Jollywatt blog ⊕ portfolio
Basic general relativity with Julia
Four years after I took general relativity, my professor asked me to send him an old animation I had made during his course showing parallel transport of vectors around a line of latitude on the sphere. Actually, I wasn’t the one who had made it (though I was flattered that... Read more
Defining Entropy with a Composition Law
My favourite characterisation of (information) entropy with a ‘composition law’, and a uniqueness proof. Read more
Daylight Hours: A spherical geometry problem
How many hours are there between sunrise and sunset? The Earth’s tilt makes this a fun geometry problem… Read more
Billiard geometry: Visually solving elastic collisions
A neat relationship between elastic collisions and ellipses. Read more
Geometric Algebra for Special Relativity and Manifold Geometry · PDF
Master’s thesis in mathematical physics. Read more
World Flags Quizzer
A game to teach you world flags. 🇨🇳🇮🇳🇺🇸🇮🇩🇵🇰🇧🇷🇳🇬🇧🇩⋯ Read more
A Simple Example of a Connection With Torsion
While learning general relativity as an undergrad, I was uneasy with the idea of torsion of an affine connection. Familiar phrases like “torsion measures how a frame twists as it undergoes parallel transport” seemed too lofty to serve as a helpful mental model. The following example is one which gave... Read more
Timeline of Scientists
Interactive timeline of famous scientists throughout history, using Wikidata. Read more