[CIMC 2015 Part 3] Monsters and Pandas and Tigers, Oh My!

My inner perfectionist is crying that I have to post this, in particular over my pathetic snowclone title, but my inner pragmatist knows that, judging by my old blogging patterns, it’s now or never.

18.06: 56%, haven’t touched it in a while, but I think I can do lots more on the plane.

As a non-contestant, I confess I feel totally uninvested in the results and find the Closing Ceremony boring. All contestants go up, country by country, and have their awards read off. No effort is made to make any sort of buildup to a climax. But maybe this is for the best; we don’t want anybody feeling shafted or discouraged from continuing to do math due to a mere elementary-/middle-school competition. Meanwhile, though, I’m browsing reddit on my phone.

After this ceremony, the entire Taiwan delegation spends some time walking around outside while the guides make confused phone calls trying to decide where we eat lunch. My parents offer me some potato chips they bought somewhere, which are (as the label is really eager to point out) baked, not fried. Some time passes this way; eventually, the guides figure it out and we go through amazingly long queues to eat at the cafeteria, as usual. Then we are sent to a massive shopping mall for the afternoon, a place so large that its exits have number labels that go up into the double digits so that people don’t get lost.

I take trippy failed panorama photos from the bus windows.

[trippy panorama of a shopping mall]
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[CIMC 2015 Part 2] Journey of the Blue-White Slippers

(Nontopical life update: Current 18.06 homework status: 34% (mildly screwed, probably won’t finish before I leave my cozy home for the U.S. and I usually struggle to get into the mood for homework while traveling, but I guess I’ll have to))

[18.06 status panel: 34%]

(I’ve been spending most of my uptime doing said homework and running errands, and my downtime catching up on Last Week Tonight with John Oliver while farming the Flight Rising Coliseum. And, okay, making the above status panel. Live version here courtesy of Dropbox’s Public folder. No regrets.)

Day 3 (Excursions)

Morning routine snipped. We come to the middle school again to eat breakfast and gather; the contestants will be taking their tests here (accompanied by one bottle of “Buff” energy drink each) while the rest of us will be going on an excursion. Before this happens, though, two Taiwanese contestants ask me and Hsin-Po some math problems. There’s a geometry problem, which I fail to solve:

(paraphrased) In triangle △ABC, ∠A is 40° and ∠B is 60°. The angle bisector of ∠A meets BC at D; E is on AB such that ∠ADE is 30°. Find ∠DEC.

Hsin-Po figures out that, once you guess (ROT13) gur bgure boivbhf privna vf nyfb na natyr ovfrpgbe naq gurl vagrefrpg ng gur vapragre, lbh pna cebir vg ol pbafgehpgvat gur vapragre naq fubjvat sebz gur tvira natyr gung gurl vaqrrq pbvapvqr.1 Then, there’s a combinatorics problem in a book with a solution that they’re not sure about:

(paraphrased) 15 rays starting at the same point are drawn. What is the maximum number of pairs of rays that form obtuse angles?

This happens really close to the test starts and although I have this feeling it’s isomorphic to a notable combinatorial problem, I don’t manage to articulate the isomorphism until it’s too late and they have to go. Indeed, this is more or less equivalent to (ROT13) Ghena: gur tencu unf ab sbhe-pyvdhr naq n pbzcyrgr guerr-cnegvgr tencu vf pbafgehpgvoyr. After thinking though the solution on their book, though, I realize I’ve never seen this proof of said theorem before! (But later I realize it’s actually the just very first proof that Proofs from the BOOK offers. I probably skipped it because it involved induction as well as some algebraic manipulations that looked much less intuitive and natural than they really were, so it didn’t look as cool as the later proofs. Oooooops.)

I suspect I wouldn’t do too well if I had to participate in that contest right then. But anyway, excursion.

After a long bus ride, we arrive at our first destination, Jingyuetan (淨月潭 lit. Clear Moon Lake2), allegedly the sister lake to Taiwan’s own famous[citation needed] Sun Moon Lake. We tour the place on a wall-less car and look at the lake and lots of trees. During a stop, I take some pictures of sunflowers and bees, as well as a stand selling Taiwanese sausages.

[Lake and ferry]

[Bee and sunflower]

[Sausages advertised as from Taiwan!]

