The volume of the cone was discovered by Democritus... He did not prove it, he guessed it... not a blind guess, rather it was reasoned conjecture. As… - George Pólya
" "The volume of the cone was discovered by Democritus... He did not prove it, he guessed it... not a blind guess, rather it was reasoned conjecture. As Archimedes has remarked, great credit is due to Democritus for his conjecture since this made proof much easier. Eudoxes... a pupil of Plato, subsequently gave a rigorous proof. Surely the labor or writing limited his manuscript to a few copies; none has survived. In those days editions did not run to thousands or hundreds of thousands of copies as modern books—especially, bad books—do. However, the substance of what he wrote is nevertheless available to us. ...Euclid's great achievement was the systematization of the works of his predecessors. The Elements preserve several of Eudoxes' proofs.
About George Pólya
George Pólya (December 13, 1887 – September 7, 1985) was a Hungarian mathematician and professor of mathematics at ETH Zürich and at Stanford University. His work on heuristics and pedagogy has had substantial and lasting influence on mathematical education, and has also been influential in artificial intelligence.
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Additional quotes by George Pólya
Life is full of surprises: our approximate condition for the fall of a body through a resisting medium is precisely analogous to the exact condition for the flow of an electric current through a resisting wire [of an induction coil<nowiki>]</nowiki>. ...
<math>m\frac {dv}{dt} = mg - Kv</math>
This is the form most convenient for making an analogy with the "fall", i.e., flow, of an electric current.
...in order from left to right, mass <math>m</math>, rate of change of velocity <math>\frac {dv}{dt}</math>, gravitational force <math>mg</math>, and velocity <math>v</math>. What are the electrical counterparts? ...To press the switch, to allow current to start flowing is the analogue of opening the fingers, to allow the body to start falling. The fall of the body is caused by the force <math>mg</math> due to gravity; the flow of the current is caused by the electromotive force or tension <math>E</math> due to the battery. The falling body has to overcome the frictional resistance of the air; the flowing current has to overcome the electrical resistance of the wire. Air resistance is proportional to the body's velocity <math>v</math>; electrical resistance is proportional to the current <math>i</math>. And consequently rate of change of velocity <math>\frac {dv}{dt}</math> corresponds to rate of change of current <math>\frac {di}{dt}</math>. ...The electromagnetic induction <math>L</math> opposes the change of current... And doesn't the inertia or mass <math>m</math>..? Isn't <math>L</math>, so to speak, an electromagnetic inertia?
<math>L\frac {di}{dt} = E - Ki</math>