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Chapter 7: Hyperbolic Geometry. References : Euclidean and Non-Euclidean Geometries: Development and History 4 th ed By Greenberg Modern Geometries: Non-Euclidean, Projective and Discrete 2 nd ed by Henle Roads to Geometry 2 nd ed by Wallace and West
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Chapter 7:Hyperbolic Geometry References: Euclidean and Non-Euclidean Geometries: Development and History 4th ed By Greenberg Modern Geometries: Non-Euclidean, Projective and Discrete 2nd ed by Henle Roads to Geometry 2nd ed by Wallace and West Hyperbolic Geometry, by Cannon, Floyd, Kenyon, and Parry from Flavors of Geometry http://myweb.tiscali.co.uk/cslphilos/geometry.htm http://en.wikipedia.org/wiki/Tessellation http://www.math.umn.edu/~garrett/a02/H2.html http://www.geom.uiuc.edu/~crobles/hyperbolic/hypr/modl/
Euclid’s Postulates (Henle, pp. 7-8) • A straight line may be drawn from a point to any other point. • A finite straight line may be produced to any length. • A circle may be described with any center and any radius. • All right angles are equal. • If a straight line meet two other straight lines so that as to make the interior angles on one side less than two right angles, the other straight lines meet on that side of the first line.
Euclid’s Fifth Postulate • Attempts to deduce the fifth postulate from the other four. • Nineteenth century: Carefully and completely work out the consequences of a denial of the fifth postulate. • Alternate assumption: Given a line and a point not on it, there is more than one line going through the given point that is parallel to the given line.
People Involved • F.K. Schweikart (1780-1859) • F.A. Taurinus (1794-1874) • C.F. Gauss (1777-1855) • N.I. Lobachevskii (1793-1856) • J. Bolyai (1802-1860)
Circle Limit III by M. C. Escher (1959) from http://en.wikipedia.org/wiki/Tessellation http://www.math.umn.edu/~garrett/a02/H2.html
Disk Models Poincare Disk Klein-Beltrami Model