Here is what you can do this week, between the second and third pseudolectures.  Everything here refers to The Rising Sea notes.

About the pseudolecture

The pseudolectures are to give general guides for learning things from reading and problem-solving.

Did viewing and using a single zulip stream work well (as compared to, for example, last week)?  Did the half hour post-pseudolecture work well/better/fine?  I felt that this was a reasonable approximation of what might happen in the future, but I am intending to tweak things more.


Catch up on any sections before that you feel the need to look at and review.

If you are not super-comfortable with the ins and outs of modules:  Read section 1.6, on abelian categories, stopping just before the start of 1.6.5 (on complexes).  But don’t read it to learn what abelian categories; instead see why the (category of) modules over a given ring satisfy all these properties.     Read the first three sections of chapter 2 as well, but starting at the bits about presheaves forming an abelian category (2.3.5), just skim.

If you  are quite comfortable with modules over a ring, then you can read the seciton on complexes, exactness, and homology (again, thinking only of modules over a ring, not abelian categories in general), up to and including Exercise 1.6.D.  Read the first three sections of chapter 2.

If you are an expert already, then take a look at the useful facts in homological algebra (1.6.9), and possibly continuing to the end of the section.    Read the first three sections of chapter 2.  Feel free to browse ahead, or to take a side trip to spectral sequences.  Please quibble and argue with my point of view.


For everyone:

Keep thinking about and working on the problems from last week.  We can focus on them less as of next week (so you’ll have a couple of weeks to think deeply about each set of problems).

Also, please do problems 5 through 7 from last week again for this week.  Please also make sure to discuss your answers in zulip so I can see them — I intend to let them guide what I say on Saturday.

5. What’s your favorite exercise (not necessarily from the notes), and why? (This is important: you are not a passive robot doing exercises. You are deliberately refining your thinking.)

6. What was a big insight here (either new to you, or perhaps not), and why?

7. What is a confusing notion you want to hear more about? (If you talk about stacks or infinity-categories, then you are showing a lack of wisdom.)

If you are not super-comfortable with modules:   How comfortable are you with localization and tensor products?  (Tensor products in particular really are confusing, so don’t be surprised, or feel stupid.)  Perhaps try an exercise in each to see if you can do them.  If you can, then declare victory and move on; you’ll digest these ideas better later, when you use them.       Do 1.5.F (if you have to work hard, you are working too hard — t has a one-sentence answer.)  Do 1.5.G (and realize that if you understand negative numbers, you understand this exercise).   Do exercise 2.1.A (even though I allegedly did it in the pseudolecture).  If you have some background in differential geometry, you will find Exercise 2.1.B enlightening.    Exercise 2.2.B will give you an idea of when things might not quite be sheaves, but still be presheaves.    Do Exercise 2.2.E, 2.2.F, 2.2.H,  and even 2.2.J.  Do 2.3.A, , and 2.3.C.

If you are quite comfortable with modules over a ring:    Make sure you can do all the localization and tensor product exercises without referring to anything.  Exercise 1.5.H  will ensure you understand the “ification” functor.     Do  1.6.A, 1.6.B, 1.6.C, and 1.6.D (for modules over a ring).    Do 1.6.I, and possibly 1.6.K  Do 2.1.A, and (if you know some differential or complex geometry) 2.1.B.    Do 2.2.E; 2.2.F or 2.2.G; 2.2.H; 2.2.I; 2.2.J; 2.3.A.  Definitely do 2.3.C.  You can do 2.3.E and 2.3.F, and in anticipation of the next problem set, 2.3.I and 2.3.J.

For experts:   If you are an expert already:  do you agree with the useful facts in homological algebra (1.6.9)?  Are there other things that I might not know or realize the power of, that you have found very handy to know?    If you are happy with either (smooth) manifolds, or homolomorphic modules, do 2.1.B.    In order to do this, you need to be clear in your own mind what your definition of cotangent space in the smooth or holomorphic setting.    If you are an algebraic topological person, try the exercises on “categorical phrasing”, because you might like them.  Do 2.2.F and 2.2.G, 2.2.H, 2.2.J, 2.3.A.  Make sure you understand 2.3.C.  Do 2.3.E and 2.3.F, and 2.3.I and 2.3.J.  There is something important in these last exercises — in many places, the kernel and cokernel of maps of sheaves (of abelian groups) is defined, but it isn’t made clear *why* these are the right definitions.

