Editing Thought experiment (section)

==History==
The ancient Greek {{langx|grc|δείκνυμι|deiknymi|thought experiment|label=none}}, "was the most ancient pattern of [[mathematical proof]]", and existed before [[Euclidean geometry|Euclidean mathematics]],<ref>Szábo, Árpád. (1958) " 'Deiknymi' als Mathematischer Terminus fur 'Beweisen' ", ''Maia'' N.S. '''10''' pp. 1–26 as cited by [[Imre Lakatos]] (1976) in ''[[Proofs and Refutations]]'' p. 9. (John Worrall and Elie Zahar, eds.) Cambridge University Press {{ISBN|0-521-21078-X}}. The English translation of the title of Szábo's article is "'Deiknymi' as a mathematical expression for 'to prove'", as translated by András Máté {{cite journal | doi=10.1162/posc.2006.14.3.282 | url= http://cimm.ucr.ac.cr/ciaem/articulos/historia/filo/%C3%81rpad%20zs%C3%A1bo%20and%20imre%20lakatos,%20or%20the%20relation%20between%20history%20and%20philosophy%20of%20mathematics.*M%C3%A1t%C3%A9,%20Andr%C3%A1s.*Lakatos.pdf | archive-url=https://web.archive.org/web/20120425231500/http://cimm.ucr.ac.cr/ciaem/articulos/historia/filo/%C3%81rpad%20zs%C3%A1bo%20and%20imre%20lakatos,%20or%20the%20relation%20between%20history%20and%20philosophy%20of%20mathematics.*M%C3%A1t%C3%A9,%20Andr%C3%A1s.*Lakatos.pdf|archive-date=25 April 2012 |title= Árpád Szabó and Imre Lakatos, or the Relation Between History and Philosophy of Mathematics | journal=Perspectives on Science | date= Fall 2006 | volume= 14 |issue=3|pages= 282–301 especially pp. 285,288 | last1= Máté | first1= András }}</ref> where the emphasis was on the conceptual, rather than on the experimental part of a thought experiment.

Johann Witt-Hansen established that [[Hans Christian Ørsted]] was the first to use the equivalent German term {{lang|de|Gedankenexperiment}} {{circa|1812}}.<ref>Witt-Hansen (1976). Although {{lang|de|Experiment}} is a German word, it is derived from [[Latin]]. The synonym {{lang|de|Versuch}} has purely [[Germanic languages|Germanic]] roots.</ref><ref name = "B&F">{{Cite encyclopedia |title= Thought Experiments | orig-date=1996 | last1=Brown |first1=James Robert |url=https://plato.stanford.edu/archives/win2019/entries/thought-experiment/ |encyclopedia=The Stanford Encyclopedia of Philosophy |last2=Fehige |first2=Yiftach |date=30 September 2019 |publisher=Metaphysics Research Lab, Stanford University |editor-last=Zalta |editor-first=Edward N. }}</ref> Ørsted was also the first to use the equivalent term {{lang|de|Gedankenversuch}} in 1820.

By 1883, [[Ernst Mach]] used {{lang|de|Gedankenexperiment}} in a different sense, to denote exclusively the {{em|imaginary}} conduct of a {{em|real}} experiment that would be subsequently performed as a {{em|real physical experiment}} by his students.<ref>Mach, Ernst (1883), The Science of Mechanics (6th edition, translated by Thomas J. McCormack), LaSalle, Illinois: Open Court, 1960.  pp. 32–41, 159–62.</ref> Physical and mental experimentation could then be contrasted: Mach asked his students to provide him with explanations whenever the results from their subsequent, real, physical experiment differed from those of their prior, imaginary experiment.

The English term ''thought experiment'' was coined as a [[calque]] of {{lang|de|Gedankenexperiment}}, and it first appeared in the 1897 English translation of one of Mach's papers.<ref>Mach, Ernst (1897), "On Thought Experiments", in ''Knowledge and Error'' (translated by Thomas J. McCormack and Paul Foulkes), Dordrecht Holland: Reidel, 1976, pp. 134-47.</ref> Prior to its emergence, the activity of posing hypothetical questions that employed subjunctive reasoning had existed for a very long time for both scientists and philosophers. The [[irrealis moods]] are ways to categorize it or to speak about it. This helps explain the extremely wide and diverse range of the application of the term ''thought experiment'' once it had been introduced into English.

[[File:Thought-experiment-free-falling-bodies.svg|thumb|Galileo's thought experiment concerned the outcome (c) of attaching a small stone (a) to a larger one (b).]]
[[Galileo Galilei|Galileo's]] demonstration that falling objects must fall at the same rate regardless of their masses was a significant step forward in the history of modern science. This is widely thought<ref>Cohen, Martin, "Wittgenstein's Beetle and Other Classic Thought Experiments", Blackwell, (Oxford), 2005, pp. 55–56.</ref> to have been a straightforward physical demonstration, involving climbing up the Leaning Tower of Pisa and dropping two heavy weights off it, whereas in fact, it was a logical demonstration, using the thought experiment technique. The experiment is described by Galileo in {{lang|it|[[Two New Sciences|Discorsi e dimostrazioni matematiche]]}} (1638) (from [[Italian language|Italian]]: 'Mathematical Discourses and Demonstrations') thus:

{{blockquote|{{lang|it|Salviati}}. If then we take two bodies whose natural speeds are different, it is clear that on uniting the two, the more rapid one will be partly retarded by the slower, and the slower will be somewhat hastened by the swifter. Do you not agree with me in this opinion?

{{lang|it|Simplicio}}. You are unquestionably right.

{{lang|it|Salviati}}. But if this is true, and if a large stone moves with a speed of, say, eight while a smaller moves with a speed of four, then when they are united, the system will move with a speed less than eight; but the two stones when tied together make a stone larger than that which before moved with a speed of eight. Hence the heavier body moves with less speed than the lighter; an effect which is contrary to your supposition. Thus you see how, from your assumption that the heavier body moves more rapidly than the lighter one, I infer that the heavier body moves more slowly.<ref>{{Cite web |title=Galileo on Aristotle and Acceleration |url=http://galileoandeinstein.physics.virginia.edu/tns61.htm |access-date=2008-05-24}}</ref>}}