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From the BBC about Fukushima:
The Tokyo Electric Power Company (Tepco) had originally said the radiation emitted by the leaking water was around 100 millisieverts an hour.

However, the company said the equipment used to make that recording could only read measurements of up to 100 millisieverts.

The new recording, using a more sensitive device, showed a level of 1,800 millisieverts an hour.

Okay, hands up everybody who pegs the needle in a gauge and says "eh, it's probably not more than the peg". I thought so.
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EventMachine

Sep. 3rd, 2010 08:41 pm
This is probably only of interest to perhaps three of you, but what the heck.

I discovered today that EventMachine, a very commonly used Ruby library, has a completely broken popen implementation. Specifically, it doesn't ever call waitpid unless you are

  • Running on Linux and have selected the epoll option
  • or the process closes all of its input sockets.
In practice this means that if your subprocess spawns a background process and exits, EventMachine will not notify you of that process exiting until the subprocess dies too.

Lost a couple hours to this. It is in no way atypical of either EventMachine or Ruby, sadly.

Unix arcana

Sep. 2nd, 2010 06:00 pm

Fun fact: the checksum size computed for tar archives is 16 bytes long. This is not documented anywhere.

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Photography

Aug. 23rd, 2010 01:01 pm
I've been finally (after around two years) getting around to developing some of my backlog of film, while waiting impatiently for my blackout cloth to arrive so that I can actually have a darkroom. It is amusing in some ways to contrast my two main hobbies these days; long obsolete Nikon lenses that won't work on most current bodies are still $300 a pop which will buy you damn near any hand tool you could want in woodworking. Mostly I'm finding a strange budding desire to go shooting with my 4x5 camera (a bit of a production because I can't remember which film holders, if any, have any film in them!).

Incidentally, Rachel, I have some photos from your wedding now :)

Teamwork

Aug. 18th, 2010 02:05 pm
It's weird working on something as part of a team, or especially as something someone else wants done but where the spec is a little bit different every day. They're good about it, it's not the usual spec hell stuff, but it can be very disorienting to come in and discover someone has e.g. decided your internal structures should really look like Y rather than X.

Similarly strange is the insistence folks have about me contacting e.g. the Subversion developers when I am having trouble using their ludicrously poorly specified library bindings. I eventually made myself understood by saying that "ok, if I haven't resolved the problem by this evening I'll email them but usually butting my head against stone walls takes less time than talking to people". Which is, I think, true for me with email. Less so with in-person type stuff but I have much less hesitation about going up to a coworker and saying "so, uh, WTF. Seriously."

New toys

Aug. 17th, 2010 11:56 pm
My iPad arrived today, when I was home sick due to weird intestinal problems (the less spoken of, the better). Man, there is no surer way to make an iPhone look tiny than to compare it to Big Brother here.

I think it'll do what I bought it to do admirably, that being reading papers for work and the like. Not sold on it as a web browser quite yet, but perhaps. The landscape keyboard is so close to being almost useful at it hurts, but the portrait is … I dunno, less useful for actual input? I can make it work but it isn't exactly flawless.

Minor annoyance is that there is as far as I can tell no iPad native LiveJournal apps. I could run the iPhone versions (which operate fine) in reduced screen mode but that is profoundly unsatisfying in a way that is difficult to coherently express. I dunno. We'll see, for sure. OS 4 for the iPad can't get here soon enough.
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LJ being evil

Mar. 4th, 2010 02:12 pm
Summary at a friend's page. As he puts it Livejournal is secretly, and deliberately, changing certain outbound links that you post.
GRAHAM:
Phone? Phone? Wake up, I want to play games.
PHONE:
*iz ded*
GRAHAM:
Bollocks. Out of batteries. *unpacks computer* Power? Power? Where are you?
POWER:
*iz hiding*
GRAHAM:
Oh, there you are.
POWER:
*panicks and cowers in a narrow space smaller than Graham's arm*
GRAHAM:
Fuck. *scrapes up arm getting power plug in* *spends hour sorting out which power adapter belongs to which appliance* *is finally ready to power Phone* Ah, finally. Now then, to plug phone in. …. Phone? Where the devil did you get with no batteries?!
PHONE:
*iz hiding in book in bathroom for no adequately explored reason*
In happier news I am nearly moved in to the new house. Unpacking is something else but already my garage is 8x more useful than the old workshop was. Now I just need to find antifatigue mats…
First, the joke: joke )

And then some food for thought: on learning )

I've come across a rather interesting CS problem during work that I thought I'd throw out there. The problem is this: given a finite lattice (L, ⊑) (our problem has a lattice that is also distributive, so you may presume that) and a node x in that lattice, efficiently compute the set SL = { yL : xy ∧ ∄ z xzy }. This is well defined, and starting from ⊥ it is possible to walk the entire lattice easily (which is why we care). If you precompute the lattice you can do this trivially. Is it possible to do so without considering every node in the lattice?

