Linking Number:
Gauss' linking number of closed curves and algebraic topology.

Winding Number:
Understanding the Algebraic Topology underlying the winding number of a closed curve in the plane.

Hyperbolic Springs:
Deriving the ODE for a spring which is pushed in hyperbolic geometry (it oscillates!)

Convolution and Differentiation of Distributions:
If F is a distribution and g is a function, why is (DF)*g equal to F*Dg?

Topologizing The Space Of Distributions:
Why do we need to require convergence of the derivatives when defining a topology on the set of distributions?

Deep Time:
Some thoughts on the importance of appreciating the immensity of earth's history.

Life in Hyperbolic Space:
The dangers of life in a negatively curved space

Cassini:
Saying goodbye to my favorite space craft, on the eve of its entry into Saturn's atmosphere.

Cubics and Braids:
The bridge between the 3-strand braid group and the trefoil knot complement

Hopf:
An old note, from my early graduate school days, explaining the hopf fibration.