Mathematics in Action (1954) page 3
Time Reborn: From the Crisis in Physics to the Future of the Universe (2013)
An Outline of Philosophy Ch.15 The Nature of our Knowledge of Physics (1927)
1920s
Context: Physics is mathematical not because we know so much about the physical world, but because we know so little: it is only its mathematical properties that we can discover.
Book 9: "Nsara", § 5
The Years of Rice and Salt (2002)
From Lettre à Maurice Solvine, by A. Einstein (Gauthier-Villars: Paris 1956)
Attributed in posthumous publications, Albert Einstein: A guide for the perplexed (1979)
Elements de la géométrie de l'infini (1727) as quoted by Amir R. Alexander, Geometrical Landscapes: The Voyages of Discovery and the Transformation of Mathematical Practice (2002) citing Michael S. Mahoney, "Infinitesimals and Transcendent Relations: The Mathematics of Motion in the Late Seventeenth Century" in Reappraisals of the Scientific Revolution, ed. David C. Lindberg, Robert S. Westman (1990)
Inaugural lecture for his professorship of mathematical physics at the University of Utrecht (1913), as quoted by Davies, Mansel. Peter Joseph Wilhelm Debye: 1884-1966. Biographical Memoirs of Fellows of The Royal Society, Vol. 16 (1970).
Das Naturgesetz und die Struktur der Materie (1967), as translated in Natural Law and the Structure of Matter (1981), p. 34
Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, Vol. 123, No. 792 http://doi.org/10.1098/rspa.1929.0094 (6 April 1929)
Context: The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble. It therefore becomes desirable that approximate practical methods of applying quantum mechanics should be developed, which can lead to an explanation of the main features of complex atomic systems without too much computation.
Quoted by C. S. Hastings in "Biographical Memoir of Josiah Willard Gibbs 1839-1903," National Academy of Sciences Biographical Memoirs, vol. VI (Washington, D.C.: National Academy of Sciences, 1909), p. 390. Complete memoir http://books.nap.edu/html/biomems/jgibbs.pdf
Attributed