Failing that, can you give me an efficient algorithm for computing the structure of the lattice from a set L and a partial order ⊑ ?

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I do not yet understand how to be both crazy and compassionate.
BEING CRAZY IS NOISY | More Intelligent Life

Interesting article in some ways.

Philosophy

May. 13th, 2009 03:23 pm
Wittgenstein is popularly credited with the idea that most philosophical controversies are due to confusions over language. I'm not sure how much credit to give him. I suspect a lot of people realized this, but reacted simply by not studying philosophy, rather than becoming philosophy professors.
From Paul Graham's essay How to Do Philosophy

C++

May. 10th, 2009 11:15 pm
Almost everyone likely to be reading this is going to be totally uninterested. However due to some rash statements I made in my youth that can be found on Usenet if you are sufficiently determined, and the impending threat of the C++0x standard, I thought I might reaffirm my position on the language.

Briefly, it is the most terrible programming language anyone has seriously advocated programming in for the last 20 years.

details, if you're curious )

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Jesusita fire

May. 7th, 2009 10:45 pm

Jesusita fire
Originally uploaded by gchpaco
The fire has spread west, and was quite impressive in the background today.

Jesusita fire

May. 6th, 2009 05:50 pm
The world is on fire. Again. Something like the 4th time in 2 years. Local news reporting and a map showing evac zones.

Truthfully I have trouble getting concerned about the homes there, but the idea of the Mission or the Post Office or the Courthouse going away makes me sad.

I am also experiencing a sudden, intense and difficult to fully rationalize desire for a fiddle.

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A new hat

Apr. 19th, 2009 10:08 pm

A new hat
Originally uploaded by gchpaco
I finished the hat I started last Thursday. It's quite comfortable, actually, although I've yet to try using it outside. The material is actually a deep blue, not black, but it's so deep it's not easy to photograph well.

Hide glue

Apr. 19th, 2009 01:45 pm
I need to stop fretting about the possibility of hide glue joints coming undone if they get wet. I soaked a botched edge joint, exposed it to steam, and it still required a tremendous amount of force to undo. I suppose this qualifies as "reversible" in a strict technical sense, but if I hadn't botched it it would have been even worse.

To whomever decided that not only does exit 1 of the 134 not need an onramp westbound, but that exit 2 doesn't merit any kind of onramp at all and all onramps for exit 3 should involve some kind of massive construction job of the type to be finished in a decade if they're feeling plucky: I hope badgers invade your home and feast upon your reproductive equipment.

That said, to the cop who came up behind me at at least 90 desperately needing to get to somewhere on Fairview in a hurry: thank you for ignoring my speeding arse and going on to do whatever the fuck needed doing at 90 mph at 2:00 in the morning on a Saturday evening but somehow did not warrant turning your lights on.

To whomever decided that not only does exit 1 of the 134 not need an onramp westbound, but that exit 2 doesn't merit any kind of onramp at all and all onramps for exit 3 should involve some kind of massive construction job of the type to be finished in a decade if they're feeling plucky: I hope badgers invade your home and feast upon your reproductive equipment.

That said, to the cop who came up behind me at at least 90 desperately needing to get to somewhere on Fairview in a hurry: thank you for ignoring my speeding arse and going on to do whatever the fuck needed doing at 90 mph at 2:00 in the morning on a Saturday evening but somehow did not warrant turning your lights on.

A hundred prisoners are each locked in a room with three pirates, one of whom will walk the plank in the morning. Each prisoner has 10 bottles of wine, one of which has been poisoned; and each pirate has 12 coins, one of which is counterfeit and weighs either more or less than a genuine coin. In the room is a single switch, which the prisoner may either leave as it is, or flip. Before being led into the rooms, the prisoners are all made to wear either a red hat or a blue hat; they can see all the other prisoners' hats, but not their own. Meanwhile, a six-digit prime number of monkeys multiply until their digits reverse, then all have to get across a river using a canoe that can hold at most two monkeys at a time. But half the monkeys always lie and the other half always tell the truth. Given that the Nth prisoner knows that one of the monkeys doesn't know that a pirate doesn't know the product of two numbers between 1 and 100 without knowing that the N+1th prisoner has flipped the switch in his room or not after having determined which bottle of wine was poisoned and what colour his hat is, what is the solution to this puzzle?

(not original to me, sadly)