@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.

**Andrew 🔢** @andrewt@mathstodon.xyz · Oct 14, 2019, 10:51

**Andrew 🔢** @andrewt@mathstodon.xyz · Oct 14, 2019, 10:51

Oct 14, 2019, 10:51

Andrew 🔢 @andrewt@mathstodon.xyz

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?

**Andrew 🔢** @andrewt@mathstodon.xyz · Aug 20, 2019, 13:31

**Andrew 🔢** @andrewt@mathstodon.xyz · Aug 20, 2019, 13:31

Aug 20, 2019, 13:31

Andrew 🔢 @andrewt@mathstodon.xyz

update: it works with 3d rotation too: https://www.shadertoy.com/view/tljSRG

**Andrew 🔢** @andrewt@mathstodon.xyz · Aug 20, 2019, 13:25

**Andrew 🔢** @andrewt@mathstodon.xyz · Aug 20, 2019, 13:25

Aug 20, 2019, 13:25

Andrew 🔢 @andrewt@mathstodon.xyz

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:

https://www.shadertoy.com/view/3t2Xzy

**Andrew 🔢** @andrewt@mathstodon.xyz · Apr 20, 2019, 20:56

**Andrew 🔢** @andrewt@mathstodon.xyz · Apr 20, 2019, 20:56

Apr 20, 2019, 20:56

Andrew 🔢 @andrewt@mathstodon.xyz

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

**Andrew 🔢** · Mar 28, 2019, 15:39

Andrew 🔢 boosted

**Andrew 💻** @andrewt@mastodon.technology · Mar 28, 2019, 15:39

Mar 28, 2019, 15:39

Andrew 💻 @andrewt@mastodon.technology

Made a binary adder as well

https://www.youtube.com/watch?v=nuIv8fzxMtw

no idea why i do these things

**Andrew 🔢** · Mar 27, 2019, 23:36

Andrew 🔢 boosted

**Andrew 💻** @andrewt@mastodon.technology · Mar 27, 2019, 23:36

Mar 27, 2019, 23:36

Andrew 💻 @andrewt@mastodon.technology

For some reason I have built Conway's Game of Life in Baba is You.

https://www.youtube.com/watch?v=YH0NR1kmMUo

**Andrew 🔢** · Mar 17, 2019, 23:04

Andrew 🔢 boosted

**will((i)a(m))** @will@catgirl.science · Mar 17, 2019, 23:04

Mar 17, 2019, 23:04

will((i)a(m)) @will@catgirl.science

@11011110 @andrewt fun fact. there's an exact formula for how many x,y satisfy x²+y²=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 π through the Taylor expansion of arctan(1)=π/4

**Andrew 🔢** · Mar 15, 2019, 13:26

Andrew 🔢 boosted

**ColinTheMathmo** @ColinTheMathmo@mathstodon.xyz · Mar 15, 2019, 13:26

Mar 15, 2019, 13:26

ColinTheMathmo @ColinTheMathmo@mathstodon.xyz

My latest bloggy thing:

https://www.solipsys.co.uk/new/TheSidewaysTide.html?sc15m

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

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

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 14, 2019, 13:33

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 14, 2019, 13:33

Mar 14, 2019, 13:33

Andrew 🔢 @andrewt@mathstodon.xyz

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

Adding the brackets from this Alex Bellos column https://www.theguardian.com/science/2019/mar/11/solve-it-can-you-speak-yoda-how-to to the numbers 1, 2, 3, 4 —

[1, 2] → 12
⟨1, 2⟩ → 21
⟨[⟨1, 2⟩, 3], 4⟩ → ⟨[21, 3], 4⟩ → ⟨213, 4⟩→ 4213

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

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 14, 2019, 13:30

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 14, 2019, 13:30

Mar 14, 2019, 13:30

Andrew 🔢 @andrewt@mathstodon.xyz

I wrote a thing for the Aperiodical:

https://aperiodical.com/2019/03/buzz-in-when-you-think-you-know-the-answer/

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 08, 2019, 09:16

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 08, 2019, 09:16

Mar 08, 2019, 09:16

Andrew 🔢 @andrewt@mathstodon.xyz

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?
https://www.mirror.co.uk/news/weird-news/mans-brilliant-maths-trick-means-14099670

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 01, 2019, 21:39

**Andrew 🔢** @andrewt@mathstodon.xyz · Mar 01, 2019, 21:39

Mar 01, 2019, 21:39

Andrew 🔢 @andrewt@mathstodon.xyz

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

Also v good doggo in VR, which is a plus
https://youtu.be/TCwQweljegc

**Andrew 🔢** · Feb 20, 2019, 08:29

Andrew 🔢 boosted

**Christian Lawson-Perfect** @christianp@mathstodon.xyz · Feb 20, 2019, 08:29

Feb 20, 2019, 08:29

Christian Lawson-Perfect @christianp@mathstodon.xyz

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__

**Andrew 🔢** · Mar 01, 2019, 15:05

Andrew 🔢 boosted

**Henry Segerman** @henryseg@mathstodon.xyz · Mar 01, 2019, 15:05

Mar 01, 2019, 15:05

Henry Segerman @henryseg@mathstodon.xyz

Try it for yourself at http://www.michaelwoodard.net/hypVR-Ray/, it even works on phones!

**Andrew 🔢** · Mar 01, 2019, 15:05

Andrew 🔢 boosted

**Henry Segerman** @henryseg@mathstodon.xyz · Mar 01, 2019, 15:05

Mar 01, 2019, 15:05

Henry Segerman @henryseg@mathstodon.xyz

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. https://youtu.be/ivHG4AOkhYA

**Andrew 🔢** · Jan 25, 2019, 16:30

Andrew 🔢 boosted

**Gerard Westendorp** @GerardWestendorp@scholar.social · Jan 25, 2019, 16:30

Jan 25, 2019, 16:30

Gerard Westendorp @GerardWestendorp@scholar.social

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

69eecbc0da1fd86a.jpeg

**Andrew 🔢** @andrewt@mathstodon.xyz · Jan 13, 2019, 13:29

**Andrew 🔢** @andrewt@mathstodon.xyz · Jan 13, 2019, 13:29

Jan 13, 2019, 13:29

Andrew 🔢 @andrewt@mathstodon.xyz

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 — and therefore making different connections — depending on whether or not a current is flowing through them.

http://www.ireneposch.net/the-embroidered-computer/