I’ve been going through some of the videos of the invited talks from the Joint Math meetings and trying to figure out how to share them with kids. The tallks and our first two projects are here:

Today we looked at Lázló Babai’s talk on graph isomorphisms:

I started by explaining what “graph” meant in this context and then exploring a few examples:

I decided to break the final conversation at the end of the last video into two pieces so that the boys wouldn’t feel rushed talking about the last two graphs:

Before moving on to a pretty challenging example, I decided to show them a connection between shadows and graphs – the conversation here was actually much more fun than I expected!

Next we moved on to a pretty challenging example of two isomorphic graphs. The boys did a nice job showing that these two graphs are indeed isomorphic.

To wrap up we looked at a more complicated example from Babai’s talk. From that example I think the boys were able to see that the graph isomorphism problem can be pretty hard!

This was a fun project. I think that kids really enjoy introductory graph theory. Another fun project we’d done in the past on the subject is here: