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The history of experimental research is long and varied. Indeed, the definition of an experiment itself has changed in responses to changing norms and practices within particular fields of study. This article documents the history and development of experimental research from its origins in Galileo's study of gravity into the diversely applied method in use today. ==Galileo Galilei== Galileo Galilei was a scientist who performed many quantitative experiments addressing many topics. Using several different methods, Galileo was able to accurately measure time. Previously, most scientists had used distance to describe falling bodies using geometry, which had been used and trusted since Euclid.〔Drake, Stillman; Swerdlow, Noel M.; Levere, Trevor Hardly. Essays on Galileo and the history and philosophy of science, Volume 3. Page 22. University of Toronto Press. 1999. ISBN 978-0-8020-4716-8.〕 Galileo himself used geometrical methods to express his results. Galileo's successes were aided by the development of a new mathematics as well as cleverly designed experiments and equipment. At that time, another kind of mathematics was being developed—algebra. Algebra allowed arithmetical calculations to become as sophisticated as geometric ones. Algebra also allowed the discoveries of scientists such as Galileo—as well as later scientists like Newton, Maxwell and Einstein—to be later summarized by mathematical equations. These equations described physical relationships in a precise, self-consistent manner. One prominent example is the "ball and ramp experiment."〔Solway, Andrew. Exploring forces and motion. Page 17. The Rosen Publishing Group. 2007. ISBN 978-1-4042-3747-6〕 In this experiment Galileo used an inclined plane and several steel balls of different weights. With this design, Galileo was able to slow down the falling motion and record, with reasonable accuracy, the times at which a steel ball passed certain markings on a beam.〔Stewart, James. Redlin, Lothar. Watson, Saleem. College Algebra. Page 562. Cengage Learning. 2008. ISBN 978-0-495-56521-5〕 Galileo disproved Aristotle's assertion that weight affects the speed of an object's fall. According to Aristotle's Theory of Falling Bodies, the heavier steel ball would reach the ground before the lighter steel ball. Galileo's hypothesis was that the two balls would reach the ground at the same time. Other than Galileo, not many people of his day were able to accurately measure short time periods, such as the fall time of an object. Galileo accurately measured these short periods of time by creating a pulsilogon. This was a machine created to measure time using a pendulum.〔Massachusetts Medical Society, New England Surgical Society. The Boston Medical and Surgical Journal, Volume 125. Page 314. Cupples, Upham & Co. 1891〕 The pendulum was synchronized to the human pulse. He used this to measure the time at which the weighted balls passed marks that he had made on the inclined plane. He measured to find that balls of different weights reached the bottom of the inclined plane at the same time and that the distance traveled was proportional to the square of the elapsed time.〔Tiner, John Hudson. Exploring the World of Physics: From Simple Machines to Nuclear Energy. New Leaf Publishing Group. 2006. ISBN 0-89051-466-6〕 Later scientists summarized Galileo's results as The Equation of Falling Bodies.〔Longair, M.S. Theoretical concepts in physics: an alternative view of theoretical reasoning in physics. Page 37. Cambridge University Press. 2003. ISBN 978-0-521-52878-8〕〔Schutz, Bernard F. Gravity from the ground up. Page 3. Cambridge University Press. 2003. ISBN 978-0-521-45506-0〕 gt^2 |-valign="top" |} These results supported Galileo's hypothesis that objects of different weights, when measured at the same point in their fall, are falling at the same speed because they experience the same gravitational acceleration. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「History of experiments」の詳細全文を読む スポンサード リンク
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