John Strutt, 3rd Baron Rayleigh

“Without encroaching upon grounds appertaining to the theologian and the philosopher, the domain of natural sciences is surely broad enough to satisfy the wildest ambition of its devotees. The work may be hard, and the discipline severe; but the interest never fails, and great is the privilege of achievement.,”

John Strutt, 3rd Baron Rayleigh

Entropy

“You should call it entropy, for two reasons. In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, no one really knows what entropy really is, so in a debate you will always have the advantage.”

Suggesting to Claude Shannon a name for his new uncertainty function, as quoted in Scientific American Vol. 225 No. 3, (1971), p. 180.

Ernst Mach

“I know of nothing more terrible than the poor creatures who have learned too much. Instead of the sound powerful judgement which would probably have grown up if they had learned nothing, their thoughts creep timidly and hypnotically after words, principles and formulae, constantly by the same paths. What they have acquired is a spider’s web of thoughts too weak to furnish sure supports, but complicated enough to provide confusion.”

Ernst Mach

Leonardo da Vinci

“The object that strikes the air develops a force equal to that of the air that strikes the object. Observe how the beating of its wings against the air suffices to bear up the weight of the eagle in the highest and thinnest air. Observe too that, conversely, the air fills the sails and pushes the heavily laden ship. From this you can understand that man, with great wings, acting against the resistance of air, might overcome it victoriously and rise above it,”

Leonardo da Vinci

Lucasian Professor George Gabriel Stokes

“I was capable of being moved, mathematically, as it were, by the belief that a particular course was right; and I do believe that God put these views in my mind, working by means of that which was in me to supply that which was wanting,”

Lucasian Professor George Gabriel Stokes

“Then it is right that you should even now draw back, nor heed though I should go to the grave a thinking machine unenlivened and uncheered and unwarmed by the happiness of domestic affection,” (on receiving reply of his 55 page essay to his future wife on why they should not be marreid)

Lucasian Professor George Gabriel Stokes

Leonardo da Vinci

“The great bird will take its first flight on the back of a great swan; filling the universe with wonders; filling all writings with its fame and bringing eternal glory to the nest from which it came,”

Leonardo da Vinci

Constatin

The Reynolds equations are still a riddle. They are based on the Navier-Stokes equations, which are still a mystery. The Navier-Stokes equations are a viscous regularization of the Euler equations, which are still an enigma. Turbulence is a riddle wrapped in a mystery inside an enigma.

~Constatin, P. “Euler equations, NSE and turbulence,” Mathematical Foundations of Turbulent Viscous Flows, Lecture notes in mathematics, 2006. pp. 1-43

Pierre-Simon Laplace

“Were she then to watch me live through it, she might smile condescendingly, as one who watches a marionette dance to the tugs of strings that it knows nothing about”

Causal Determinism, The Stanford Encyclopedia of Philosophy (Winter 2008 Edition), Edward N. Zalta (ed.). Pierre-Simon Laplace

“The curve described by a simple molecule of air or vapor is regulated in a manner just as certain as the planetary orbits; the only difference between them is that which comes from our ignorance.”

Laplace, P., 1820, Essai Philosophique sur les Probabilits, Paris: V Courcier; repr. F.W. Truscott and F.L. Emory (trans.), A Philosophical Essay on Probabilities, New York: Dover, 1951. Pierre-Simon Laplace

“Je n’avais pas besoin de cette hypothèse-là”

Rouse Ball (1908) Pierre-Simon Laplace

“Lisez Euler, lisez Euler, c’est notre maître à tous.”

Dunham, William (1999). Euler: The Master of Us All. The Mathematical Association of America. xiii. Pierre-Simon Laplace