Misc: November 2007 Archives


November 29, 2007

I've written before about Asimov's blind spot about hardware versus software. A related issue in more recent science fiction is the treatment of various kinds of input overload. The two cases that come most naturally to mind are:
  • In Haldeman's The Forever War Mandela gets badly burned when he looks at a laser with his image intensifiers on and resulting in massive amplification:
    When the laser hit my image converter there was a red glare so intense it seemed to go right through my eyes and bounce off the back of my skull. It must have been only a few milliseconds before the converter overloaded and went blind, but the bright green afterimage hurt my eyes for several minutes.


    We knew enough not to groan or anything, but there were some pretty disgusted looks, epsecially on the faces that had singed eyebrows and a pink rectangle of sunburn framing their eyes.

    (This is actually from the original short story Hero because I can't find my copy of TFW, but the plot point is in TFW, as I recall).

  • In Gibson's Neuromancer, if you run afoul of sufficiently bad ICE you can actually get electrocuted:
    Sure. I was crazy. Figured I'd try to cut it. Hit the first strata and that's all she wrote. My joeboy smelled the skin frying and pulled the trodes off me. Mean shit, that ice."
    "And your EEG was flat."
    "Well, that's the stuff of legend, ain't it?"

    (Transcription here).

Now, whole volumes could be written about Gibson's ignorance of how computers work, but Haldeman was scientifically trained so it's a little more surprising coming from him, but both of these examples are basically nuts. You'd have to be nuts to build a system that could potentially pump enough energy into the human body to actually burn your skin.

The Neuromancer case is particularly egregious because you've presumably got some digital system plugged into your brain-computer interface, so it's just a simple matter of never giving the BCI enough voltage that it could potentially damage you. Even if you can't do that for some reason, it's easy to add physical voltage (e.g., zeners) or current limiting devices (e.g., fuses) to the leads to make electrocute you. This is pretty basic electronics and not really subject to circumvention no matter how malware infested your computer gets.

The Forever War passage is more interesting because at least in the past image intensifiers were quasi-analog devices. However, it's pretty hard to believe that one would make an amplification stage that could actually emit enough power to burn your skin in milliseconds, especially since the amount of energy emitted by the displays in analog image intensifier systems is partially gated on the relaxation time of the phosphors— no matter how many electrons you pump into the phosphor, it only phosphoresces so fast, so once all the molecules are in the excited quantum state, the electrons simply aren't absorbed. As I understand it, when standard night vision systems are overloaded (e.g., someone shines a light on them) they just stop working, not burn your face off. And of course any system in which the amplifier stage is digitally read and then displayed on a screen can be easily set with a maximum emission power. So, ultimately, I don't think getting burned by your image intensifier is a plausible story either, but I guess in both cases having your face catch on fire is more exciting than saying "my computer crashed".


November 28, 2007

If you're an American with an iPhone or are just crazy enough to use AT&T as your wireless carrier, you may be wondering how much you're going to get gouged to use your phone in Canada. The answer is: a lot.

  • Basic per-minute rate is $.79.
  • For $3.99/month you can bring this down to $.59
  • There are two data plans available: 20MB for $29.99/month and 50MB for $59.99/month. I wasn't brave enough to ask what the roaming data rate was if you didn't do this, but I imagine it's insane.
  • You can turn off Edge data when roaming in Settings|General|Network. Actually, this seems to be the default.

Welcome to Canada!


November 26, 2007

California law require vehicles to be smog tested in order to be registered in the state of California. The smog testing is done by independent (but licensed) operators. This creates two major principal/agent problems:
  • The tester can falsely report a passing grade in return for a bribe—or just cause you're a good customer.
  • The tester can falsely return a failing grade in order to get you to spend money on "fixing" whatever they say is wrong with your car.

There are a number of countermeasures used against these problems. The first is to have "check only" stations, which will test your car but not fix it. The state requires some vehicles to be tested at check only stations, both by random assignment and by preferentially selecting vehicles they expect to be high emitters. The idea here seems to be that check only stations have no incentive to give a false failing grade because they can't profit from it. Similarly, because they don't have a relationship with you—unlike your regular mechanic—it's harder for you to bribe them since they're less likely to trust you're not entrapping them (see below).

This program seems like it's likely to be of limited effectiveness. First, only a small fraction of vehicles are assigned to check only stations and so you're only decreasing the amount of fraud by that fraction. It doesn't serve as a deterrent to fraud in itself. Second, at least for the second kind of fraud, the check only station could at least potentially get a kickback from your mechanic, though it might be hard for them to get together.

Another countermeasure is that the smog testing machines transmit their results to the state directly before (at least according to my mechanic) they're displayed to the mechanic. This is actually pretty clever, since it reduces the opportunities for a fraudulent mechanic to see the result and offer to fix the results for you. Obviously, you can still bribe the mechanic in advance, but that requires you to know in advance what's wrong. I tend to think it's less useful for the second kind of fraud, since it's surely pretty easy to gimmick the sensors to produce a positive reading. I should also mention that the connection between the machine and the state appears to be via modem, and, unless cryptography is being used, is probably pretty easy to spoof, which would let you bypass the initial negative test.

Another countermeasure against the first kind of fraud is that only test only and "gold shield" test stations can certify a vehicle once it has failed its smog check. It's obvious why this makes sense for test only and I assume that gold shield are subject to extra scrutiny by the state.

Finally, I assume that the State periodically sends people out with pre-calibrated vehicles to see if the testing stations are producing accurate results, if they offer to falsify the results for you, etc.

By the way, my car passed, though I needed a new gas cap.


November 25, 2007

OK, I totally understand why there is a race to the front for state primaries. The earlier primaries have a disproportionate effect on who gets selected as the final presidential nominee. Obviously, if you want to get pandered to the way Iowa and New Hampshire do, it would be to your advantage to move the primary up.