The car blares weird music during the tour, such as a version of Für Elise with all the accents on different beats and a disjointed remix of the viral Chinese song 小蘋果 (Little Apple)3 with two other Chinese songs, connected with mumbling English rap segues. We also eat boxed lunches here while sitting on tiny, cramped foam mattresses on the dirt floor.

Our next stop is a museum, where there are lots of ancient historical artifacts I’m not very interested in. I find a collection of certificates involving or quoting Chairman Mao more intriguing:

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[CIMC 2015 Part 1] Rainy Days in July (and Other Months)

We get up at 3:40 AM. By 4 AM we have left our house, speeding like a bullet into the dark.

(Ohai. Somehow it slipped my mind that I was ending my streak by leaving the country for a competition that would likely be highly bloggable, like my last two international olympiads, both of which led to notable post sequences on this blog. (Admittedly, the first one was never really completed…) My only excuse was that I was worried I might not be able to access my blog from inside the Great Firewall, but I did (via vpn.mit.edu) and even if I hadn’t, I could still have drafted posts locally in Markdown as I usually do, so I don’t know what I was thinking.)

(Also: because, as I’ve said way too many times recently, I need to do linear algebra homework, these posts aren’t going to be as complete or as perfect as I’d like them to be. Although I’m probably just saying this to persuade myself; I tend to include many of the boring parts as well as the interesting parts of the trip, which maybe benefits my future self at the expense of other readers. I probably need to get out of this habit more if I want to blog for a wider audience, though. Oh well.)


The International Mathematics Competition (IMC) is, as it says, an international mathematics competition. But I should add that it is for elementary and middle-school students (in other words, I am not competing, okay??). (edit: Also, one or two letters are often prefixed to indicate the host country, for whatever reason. This year it would be CIMC, C for China.) I am tagging along because I am a student of Dr. Sun, one of the chief organizers, and have been slotted to give a talk and possibly help with grading the papers and translating. My father is coming to help arrange a side event, a domino puzzle game competition, which he programmed the system for; and my mom and sister are also coming to help with translation and other duties. Other people in our group: Dr. Sun himself, his longtime assistant slash fellow teacher Mr. Li (wow I’m sorry I forgot you while first writing this), my friend and fellow math student Hsin-Po, who is an expert at making polyhedra from origami or binder clips (and at Deemo); Chin-Ling, my father’s student/employee who also programmed lots of the domino puzzle server and possesses a professional camera; and, of course, all the elementary- and middle-school contestants, as well as most of their parents.

I don’t think I’ve ever given this amount of background exposition about any event I’ve attended to my not-so-imaginary audience before. It feels weird. Some part of me is worried about breaking these people’s privacy by posting this, which makes a little bit of sense but not enough for me to think that it’s actually a valid reason to avoid or procrastinate blogging. I think it’s a rationalization.

Here we go.

Day 1

The only interesting thing that happens at the airport is a short loud argument in the queues for luggage check-in, perhaps partly fueled by our high number of people and of heavy boxes (gifts for other countries and raw materials for Hsin-Po’s polyhedra). I don’t know whose fault it is.

In case I fail to scale the firewall, I attempt to download Facebook on my phone for one last look before boarding, but it fails during installation twice and I give up.

Our plane is not fancy enough to offer personal screens and entertainment centers for everybody, but thankfully the ride lasts only three hours, so this is tolerable. Instead, the plane plays the second Divergence movie on overhead screens, which I watch half-heartedly. The plot setup seems interesting but the ending seems to me to involve two Ass Pulls™, although since I haven’t been paying much attention I am not confident if I just missed some foreshadowing or character development. On the flight, I also read the proof of the irrationality of powers of e in Proofs from THE BOOK and leaf through the magazines.

I don’t hear any good music on-board, except maybe “Space Oddity”, which is a little freaky to be listening to while cruising at so may kilometers in the sky. Perhaps because of this, I find myself singing and humming “Space Oddity” unexpectedly often over the next few days.


The very first sign we see after alighting the plane consists entirely of characters that are the same in Simplified and Traditional Chinese — if I remember correctly, 「前有坡道,小心慢走」1. The Changchun airport looks like any other airport, coolly blue-themed with moving platforms. The restrooms have fancy bright purple soap. Even though I consciously think about how I have suddenly arrived in a country that places notable restrictions on freedom of speech and Internet access, I don’t feel it. Eep, what an anticlimax.

[People dragging luggage boxes over gravelly ground outdoors.]
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