My (regionally) high (they're not high) AMC and AIME scores caught the attention of a group of students at Canadian Academy, where I took the tests. One of them contacted me a few weeks ago, and I've been joining them in their unofficial 3-hour meetings every Saturday since.

Actually, I will probably not be going anymore, as the Purple Comet! Math Meet contest was today, and it takes me nearly three hours just to get there and back. With summer break approaching, they are adjourning until next year.

But verily, what they did was great. Canadian Academy currently does not have an official math club, but they have been getting together every weekend, three hours at a time without an adult supervisor, for seven months. I think the persistence is admirable.

I put together a practice Purple Comet test for them last Saturday using problems from the AMCs and some that I made myself. Fortunately, they liked it. I've always wanted to help teach math in some way (and I respect and admire many, many AoPS users for doing just that). It's a start. Maybe I'll start my own club when I get back to the states?

Anyway, thanks for inviting me to join your club, guys!

Has anyone noticed it? meh.

I have had chronic back pain for almost ten years. It's not severe, but lately it's been bothering me so much that I can't sit still for more than 10 minutes at a time. That, and a throbbing headache.

My mom took me to a doctor. After a two-hour wait and a few X-rays, he stretched my legs, tapped a few tendons, and pressed on some vertebrae to test for neurological problems or stress fractures. To my relief, he found none and explained that back pain was common among growing kids whose bones grow too fast for other organs to keep pace. The result is tight muscles and stretched nerves, both of which can cause pain.

I learned that my hamstring is too tight, which apparently is why my back curves forward so much when I sit; it's actually normal! The doctor also explained that many swimmers suffer from back pain and told me to slow down. (My coach is currently pushing me hard to beat my record, which isn't that great anyway.)

But when he pressed on my shoulders---OUCH. My headache is due to tight shoulders. I should stretch and rest up a bit. Maybe I should relax my head in the water when I swim.

Surprisingly, my back isn't twisted like it used to be back in grade school. Whew. Anyway, no surgery for me.

Many online sources say that Lisp is a "programmable programming language." Defining my own macros, being creative, and all that sounded a lot like the Art of Problem Solving spirit. So I decided to learn it. I'm reading Practical Common Lisp by Peter Seibel. The examples make things clear. I can't say much else because I'm still a novice.

From "If programming languages were cars...":



And from Paul Graham, author of On Lisp, another ostensibly good book:



For good measure, other entries from "If programming languages were cars...":



I hope I'm getting somewhere with all this.

My dad is a nuclear engineer, and he likes fluid dynamics. Last night he explained to me how the specific heat of a supercritical fluid sharply peaks at a certain pressure range (this relates, in some way too complicated for me, to the delta function). Okay, I didn't understand all of it, but this is the idea behind supercritical water reactors (SCWRs) currently under investigation in 13 countries around the world. If the pressure of the coolant can be maintained within that range, we could get more efficient, simpler, and generally safer reactors because there would be no worry of such things as steam bubbles (different density = problems), pumps, or condensers.

In light water reactors (most reactors in the world are LWRs), water enters the reactor core at 290°C and exits at around 315°C---only a 35°C difference due to water's high specific heat, but this could be improved by using supercritical fluids.

Wikipedia has better writers: