Pinned toot

This predates my Mastodon accounts but it ought to be on here so here it is: my interactive blog about the domino computer.

@andrewt As if this weren't all confusing enough, I believe the set of points depicted here is what's technically known as collielinear.

@andrewt It's the prefix col- which sometimes occurs in latin-derived words instead of co- or com- with base words that begin with an 'l'. You see it in "collateral" and "colloquial" and even in "college" and "collegial." That said, I think the one-l version, "colinear" is widely accepted as correct these days.

OK so today all the available evidence is telling me that the maths word for "on the same line" is "collinear" with two Ls and it's pronounced like it's spelled, like it's about Colin's ear, and just what the hell? I've been writing and saying "colinear" and just what is this?

Someone posted a gif of this effect on birdsite and I wanted to understand it so I've built it as a space-warping raymarcher.

Its some lovely maths that I think I *mostly* understand now:

A problem shared is equal to the sum of the problems on the other two sides.

@11011110 @andrewt fun fact. there's an exact formula for how many x,y satisfy xΒ²+yΒ²=n. it's 4 times (the number of factors of n of the form 4k+1 - the number of factors of n of the form 4k+3). another fun fact: this ties into the average being Ο€ through the Taylor expansion of arctan(1)=Ο€/4

My latest bloggy thing:

As always, comments, thoughts, criticisms, and feedback, all welcome.

Have to say that this "one blog post per week" is a brutal schedule.

Also, here's a maths puzzle for Ο€-day:

Adding the brackets from this Alex Bellos column to the numbers 1, 2, 3, 4 β€”

[1, 2] β†’ 12
⟨1, 2⟩ β†’ 21
⟨[⟨1, 2⟩, 3], 4⟩ β†’ ⟨[21, 3], 4⟩ β†’ ⟨213, 4βŸ©β†’ 4213

…we can make any number except 2413, and which other?

This is a nice little trick but a bafflingly poor article. How can anyone write an entire article about a single tweet without having understood the tweet?

This would make a strong contender in the MathsJam bake off.

Also v good doggo in VR, which is a plus

Further evidence the tiny L-P is a mathematician, at bathtime last night:

* holding a bottle full of water *
"Can you put some water in the jug, please?"
* stands bottle upright in jug, spilling none *

Must learn to speak more precisely __to my 1 year old__

Here’s a video on simulating a non-euclidean space in virtual reality with ray marching. This project is joint work with Michael Woodard and Roice Nelson.

Made a snowdecahedron. Not as nice as some people on the web, but still, I deserve a beer.

This embroidered computer is lovely. I think it works by the gold coils over the large beads being magnetically drawn to one side or the other of the base β€” and therefore making different connections β€” depending on whether or not a current is flowing through them.

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A Mastodon instance for maths people. The kind of people who make \(\pi z^2 \times a\) jokes. Use \( and \) for inline LaTeX, and \[ and \] for display mode.