Template:Are You Sure/October 24

Letter from Isaac Newton to Gottfried Wilhelm Leibniz (via Henry Oldenburg). Newton writes partially in code, with the intention of establishing his priority in the calculus dispute while simultaneously concealing his method from Leibniz.

• ... that Isaac Newton (25 December 1642 – 20 March 1726/27) wrote, in a letter to Gottfried Wilhelm Leibniz (via Henry Oldenburg): "the basis of these operations, sufficiently obvious (since now I cannot continue my explanation) I have thus rather concealed 6a 2c d æ13e 2f 7i 3l 9n 4o 4q 2r 4s 9t 12v x."; and that the decoded sentence was later published by Wallis as Data Æquatione quotcumque, fluentes quantitates involvente, fluxiones invenire, et vice versa ("Given any equation, involving fluent quantities, to find the fluxions, and vice versa"); and that fluentes in the work of Newton are changing quantities, and fluxions their rates of change?

• ... that minister, scholar, astronomer, mathematician, cartographer, and inventor Wilhelm Schickard (22 April 1592 – 24 October 1635) designed and built calculating machines; and that he also invented techniques for producing improved maps?

• ... that physicist, inventor, and crime-fighter Galileo Galilei uses Tycho Brahe's observatory to detect and prevent crimes against astronomical constants?