Archive for July, 2012

science continues to ruin everything

I’ve been meaning to write about the Breaking Bad season premiere all week; now with the next episode about to air, my window for having anyone care about the viability of last week’s (spoiler alert!) magnet caper is rapidly closing. Nevertheless!

I was curious to know whether the episode’s scheme — which centers around the use of a salvage yard electromagnet to erase a laptop drive from outside a police station’s walls — was at all plausible. I imagine the Mythbusters will tackle this in highly entertaining fashion a year or so from now, but I wanted quicker answers. Conveniently enough, my friend M works at a related job, figuring out the chemistry that allows hard drive platters to be coated with various metals. So I wrote her and asked if she knew anything about whether this was plausible. Not specifically, she said. But! Her all-around science talent and experience provided some promising leads:

I’m not sure how feasible this is. You would need to generate a strong enough field, get the field close enough, and also sustain the field long enough. I think that article mentioned that the power from the batteries were an issue and I think that is the biggest obstacle for a “portable” system. Not sure if the car batteries could sustain the juice long enough for the hard drive to get completely erased. Also distance is an issue. I think the field drops off exponentially away from the source, and other materials in the way (like the building wall) can dissipate the field depending on its dielectric properties. I don’t know how well computer hard drives are shielded or what strength field you’d need to erase one, but it could be possible. Do you know what you would need for that in terms of strength and time? Seconds? Minutes?

We never erased a computer when I was in grad school, but we always kept metal and electronics outside the 5Gauss line when working near magnets. In the fringe field of a couple Gauss outside this, it was strong enough to erase subway tickets but not credit cards and definitely not a computer. To get a feel for lengthscales, a magnet of ~90,000G had dissipated to 5G by about 7-9ft away from the magnet. Metal would not get pulled from our hands toward the magnet unless we were within ~3 feet away.

I would be curious to find out how strong a field you need to lift a car though. I thought those junkyard magnets you have to be really close to the surface before it actually sticks?

This led me to some productive Googling — well, productive in a certain sense — that turned up a few more interesting details. The following has been written by a guy who never even took enough physics to get through Maxwell’s equations. Still, I think it’s not too hard to reach a plausible conclusion through some back-of-the-envelopery.

There are basically two considerations that M is pointing to: field strength and how easy it is to erase a given type of magnetic media.

On the field strength side, the news is not good for Walt and Jesse. Unlike most emissive sources (light bulbs; radioactive materials), magnetic field strength declines with the cube of distance rather than the square. Exactly why has something to do with the nonexistence of magnetic monopoles (outside of Star Control 2 anyway) and seems to be one of those mind-bending situations where reality knuckles under to some particularly inescapable math. But the upshot is that magnetic fields get weaker very, very quickly as your distance from them increases — faster than your experience with other radiative sources might make you think.

But how strong would the field be at its source, anyway? Here it’s tough to say: salvage magnets seem to be specced by how much scrap iron they can lift, not the precise attributes of the fields they generate. But MRI machines top out around 30,000 Gauss. Is a salvage magnet more powerful? M subsequently warned me about reading too much into the fancy cryogenic cooling of an MRI’s superconducting magnet versus the air-cooled conventional tech in the salvage magnet. They’re different machines built for different things, with very different field shapes, she stressed. All this is true. Still, to me it seems at least unlikely that a salvage magnet could outpace an MRI machine. And judging by the example distances and field strengths in M’s email, it would clearly need to.

Then there’s the question of how much of a field it takes to erase a hard drive. I know a little bit about the considerations here, having looked into magstripe reader technology back when I was fooling around with Metro’s farecards. The ease with which a magnetic medium can be altered is called its coercivity, and as M hints, there are high- and low-coercivity magstripe standards (for any that care, WMATA’s farecards are low-coercivity, and I think not even digital; based on my abortive experiments with them, I believe that they use an acoustic encoding scheme, though I’m not positive).

Anyway! How hard is it to flip a bit on a hard drive platter? Things get tricky here — coercivity is measured in Oersted rather than Gauss, and concerns the B component of a magnetic field rather than the H component (actually, neither are measured in those pre-SI units any more, but “Gauss” and “Oersted” sound a lot cooler than “amp-meter”). (H and B are linearly related based on some constants specific to each material (the fields are functionally identical outside the domain of a given magnetic medium), so all the above business about field strength still applies). Quantifying the coercivity of a typical hard drive — to say nothing of the magnetic shielding effect of the case and other junk around it — is not something I’ve been able to do.