The next pseudolecture

Some of you wanted to understand “complex analytic varieties” at the same time as “algebraic varieties” and “schemes”.  We’ll do that.  I’ll define all of these, and smooth manifolds, in the first few minutes of the next pseudolecture, in a way that will likely infuriate you.

Here is the plan for the second pseudolecture. It will be Saturday July 4, 8-9am Pacific time, with a half hour after for further discussion. Here is how it will go.

I’ll give the lecture on zoom, and some shepherds will be there, as well as people who let me know enough in advance that they can’t access youtube. (I’ve already sent zoom information to people I know about — so if you can’t access youtube please let me know.)

Then the lecture will appear on youtube live. I’ll try to have the livestream going by 8 am. I am hoping it will be immediately visible in the AGITTOC channel on youtube:

If not, then someone will (if all goes well) post a link on #AGITTOC announce and this stream #pseudolecture 2 (July 4, 2020) . Maybe on wordpress and discord too. (I think this might get further improved for next week.)

My slides should be available in real time here: .  If you go there now (July 3), you should see the “cover sheet”, and I’ll copy in my pre-made templates near the start of the pseudolecture. Then periodically I’ll back-up the things on my screen, so you can just refresh your screen to see past slides.

For discussion and questions, this week let’s try to do it in one zulip stream (not one per groupoid). I have started a new stream, and it is public, so you just have to subscribe to it. During the pseudolecture, shepherds will be watching the stream, and can relay comments and questions to me that they find worthwhile. These can be substantive, to “please remember to refresh so we can see the old slides”.

After the hour, I’ll stop the recording, and rather than having a subset of people coming on to zoom, let’s stick to the zulip channel you are in. I’ll go to that channel and take questions there. Hopefully that will work better. And in any case we can retool the week after.

Then after the lecture, I’ll post an edited version to youtube (probably just chopping off things before the start and after the end), and take down the livestream. I will also (hopefully later that day) post a problem set / discussion post with “homework”. This coming week, you can do more on the first problem set (there might be more worthwhile discussion in the 2nd week after it is given), and also work on the second problem set (enough to be ready for next week’s pseudolecture).

(Less important for now: Regarding the working groups: It is about time for a rationalization of the working groups. Quite a number of working groups are working either very well or well. A good number are not working, or essentially not working. There are a number of relatively new people who are not yet added to groups. Some of the high-functioning groups have distinct personalities (people with certain backgrounds or interests, say). So for now, please continue to move groups (or be in more than one) — if there is one you know of that would be willing to have you, please join them (and maybe let us know). And before long, I’ll make a post about re-organizing a bit. Perhaps if your group is working reasonably well, you can (in “about the group”) say something about who is in your group (not names, but types), and even if you think you are already at the optimal size, or if you would be willing to have more people who would fit in.)

Hi everyone,

I’m pretty ready for Saturday’s pseudolecture, and I think I’m another step towards having things work smoothly. I’ll first tell you where things are, and then ask for advice on the things where I think I need the most advice. (All sentences below should be prefaced “I think…”)

I have zoom set up for Saturday, and will give links to those who really can’t easily use youtube by Thursday. So if you haven’t heard from me by Friday, please send me an email.

I don’t see yet how to have a link for youtube live ready in advance, as I can only connect to youtube from zoom once the meeting launches. (I have some workarounds in mind to try next week, but want to see if something easy works.) You have the AGITTOC youtube channel link (somewhere — I’ll repost it soon), and I am hoping it will just appear there. I will also start the livestream early (at least 15 minutes early), and then get the link, and post it in the #AGITTOC announce stream on zulip.

Notability/dropbox. I think this should work now. There is already an existing link for the slides for Saturday (which I may have posted somewhere, but will in any case post soon). Shortly beforehand, I will copy in my prepared slides (intended for me to write on) for Saturday into that file, and so they should be visible to you.

Where people “watch” the talk and discuss, and also Q+A: I’d intended last week for people to watch and discuss in their zulip groupoids, although some did so on youtube or even (I think) dropbox. Dividing up into groupoids may not be necessary — I propose having a single new channel for the 2nd pseudolecture, and everyone can watch there instead. And after the hour, for the informal Q+A, I will turn off the recording (so people feel more comfortable with questions), and then I will go to that zulip channel, and answer questions from there, with shepherds also calling out questions that are interesting (as they can during the pseudolecture itself). I will try to repeat the questions before answering them, and the shepherds will do their best to remind me. (I am hoping that the 20-second delay between youtube and zulip will not be noticeable…) Could that work? (I couldn’t think of a perfect solution, although there were a number of good ideas — we can try something different the week after if need be.)

