Theories for Everything [antikvár]

INTRODUCTION When we turn on the radio or TV; when we receive a vaccination to prevent disease; when we recognize that although the sun seems to rise and set, it's actually the Earth and not the sun that is moving—in aU these moments, we are reaping the benefits of thousands of years of human efforts to comprehend Earth's physical and biological phenomena. While mysteries do remain, we have come to know a great deal about the nature of the planet on which we live as weU as the universe beyond. The pursuit of such knowledge we call science, a word whose Greek root means not only "to know" but also "to discern" or "to separate one thing from another." The object of science is not simply to discover facts but to find general truths and articulate fundamental laws. Scientist call such intellectual constructs "theories." In science, "theory" does not mean "speculation" or "idea," as it does in everyday conversation. A scientific theory is a presentation of fact. It has been arrived at by what is known as the scientific method, an accepted procedure of logic by which scientists test a hypothesis through carefiil observation, experimentation, and measurement. A hypothesis, or a set of hypotheses, that has withstood every attempt to prove it false may be called a theory. Thus the theories of gravity or evolution are not conjectures. They describe fundamental facts about Ufe on Earth just as do Newton's laws of motion, Boyle's law of gases, Mendel's laws of heredity, and the law of conservation of energy. Can a theory be proved false? If science finds contradictory evidence, and if that evidence, once tested, proves sound, then a theory will either be changed, if it can be, to accommodate the new evidence or it will be discarded. A theory must be potentially falsifiable—that is, made up of assertions that in principle can be proved wrong by evidence— since, as opposed to conjectures or