But we have some circumstantial evidence. For one thing, any dedicated nerd will tell you that a broken hard drive is a great source for extremely powerful neodymium magnets. These have nothing to do with flipping the bits on the disk (they’re in place for the voice coil that positions the read/write head over the platter). But it does seem safe to say that having a very powerful magnet — powerful enough that, given a pair of ‘em, you’ll have a hell of a time separating them with just your hands — mere centimeters away from a hard drive platter is not enough to influence the data on the disk one bit, even as it whirls through the magnet’s field at several thousand RPM. It therefore also seems pretty safe to say that you would need a noticeably strong magnetic field outside the device before data loss became an issue. In the show, of course, stuff flies all over the place, so in this respect, at least, Breaking Bad’s verisimilitude isn’t in question.

Finally, I am a little more optimistic about the viability of a battery power source than M is. This kind of project is a great way to wind up with a bunch of burning, half-melted plastic tubs of acid and lead (a horrifying clean-up problem, but I suppose Walt’s seen worse), but an array of lead-acid batteries really can deliver an impressive amount of juice (turning over an engine takes quite a lot of it). Judging from the afore-linked salvage magnet vendor’s site it looks like the show’s creators settled on a realistic voltage; and indeed, Vince Gilligan has said that this was something the writers wasted a bunch of time worrying about.

All in all, though, I think Walter and Jesse probably should’ve stayed in the chemistry lab rather than wandering over to the physics department: for all of Mike’s talk about the evidence room’s impregnability, it sure looked like it was just a cinderblock wall. I suspect some explosives and incendiaries would’ve done a better job of killing the data on that hard drive than an electromagnet could. After all, there’s a reason why geeks tend to talk about degaussing wands for sanitizing videotape, and thermite for securing old hard drives:

stigmatizing lobbying

Just a quick thought (Sunlight’s about to head out to a company outing at Nationals Park), but via Matt, this Luigi Zingales quote hit a chord:

When the economist Milton Friedman famously said the one and only responsibility of business is to increase its profits, he added “so long as it stays within the rules of the game, which is to say, engages in open and free competition without deception or fraud.” That’s a very big caveat, and one that is not stressed nearly enough in our business schools.

Lobbying to secure a competitive advantage from the government certainly does not represent “open and free competition.” Similarly, preying on customers’ addictions or cognitive limitations constitutes deception, if not outright fraud. Not to mention using clients’ confidential information for personal gain, manipulating a major interest-rate benchmark such as Libor, or selling financial products you know to be flawed.

Emphasis mine. This has been an idea I’ve been noodling on for a while: that stigmatizing corporations’ presence in DC — whether through direct purchases of lobbying or involvement in trade groups — might be a productive path for activists.  By this I mean to distinguish the stigmatization of lobbying, lobbyists and specific instances of corruption or malign influence (which everyone already hates) from the stigmatization of being here at all.

There’ve been recent, successful actions in opposition to corporate involvement in politics, but at the moment there’s no realistic legislative or judicial path to constraining their influence.  Maybe I’m kidding myself, but “stop gaming the system” seems like a viably nonpartisan message.

Also relevant to this is the work of my colleague Lee Drutman, whose dissertation makes a convincing argument that the appropriate time to intervene in these matters is before an industry decides to head to Washington (Lee shows that once an industry sets up shop in DC they tend to stick around, even as the presence of their concerns on the policymaking calendar diminish) — though presumably there’d need to be efforts to disarm existing lobbies (Google & co. aren’t going to be willing to sit on their hands while the long-established IP and telecom lobbies make trouble for them).

Anyway, something to consider.

how to think about reboots

Like every other self-respecting fanboy, I was outraged by Anthony Lane’s review of the new Spider-man movie. But my reasons are idiosyncratic — I don’t care that he disdains geek culture (to each his own), and I don’t care to defend my ilk against his charges of emotional immaturity (that’s a fool’s errand). No, I’m pissed because Lane tosses off an observation that I’ve been meaning to write up ever since it hit me during the drive to Ezra’s bachelor party:

If you are a twenty-year-old male of unvarnished social aptitude, those movies will seem like much-loved classics that have eaten up half your lifetime. They beg to be interpreted anew, just as Shakespeare’s history plays should be freshly staged by every generation.

