On Principles III (Least Action)

"Nature is thrifty in all its actions." (Pierre L M Maupertuis, Accord de différentes lois de la nature qui avaient jusqu'ici paru incompatibles. Mémoires de l'Académie royale des Sciences, 1744)

"The laws of movement and of rest deduced from this principle being precisely the same as those observed in nature, we can admire the application of it to all phenomena. The movement of animals, the vegetative growth of plants [...] are only its consequences; and the spectacle of the universe becomes so much the grander, so much more beautiful, the worthier of its Author, when one knows that a small number of laws, most wisely established, suffice for all movements." (Pierre L M Maupertuis, "Les Loix du mouvement et du repos déduites d'un principe metaphysique", Histoire de l'Académie Royale des Sciences et des Belles Lettres, 1746)

"Nature does nothing in vain when less will serve; for Nature is pleased with simplicity and affects not the pomp of superfluous causes." (Sir Isaac Newton, "The Mathematical Principles of Natural Philosophy", Voll. II, 1803)

"The chief law of physics, the pinnacle of the whole system is, in my opinion, the principle of least action." (Max Planck, “A Survey of Physics”, 1925)

"In classical science, it was strange to find that action [...] should yet present the artificial aspect of an energy in space multiplied by a duration. As soon, however, as we realise that the fundamental continuum of the universe is one of space-time and not one of separate space and time, the reason for the importance of the seemingly artificial combination of space with time in the expression for the action receives a very simple explanation. Henceforth, action is no longer energy in a volume of space multiplied by a duration; it is simply energy in a volume of the world, that is to say, in a volume of four-dimensional space-time." (Aram D'Abro, "The Evolution of Scientific Thought from Newton to Einstein", 1927)

"Growth is limited by that necessity which is present in the least amount. And, naturally, the least favorable condition controls the growth rate." (Frank Herbert, "Dune", 1965)

"To a considerable degree science consists in originating the maximum amount of information with the minimum expenditure of energy. Beauty is the cleanness of line in such formulations along with symmetry, surprise, and congruence with other prevailing beliefs." (Edward O Wilson, "Biophilia", 1984)

"Physicists are all too apt to look for the wrong sorts of generalizations, to concoct theoretical models that are too neat, too powerful, and too clean. Not surprisingly, these seldom fit well with data. To produce a really good biological theory, one must try to see through the clutter produced by evolution to the basic mechanisms. What seems to physicists to be a hopelessly complicated process may have been what nature found simplest, because nature could build on what was already there." (Francis H C Crick, "What Mad Pursuit?: A Personal View of Scientific Discovery", 1988)

"It [science] has as its highest principle and most coveted aim the solution of the problem to condense all natural phenomena which have been observed and are still to be observed into one simple principle, that allows the computation of past and more especially of future processes from present ones. [...] Amid the more or less general laws which mark the achievements of physical science during the course of the last centuries, the principle of least action is perhaps that which, as regards form and content, may claim to come nearest to that ideal final aim of theoretical research." (Max Planck)

"[...] light travels between two given points along the path of shortest time [...]" (Pierre de Fermat)