Peter Rowlett
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peterrowlett.net
Peter Rowlett
@peterrowlett.net
2.1K followers 2.3K following 240 posts
I teach maths at a UK university and work as a maths communicator. Sheffield/Nottingham based. Aperiodical blog, Mathematical Objects podcast. Part of http://finitegroup.co.uk

peterrowlett.net
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peterrowlett.net
Oh no
The word dodecahedron is underlined as misspelled, the correction suggestion is rhododendron.
November 7, 2025 at 7:13 AM
peterrowlett.net
My son, everybody.

#tmwyk #MathsToday
Question is Shade 1/5 of the shape blue. A rectangle is divided into ten equal parts by one horizontal divide and four vertical ones. Two parts are shaded: top right and bottom left. Similarly, 3/4 of an eight-part rectangle is shaded irregularly. Shade shape B so both shapes have an equal amount shaded. Shape A is a rectangle divided into three by two horizontal lines, the top two are shaded. Shape B is a similar rectangle with nine regions, shaded irregularly. Similarly, half of 16 regions are shaded irregularly.
November 2, 2025 at 6:52 PM
peterrowlett.net
It’s Mathematics of Life week at New Scientist and my turn to write. I wrote about game theory and the evolution of cooperation in the iterative prisoner’s dilemma. In the magazine this weekend or on the website/app.
Mathematics of life Play nicely How did cooperation emerge in a cut-throat world? There are clues in the prisoner's dilemma experiment, says Peter Rowlett It is a dog-eat-dog world. Everyone for themselves, no matter the cost. If so, how would a behaviour like cooperation ever emerge? From evolutionary biology to international diplomacy, we can model many situations using so-called game theory. These games have actions or strategies available to each participant, plus payoffs, which are positive or negative values that each player gains or loses from each outcome. Some games are "zero-sum", where one player's gain is equal to another's loss. Some aren't.
October 10, 2025 at 7:07 AM
peterrowlett.net
When I woke, my son greeted me with a proposed counterexample to the Four Colour Theorem. He said he’d woken with the idea.

1/2 #tmwyk
A big outer green region. Inside this effectively a line of squares: brown, blue, then one that’s vertically separated half grey, half dark green, then brown, then blue.
October 9, 2025 at 7:49 AM
peterrowlett.net
Came home to find the MA’s Mathematical Angles, which includes a spread about me taking over as editor of The Mathematical Gazette.
Two pages including an announcement about me being the next editor of The Mathematical Gazette and a call for peer reviewers.
October 8, 2025 at 5:23 PM
peterrowlett.net
Tomorrow at 12 UK time is the latest Finite Group livestream - Katie @steckl.es and Hana Ayoob on maths of colour. I will be teaching, but there will be a recording available afterwards. Join to take part or watch later: finitegroup.co.uk
25th September, 12-1pm BST Maths of Colour Katie Steckles & Hana Ayoob
September 24, 2025 at 4:26 PM
peterrowlett.net
Lovely day for it.
University buildings, trees and blue sky.
September 22, 2025 at 8:35 AM
peterrowlett.net
Just found out Academia edu has taken it upon itself to copy one of my open access papers to its site and then used "our AI" to generate a podcast based on the paper. They've added this to settings and it was on by default, which is extremely yuck.

