Summer of Math Exposition

Presented by 3Blue1Brown 3blue1brown

⚡Death rays⚡, Rothe diagrams, and sorting lists

Audience:

This is a short video about permutations and Rothe diagrams. It's (roughly) for high schoolers and above.


Analytics

5 Overall score*
120 Rank
20 Votes
15 Comments

Comments

5.7

it was very monotone and scripted but was also straight to point.

6

i like the things it talks about but i dont like short math explainers that dont dive into the topic much, but its cool you left something for the viewer to think about after the video

3

The video is too short, and feels rushed to finish before the end

5

This is a cool trick, and I enjoyed the back-and-forth narration. I think the YouTube short format is a little bit too short for this, though, and I really would have enjoyed a more thorough explanation of why the inversion number is well-defined and why the diagram’s empty square count is equal to the inversion number.

7

Fun! I also didn’t know about the Rothe diagram despite working with Coxeter groups quite a lot, so very cool. I really like the dialogue as a format, especially for a short like this. More of this! (P.S. I thought I recognised that voice :))

4.2

I like the structure of having two presenters who are having a conversation with each other (I think in general having more than one person around at once is probably an underutilized space) but I do think that the audio editing and some aspect of the takes make it a little disjointed.

The content here is interesting, naturally sorting algorithms are a topic of a lot of conversation for people learning about things like algorithmic complexity for the first time, and the Rothe diagram is quite a novel way to explain the worst case and its efficiency. That said, the length of your video does mean you weren’t quite able to fully realize the explanation of why the Rothe diagram is related to the inversion number, or get into a lot of those related details. (I do like the choice to leave figuring out the worst case as a problem for the viewer, but it doesn’t help with the issue of it feeling more like you’re just introducing the concept for the viewer to go learn more about themselves as opposed to really explaining it.)

As a proof of concept, I like the short quite a bit, I think there are a lot of positive things to say about it, I just think it’d be more substantial if it wasn’t just a short, and that there are some things in the execution which could be cleaned up. I’d love to see you keep working toward a more fleshed out version of this though!

7

intriguing, can be a good start for a lesson / a discussion with students.

4

I think this was a really fun fact, which I’d never heard of, and will definitely remember. Also I thought it was very well motivated given the time constraint. However, I think if someone isn’t familiar with partitions, or combinatorics in general (i.e. the approach of turning it into a grid), I think it might be quite hard to follow. Also, it would have personally been nice to see why it is true, which I realise is difficult given the time constraint, but I would guess it could be done in just a bit more time. So generally, I enjoyed it, but think it’s probably suited for people who are already comfortable with combinatorics.

5

Was some nice quick info on a topic I hadn’t heard of before, but it seems like the topic could use even just a 5-10 minute video format to add a bit more info and allow a little time for digestion and building understanding.

3

I felt like the fact presented was interesting, but there wasn’t any discussion of why it was true or how it was a more efficient way of computing the inversion number.

6

Short and sweet, and I like the back and forth style of explanation used.

4

It seems that the diagram could help you find multiple ways to sort a list with only bubble-sort like swaps, but its not entirely clear how one would do that.

5.6

The video was solid given that it is in shorts format, but I would love to see the topic explored more. The idea of using death rays is cute and appeals to the fantastical side of me, but I had to go through the effort of confirming to myself that the Rothe diagram works. Good video, but it is really hard to make a great video in a short.

8.1

I loved the super quick format!

9

This is really good. Super rewatchable because it’s packed with information. The dialouge format is very engaging and the visuals too.