51 karma · joined June 19, 2021
Eugenia Cheng - The Joy of Abstraction: An Exploration of Math, Category Theory, and Life
She builds up to the category theory chapters.
Book club: https://youtube.com/playlist?list=PLhgq-BqyZ7i7tEEQVG5rlOG8y...
Do you plan to make a proofs based book available as well?
If so, it could be due to things like this:
https://tech.okcupid.com/evaluating-perceptual-image-hashes-...
Match Group owns OkCupid, Hinge, Tinder and so on.. so wouldn’t be surprising if they all used the same or similar algorithms for spam prevention and noob boost abuse.
They probably also collect other data like your phone number, deviceID, etc.
This is bad because if you ever delete your profile and remake it then your internal ranking could plummet due to these aggressive spam filters.
My complaint with this is the audience reading this book aren’t students in classes and likely a lot of them don’t have access to mathematicians or professors. Working with others is a great way to learn how to properly do proofs when first starting out. I think the FB groups / discord groups or whatever communities of learners should discuss their proofs and suss out difficulties or logical errors with each other.
This approach instead seems to assume the learner will know whenever they develop a correct proof but often one can just fool themselves into thinking their proofs are correct or even get utterly stuck. Or it assumes seeing solutions will “rob” the readers of learning.
Also, who really cares? Most of the people working through this book aren’t getting a grade from it. If they want to rob themselves of learning something just by seeing solutions without thinking first, then that’s on them.
Otherwise, beyond that complaint this seems like a good resource and it’s impressive it’s all free. I’d also recommend another topology book that’s free https://topology.mitpress.mit.edu/, albeit it’s more advanced.
Some parts require more math than probably the general audience will be able to grasp but if they gloss over those sections they could still get the gist of what follows.
I think I’d rephrase it as “quite approachable for a talented high schooler / someone with knowledge in undergraduate mathematics”
supplement those books with these lecture videos:
https://youtube.com/playlist?list=PLl-gb0E4MII28GykmtuBXNUNo...
they appear to follow rosen but they’re the same topics you’d see in epp
if you’re the complete beginner go with epp and then use rosen as a supplement.
if you are an advanced undergraduate in math but don’t know category theory then:
https://math.jhu.edu/~eriehl/context.pdf
or
Basic Category Theory by Tom Leinster
(even though i’ll list a bunch more resources below i’d probably start with leinster and work up enough math maturity to push through it.)
i also liked this: https://arxiv.org/pdf/1912.10642.pdf
if you don’t know advanced math then there is an upcoming (not yet released book) called “the joy of abstraction”
i cannot attest for the book as i haven’t read it but may be good for true beginners:
https://www.cambridge.org/us/academic/subjects/mathematics/l...
(click “look inside”)
they say “no formal mathematical background needed”
you can read the description and see if that is something that would be of interest to you.
this guy has videos + a book
there are a lot of books like “category theory for programmers”, “programming in categories” and the “seven sketches” books along with lecture recordings and videos that you may find helpful.
category theory for programmers might be the easiest of those three books. i worked a bit out of the programming with categories (http://brendanfong.com/programmingcats_files/cats4progs-DRAF...) book and ignored all the haskell sections and just focused on the math parts (this is a distinct book from “category theory for programmers”. people confuse the two due to the names and the fact they both use haskell).
if you know category theory and want to learn topology then there is “ Topology A Categorical Approach” by bradley et al.
If abstracts algebra is too difficult then learn introduction to proofs before continuing with abstract algebra.
Try doing problems and posting them online to have them checked. Currently you can use discord, reddit, math stack exchange etc
Don’t worry about rushing it. Everything builds on itself. For instance once you rigorously study introduction to proofs you’ll see the same sort of proofs again when you begin studying abstract algebra and will already be familiar with the concepts.
https://www.newyorker.com/magazine/2015/02/02/pursuit-beauty
I worked a bit and want to return for a PhD in CS. I took some courses at a nearby (and good) institution and did well (for fun). I want to continue taking graduate courses and and get involved in research before I apply for PhD programs (since I been out of school for a while).
Curious to hear from older students their experiences or from professors on thoughts about older students (say late 30s/early 40s) and whether there are job opportunities in industry for folks in this age range upon completion (in say applied areas).
I’m doing it because I really want to do research and enjoy hard theoretical problems outside the scope of your regular SWE job.
This doesn’t provide solutions to the problems and doesn’t show you how to do the mathematical calculations. It assumes you know proof based linear algebra and if you’re a math beginner the level that this is written at will be beyond you.
Instead I recommend
https://www.thomaswong.net/introduction-to-classical-and-qua...
which doesn’t assume much pre-req knowledge and contains solutions so you can check your work
Instead I recommend http://www.thomaswong.net/introduction-to-classical-and-quan... which doesn’t assume much pre-req knowledge and contains solutions so you can check your work
Another mathematician that reminds me of Von Neumann is Euler. He also memorized long passages and could do complicated calculations in his head quickly.
A quote on Euler from wikipedia:
“He was able to, for example, repeat the Aeneid of Virgil from beginning to end without hesitation, and for every page in the edition he could indicate which line was the first and which was the last even decades after having read it”
*I should have clarified there is some proof generation, see the comment below by opnitro, but I meant the meat and potatoes of novel non-trivial proofs currently has to be supplied by the user.