# Pairs ancient and modern for security

I was struck recently by how often pairs crop up in things to do with security, and for how long this has been true. I’ll go into two similar old techniques to do with documents – indenture and chirograph, and an old pair-based object (the split tally) and then two things enabled by the current … Continue reading Pairs ancient and modern for security

# Representing numbers

I’ve recently been doing more maths than usual using Roman numerals, which has got me thinking about the relationship between how numbers are represented and how easy it is for them to do different jobs for us. I’ll go into a few representations below, and their good and bad points. I won’t talk about floating … Continue reading Representing numbers

# Multiplying using halving, doubling and summing

I was introduced to an interesting way of multiplying two numbers (integers greater than 0) recently, at a Tudor re-enactment at Kentwell Hall. It took me a while to realise what was going on behind the scenes, at least in terms of things I already understood. As it also made me think in a new … Continue reading Multiplying using halving, doubling and summing

# The seven (or four) ages of man

This article is mostly about visualising some data from the 15th and 16th centuries, about how someone's lifespan can be divided up into stages. It happened because my friend Tamsin Lewis (a historical music expert) pointed me at a tweet by Dr Alun Withey (a history lecturer). The tweet had a photo of some lovely … Continue reading The seven (or four) ages of man

# How permanent is your data?

This article was inspired by a video from the British Museum, where a conservator discusses a 500-year-old khipu.  A khipu is a document, used for keeping records or accounts, made of knotted strings. https://www.youtube.com/watch?v=-mvjiMjZf-4 I recommend you watch the video – I found it really interesting and well-presented. I hadn’t come across khipus before, and … Continue reading How permanent is your data?

# Visualising wealth inequality using Lorenz curves

In this article I will do some analysis and visualisation of data on wealth inequality.  The data is, slightly randomly, a combination of historical data from three towns in Suffolk from 1522, and the most recent data about Great Britain.  I’ll go through the data a little, the analysis, the visualisations, and why I think … Continue reading Visualising wealth inequality using Lorenz curves