I meant to post this sooner — my birthday was a month ago — but I just got busy. Anyway, these two wonderful objects came in the mail right on my birthday…
The first was a gift from Jim Blandy :
It’s a Lichtenberg Figure , that is to say, lightning captured in a solid medium. Whoa. They use a linear accelerator to bombard a block of acrylic (Polymethyl Methacrylate, which I can only assume is as cool as it sounds) with a beam of electrons. Eventually the negative charge builds up to a high enough level that the trapped charge surges out along branched pathways, I guess because the first bits of the surge create pathways that the next bits are more likely to follow, leading to the same kind of pattern — and for the same reason — as diffusion-limited aggregation . It is even more beautiful in real-life than it is in the photograph. Read more about it here here .
The other arrival was a gift from the choir I used to sing in in Chicago (and still miss every day): Golosá , the Russian Choir of the University of Chicago. Their second CD, Until Bright Day is out, and it’s absolutely beautiful — I can’t stop listening to it:
Listen to some tracks  — you’ll be glad you did, and you’ll probably want to order  the CD afterwards. If you live in Chicago, consider joining their mailing list  (it’s low-traffic) to learn about upcoming concerts. They released the CD under a Creative Commons Attribution-ShareAlike license, by the way — so please spread that music around, especially if you live near Chicago.
Thank you, Tammy, for sending the CD! Thank you, Jim, for sending the lightning! (Now there’s a sentence you don’t see every day.)