There are some questions about outer space that I would like to be able to answer. Some nice survey articles look to be:

Bestvina, Mladen. The topology of $\rm Out(F_n)$. 2002. 373–384. MR.

and also:

Vogtmann, Karen. Automorphisms of free groups and outer space. Geom. Dedicata 2002. 1–31. MR.

Here is a ridiculously simple question I have wondered about: given $A, B \subset F_n$, say with $[F_n : A] = [F_n : B]$, how can I tell if $A$ and $B$ are conjugate? I suspect I’m being stupid here.

In light of my recent comments on LINCOS and communiating with extraterristrials, I found an article:

Ruelle, David. Conversations on mathematics with a visitor from outer space. 2000. 251–259. MR.

Putnam also makes use of the idea of mathematicians from other planets, to more philosophical ends.

I’m fond of the Pineapple Sauce Pancake graph: the vertices are English words, and there is an edge from $a$ to $b$ if $ab$ is also an English word (e.g., “pan” and “cake” are English words, and there is an edge from “pan” to “cake” because “pancake” is also an English word).

To play around with this, I wrote a Javascript program, complete with a Web 2.0 logo–which reminds me, I wonder if there is an interpreter for the programming language logo, written in Javascript?

Anyway, what I really wanted to do was to make a wall-sized picture of the Pineapple Graph, but Graphviz isn’t quite able to handle it, but maybe with some tweaking, I’d be able to produce a beautiful poster.

I’ve spent a lot of time constructing languages (Kisonef and Naedari being my favorites); in a similar vein, I also tried to create a language that an alien civilization would be able to understand. I had hoped to put a message written in my universal language in a conspicuous place (say, on a college campus), just to test if what I made really was understandable, even to humans!

But I never got around to that, and plenty of other people have done exactly that. This is related to the following question: state and prove a theorem in such a way that an alien would be able to follow your proof.

But whoa! I found out that Freudenthal (the mathematician) did the same thing: he created LINCOS. Bizarre. I also enjoyed looking at this image that we sent into space and trying to imagine what the aliens must think of people who write with such strange characters.

Last night, there was a terrible thunderstorm in Chicago; I’ve never seen so many trees on the road! I was supposed to land at Midway at 7:30pm last night, but we were diverted to Indianapolis, so I didn’t land in Chicago until 2:00am, and then I waited until 3:00am to get a taxi, so I didn’t get home until almost 4:00am. Crazy!

My house lost power last night, and today some places are still without power. In particular, Co-Op Market’s 53th street store was closed, merely displaying a sign “Closed No Power Mgmt.” Considering that their 47th street store shut down, and that their 55th still (?) lacks price scanners, I can only expect that this power outage is the final blow to Co-Op.

In contrast, the also-powerless-but-superior Hyde Park Produce Market was using a generator to power their cash registers (and to provide one very bright light in an otherwise dark store).

My cell phone still works, even after being dropped into water.

There is a program called PawSense for Windows which detects “cat-like” typing, and then prevents further keyboard entry.

I found some code for filtering keyboard events on Mac OS X, and I wanted to implement something similar. But this raises an interesting question: just what characterizes “cat-like” typing?

The PawSense website suggested that cat paws are very broad, and usually strike nearby keys simultaneously. Another idea is to detect “human-like” typing and then freeze the keyboard whenever non-human typing is detected (which has the useful feature of detecting a future version of cat with smaller paws).