Irrationally effective

Everyone knows that e has some nice combinatorial properties, but occasionally a counting result comes along that transcends the well-known mundanity of cute factorials.

Counting and Computing by e
M. Hassani

The problem that just won't go away

Do you like maps? Do you like colors? Do you like coloring maps? Do you like signed permutations? I like signed permutations because they describe genetic mutations. I also like the fact that maybe, just maybe, there's a connection between mutations and how many colors are necessary for map-making.

Signed permutations and the four color theorem
S. Eliahou, C. Lecouvey

Cubicles have no doors

While I, unlike the heroes of this comic strip, am quite productive at my workplace, I am highly attuned to passersby. My back is to the entry-break in the carpeted wall, so my reactions are as follows:

1. When I do not have headphones on, I turn to look every time someone passes by;
2. When I have headphones on, I am startled by a tap on my shoulder by whoever needs my attention.

The first is less disruptive, but more frequent, so there is clearly an optimization problem buried here. In either case, it is clear why the principles of feng shui dictate that one should always have a clear view of the entrance to their space.

When does a hiatus become a leave of absence?

Abject apologies to those who would like to have read more frequent musings in this space. You have witnessed the effect of finishing a doctoral dissertation. After a decent run of at-least-weekly posts, I realized that I wasn't going to be able to keep it up during my home stretch. Having recently begun a transition to a new phase of my career, I expect to be able to devote an appropriate amount of time to this pursuit again.

I guess you can write a paper about just about anything these days

But I really shouldn't be so harsh. The authors suggest that their work "rediscovers" a lost proof of a very interesting set theoretic result. And attention-grabbing titles can only help to spice up the literature-scape.

Division by three
Peter G. Doyle, John Horton Conway