So, what I don't get is why the Democrats are pushing back on the states (e.g., refusing to seat Florida's delegates), since it's not clear that it's in their interest to have the current early primary states be so influential. In this case, since the party's interest is to have the most credible candidate for the general election, and Florida is often a determining state, it would be to their advantage to encourage Florida go first. In any case, it's not clear to me why they are actively discouraging it.


November 19, 2007

This page, representing information conveyed in rap songs in visual form (e.g., the relationship between money and problems) has been making the rounds. I didn't see a way to submit your own entries, but here's my attempt:


November 2, 2007

Truepath objects to complaints about the way that women's bodies are portrayed in media:
So I've long been disgusted by the socially approval of complaints about models being too skinny and demands that 'real' women, i.e., less skinny women, be depicted in the media. I've already skewered most of the arguments elsewhere but the long and short of it is that the people who complain about skinny models aren't demanding we show more ugly people on TV. Rather they are just complaining about which features are considered beautiful.

Sure, often these views are voiced as mostly meaningless gripes the same way men might gripe that it should be illegal for women to prefer the guy with the fancier car, full head of hair etc. So long as these complaints are taken no more seriously than this they are a harmless way to express frustration and worry about one's sexual desirability. However, some speakers take these complaints quite seriously and that amounts to an (unconsciously) selfish ploy to get ahead by denigrating the competition. After all some people will always be more beautiful than others so at best they are demanding we change the standards to put themselves closer to the top. In men we recognize the analogous unpleasant behavior (dismissing every guy who is popular with the ladies as an asshole or sissy) isn't praiseworthy and we should do the same in women.

This is simple human psychology. We all (men and women) resent those we fear are more attractive/more successful than us and we look for ways to bring them down so we don't feel so bad about ourselves. It would thus be unfair to assign more than a little blame to the men and women who look for excuses to dismiss their potential competitors. They are just groping for ways to feel better about themselves. The true culprit here is society which doesn't call out this behavior for what it is.

I agree with some of the later argument about anorexia versus obesity, but I don't find this argument very convincing. It's certainly likely true that many who complain about extremely thin body images would like society to accept a body image that makes them feel better about themselves, but that doesn't mean that that wouldn't be a net win as well, even if we're just looking at self-image.

Let's start with an unreasonable model and assume that we can characterize body size by a single metric M corresponding to body mass index. To simplify things, we'll say that the smallest possible M value is 0 and the largest is 1. Further, we'll assume there's some ideal M value MI. If we assume that individual A has a size MA, then we can write their happiness as F(MA, MI). We could posit a large number of different forms for F, but in the spirit of oversimplification, let's say that unhappiness is always positive and is linear in the distance between your size and the ideal size:
Unhappiness = | MA - MI |
So, is there an optimal value of MI, i.e., one that maximizes average happiness? It turns out that the answer is probably yes. Let's assume (again unrealistically) that people's sizes are uniformly distributed between 0 and 1. As an example, let's assume that MI is 0. Remember that the average size is .5, so the average happiness is also .5. Because the distribution is uniform, we can extend this for any value of MI. We simply partition the space around MI and then note that the average size (and hence happiness) on either side of the partition is equal to halfway between the partition and the end. And since the fraction of people on either side is also proportional to the point of partition...
Avg-Unhappiness = 1/2((MI)2 + (1-MI)2)
or Avg-Unhappiness = 1/2(1 - 2MI + 2MI2)

It's not hard to convince yourself that the minimum of this function is at MI = .5. Moreover, unhappiness gets worse the further away MI gets from 0.5, reaching a maximum at 0 and 1.

Now, obviously, this model is unrealistic in a number of ways. For instance:

  • There's no single metric of body size that's useful.
  • Body sizes aren't anything like uniformly distributed (it's more like a bell curve, which actually would make the pull towards the center more powerful).
  • Body image happiness isn't a linear function of distance from some ideal body image.

The last objection is probably the most serious. In fact, it's not clear it's any kind of distance function. You could imagine instead that it's a function of how many people are between you and the top. However, I doubt that's completely true. For most practical purposes, being merely more attractive than almost everyone you meet is almost as good as being the most attractive person in the world. Most women are never going to meet Brad Pitt, so if I just look more attractive than nearly every man they ever meet (which is regrettably not true), that's nearly as good as being as attractive as Brad as far as getting dates is concerned. And yet, very attractive people—even those more attractive than almost everyone they know—seem to be reasonably likely to be unhappy with their bodies as well, at least in part because they're judging themselves against people with whom they're not really competing directly.

This brings me to what I think is the more important point: it's not clear that the current media-portrayed ideal body image is within the possible range at all. I've never seen any supermodel in person, so I'm operating pretty much on the basis of photography and video, which (1) are very heavily made up (2) are posed and cherrypicked to be those people at their most attractive and (3) at least in the case of still photography, are extremely heavily photoshopped. In other words, it's quite possible that they appear to be at (say) -.2, which isn't actually achievable. And since the further away from the center of gravity the ideal image gets the more unhappy people get, having the ideal image outside the possible range creates unnecessary unhappiness. Even if we moved it to just the outer limit of the possible range, i.e., MI=0 that wouldn't upset the orderings but would make people happier because they would feel closer to the perceived ideal (this is actually Pareto dominant).

As I said at the beginning, this is a ridiculously oversimplified model. I don't know if any of these properties would hold up in a more realistic model, but it certainly seems possible they would, and if so, then it's possible we would in fact benefit—at least in terms of happiness with one's appearance—from an ideal body image more closer to the population norm, in which case wanting to change the ideal body image is potentially more than just a matter of rearranging the pecking order.