I’m not in my twenties anymore (does that make this better or worse? probably worse). But he’s right: I think the best analogy for understanding superhero reboots is new stagings of Shakespeare. Lane mentioned this dismissively, but he’s more right than he realizes.

For a while I was confused on this point: why were these franchises being remade so quickly? Why did the plotlines (if not the spectacle) become unsatisfying as soon as the origin story was concluded? I left X-Men: First Class thinking the movie was a promising sign of these films evolving — of the audience becoming conversant enough to dive into the non-origin plots that fascinated me through my childhood. First Class had a decent story, and more importantly it felt like a comic book story. Yet it wasn’t an origin story — well, not wholly.  Given the now-consistent commercial success of tights-and-capes movies, maybe it wouldn’t be too long before we got that Secret Wars or Infinity Gauntlet movie after all…

Now, though, I realize that this was stupid. In fact, the innovation of X-Men: First Class was its setting. Sure, they fudged things by picking some particularly venerable and/or long-lived mutants. But this was just an excuse to move the X-Men origin story into a “Greatest Generation starts fighting the Cold War” atmosphere. My favorite scene had Xavier and Magneto tweedily philosophizing in a Cambridge club.

This happens all the time with Shakespeare. Romeo and Juliet in 1950s Cuba. The Merchant of Venice with Christians in post-Saddam Baghdad. King Lear in space. Whatever. Or hell, just different stagings in roughly traditional time periods, with different actors, performances and directorial choices. These are perfectly fine reasons to revisit a work.

Admittedly, the legal reasons that motivated Sony to make this latest Spider-man movie are not as good. And the movie that resulted is not that good, either — I preferred it to Sam Raimi’s films (his stuff is inescapably campy, which feels vaguely insulting), but it’s inessential: it doesn’t make many interesting choices other than giving Peter Parker a skateboard and Justin Bieber haircut (part of the coolification of Marvel’s outcast protagonists — a larger trend that coincides with the mainstreaming of geek culture, and one that I’m not happy about, this sentiment notwithstanding).

Of course, the reasons for new adaptations of Shakespeare are different from those motivating endless Hulk movies. If there’s a spectrum of dramatic specificity, with George Lucas deploying nebulous Jungian archetypes at one end and, at the other, Prohibition-era gangsters talking about mercy droppething as the gentle rain, comic books sit somewhere in the middle. Exactly where is up for debate: how much of the experience’s value lies in the canonical text (“organic webshooters are an outrage!”), and how much is in the archetypal gesture (“yeah, Uncle Ben didn’t say ‘with great power…’ but the theme was there”)?

Although different adaptations can and should make different choices, my own sympathies tend to lie with the latter camp. The details of specific comic plotlines are satisfying to crazed obsessives like myself, but it’s the broad themes — myths set in the context of the modern world — that make these franchises compelling.  Even the comics themselves have realized that the characters, broadly understood, are the important thing. The retcon has always been a necessary tool to scrape away peskily accreting continuity, letting creators once again show the smooth lines of their franchises’ lovely archetypes. This process has recently managed to drop most of its shame and self-hatred, as the consolidation of universe-wide plot-planning at the publishers’ executive level has allowed reboots to become well-branded corporate events rather than cringe-inducing disasters that individual writers cobble together from clones, Skrulls, secret robots, alternate dimensions and cosmic energy beings.

But although I think the correct dramatic approach is clear, it’s hard to say how these efforts will actually evolve. There are commercial reasons for pushing audiences toward the specificity of costumes and theme songs and collectible Slurpee cups. I don’t think Avi Arad earned a penny from Chronicle,  but it can certainly be understood as a stripped-down adaptation of any number of Marvel origin stories. I count that film’s creative and commercial success as solid evidence for this being the most promising direction for such films: to continue to use superpowers as a way of telling stories about alienation, duty, agency and the limits of human identity. These are all excellent themes for the digital age, and mixing CGI with a spandex-heavy wardrobe department turns out to be a surprisingly good way to investigate them.