I hope the discussions are going well (the ones I’ve seen are great, but of course I don’t see the conversations that are not happening).

I am hoping that in the next day or so, it will be clearer which working groups are working well, and which ones are quiet, and which ones should be recombined. I also am hoping the shepherds will also hear from you the answers to the meta-questions on the “problem set”, as well as which problems you did, and your related thoughts. (They can pass them to me on Thursday night, perhaps.) So please write to your shepherd and let them know!

Recent arrivals: I think everyone who signed up as of a few days ago should have gotten an invitation to zulip (although not necessarily to a working group). If you haven’t (and you didn’t just sign up!), just let me know (after checking your spamfolder). If you are on zulip, feel free to join a working group that you know about, if they are happy to have you. Let me know if you do that (if you remember — not really essential) so we have a better idea of what different groups are up to.

Last but not least: I’ve been holding off putting new people into working groups, basically because it takes a lot of time (and doing it randomly means the groups are less likely to work well — even with the nonrandom assignments so far there is great variation in how the groups are doing).

(As with other posts, this is hastily written in order to get it out with reasonable speed.)

The video for today’s lecture is available here. I need to figure out another place to post it so it is also visible to those without access to youtube. I had hoped that I could do it on zoom, but it appears that I can’t put edited things there.

I’m now going to give some pseudo-homework for the next two weeks. The point of this pseudohomework is to give you some specific things to focus on, and to be a starting point for discussion in smaller groups. (I hope the working groups you are a reasonable start.)

Ideally do some serious thinking about these things over this week. The point of the problems is for you to think hard about them, not to go and find the right source to quote or copy. For almost all of you, the question “what should I read to understand more about this topic” is the wrong one. Instead, fight with some specific problem.

Cognitive trap I want you to avoid, but that many of you (especially the less experienced ones) will fall into

There are a lot of fancy exciting things to hear about, and you will want to roam ahead and learn about them. (It’s clear to me that the notion of a “stack” has that sort of mystical attraction.) You might be impressed by others at a similar stage who use all sorts of fancy words. Do not be tempted! Instead, meditate long and hard on simple and fundamental things. Those are the ideas that will make the fancy stuff much simpler in the long run. Thoughtful contemplation of a few judiciously chosen ideas or problems trumps quick reads of advanced papers. Yes, I can see that you are ignoring me right now. But ask someone you admire who knows fancy things.

In particular, with the problems I suggest below, it is important to understand some well, which means writing things up completely. You could do this individually and trade. Or in this setting, a group of you might want to work through some problems, and type them up communally. (Zulip and discord let you upload files. Or you can use dropbox or email or anything else.)

I’m going to ask each of the groups, at the end of the week, to let others know (perhaps in the groupoid channel, or perhaps just by messaging shepherds) what happened and where you are as a group.

For those new to proofs, or who haven’t seen modules

Deliberately try to get three new ideas out of what follows. Try to do three exercises, no matter how “trivial” someone tells you they are (because whenever someone tells you something is “trivial” or “obvious”, you should hit them with a stick).

For those comfortable with proofs, and perhaps familiar with modules, but not more:

Read The Rising Sea up to section 1.4 Make a personal list of definitions you should know, and in particular know which ones are Important, and which ones are Less Important. “Important” here is meant in a technical sense: for later understanding on these particular topics. Try to digest the definitions, and ideally don’t memorize any definitions.

Glance at section 1.5, and browse through it if you wish. But adjoints require time to really come to terms with, so you’re better off digesting what you already know.

Don’t read sections 1.6 and 1.7.

Read ahead on sheaves and presheaves and morphisms of sheave and presheaves, without worrying too much about it, to seed your mind for next week.

Problems to do:

1. why is a group? (This problem is not a joke! Do you know about groups because someone told you to? Well, if they told you to go jump in lake, would you do that too?)

2. Make a list of categories (both objects and morphisms) you are already friends with, and functors you already know about.

3. You needn’t know any “definition” of manifold, but figure out with others why the “notion” of a manifold is a reasonable one (even if you can’t formalize it well), so we can use it in conversation.

