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My adventures in 3D printing: Wallis’ Sheldonian theatre roof

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

Several dozen black beams woven together to make a single structure, supported only at the edges.

The roof of the Sheldonian theatre in Oxford, built from 1664 to 1669, is constructed from timber beams which are unsupported apart from at the walls, and held together only by gravity.

My adventures in 3D printing: Spherical pseudo-cuboctahedron

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

This shape is a “spherical pseudo-cuboctahedron”, prompted by a request from Jim Propp on the math-fun mailing list.

3D printed sphere with edges cut out of it, making squares and triangles which meet halfway along the edges

It has 24 vertices, 12 edges and 14 faces. That doesn’t satisfy Euler’s formula $V – E + F = 2$, so it can’t be a proper polyhedron – hence “pseudo-cuboctahedron”.

However, if you push all the vertices onto the surface of a sphere, all the edges are spherical arcs, it sort of works.

While designing this object, I got fed up with OpenSCAD‘s awkward control syntax, and switched to Python. I wrote Python code to produce the coordinates of points along the edges, which the SolidPython library turned into something that OpenSCAD can cut out of a sphere.

You can download all the files needed to print your own spherical pseudo-cuboctahedron from Thingiverse.

My adventures in 3D printing: Write Angles Cube

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

Three whiteboard stuck in the write angles cube at right angles.

This is one of the first ‘proper’ things I’ve designed – I wanted to have a go at making something based on an object I already had. A colleague asked if I could make some props to explain coordinate systems, and I was holding a whiteboard pen at the time, so I decided to make a set of orthogonal axes out of whiteboard pens.

TeXnique: a LaTeX typesetting game

You know what’s fun? Typesetting mathematics! Glad you agree, because here’s a game that puts the fun in ‘underfilled hbox’.

Screenshot of TeXnique. A box showing the target formula above a box showing a rendering of code typed in the box below.

In TeXnique, you’re shown a typeset bit of mathematical notation, and have to frantically type LaTeX to reproduce it. You get three minutes, and you’re awarded points when you produce something that’s a pixel-perfect replica of the original. Think Typing of the Dead crossed with The Art of Computer Programming.

When I first saw this I rolled my eyes, but now my high score is 68 and I don’t know why I keep going back to it.

The formulas are largely well-known snippets of notation, so you might find some of them coming out through muscle memory, but if a symbol shows up that you can’t remember the macro for, there’s always the brilliant Detexify tool.

Play: texnique.xyz by Akshay Ravikumar.

I’m streaming digits of π for π day

It’s π eve, and I’ve had a silly idea: I’m going to take the ridiculous website I made to show all the digits of π, and stream it scrolling indefinitely through them over the internet.

Starting at midnight GMT on 2019-03-14, the stream below will start scrolling down through the digits of π:

I had this idea this morning, and it’s running on my desktop PC which I’ll be away from until 8am tomorrow, so I won’t be surprised if something goes wrong.

But if it doesn’t: hooray!

I’ve made some maths t-shirts, and you can buy them

Because of my statistically improbable stature, it’s really hard to find clothes that fit me. So, most days I wear the lowest common denominator of all clothing styles, a t-shirt. And if I’m wearing a t-shirt, it might as well be Extremely On Brand CP and have some obscure mathematical motif on it.

Good maths t-shirts are hard to come by, so I’ve made four of my own.

Four t-shirts laid out on the floor. Clockwise: the aperiodical logo; two men considering an octahedron; "all mathematical progress has measure zero"; keep calm and multiply matrix

I haven’t let lack of illustrating ability get in my way, and I’m quite pleased with how they’ve turned out.

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