Geek stuff – Page 96 – a sibilant intake of breath

Crime fighting with DNA ‘family searches’

Over at Slate, there is an interesting and somewhat frightening article about the use of DNA in law enforcement in the United States. As in the UK, the US is now collecting DNA from many people who have been arrested, and retaining the samples even from those never charged or convicted. The next step along this path of DNA surveillance seems to be ‘family searches.’ Here, police look for near matches between crime scene DNA and people in their database. When they find a near match, they investigate that person’s family members.

This is worrisome for many reasons. As the article explains, “courts could well be troubled by the open-ended idea that once you’re arrested and cleared, the state can subject you and future generations of your family members to permanent genetic surveillance.” It is quite shocking really. These days, people are getting arrested for such trivialities as taking photos of major landmarks. The idea that this would then subject their entire family to future police DNA surveillance seems deeply illiberal. The article also makes the point that the DNA kept on file may be re-examined later to test for other traits: for instance, if genes that predispose people to committing rape or murder are discovered. Finally, the article mentions some of the major racial implications of the policy: given the high rates of arrest and incarceration in the African American community, members of that ethnic group are unusually likely to be subject to police surveillance via family searches.

Maintaining a functioning justice system in an era of rapidly changing technologies is a huge challenge. Arguably, search and surveillance are the most worrisome new issues. The automation of both means that huge databases can be maintained tracking emails, cell phone locations, DNA, and much else besides. These databases will inevitably be accidentally leaked and intentionally abused. Just another reason why governments are far more dangerous than terrorists.

Given the popularity of being ‘tough on crime,’ it is easy to see why many people favour a system that sacrifices privacy in exchange to a higher chance of catching criminals. There are certainly arguments on both sides. DNA can help to free the wrongfully convicted, as well as increase the conviction rate for crimes like rape, when the justice system generally does a rotten job of catching perpetrators. Arguably, the fairest system would be to put everyone’s DNA on file. At least that way people would be receiving equal treatment. Of course, that requires putting even more trust and power in the hands of governments and security services that have too often abused it in the past.

Digital cameras beyond megapixels

As I have been telling friends for quite a while now, megapixels are no longer a key metric for deciding between different digital cameras. For relatively inexpensive cameras with small lenses, there is probably no advantage to having any more than about six megapixels, in terms of the quality of images you will get. Indeed, having too many pixels crammed onto a small sensor can start to decrease image quality, as pixels that are overwhelmed by the amount of light hitting them ‘leak’ into neighbouring ones. Images from sensors with unnecessary megapixels also clog up memory cards and hard drives, and mean that you need a very powerful processor to deal with large numbers of them at a time.

Akira Watanabe, manager of Olympus’ SLR planning department, has declared that twelve megapixels is adequate for all consumer purposes. Furthermore, he has declared that Olympus will now focus their attention on other issues, such as dynamic range, colour reproduction, and low-light image quality.

From a photographer’s perspective, this is very good news. I have taken plenty of great photos with a 3.2 megapixel camera, and subsequently blown up some of them as large as 11 x 14″. At the same time, most small digital cameras have poor performance in low light and problems addressing dynamic range. At this stage, improvements in those areas are a lot more valuable than cramming more pixels onto their sensors.

Of course, it will cause a bit of trouble for people selling cameras in big, non-specialist retail outlets. When I worked for Staples, I was never given any information on products beyond what was written on the little information card in front of it. While it is easy to say: “This camera has eight megapixels, that one only has seven,” it is a lot harder to test, understand, and express more subtle photographic characteristics.

Watchmen

I saw Watchmen last night and didn’t feel particularly inclined to review it. That said, it was getting late and I couldn’t think of anything else. As with all my reviews, it it is likely to contain ‘spoilers.’

When it comes to comic book films, the mark of success or failure is often whether it is compelling enough to make you stop asking questions about the unreality of what is presented. Judging by the conversations I had with friends after the film, this one didn’t quite clear the hurdle. While it was very strong visually, it lacked the originality of something like The Matrix or Sin City – both of which it clearly drew from. While some of the characters were interesting, most were either flat or very clearly derivative (James Bond villains, vengeful detectives, etc). The plot was fine, but not especially inspired, particularly in terms of ‘surprises’ that failed to surprise.

The central enigma of the film is the character of Dr. Manhattan, and I think that is where it fails most comprehensively. He isn’t compelling. He’s a dull kind of guy who likes the arid emptiness of Mars and has no special problem with killing Vietnamese soldiers for the American government, Apocalypse Now-style helicopters beside him. He is boring, rather than deep. In the end, he comes across as a kind of powerful dimwit, and nobody is emotionally affected when he wanders off. All kinds of things are deeply implausible about Dr. Manhattan, in terms of the plot, also. For instance, why the military research facility where he was actually created never tried to make any more supermen. Also, why the government seems to think he is able to stop 99% of Russian nuclear weapons, without any special system to inform him they that are coming or where they are. If he could do so without any outside assistance, he should presumably have noticed that the arch-villain had destroyed Moscow, during the climactic period of the film. The other enigma, which isn’t addressed in any way, is why some people who decide to become vigilantes have superhuman powers; it’s like X-Men, but with no premise of explanation. Presumably, the graphic novel version is more fleshed out.