4. In the notes, try problems 1.2.B, 1.3.A. (Localization and tensor products are harder than people think!) 1.3.N, 1.3.Q, 1.3.O, 1.4.B, 1.4.C. Maybe 1.4.D and 1.4.G. Ponder 1.4.8. Pick another exercise on this list on the basis of your judgement and taste that you think is worth thiking about.

5. What’s your favorite exercise (not necessarily from the notes), and why? (This is important: you are not a passive robot doing exercises. You are deliberately refining your thinking.)

6. What was a big insight here (either new to you, or perhaps not), and why?

7. What is a confusing notion you want to hear more about? (If you talk about stacks or infinity-categories, then you are showing a lack of wisdom.)

(I might respond to your answers of 5 through 7 next Saturday.)

If you are already very comfortable with modules and point-set topology, and trying to digest the core material in a more systematic way

Read up to section 1.5. There are some notions (including adjoints) that one understands more completely and deeply the more times one revisits them, so if you think you “know” these ideas, then think harder. Read starred sections too. Truly digest tensor products, limits, and colimits as much as possible.

Some interesting questions to make friends with: 1.3.K, 1.3.N, 1.3.S, 1.3.Y (baby Yoneda). (1.3.Z is Yoneda — but if you are just doing 1.3.Y now, then leave 1.3.Z for two weeks, other things can marinate in your mind.) 1.4.B, 1.4.D, 1.4.G. 1.5.D, 1.5.E, 1.5.F, 1.5.G.

Then problems 5 through 7 from above!

If you already know these ideas well

Ideally you are in a group with others like you. Hopefully you can share how you think about things that makes them “easy” or “clear” to you. Other things to discuss: what’s the simplest thing in the notes (or not in the notes, but intellectually adjacent) that you have not seen sufficiently? Is there an exercise that you think would be painful for you to do, but that you can imagine someone else might have a clean way of attacking? What things are missing from the discussion in the notes, from your point of view — some key insight, or exercise, or fact?

You already have a lot of familiarity with this material, and maturity mathematically, so follow your instincts.
Read up to 1.5 for sure. You can read ahead into chapter 2, since you’ve already made friends with sheaves. You can read 1.6 and 1.7 if you feel like. (Debatable point of view in those sections that you can argue with: one shouldn’t memorize the definition of abelian category. And spectral sequences, at the level at which they are most used at least by algebraic geometers, are not difficult — the most annoying thing is the proof. I think it is best to learn how to use them first, and then see why they work. I also believe it is best to learn how to drive a car without knowing how to take one apart and put it back together again.)

(A proper post is coming soon, with problems, discussion, and more!)

I personally learned a lot during the first pseudolecture. As expected, a number of technical things went unexpectedly wrong, but thanks to the shepherds, everything important went smoothly.

Notability: I couldn’t use my prepared notes because they weren’t syncing to dropbox, so I had to just write from scratch. (Anecdote: Twice, Christopher Hacon has come to speak at a seminar I was co-organizing, with a carefully prepared talk on his computer, and the computer wouldn’t connect. So both times he just immediately moved to a spontaneous board talk, without breaking a sweat. The talk was somehow meticulously structured.)

Youtube live: Youtube wouldn’t let me use the new channel yet (hopefully by tomorrow!), so the livestream didn’t appear where it was supposed to. The in the busy-ness of dealing with these, I didn’t have a chance to invite one person to zoom who didn’t have youtube access.

Still, most of the important things happened — people watched, and the unrecorded discussion afterwards was also interesting.

For next week, I am going to try to make better friends with notability (I use goodnotes for my own notes), and see if everything can be better set up in advance, so links are available beforehand. I am curious how the zulip groupoid “discussions” were, because that was the most experimental part of what we were doing. (Experiments do not have to be completely successful, but ideally we should learn something from them!)

Please let’s now discuss (in zulip? discord? comments here?) what we should try differently next week — what things need tweaking, etc. Next week will also be more “typical” in that there won’t need to be any philosophical set-up.

I expect to have the video of the pseudolecture posted before long. (It is trimmed and sitting on my computer.)

Update later that same evening: the youtube channel is: here.

(In the process of getting involved, and wondering what you need to do next?   I’ve now put everything under the AGITTOC 2020 tab up top.)

Thanks to David Zhang, Aaron Landesman, Sean Cotner, Matthew Stevens, and Nikolas Kuhn, I tested out the technology today.

Here is the plan, and what you need to do.

