Editing Simon Stevin (section)

=== Geometry, physics and trigonometry ===
[[File:StevinEquilibrium.svg|thumb|Stevin's proof of the [[Inclined plane#History|law of equilibrium on an inclined plane]], known as the "Epitaph of Stevinus".]]
Stevin was the first to show how to model regular and semiregular [[polyhedra]] by delineating their frames in a plane. He also distinguished stable from unstable equilibria.<ref name=EB1911/>

Stevin contributed to [[trigonometry]] with his book, ''De Driehouckhandel''.

In ''The First Book of the Elements of the Art of Weighing, The second part: Of the propositions [The Properties of Oblique Weights], Page 41, Theorem XI, Proposition XIX'',<ref>[http://www.dwc.knaw.nl/pub/bronnen/Simon_Stevin-%5BI%5D_The_Principal_Works_of_Simon_Stevin,_Mechanics.pdf The Principal Works of Simon Stevin]</ref> he derived the condition for the balance of forces on [[inclined plane]]s using a diagram with a "wreath" containing evenly spaced round masses resting on the planes of a triangular prism (see the illustration on the side). He concluded that the weights required were proportional to the lengths of the sides on which they rested assuming the third side was horizontal and that the effect of a weight was reduced in a similar manner. It is implicit that the reduction factor is the height of the triangle divided by the side (the [[Sine#History|sine]] of the angle of the side with respect to the horizontal). The proof diagram of this concept is known as the "Epitaph of Stevinus". As noted by [[E. J. Dijksterhuis]], Stevin's proof of the equilibrium on an inclined plane can be faulted for using [[perpetual motion]] to imply a [[reductio ad absurdum]]. Dijksterhuis says Stevin "intuitively made use of the principle of [[conservation of energy]] ... long before it was formulated explicitly".<ref name=EJD/>{{rp|54}}

He demonstrated the resolution of forces before [[Pierre Varignon]], which had not been remarked previously, even though it is a simple consequence of the law of their composition.<ref name=EB1911/>

Stevin discovered the [[hydrostatic paradox]], which states that the pressure in a liquid is independent of the shape of the vessel and the area of the base, but depends solely on its height.<ref name=EB1911/>

He also gave the measure for the pressure on any given portion of the side of a vessel.<ref name=EB1911/>

He was the first to explain the [[tides]] using the [[Theory of tides|attraction of the moon]].<ref name=EB1911/>

In 1586, he [[Delft tower experiment|demonstrated]] that two objects of different weight fall with the same acceleration.<ref>Appendix to [[De Beghinselen Der Weeghconst]]</ref><ref>{{Cite book|url=https://books.google.com/books?id=YicuDwAAQBAJ&q=delft+tower+experiment&pg=PA26|title=Ripples in Spacetime: Einstein, Gravitational Waves, and the Future of Astronomy|last=Schilling|first=Govert|date=2017-07-31|publisher=Harvard University Press|isbn=9780674971660|language=en}}</ref>