One amusing thing I realized about the film is that, for at least some teenagers, it will be their first introduction to the music of Simon & Garfunkel, as well as Jimi Hendrix. The opening credits, which consist of an interesting montage of film and semi-ironic music, were actually the best part of the film. Second to those were the comic touches included from time to time. Third best was looking at Malin Akerman, though she looks a bit like a digital amalgamation of Kirsten Dunst and a few other recent female love-interest figures.

Watchmen is certainly an enjoyable enough film to watch. There are some cringe-inducing moments of violence, though they don’t have the same awful character as the ones in Sin City. It is not, however, a comic film good enough to make you forget its flaws. It will please those who are primed to appreciate it, but I doubt it will have a lasting influence on anyone.

Useful-looking manual flash

The LumoPro LP120 manual flash is interesting for two major reasons.

First, it defies the design logic of the big camera companies. They want to sell snazzy proprietary technologies, like through-the-lens (TTL) metering. This flash generally omits them. The big companies also want to exclude low-cost, useful features from cheap products. That way, they can drive people to buy more expensive ones. For instance, Canon doesn’t include a PC-connection on its US$275 430 EX II flash, but it does on the US$400 580 EX II. The LP120 includes a built-in PC connector, hotshoe connector, 1/8″ jack, and an integrated optical slave. It also has output roughly comparable to the 430 EX II, for US$130.

Second, it seems that the flash was designed primarily to serve a single web-based community: the talented and flash-obsessed photographers at Strobist. That seems like the kind of thing that could produce a very clever trend, where like-minded people assemble with specific needs and niche products are developed to accommodate them effectively.

In any case, I am strongly considering getting an LP120 as a second flash. It would let me do more elaborate things than are possible using just a single flash and an umbrella. I have an upcoming photographic project where better portrait capabilities would be a distinct asset.

[Update: 24 March 2009] I got the LP120 flash today. My first impression is that it feels cheap. The battery compartment is finicky, and flash head doesn’t lock in place, and the flash emits a constant high-pitched whine when on. It certainly shows me part of why people shell out money for flashes like the Canon 430EX II.

We will see whether the photographic performance of the flash is better than the build quality.

Apple’s new iPod Shuffle

While I approved of the first major remake of Apple iPod Shuffle – replacing the white stick with a clip-on aluminum square – the latest update seems like a big step backwards. The new unit is a featureless piece of aluminum with no controls. Those are provided on the proprietary headphones. That means it cannot be used with conventional headphones, which is lamentable, since Apple’s are of such poor quality. It also means the new players cannot be plugged into a stereo using a miniplug cable: a feature that Emily and I found quite valuable over the summer.

It seems that minimalism and a tendency towards proprietary engineering can both be taken too far.

Gaffer tape

Duct tape is a material with legendary status among nerds, and has been used to build or repair countless things. Recently, I discovered that all the admirable qualities of duct tape, along with a few extras, can be found in matte black gaffer tape. The principle advantages of gaffer tape are that the adhesive won’t get deposited on materials where it is used, leaving them sticky once the tape is removed, and the more closely-spaced fibres. Like duct tape, gaffer tape can be ripped into neat strips and used without other tools. The more closely-spaced fibres allow for more control over the shape of the pieces, and neater strips overall. It can also be unstuck and re-stuck more cleanly and easily than duct tape can.

So far, I have used the new tape to repair the fraying bits on my bike handlebars, repair and reinforce the leather folder where I carry issues of The Economist, tape down the switch on the power bar beneath my desk that I sometimes hit accidentally, and strengthen the bindings on some used hardcover books. I plan to use it to make some flash accessories.

One disadvantage of gaffer tape, aside from the somewhat higher cost ($0.26 per yard rather than about $0.20), is that it is much harder to find. Since I first learned about it in a photography textbook, I thought it might be available in photo stores. After having no luck there, I ordered some online from National Hardware Sales. For those looking for something bolder than matte black, they also have the stuff in neon colours.

The magnitude of climate change energy flows

Some statistics from Oliver Morton’s book on photosynthesis illustrate just how massive the energy flows involved in climate change already are. Anthropogenic climate change has increased the amount of solar radiation being retained by every square metre of the planet’s surface by 1.66 watts. In total, that is equivalent to 850 trillion watts (terawatts, TW) of power.

By comparison, a large nuclear reactor produces about 1 gigawatt (GW) of output, 1/1000th of a TW. The total energy usage of humanity (power plants, vehicles, etc) is 13 TW. At any average moment, we are therefore experiencing about 65 times more climate change power than power intentionally employed by human beings. A comparison that may be even more startling is with the flow of heat from the Earth’s core outwards – the power that drives volcanism and continental drift. That energy flow is only 40 TW – one twentieth of the climate change we have already generated.

Of course, if we keep emitting at the present rate, we will increase the 1.66 watt per metre and 850 TW numbers considerably. It is vital to understand that these numbers arise from the amount of greenhouse gasses in the atmosphere, not the amount we emit in any particular year. As such, all increases are effectively permanent, at least from the perspective of centuries. That is something to remember whenever somebody talks about ‘stabilizing emissions.’ Doing so only stabilizes the rate at which these energy statistics are increasing.