By now many of you are in groups, which you know because you are subscribed to a stream on zulip with a name like [letter][3-digit-number]. Please then make sure you are also subscribed to your zulip groupoid, which is the [letter]. E.g. if you are D012, you should be subscribed to groupoid D. (Very likely you already are!)

Some of you signed up more recently, or were not yet in groups for some reason or another. In that case I have invited you to zulip tonight, but not yet to a group; please temporarily subscribe to one of the groupoids at random.

Tomorrow (Saturday) morning (for me!), some time before 8 am Pacific, I will post a link to youtube live. (In later weeks I will undoubtedly be able to post the link in advance; I’ve not yet figured out how to do this before starting, and I have other more urgent things to figure out first.) So you can go there before 8. Also, log in to zulip, and go to the stream in your groupoid for the first pseudolecture (already set up!). I’ll also give you the link to view the slides, which will update in close to real time as I write. Probably shepherds will post it in the groupoids — might be easiest?

(If you can’t access youtube, please let me know in advance, so you can watch elsewhere, likely on zoom! To my surprise, no one has written to tell me that they can’t access youtube.)

Then 8-9am (plus or minus epsilon) I’ll attempt the pseudolecture, undoubtedly with some entertaining technical difficulties. You can discuss and ask questions in the zulip stream. (No one will be watching chat comments on zoom, youtube, discord, etc. etc.) A shepherd will be watching the groupoid discussion, and may ask me questions on zoom during the talk. (The 20-second lag between zoom and youtube will make this a bit weird.) Other questions will of course remain on zulip, so can be discussed later (by you, or anyone else, or me).

At 9-ish, I’ll stop, and stop the recording (or later cut the recording there), and we’ll then discuss a bit. I’m not sure best how to do this; perhaps keeping the same format? Perhaps letting a bunch of people into zoom, who have questions or comments? (The meeting’s limit is 100.)

Then later we’ll see how it went and what should be different next week.

(This first week, I’ve found that setting the stage and giving introductory philosophy accounts for about an hour of what I want to say, so right now I’m intending to say a third of it, then move to math, and return to “setting the stage” at the start of pseudolectures.)

If you are in more than one group (!), and you don’t want this, please let me know.

(In the process of getting involved, and wondering what you need to do next?   I’ve now put everything under the AGITTOC 2020 tab up top.)

Here is the plan for tomorrow’s first pseudolecture, and how to take part.

The plan is for it to happen 8-9 am Pacific time (you do the translation for your own time zone), with up to half an hour afterwards for questions/discussion. This first one will be highly unpredictable and unlike later ones, for many reasons. It will be the first time trying this out for the entire AGITTOC experiment. It will be my first time trying out any of this technology in the wild. The substance will be mainly about setting the stage for later weeks. It will be the first time you do anything like this. It will be the first time the shepherds do this. Etc. etc.

So before the start go to your groupoid on zulip. (If you are not on zulip yet, I’m going to try to move many of you on today. If you end up on zulip and aren’t yet in a group, then go temporarily to any groupoid.) During the pseudolecture, you can ask question and discuss freely. A shepherd will be there looking for things to potentially ask me.

I’ll post here (and I guess the shepherds can post in the stream on zulip) a youtube link, hopefully about 5 minutes before the start. (I think youtube generates the link only when the stream is already live.) The shepherds will be watching on zoom, and will ask questions when they feel like it, based on your discussion.

(There is a 20-second delay between zoom, where I’ll be recording, and youtube, where it will be appearing. That will make things weird, but I’m not sure exactly how.)

At the end of the hour, I’ll conclude, and probably stop the zoom’s part of the recording. Then many of you will head off (to sleep, to breakfast, etc. depending on your time zone and your circadian clock). But we can then have time for questions and discussion (about the substance, the technology, the experiment, anything), say for up to half an hour. Possibly some people can just come on to zoom if they want to discuss (there is a 100-person limit because I’ll do this as a zoom meeting rather than a zoom webinar, which has a 1000-person limit and is less good for discussion), and others can stay on youtube live, and the shepherds might stay with their groupoids too. That part we can play by ear — the 20-second delay may cause more weirdness.

Then when it is all done, we’ll see how it went, and see what should be tweaked for the following week. Also, I think the youtube live link will still be viewable by those watching at later times. Some time probably on Saturday, I will put up a youtube video of the actual hour (ie, trimmed), and take down the livestream.

During the pseudolecture, I will be focused on one thing, so the only way I will be reachable will be by zoom, where shepherds can call things out. I won’t be watching zoom chat, zulip, discord, email, or anything else!

