A few people here have been posting about category theory. I’ve been learning category theory for the last few weeks trying a few different approaches and found resources that work well for me. If you’re interested here's my current “curriculum”: https://gist.github.com/stefanlesser/7f0749b3a38078b3eebe0cc408345e9f Is anybody here interested in forming a (virtual?) study group? I noticed how much more effective it is to talk to people about it. Would be great to find people who are actually interested in me explaining it to them. ;-) Obviously, I’d also be very interested in having others explain it to me as well. Pretty open about the structure. Could be sort of a book club working through the resources, weekly video calls to discuss and explain to each other, share exercise results, or even do “pair programming” on the exercises. Whatever you feel comfortable with and are interested in. However, you should be genuinely interested in putting some effort into it, which maybe means you can commit to read a few chapters a week and then meet online to discuss them. My goal is to build intuitive understanding for category theory concepts and its applications. I’m less interested in learning all the proofs and more in what it means that for instance natural transformations map to parametric polymorphism and what we can use these kinds of insights for to create better programming languages and environments. I’ve made it far enough to totally believe in but not yet far enough to know how to take advantage of the Eric Weinstein quote:

“Theoretical mathematicians are sitting on top of a giant stockpile of intellectual gold. They have so many things that have not been manifested anywhere. You have no idea how much great stuff that these priests have in their monastery.”

which is on the Conexus website that @Daniel Hines linked to above. Reply here or DM me.

Count me in! I've been meaning to tackle category theory texts for a whole now

I’ll give it a few days for others to comment and then will propose some possible format.

I'd be interested as well!

I'm in and I have a couple video resources to contribute (on mobile for now so just a few): andre staltz on profunctor state (less scary than it sounds): Douglas crockford with a problematic but very clear explanation of monads (and a sneaky good argument for structuring it as an object for learnability):

I can't promise any particular level of dedication, but I'm highly interested in this subject, and would participate how I can.

I am interested. The following is a tutorial that teaches you a visual programming language / graphical mathematical notation based on category theory: https://graphicallinearalgebra.net/

One thing that would help tremendously: please let me know where you are (timezone!) — either by stating it here or by making sure it’s correctly set in your Slack profile.

EST

Yes, the Graphical Linear Algebra blog is good fun, but the best ever, but a great idea. If you read any one post try this one https://graphicallinearalgebra.net/2016/06/22/29-inverting-matrices-and-dividing-by-zero/.

@wtaysom I’d love for you to join our little group! If not to learn then to teach. And if you can’t make time, maybe you’d be willing to join us for a single call a little later on, where we can pester you with more specific questions?

@Stefan I'd be more than happy to join in.

Ok, I have (in order of time zones): @wtaysom is that Asia or Australia? @Felix Kohlgrüber CET? @stevekrouse and @Stefan (myself) London @Daniel Hines, @Doug Moen, and @Garth Goldwater EST As we’re missing someone from the west coast, it’s only the second worst possible combination of time zones. :-) It's a challenge, but I'd really love to kick this off with a video call, where we can talk about logistics and format, and get to know each other a little bit better. Shall we give that a try?

CE(S)T is correct. Do you guys prefer weekdays or weekends? Looks like meetings would have to be at noon / afternoon for me (europe time), right?

@Stefan I'm UCT+8 for me. For reference https://everytimezone.com/. I'm all for a video call. Used to taking meetings at what are for me odd hours.

weekends are probably worse for me? EST business hours are probably best. Or, whatever, and I'll see if I can make it work.

@Doug Moen I've been meaning to say thank you for pointing me at https://graphicallinearalgebra.net! Totally gripping; I went through it in an afternoon.

There is something delightfully symmetric about string diagrams. At times, I dream of having some spacial computing fun with them.

Srsly. This figure from episode 9 is worth the cost of admission all on its own:

(B1) for instance looks nice if the black dots are lined up in one dimension, the white does in another, and the flow (left-right) in a the third.

http://xahlee.info/math/i/category_theory_brendan_fong_david_spivak_2018-03.pdf this article got good reviews on LtU

Sorry for radio silence — I’ve been traveling and just came back, unfortunately now suffering from “conference sickness”, guess I shook too many hands… I thought I’ll set up a few time slots in the coming two weeks and see who can make which one. Is Doodle still the thing for that? Also does anybody here happen to have a pro Zoom account we can use (the free one used to have a time limit for groups > 2). Alternatively, is Hangouts or Skype what people use these days?

I still use doodle! (no zoom pro, sorry 😕)

doodle sounds good! I've had success with ending and recreating zoom meetings on the free version

Ok, here are a few options for later this week and next week: https://doodle.com/poll/454fbh823939bxa4 /ping @wtaysom @Felix Kohlgrüber @stevekrouse @Daniel Hines @Doug Moen @Garth Goldwater

I like to keep things in Slack wherever possible, since i’m already here for my work slack.

I am eager to join. Weekend will be tricky since I'll be visiting China, and they like to have their own internet there. Zoom might work. I don't think Slack works these days.

Ok, lets go for tomorrow: https://doodle.com/poll/454fbh823939bxa4 Check back on Doodle for your local time.

Yes, Zoom disconnects after an hour. Oh! That's Friday morning at 1am. That will work for me. I look forward to chatting with you all.

@wtaysom Appreciate that you want to join us at such an unreasonable time!

yes this works for me

Here's the link for tomorrow's call: https://zoom.us/j/205742379

another good category theory intro (super basic but I'd argue charming):

@Garth Goldwater that was delightful.

I got dragged into something at work. Gonna be late

Ready to go! /ping @wtaysom @stevekrouse @Doug Moen @Garth Goldwater

Im traveling now. Sad I can't make it. Take good notes for me :)

Calling in...

my computer seems to be having a stroke—closing some chrome windows.

Finished! One sec...

Oh lawd, I didn't knew Andre was such a terrible speaker 😢 . Disregarding that the content of the video is really good.