This is the second article about how working with temporal information in computer systems. The first article was about contained some definitions about astronomical time and timezones.

This article describes options for storing temporal values in your programs, and their limitations. In particular, it describes two pitfalls that can happen …

Here are some notes for my Fluid Dynamics II students about vectors, pseudovectors and how they transform under reflections.

Let n be a unit vector and consider the reflection R in the plane perpendicular to n.

Quantities such as the position r and velocity v are regular vectors and transform …

This is a collection of notes about time and related concepts. A future post will talk about the problems of representing time in computer systems, especially distributed systems. These notes will be occasionally updated.

Introduction

Time is taken to be a primitive concept that cannot be defined in terms of …

I have been reading – at a very shallow level – about category theory (wiki), and thinking about its applicability to software and system design for data engineering. This post is a loose collection of thoughts on the subject, and a manifesto for employing a more rigorous language when building such systems …

What is a variational principle?

A variational principle is a mathematical or physical law expressed in terms of maximising or minimising a certain quantity. The simplest example was known to ancient Egyptian builders and surveyers: a taut rope stretched between two points takes the shape that minimises its length. This …