Also "AI-generated reviews"? Of my papers? Why?
AI-enhanced Outputs Control how AI uses your research across Academia.edu. AI-enhanced outputs: Disabled AI Features are disabled for your account. Your uploaded works are not eligible for: AI-generated reviews AI-generated podcasts AI-generated key takeaways AI-generated abstracts AI-generated FAQs
September 18, 2025 at 8:18 AM
peterrowlett.net
I wrote about Mary Everest Boole’s curve stitching, string art, and Bézier curves in this weekend’s New Scientist.
Mathematics of life A creative curve What have holey cards and a ball of string got to do with geometry? Let's make "string art" and find out, says Peter Rowlett When she was young, Mary Everest Boole found some cards with evenly spaced holes around the edges. She laced a thread from each hole to the one opposite, covering the card with lines that crossed in the middle. When she tried connecting each hole to one not exactly opposite, she was delighted to find the threads left a symmetric curve in the middle of the card. She felt this activity gave her an intuition that helped her learn formal geometry. Years later, in 1864, she was widowed with five children.Even though the academic system didn't value the contributions of women, she worked as a librarian and maths tutor in London.
August 1, 2025 at 7:40 PM
peterrowlett.net
I haven't logged into Twitter/X for ages, but I wanted to view some replies on an ancient tweet so did it. There was one thing in my notifications and it's this beautiful mixture of Bitcoin and generative AI nonsense, happily reinforcing that what I've been missing isn't worth having.
A tweet about Bitcoin, to which someone has replied asking Perplexity to tag 15 prominent mathematicians, which includes me.
July 6, 2025 at 8:51 AM
peterrowlett.net
Here goes, wish me luck!
Find A Grave contact form. I am writing to report an incorrect photo. I contacted the account which added it over a month ago and have not had a response. There is a picture of the wrong George Green on this page: https://www.findagrave.com/memorial/20882/george-green The memorial page is for George Green (1793-1841) of Sneinton, Nottingham, UK, of whom no picture exists, for example his biographer D.M. Cannell says "the sad truth is, we have very little direct or first-hand information about him. We do not know what he looked like" (George Green: Miller and Mathematician 1793–1841, Nottingham: Green’s Windmill Trust, 2nd edition. 2017, p. 17). The picture is actually of George Bernard Green (1822-1863) of New York and Arkansas, and is included correctly here: https://www.findagrave.com/memorial/13638561/george_bernard-green I believe this is the right Green because the picture was uploaded by Jaimee Hedlund who claims to be a descendent.
July 6, 2025 at 6:41 AM
peterrowlett.net
There is a picture of George Green, the mathematician from Nottingham, doing the rounds on the internet. Alas, this is not the right George Green. Details:

www.tandfonline.com/doi/abs/10.1...

#MathsHistory #MathsHist #MathsToday
Pictures of George Green of Sneinton There is no picture of George Green of Sneinton. Cannell, who spent years looking at various archives of letters and other documents, reports (Cannell 2017, 17) the sad truth is, we have very little direct or first-hand information about him. We do not know what he looked like. Figure includes a picture of Figure 1. George Barnard Green (1822-1863) of Adams County, Wisconsin.
July 3, 2025 at 6:20 PM
peterrowlett.net
“The most mind-bending concepts in science”

👀
New Scientist HOW TO THINK ABOUT 12 of the most mind-bending concepts in science Quantum superposition The anthropic principle Animal consciousness Quantum computing Geoengineering Quasiparticles Metaphysics Friendship Language Symbiosis Geometry Mindset Close up on “Geometry”
June 27, 2025 at 5:46 PM
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I'm chatting maths and games with @jamesgrime.com next Wed 25th June 2-3pm BST.

Sign up at finitegroup.co.uk#join
Either join a paid tier to watch live or join for free & get the option to pay one-off for the recording. Either way gets you into our Discord chat community, a lovely place to be.
Finite Group Livestream: 25th June, 2-3pm BST. Games Time with James Grime.
June 18, 2025 at 10:24 AM
peterrowlett.net
This afternoon we made the pattern on a Lego board and he picked some rules. We used red/pink bricks for alive cells. We made a few iterations until we ran out of time.

#tmwyk #MathsToday
June 14, 2025 at 4:11 PM
peterrowlett.net
When was the last time we talked about cellular automata? Months, maybe a year. Anyway, as we came out of a shop earlier, my son said “would the Game of Life be different if it was played on rectangles?” It turns out he was thinking about the floor we were on. So… (next post)

#tmwyk #MathsToday
Herringbone brick paving.
June 14, 2025 at 4:11 PM
peterrowlett.net
Counting sure is hard, Amazon.

