Math Blog

Photograph of a rhodium-plated flower-like Harmonia pendant with six-fold symmetry on a black background

Symmetry and Groups

Symmetry Natural forms such as snowflakes, sea shells, water droplets, mineral crystals, and faces exhibit "symmetry." Often, symmetry correlates with beauty: a visual stimulus translated directly to sensations of pleasantness...

Symmetry and Groups

Symmetry Natural forms such as snowflakes, sea shells, water droplets, mineral crystals, and faces exhibit "symmetry." Often, symmetry correlates with beauty: a visual stimulus translated directly to sensations of pleasantness...

An algebraic plane curve rendered as a cone over a curve on the unit sphere

Projective Geometry

Rays and Perspective Imagine a flat floor extending to infinity in all directions and covered with square tiles, creating a Cartesian coordinate system. A parabola, such as the graph \(y...

Projective Geometry

Rays and Perspective Imagine a flat floor extending to infinity in all directions and covered with square tiles, creating a Cartesian coordinate system. A parabola, such as the graph \(y...

Conformal Torus Knots

Conformal Torus Knots

In this post we'll meet a staple at the Differential Geometry math art shop: Flat tori in four-space, and "conformal torus knots" lying on these surfaces. Although we generally strive...

Conformal Torus Knots

In this post we'll meet a staple at the Differential Geometry math art shop: Flat tori in four-space, and "conformal torus knots" lying on these surfaces. Although we generally strive...

A collection of hypocycloid curves with 15-fold symmetry, represented as green and blue dots on a black background

Compound Circular Motion

Circles and Parametrization Recall that a circle is the set of points in a plane lying at fixed radius \(r\) from a point, the center. In Cartesian coordinates, if \(c...

Compound Circular Motion

Circles and Parametrization Recall that a circle is the set of points in a plane lying at fixed radius \(r\) from a point, the center. In Cartesian coordinates, if \(c...

The complex squaring map between the complex plane at top and a surface obtained by wrapping the complex plane around itself twice at bottom.

Square roots with a complex twist

In this post we'll build a bridge starting with the parabola familiar from plane geometry and arriving at the “Riemann surface of the complex square root,” which often mystifies complex...

Square roots with a complex twist

In this post we'll build a bridge starting with the parabola familiar from plane geometry and arriving at the “Riemann surface of the complex square root,” which often mystifies complex...

Stereographic projection from a punctured sphere to the plane

Stereographic Projection and Möbius Transformat...

Perspective “Point projection” is a simple model for representing a three-dimensional scene on a planar canvas in perspective. Fix a plane \(P\) in Euclidean three-space and a point \(p\) not on \(P\). For...

Stereographic Projection and Möbius Transformat...

Perspective “Point projection” is a simple model for representing a three-dimensional scene on a planar canvas in perspective. Fix a plane \(P\) in Euclidean three-space and a point \(p\) not on \(P\). For...