‘Book club’ idea

If you count the time spent reading, my book review posts are certainly the ones that have the most effort invested in them. Yet, they generally fail to spawn any substantive discussion. Generally, this is because most readers won’t have read most of the books in question. As a result, any discussions are based around things I happen to mention in my post, rather than the overall content of the book in question.

As a solution, I was wondering if anyone would be interested in a monthly non-fiction book club, to be operated through this and other blogs. We would choose a book per month, read it, and then all write posts and/or comments about it. That way, some substantive discussion of the material could take place. I would be most keen about books in subject areas covered on this site, but am not fundamentally averse to trying something more unusual. Even fiction might be considered, provided it is of a practical variety.

Would anyone be interested?

Eating the Sun: How Plants Power the Planet

Oliver Morton’s exploration of the nature and consequences of photosynthesis makes for a remarkable and informative book. It is divided into three sections: one covering the span of a human life and covering the scientific investigation of photosynthesis; one on a planetary timescale, describing the evolution of the climate, atmosphere, and life; and one on the timescale of a tree’s life, covering the changes humanity has induced in the carbon cycle, and the ways through which the climate change crisis can be overcome. The book is strongest when it comes to putting scientific information into a poignant and comprehensible form that is almost poetic. Arguably, it is weakest in terms of its analysis of what needs to be done in response to climate change.

Eating the Sun contains many sections that are highly technical: descriptions of the biochemistry of photosynthesis, the geological and climatological processes that have taken place over billions of years, the scientific methods through which both have been explored, and more. It can also be quirky, philosophical, and personal. For instance, there are asides in which the author explains his aesthetic preference for one or another scientific theory, such as how photosystems I and II in plants came to be integrated. The combination is not unlike that found in Michael Pollan’s work, where an educated non-expert with a talent for writing adopts the task of explaining technical issues and making their significance clearly felt.

The book features a great deal of discussion of the Earth as an integrated chemical and energy system, including consideration for many different forms of ‘Gaia hypotheses’ – most of them far less teleological than James Lovelock’s earliest work, which (probably wrongly) attributed a kind of agency to the planet as a whole. Of particular interest, among the non-telelogical variants, is combination of the anthropic principle with the idea of systems that self-regulate. It may well be that there are planets where physical and chemical processes do not remain constrained between life-compatible bounds over the long term. Of course, there are no living and intelligent observers on these planets to make note of them.

On climate change, Morton fails to appreciate the rapidity with which mitigation must occur. He contemplates what would be necessary to stabilize greenhouse gas emissions by 2050, whereas we will actually need to make great strides towards stabilizing concentrations by then. Rather than the seven Pacala-Socolow wedges required to produce a flat emissions profile, many more will be needed to begin the decline towards zero net emissions. His calm descriptions of global concentrations of carbon dioxide passing 500 parts per million (ppm), with associated temperature increases of up to four degrees Celsius, fails to portray what a catastrophic outcome this would be. These days, those committed to avoiding change of more than two degrees are advocating concentration targets around 350 ppm.

Morton’s discussion of mitigation technologies also offers scope for criticism; in particular, his discussion of nuclear fusion, fission, and hydrogen fuel cells is fairly superficial and fails to take into consideration some of the major limitations associated with each technology. In particular, he fails to consider the practical and economic issues associated with hydrogen as a fuel. That being said, he strongly makes the point that, in the long run, it will be necessary to move from an economy powered by the built-up solar reserves in fossil fuels to one largely powered by the current energy available in sunlight: whether that energy is directed towards the production of electricity, biomass, or fuels.

At times, the level of detail in Eating the Sun can be overwhelming. In particular, I found that some of the passages about biosphere-atmosphere interaction or long-term geological trends required close and repeated reading to be understood. For the non-practitioners at whom this book is aimed, such knowledge is not likely to be long-lasting. At the same time, by providing such clear and vivid detail, Morton grants a worthwhile understanding of the history and nature of the scientific processes through which we have uncovered so much about the world. As with the very best scientific writing, this book makes you feel both awed about the complexity and power of the world and impressed with the ingenuity that has gone into better understanding it. The book is highly recommended to anyone with an interest in the history of the planet, the nature of the carbon cycle, or science generally.

On recession and the value of graduate school

Penelope Trunk, a blogger, has written an eight part list of reasons not to escape the recession with graduate school. Among them are challenges to the value of doctorates, MBAs, law degrees, and medical school. They leave you overspecialized, dependent on future earnings to pay past debt, and perhaps with skills that are poorly matched to what the market demands.

While the list seems to include some reasonably good arguments and decent points, I think it misses the most important reason for considering grad school: namely, that having such a degree is something you personally value, and that people whose respect you wish to earn will value. Outside of highly practical fields like medicine and law, grad school is primarily an investment with low financial returns. Unless you anticipate high personal returns, it may be wiser to invest your time and money elsewhere.

Over on Free Exchange, there is a partial rebuttal.