Robert Talbert's Tumbleblog

Calculus is the mathematical study of change. Its essence is best captured by its original name, “fluxions,” coined by its inventor, Isaac Newton. The name calls to mind systems that are ever in motion, always unfolding.
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Calculus thrives on continuity. At its core is the assumption that things change smoothly, that everything is only infinitesimally different from what it was a moment before. Like a movie, calculus reimagines reality as a series of snapshots, and then recombines them, instant by instant, frame by frame, the succession of imperceptible changes creating an illusion of seamless flow.

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Steven Strogatz, The Calculus of Friendship-p. xii, 1

Found at http://matlabician.wordpress.com/quotations/