October 31 – 304.
The Kuen kabuki. In mathematics, a Zoll surface, named after Otto Zoll, is a surface homeomorphic to the 2-sphere, equipped with a Riemannian metric all of whose geodesics are closed and of equal length. The Kuen surface is a special case of Enneper’s negative curvature surfaces
Background: Hubble telescope. Galaxy Cluster MACS J0717, 5.4 billion light-years from Earth. It is one of the most complex galaxy clusters ever seen.
June 30 – 181
Rhino 5.0. Variation on the initial cross-section ellipses of the Wulf net. The graph is named after Russian mineralogist George Wulf and used to plot stereographic projections.
June 29 – 180
Rhino 5.0. Geometric construction used by Hipparchus in his determination of the distances to the sun and moon. Hipparchus of Nicaea was a Greek astronomer, geographer, and mathematician. He was credited to be among the first mathematicians to divide the circle in 360 degrees of 60 arc minutes.
June 28 – 179
Rhino 5.0. In geometry, when the angles opposite the equal sides of an isosceles triangle are themselves equal, the figure is known as the pons asinorum, (Latin for “bridge of donkeys”!) This statement, Proposition 5 of Book 1 in Euclid’s Elements, and is also known as the isosceles triangle theorem. Pons Asinorum is also the name given to a particular configuration of a Rubik’s Cube and used as a metaphor for finding the middle term of a syllogism.
June 27 – 178
Rhino 5.0. Pythagoras on a shelf. The Pythagorean theorem states that the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.
June 26 – 177
In finite geometry, a Fano plane is a finite projective plane of order 2, having the smallest possible number of points and lines, 7 each, with 3 points on every line and 3 lines through every point. This quasigroup template is being used in group theory construction and block design theory. It is named after Gino Fano, an Italian mathematician of the early 1900 who participated in the Klein encyclopedia of mathematical sciences.
June 25 – 176
Rhino 5.0. Tangential trapezoid. In Euclidean geometry, a tangential trapezoid, is a trapezoid whose four sides are all tangent to a circle within the trapezoid. Every isosceles tangential trapezoid is bicentric. That particular shape was also found on a Japanese Sangaku.