“At the present time it is of course quite customary for physicists to trespass on chemical ground, for mathematicians to do excellent work in physics, and for physicists to develop new mathematical procedures… Trespassing is one of the most successful techniques in science.”
Source: Dynamics in Psychology, 1940, p. 116
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Wolfgang Köhler 12
German-American psychologist and phenomenologist 1887–1967Related quotes

Selected Papers of Freeman Dyson with Commentary. https://books.google.com/books?id=nnyNUidX1OMC&pg=PA1 American Mathematical Soc. (1996) p. 1

Richard Courant in: The Parsimonious Universe, Stefan Hildebrandt & Anthony Tromba, Springer-Verlag, 1996, page 148

As quoted in The Century: A Popular Quarterly (1874) ed. Richard Watson Gilder, Vol. 7, pp. 508-509, https://books.google.com/books?id=ceYGAQAAIAAJ&pg=PA508 "Relations of Mathematics to Physics". Earlier quote without citation in Nature, Volume 8 (1873), page 450.
Also quoted partially in Michael Grossman and Robert Katz, Calculus http://babel.hathitrust.org/cgi/mb?a=listis;c=216746186|Non-Newtonian (1972) p. iv. ISBN 0912938013.

“... like most physicists, I really enjoy talking about physics.”
[A Conversation with Nima Arkani-Hamed: The Power of Principles, Physics Revealed (Part I), April 2, 2021, Ideas Roadshow, YouTube, https://www.youtube.com/watch?v=h6_iJRY6nU4] (quote at 2:47 of 57:39)

Source: Ramanujan (1940), Ch. I : The Indian mathematician Ramanujan.