Sometimes a post is just a germ of an idea, a fleeting thought that leads to nowhere in particular. These posts are short.
Logical Formulae
Since the COVID-19 crisis and the university moving to online instruction, I've spent too much time programming WeBWorK assignments. …
Poohsticks and differential geometry
Random thought: Poohsticks illustrates well Lie differentiation
One and two (space-time) dimensional general relativity
Life is boring in low dimensions.
Where Does The π Go
It is fairly well known that experts in partial differential equations and experts in harmonic analysis prefer to define the Fourier …
Symmetry and Uniformization
A bit of trivia (can't think of any use of it now)
Theorem Let $(M,g)$ be a two-dimensional compact Riemannian manifold with …