Misc: July 2008 Archives


July 31, 2008

If you haven't seen this pair of videos by a law professor and a police officer on the topic of why, if you're under suspicion for some crime, you shouldn't talk to the police, you should check it out. The basic concept is that even if you're innocent (and it's likely you're guilty of something) if what you say doesn't directly incriminate you, it is likely to be interpreted as incriminating, or contain inconsistencies which would potentially seem incriminating. The police officer also gives some useful background on the various techniques he uses to get suspects to talk. Practice saying "I want my lawyer."

July 26, 2008

I flew from SFO to LAX today, and noticed again a phenomenon that has annoyed me before: the doors on the bathroom stalls on both airports open inward (evidence below).

Ordinarily, this isn't a big deal, but in the airport it is. There you are with your bag. You walk into the stall, and then you somehow have to close the door behind you, but since it has to clear your bag you need to cram up against the toilet to let the door clear. If the doors just opened outward, this wouldn't be a problem. In SFO, at least, this would be no problem; the aisle is at least 6 feet wide. Even the LAX aisle is wide enough, though it might be a bit cramped to walk through with the door open if you were really fat. Still, this seems like it would be a simple improvement.

Barry Leiba and Jarrod observe that doctors routinely use dictation plus transcription:

Oh boy "And Doctors." A Forensic Pathologist I know spends at least 15 hours a week outside of the office dictating cases. Especially important ones she types herself, but it takes much, much more of her time than recording a dictation, emailing the .mp3 to the transcriptionist, and then reading and correcting the report for errors before sending it out. Typing speed isn't really a limiting factor either, as she does about 80wpm.

I certainly understand why one would want to dictate material if you were doing something else with your hands at the time (cf. TV shows where you see a coroner dictate while performing an autopsy). But I must say it's not apparent to me why you would dictate instead of typing if you were a good typist. I've tried dictating material to authors and always found it much easier to just type it in myself. Is this just a skill you have to practice? Is there something special about doctors?


July 25, 2008

This Science article reports on a counterintuitive result: extensive fire suppression reduces, rather than increases the amount of carbon captured by trees.
Lightning-caused fires serve a natural mechanism within forests. They destroy small trees and underbrush while often allowing large trees to remain standing and flourish. But since roughly 1910, U.S. forest managers have sought to fight as many small forest fires as possible. That policy has allowed more shrubs and small trees to grow than in the past. The increasing quantity of vegetation, scientists calculated recently using tree measurements and other data, sucks 50 million metric tons of carbon dioxide out of the atmosphere each year--roughly 14% of the total amount of carbon pulled in by U.S. forests. However, historical data on tree sizes weren't available to allow scientists to confirm that the forests had absorbed that much carbon over the past century.

To do that, ecologist Michael Goulden of the University of California, Irvine, and a grad student used previously overlooked forest inventory measurements taken in the 1930s on 269 California forest wilderness plots. They then compared these data with measurements taken in the 1990s on 260 plots in the same general vicinity. The number of trees per hectare across all plots rose by 4% in 60 years, an increase the scientists attributed to the federal policy on suppressing fires. Yet the total amount of carbon held by trees declined by 34% over the same period, the researchers report this week in Geophysical Research Letters.

The scientists conclude that the large trees in the plots had to compete with the growing population of small trees, making the big trees more susceptible to drought, wind, and insect attack than they would have been without the crowding. Because the large trees died, they didn't absorb as much carbon dioxide. "It's counterintuitive," says Goulden

I've heard arguments before that fire suppression is bad policy because it blocks the thinning effect of occasional fires, with the result that wildfires become more serious. [*] [Note that I'm not saying that's the cause of this year's severe wildfires. According to the fireman I talked to on Wednesday, the vegetation is especially dry this year—as dry now as it usually is at the end of the summer.] It's interesting to ask whether there's some optimal, nonzero, amount of fire suppression, or whether it would be best to just let fires burn except where they actually threaten human activity. Unfortunately, this is a topic I know basically nothing about.


July 23, 2008

From Arthur C. Clarke's A Fall of Moondust (1961):
When he had finished dictating, he paused ot marshal his ideas, could think of nothing further, and added: "Copy to Chief Administrator, Moon: Chief Engineer, Farside; Supervisor, Traffic Control; Tourist Commissioner; Central Filing, Classify as Confidential."

He pressed the transcription key. Within twenty seconds, all twelve pages of his report, impeccably typed and punctuated, with several grammatical slips corrected, had emerged from the office telefax. He scanned it rapidly, in case the electrosecretary had made mistakes. She did this occasionally (all electrosecs were "she"), especially during rush periods when she might be taking dication from a dozen sources at once. In any event, no wholly sane machine could cope with all the eccentricities of a language like English, and every wise executive checked his final draft before he sent it out. Many were the hilarious disasters that had overtaken those who had left it all to electronics.

This is one of those predictions that's sort of right and sort of wrong. While practically nobody dictates letters any more, it's certainly true that you can't trust computer's attempts to interpret ambiguous human input, as anyone who has tried to use a voice recognition system, typed on an iPhone can attest, or carelessly accepted the suggestions of their spell checker can attest. It's not usually an artifact of excess load, though: computer performance doesn't usually degrade that way. Of course, a modern system of this type would most likely run on a local computer, rather than some remote centralized timesharing system that faxes you your output, but this was a common blind spot of science fiction writers prior to the personal computer era.

