|
"If a tree falls in a forest and no one is around to hear it, does it make a sound?" is a philosophical thought experiment that raises questions regarding observation and knowledge of reality. ==History== Philosopher George Berkeley, in his work, ''A Treatise Concerning the Principles of Human Knowledge'' (1710), proposes, "But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park () and nobody by to perceive them.〔''A Treatise Concerning the Principles of Human Knowledge'', 1734. section 23.〕 () The objects of sense exist only when they are perceived; the trees therefore are in the garden () no longer than while there is somebody by to perceive them."〔''A Treatise Concerning the Principles of Human Knowledge'', 1734. section 45.〕 (It is worth noting that the quote from section 45 is arguably a statement of an ''objection'' to Berkeley's view, and not a proclamation of it.) Nevertheless, Berkeley never actually wrote about the question.〔Whether Berkeley thought objects continued to exist when unperceived by finite minds, and if so, in what manner, is the subject of serious debate among Berkeley scholars.〕 Some years later, a similar question is posed. It is unknown whether the source of this question is Berkeley or not. In June 1883 in the magazine ''The Chautauquan'', the question was put, "If a tree were to fall on an island where there were no human beings would there be any sound?" They then went on to answer the query with, "No. Sound is the sensation excited in the ear when the air or other medium is set in motion."〔''The Chautauquan'', June 1883, Volume 3, Issue 9, p. 543〕 This seems to imply that the question is posed not from a philosophical viewpoint, but from a purely scientific one. The magazine ''Scientific American'' corroborated the technical aspect of this question, while leaving out the philosophic side, a year later when they asked the question slightly reworded, "If a tree were to fall on an uninhabited island, would there be any sound?" And gave a more technical answer, "Sound is vibration, transmitted to our senses through the mechanism of the ear, and recognized as sound only at our nerve centers. The falling of the tree or any other disturbance will produce vibration of the air. If there be no ears to hear, there will be no sound."〔''Scientific American'', April 5, 1884, pg 218.〕 Albert Einstein is reported to have asked his fellow physicist and friend Niels Bohr, one of the founding fathers of quantum mechanics, whether he realistically believed that 'the moon does not exist if nobody is looking at it.' To this Bohr replied that however hard he (Einstein) may try, he would not be able to prove that it does, thus giving the entire riddle the status of a kind of an infallible conjecture—one that cannot be either proved or disproved. The current phrasing appears to have originated in the 1910 book ''Physics'' by Charles Riborg Mann and George Ransom Twiss. The question "When a tree falls in a lonely forest, and no animal is near by to hear it, does it make a sound? Why?" is posed along with many other questions to quiz readers on the contents of the chapter, and as such, is posed from a purely physical point of view.〔Mann, Charles Riborg and George Ransom Twiss. ''Physics''. Scott, Foresman and Co., 1910, p. 235.〕 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「If a tree falls in a forest」の詳細全文を読む スポンサード リンク
|