Fingers crossed — but I’m not too worried because I have low expectations, and we’ll learn something by doing this.

(In the process of getting involved, and wondering what you need to do next?   I’ve now put everything under the AGITTOC 2020 tab up top.)

A brief update (mainly for my own benefit): things still seem on track for this Saturday being the first pseudolecture. Tomorrow afternoon I’ll be able to test the zoom/youtube combination for the first time (thanks to Dev Sinha). Having notes available in almost real-time is ready to go (thanks to Yufei Zhao).

If you signed up long ago and haven’t heard from me, it may be because you mistyped your email address (there are more than a few people in this boat) or because I’ve messed something up. In either case, please drop me a line.

If you can’t access youtube because of your location, or if you can’t access some other thing we use (wordpress? but then you aren’t reading this. discord?), also let me know. The plan remains that most people watch on youtube live (details later when I figure them out) and ask questions through zulip; shepherds and those who can’t use youtube are on zoom, and shepherds will ask those questions on zulip that they particularly find useful. Annotated past slides will be viewable in your browser in almost-real-time.

I want to thank those of you who gave out AGITTOC numbers in bulk on the first day they went out — it made a huge task quite reasonable, and actually fun. So I still need to go back and make sure I have a complete list, so I can list you all here!

There are many people I’m gradually moving through the process of “onboarding” (signing up, AGITTOC#, discord, working group, zulip). There are about ten people signed up earlier where there are things I’ve not sorted out. I’m mainly focused on making Saturday happen right now, but want to still get this stuff done before long.

There’s some discussion among the shepherds as to whether shepherds is the best name (or perhaps something else, e.g. field marshal, guide, liaison, invertible shepherd). No consensus yet; feel free to weigh in on this oh-so-important issue. (Best working group: perhaps “invertible sheep”. But that is a pun that only a minority of you should be able to get, so “invertible shepherds” is a less good name than I first thought it might be…)

Erik Demaine is actually on our zulip, and told us there about his which looks like a super-handy shareable whiteboard — feel free to check it out. (I haven’t yet, but will.) Some groups are also meeting on coauthor, so I will be curious to see how they use it.

(I expect that this entire AGITTOC experiment will take a lower proportion of my time in future weeks, once the machine is fully in motion. The real bulk of the work was before, in getting people into groups.)

(In the process of getting involved, and wondering what you need to do next?   I’ve now put everything under the AGITTOC 2020 tab up top.)

As most of you clearly know, by now the groups and groupoids have homes on zulip. You should (unless you signed up recently) have been invited to zulip. Even if you’re busy, please go there in the next 48 hours just I know you made it. If you’ve got some relaxed time, you can go and play around and meet people.

You should be in a stream with a name like D012, which means you are in group 12 (12 meaning a line on a spreadsheet). The stream initially is accessible just to your group, and to me and the shepherds (and possibly a few people invited to see how this experiment is working). You have a lot of control — I *think* you can start new streams, and invite people into your stream. Please introduce yourself to others in your stream! Your group has somewhere between around 7 to around 30 unless you wanted to be in a pre-defined group without any others (so there are some groups of size two), or if you are a lone wolf not wanting to be in a group but willing to take part in feedback (in which case you are in a groupoid with the other lone wolves), or if you wanted nothing to do with anyone (in which case you are in a groupoid with all such people like that).

You’ll also be in a groupoid. For example, if you are in D012, then you are in Groupoid D, whose shepherd is (currently) Taylor Dupuy (“D” is for his last name). You have access to that stream on zulip as well. That may be where people ask questions on Saturday (and Taylor or some substitute watches it and may ask me them), and where you can also chat with each other (answering questions on Saturday, or anything else).

The shepherds are a motley crew (some more motley than others):

Juliette Bruce
Taylor Dupuy
Quinn Greicius
David Lin
Alison Miller
Jackson Morrow
Natalia Pacheco-Tallaj
Jack Petok
Sasha Shmakov
Maddie Weinstein
Jonathan Wise
David Zureick-Brown

They aren’t TAs; they are just volunteering to help out. They are also participants in the experiment.

Getting towards actual mathematics

My plan is to have pseudolectures on Saturdays starting at 8 am Pacific time, weekly, to have this episode or instantiation of AGITTOC last until the “end of the summer”. It’s not clear yet what “end of the summer” means, because different people will have natural ending points at different times. (And I won’t even get into those from the southern hemisphere, who already have a hard time walking upside down.)