More off-base is the assumption that dictation plus transcription (whether manual or automatic) is a good way to write. It's true that people wrote letters that way back in 1961, but practically nobody does that now. This isn't because computer voice recognition systems suck (though they do)—plenty of people could afford to have a full time secretary type their messages—it's just vastly more convenient to use a modern word processing system than it is to dictate, even to a secretary. Pretty much only older people who never learned to type or use a computer need to dictate any more. I'm skeptical even a much better voice recognition system would be good enough to displace typed interfaces to word processing systems. Now maybe if you could use a Cerebrum Communicator... That said, the IBM Selectric was introduced in 1961, so I think Clark can be forgiven for failing to predict how convenient typewriter-style interfaces would eventually be.


July 12, 2008

On my way to gym today I caught a Living On Earth segment about Greenpeace's efforts to get large soy traders not to buy or distribute soy products produced on cleared rainforest land:
GELLERMAN: But a soybean is a soybean is a soybean. I mean once they're in the bag you don't know where they've come from. How do you enforce that?

ALLEN: Well we don't look at the soybean we look at the farm. So the mapping and the monitoring and the land registration all go together and what we do is we want to have maps to a scale where we can, as soon as we see deforestation happen, we note it. We know who owns that land, we know what has been planted there, we know if it's related to cattle grazer, rice production, soy production, and we then essentially blacklist those farmers so that the traders know that they cannot buy from these farmers even if part of the farmer's land has been used legally to grow soy if they've deforested a new area they will be blacklisted and the traders have agreed to this as part of the moratorium.

This procedure probably will work, but I wonder if there's a technological fix here. The basic idea would be to tag areas of the rain forest with chemical signatures, which would transfer to the soy beans grown in those areas, thus allowing you to determine where a given bean was grown.

The most attractive technique in terms of biocompatibility is to use isotope ratios. For instance, sulfur isotope ratios (S-34/S-32) can be precisely measured and are used as natural environmental tracers. [*]. What we want is an element which is taken up from the soil and is relatively geographically immobile (so that you don't get contamination of neighboring regions). It's possible that there is a set of isotopes that is already characteristic of each region, but more likely we'll need to tag each region so we also want an element with a rare, reasonably long-lived isotope, so that we don't need to spray/dump too much onto the soil in order to bias the isotope ratios in some measurable way. Even better if we have several elements since we can independently vary the ratios to give unique combinations—we may also be able to combine tagging with natural variation if we take measurements. I did a little looking about what elements fit this bill. Some possibilities:

  • Sulfur (S-36 has a .02% fraction)
  • Chlorine (Cl-36 is synthetic and has a 30000 year half-life)
  • Selenium (Se-80 is synthetic with a 30000 year half-life)
  • Potassium (K-40 has a .012% fraction)

Another alternative is to use tagging chemicals. Lots of compounds get taken up by organisms (think DDT, PCBs, etc.), and it shouldn't be that difficult to use compound ratios (perhaps combined with isotope ratios) to produce distinct signatures. The problem here is to find some set of chemistry that everyone agrees is safe to spray over a somewhat inhabited area (again, think DDT, PCBs). We don't really have that problem with isotope tagging as long as we stick to non-radioactive isotopes or isotopes with very long half-lives (remember that there's some baseline radioactivity in the world anyway).


July 11, 2008

Watched some of The Eiger Sanction today. What with the constant boozing, casual sexism, homosexual stereotypes (check out Jack Cassidy as the amazingly flaming Miles Mellough with a dog named "Faggot"), and prehistoric mountain climbing technology (in the early rock climbing scenes they're not even wearing swami harnesses, just a loop of rope tied around their bodies; later they're using around the waist belays) the movie feels incredibly dated. But you know what's really dated? Clint's a professional assassin who's standard fee is $10,000

July 3, 2008

Even now that public opinion has started to shift towards more concern about climate change, political inertia—and especially the inherent conservatism of the American system—make a dramatic change like a nationwide carbon tax or cap-and-trade system incredibly difficult to implement. It's just too easy for a small group of vocal opponents to block legislation, or more likely dilute it to the point where it doesn't do anything. [When I say "too easy" I'm not taking a normative position; I just mean that the system isn't designed to make change easy.]

But consider our current situation: in the past year the price of gasoline has gone from about $3.00 to about $4.00/gallon. In effect, from the perspective of 2007, we've imposed a $1.00/gallon carbon tax. For comparison, even proponents of carbon taxes are looking at more like $.10/gallon. This isn't ideal for a number of reasons:

  • The price of gasoline depends to a great extent on the price of oil and the price could go down at some point. On the other hand, there's no reason to believe it will go down and people's behavior has already started to change.
  • Oil burning isn't the only carbon emitter and coal and natural gas prices aren't going up as smoothly, though a little searching suggests they may be going up too, which is what you'd expect.

The good news, though, is that the inertia of the political system works to keep prices high. Even if there was something effective the government could do to bring prices down—which seems unlikely in any case—all that carbon control proponents need to do is block that legislation, which is a lot easier than getting their own legislation passed.