Graham

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 S ⊆ L = { y ∈ L : x ⊏ y ∧ ∄ z x ⊏ z ⊏ y }. 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 ⊑ ?

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

Interesting article in some ways.

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

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 )

The fire has spread west, and was quite impressive in the background today.

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.

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.

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)

Mom called me today to tell me that Paco was really not doing well. He is horribly thin, mostly unresponsive, and won't blink. He won't even track with his eyes, I think he's blind. He has a terrible time with his balance, won't eat and won't drink. Mom thinks he won't last the night, and we have an appointment with the vet to euthanize him tomorrow anyway. I miss him already.

Saw Watchmen tonight. It is a surprisingly good adaptation of the graphic novel; I was expecting something more hamhanded. Those of you who are squeamish may want to pass; there are a number of rather brutal injuries inflicted during some of the fight scenes. Recommended to everyone else.

My cat Paco, from whom I constructed the screen name I usually go by, has a large build-up of fluids in his abdomen. The fluid is being tested, but the vet says that only happens for cancer or heart failure.

It is, like, 12 C outside. I have spent the last few hours milling lumber in a T-shirt and am pouring with sweat. Man, that is hard work.

On the plus side, vivianteddybear, your table top is gluing up now.

Octopus survives 5 days on the run; a Kiwi octopus managed to escape from its tank and hide in a drain for five days while they looked for him. A different octopus from the same tank made it halfway up the stairs before being discovered.

Did you know? People in Palm Springs are so bored that they will back up traffic for 40 miles because one cop pulled one dude driving a truck over?

I hate LA.

Things I am very happy to have:

• iPhone


• Google Maps

Things I am incredibly happy I know how to do at night with no flashlight on a moonlit evening in the freezing cold:

• tie a bowline

It is actually hailing here now. I did not register what it was at first because it has been so long; there was white stuff on my windshield and I couldn't identify what of was at first.