Given the massive variation in what people know, my intent is to try to keep as many people for as long as possible, which means trying to speak to about three levels at once. I was thinking of speaking for an hour and a half, with a break, in order to squeeze in more content, but I think already with the unusual timing and the unusual nature of the pseudolecture, it will be hard for people to stretch their attentionm, so I should stick to an hour, but perhaps have another hour (unrecorded) for questions and follow-ups. We’ll just watch what happens.

I’m going to use The Rising Sea notes as a skeleton on which to build the lectures, because that’s what I can do most easily, but they are at a wholly inappropriate level for most of you (even those who will be able to stay).

So given the amount of actual time I’ll have to try to make a case to you in pseudo-lectures, clearly anything you get out of this can only come out of your own efforts, so I want to try to set things up to make it as possible as I can for you to learn things, and do things, and discuss things.

The first pseudolecture will necessarily be about setting the stage and laying out the philosophy. You needn’t do any reading in advance, but you can read chunks of the category theory chapter at as slow a rate as possible. (If you aren’t comfortable with rings and modules, it is far better that you review that — ideally take advantage of your new friends as you lay out to each other what you think are the important things to know about them.)

I’ll write more throughout the week. I’m curious and kind of excited to see what might happen. I think a lot of good has already happened in the discussions I’ve seen happening (and more I can’t even see), for example on discord or zulip.

(In the process of getting involved, and wondering what you need to do next?   I’ve now put everything under the AGITTOC 2020 tab up top.)

Hi everyone,

(Perhaps I should somehow flag the important posts, so I feel comfortable continuing to post often.)

Reminder: first pseudolecture will be Saturday June 27, 2020, at 8 am Pacific time.

The groups and groupoids are set up, and it’s time for people to meet each other. Here is how it will. Most people will be in some group (possibly even some of you who didn’t want to be). They vary in size, and each group is hoped to have some commonality. You should be grouped with people you wanted to be grouped with. You’ll get invited to zulip soon (in the next day I think). So you can go there and check it out, and also meet others in your group. Probably it would make sense if we tell you (on zulip) who is in your group. Only group members (and people doing stuff for AGITTOC) will have access to your group, although I think you can open it up further; we will all figure out the functionality of zulip together.

Each group has a number for convenience. They should probably have names too, and some of them basically already do because they were pre-made. Others contain smaller groups within them. But if you want a name, that should be easy to add.

Your group can talk there (and post pdfs, and videochat internally to zulip, etc.). If you want, if discord is easier, you can just set up DMs on discord, for example — just figure out what works well, and experiment.

There are a number of groupoids (about seven), and each group is in a groupoid. (Or for the category theorists: each groupoid has a number of components, each of which is a group.) Some people (who didn’t appear to want to be part of a group) will not be in a regular group, but they’ll still be in a groupoid, so they can have a home base on zulip.

Each groupoid has a shepherd watching over it: Juliette Bruce, Taylor Dupuy, Quinn Greicius, Jack Petok, Maddie Weinstein, and David Zureick-Brown. (The groupoids are called B, D, G, P, W, and Z.) There are also some other shepherds-at-large: David Lin, Jackson Morrow, Natalia Pacheco-Tallaj, and Sasha Shmakov. (If something comes up, and it’s just easier for you to bring it up in Chinese, Spanish, Italian, or Russian, you can talk to David Lin, Natalia Pacheco-Tallaj, Natalia Pacheco-Tallaj, and Sasha Shmakov respectively.) The shepherds aren’t TAs or even pseudo-TAs; they are all AGITTOC participants who are also volunteering their time to figure out how to make this work, and are sort of intermediaries between me and everyone else, so I don’t get even more overwhelmed.

Questions and comments for the pseudolectures will work as follows. You can watch on youtube live (instructions before too long when I get around to it; thanks to Dev Sinha). The shepherds, and those who can’t easily access youtube, will watch on zoom. My slides should be available in nearly real time (ie, after I finish with a slide, it should be available) on dropbox (instructions later when I get around to it — thanks to Yufei Zhao for explaining this). For questions and discussion, each groupoid will have a channel on zulip or discord (not yet decided — we can figure out what works better). Then during the lecture, a shepherd will watch that channel, and perhaps ask some of the questions out loud to me.

I’m sure I’ve forgotten something I meant to write, but I’ll write another post before long, so it doesn’t matter too much.

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