to geometry."
Royalty or wealth can buy you a ticket in a supersonic jet, thereby getting you to London or Paris quickly and comfortably. But they can't buy you an understanding of yourself, other people, and the world around you. We invite you to climb a few steep hills. The view from the top, we promise, is worth the trouble of getting there. We have been there before and can lead you along some of the best trails. Despite occasional missteps, we shall try to make your climb as enjoyable and easy as we can. But we can't do your legwork for you. We hope you join us, and we hope you know the terms: We provide guidance and companionship; you provide the time and intellectual effort.