(Both 1s and the -1 all go to the first page when clicked, and subsequent numbers are boringly sequential.)
Next and previous page buttons numbered 1, -1, 1, 2, 3, ..., 272.
June 5, 2025 at 1:15 PM
peterrowlett.net
The top of our vacuum cleaner has this on it, which is fascinating as a set of weird data communication choices.
Bottom says 22:21. Above is a bar chart with four bars. Horizontal axis is µm and goes >10, >60, >180, >500. The heights are labelled: first bar 202 billion, second 4.2M, third not labelled, fourth 2.1K. The first bar is about three times the height of the others, which are all about the same.
June 1, 2025 at 7:31 PM
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Hello Google, George Green Snr built the windmill 12 years before Queen Victoria was born, and he died 8 years before she took the throne.
Google Maps item: Green’s Windmill and Science Centre. Victorian windmill & kids’ learning zone.
May 30, 2025 at 7:13 AM
peterrowlett.net
Looks like the grass needs cutting. I wrote about scheduling in this week’s New Scientist — available on the website and currently in shops.
Mathematics of life What a chore Should you mow the lawn first or cut the hedge? A handy piece of maths can help with organising tasks, says Peter Rowlett Scheduling household chores is hard. Say you have three loads of washing: a regular load that will take 110 minutes to wash and 120 to dry; a heavily soiled load that needs an extra 30 minutes to wash; and a sensitive one that will take 130 minutes to wash and 160 to dry. In which order do you wash them? In the branch of applied maths known as operational research, this is called a two-machine problem. Lots of businesses have similar issues. One approach, to find the shortest overall time, is to identify the shortest step. If it is a wash, do that load first. If it is a dry, do that load last. This way, washing and drying the loads in the right order can save half an hour.
May 22, 2025 at 7:56 PM
peterrowlett.net
Last year I ran a primary school maths puzzles and games club with a local teacher. Our write up covers mathematical magic, variants of Noughts and Crosses and games played on chessboards, tangrams and other geometric tile fun.

Free to access on p. 25 here:
www.lms.ac.uk/sites/defaul...
Children's hands playing with geometric pattern blocks, including making a rabbit and a flower. Also on the table is a soft toy unicorn head.
May 8, 2025 at 12:35 PM
peterrowlett.net
This is fun. (No context; both ChatGPT and Claude, even though I started a new chat, converted A5 paper to miles for the second query - both gave 0.000092 miles by 0.00013 miles).
Google query: A5 in mm Response: A5 paper size in millimeters is 148 mm x 210 mm. This corresponds to half the size of A4 (210 mm x 297 mm). A5 is a widely used standard paper size, often used for booklets, brochures, and notebooks. Google query: A5 in miles Response: The A5 road in Great Britain runs for approximately 243 miles (391 km). It connects London to Holyhead, a ferry port on the Irish Sea in Wales.
May 2, 2025 at 8:59 AM
peterrowlett.net
Most of the swag I got from #stecksconf has been requisitioned by my son, including the ‘Plasti-zine’ by @alisonatkin.bsky.social. He made a collection of creatures he says are different forms of a shape-shifting Doctor Who monster he’s made up which he’s named “chromnivore” to mean time eater.
Plasticine creatures.
April 29, 2025 at 6:21 PM
peterrowlett.net
Had a nice day at Warwick. My talk closed the conference and also doubled as the weekly department seminar. I discussed my history of maths/maths and society teaching from the diversity and decolonisation perspective.
Poster in Warwick Mathematics Institute for the Diversity and Decolonisation in Mathematics conference.
April 25, 2025 at 8:02 PM
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Classic Nira Chamberlain.
Nira at the front of lecture theatre showing a slide with his parents’ advice “You don’t need anybody’s permission to be a great mathematician!”
April 25, 2025 at 12:43 PM