Writing at windmills

All of this fancy optimization stuff is called operations research.

–Joel Spolky’s latest column

As usual, Joel writes an article that is long, rambling, goes nowhere for most of its length, leaves you inclined to say “You have a point. An idiotic one, but a point.”, and is entirely a delight to read.
(To be sure, the last two seem less true for this one than usual: not only is there less of a point, the article is also less fun. But it fits the pattern.)

God save us from the Joels, Pauls and Steveys.

Update [2009-09-01]: I think what I meant by the last sentence was that these popular bloggers are such clear and entertaining writers that there’s a danger that our admiration for them might make us agree with them. Paul Graham is especially admirable: his perfectly edited writing stands out in comparison to most things on the internet… of course, if you think about what he says you’ll realise half the time that he’s completely wrong, but chances are that you wouldn’t have thought so clearly if he hadn’t written so clearly in the first place.

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A non-intuitive(?) fact

This seems counter-intuitive, at least to me, but if you can find an intuitive explanation for it, please comment!

Fact: Let G be a cycle (connected graph where every vertex has degree 2: you know what I mean) of length n (i.e., n vertices and n edges). Start a random walk on G from any node u. Then the probability that v is the last node visited (i.e., the random walk hits all other nodes before hitting v) is the same for every v other than u!

[Such a property is obviously true for the complete graph, and apparently it’s true only for cycles and complete graphs.]

I do not know a probabilist’s proof; what I could think of is a distinctly ComputerSciencey (Dynamic Programming / recurrence relation) proof.

Why doesn’t Cathy eat breakfast?

Unsolved mysteries of our time (or the 1970s):

Why doesn’t Cathy eat breakfast?

If anyone can tell me what the National Dairy Council wanted us to think, I’d be much obliged. (They have managed to include a dairy product in every kind of food shown!)

In the meantime, I can only suggest: Maybe because it’s not such a great idea after all?

IMDb Top 250

It turns out I’ve watched only 108 of the IMDb Top 250.

Update: There have been changes in the Top 250 since this post; The Dark Knight is now No. 1 with a rating of 9.5 :D

Part of the problem is that good movies keep slipping out of the list; look at some in the last 20:
231. 7.9 Pirates of the Caribbean: The Curse of the Black Pearl (2003)
234. 7.9 Strada, La (1954)
236. 7.9 Dolce vita, La (1960)
237. 7.9 Shaun of the Dead (2004)
239. 7.9 Roman Holiday (1953)
240. 7.9 His Girl Friday (1940)
241. 7.9 Brazil (1985)
242. 7.9 Network (1976)
244. 7.9 Once (2006)

(I’m not saying all of those are great; just guessing that anyone thinks at least some of those are :))

My numbers are better at the top:
10 of the top 10,
36 of the top 40 (WALL-E and the 3 LotR movies),
39 of the top 50.
But only 59 of the top 100.

Update [2009-08-02] Currently, of the “endangered” movies I listed last time,
Pirates of the Caribbean is out,
La strada is safely in at 212,
La dolce vita: 246,
Shaun of the Dead is out,
Roman Holiday: 241,
His Girl Friday safely in at 213,
Brazil: OUT!,
Network: 223,
Once: out.

And I’ve seen:
71 of the top 75 (Up! (2009) and the three LotR movies),
87 of the top 100 (getting there!),
142 of the top 250

Printing PostScript files directly to printer on Mac OS X

lp -o sides=two-sided-long-edge -P 3-49 mixtimes.ps

Or even:
lp -d printer -o media=legal -o sides=two-sided-long-edge -P 1,2 Desktop/mixtimes.ps

Fireworks

Massachusetts General Law, Ch. 148 S. 39 – the simple possession or use of fireworks, or the selling or offering for sale of fireworks is against the law. A violation of this law shall be punished by a fine of not less than one hundred dollars nor more than one thousand dollars or by imprisonment for not more than one year or both.

I wonder

• if it’s the same in other states of the US as well
• since when this has been so
• what was considered sufficient provocation to enact this law
• is there no one who considers this a violation of civil liberties
• so who shoots all those fireworks that we went and watched on the Charles River yesterday, and why the law doesn’t apply to them
• what, if anything, Indian/Hindu groups do at Diwali :)
• what it would take to get something similar passed in India :)

I’m not complaining, just curious.

Update[2009-07-04]: This looks like a useful resource on fireworks laws: http://www.fireworks.com/fireworks_laws
States that “specifically permit” no fireworks are Arizona, Delaware, Massachusetts, New Jersey, New York and Rhode Island. Other states permit some fireworks (except that the laws of Hawaii and Oregon are not immediately clear).