It’s this thematic level  where further explorations will pay off. I’ll be personally happy to see deep-continuity stories that I remember from my childhood* translated to the screen. But the moviegoing public is never going to hit the back catalog for the education in Claremont and Morrison that they’d need to join me in giving a damn. Screenwriters tend to be geeks, and the movie industry tends to not understand how to adapt comics successfully, so I do expect these backstories to be mined out. But I don’t think many of these adaptations will succeed.  It’s the myths that matter; their recitation through creative adaptation is what needs to become a tradition.

* I should probably note that my childhood comics budget was pretty meager, and so I absorbed a lot of the backstory through the efficient-but-bloodless medium of old issues of Marvel Universe. I’ll admit that this might color my thinking a bit.

the operation was a complete success

I’ve been working on an electronics project for *forever*, trying to get past some nasty linux wifi bugs and on to the exciting lasercutting/3D printing/web scraping stuff that actually attracted me to the idea (the hope is to make it a repeatable but customizable gift I can give). But to be honest, my willpower has been fading — a body can only spend so much time in a given IRC channel, asking the same obscure and tricky questions, hoping someone will deign to answer them correctly.

So I took a break to make something a lot simpler. I don’t want to give the whole backstory away — it’s going to be a gift, and the recipients might read this blog — but the core functionality is as simple as turning a garden hose on and off via remote control. And hey, it worked on the first try!

(I probably won’t actually follow through on the motion sensor part — the audio is just me talking to Kriston, Kaylyn and my neighbor Paul, who was nice enough to lend me the use of his water spigot when I found out mine was cracked)

You can see most of the components below, if this third party Flickr note embedding thing is working. The wiring’s all wrong in this photo, and it’s missing a 12v regulator to power the remote system and the automotive relay that actually switches the 24v valve. But you can see the most exciting parts.

The next steps are to arrange all this stuff in an appropriately-decorated Gladware container so that it can resist the elements and hopefully not light itself on fire: things get warm when the system’s switched on, but I think that’s got to be expected with a system this full of relays, and one that’s shedding 12v through a voltage regulator (heatsinked and well within spec, though!). If anyone feels like replicating this project, here’s the bill of materials and some approximate prices:

It’s a pretty good and easy project — if anyone’s interested in replicating it, leave a comment and I can sketch out a wiring diagram. If you buy the relay socket you wouldn’t even need to solder anything: wire nuts would work just fine (I used a couple, in fact). Well, okay, you’ll need to figure out how to attach the voltage regulator, and that’s probably best done with a soldering iron. You might be able to get away with crimping stuff and then taping it up, though.

the battle for the iron(y) throne

Kash has guest-blogger Elie Mystal talking about the relative toothlessness of the recently-released Declaration of Internet Freedom; it’s worth a read. She’s speaking about this document, hosted at internetdeclaration.org and signed by a bunch of lefty net organizations like Free Press and CDT. Almost infinitely unhelpfully, a bunch of libertarian/right-leaning net organizations released a response document that was also called the Declaration of Internet Freedom — you can find it at declarationofinternetfreedom.org.

As my friend Tim Lee has pointed out, both of these documents are so broad and vague as to be more or less perfectly compatible with one another. But of course their supporters will never acknowledge this, because behind the pabulum is a desire to attract the anti-SOPA campaign’s politically naive but newly-engaged internet advocates behind one or another camp’s tribal ideological banner. The declarations are as broadly agreeable as an Expression Of Approval Of Apple Pie so as to appeal to as many potential supporters as possible. But you can reasonably expect the camp behind Declaration A to eventually email their new list members about net neutrality, and the folks behind Declaration B to do the same about government efforts to regulate telecoms.

These efforts should be understood as part of a larger race to grab leadership of what looks like a temptingly huge and ideologically-uncommitted political bloc.  I think it’s fair to view Rand and Ron Paul’s new initiative through this lens, and Darrell Issa and Ron Wyden’s Digital Bill of Rights, and the Internet Defense League.

I’m sure that no one undertaking these efforts is behaving wholly cynically.  But it seems pretty obvious that a number of people think that they can get themselves crowned King of Reddit, then use the vast armies that come with that title to wrangle a bunch of small dollar campaign contributions or nonprofit membership dues or advocacy actions or invitations to speak at conferences.  There’s nothing particularly wrong with any of this — though I kind of suspect that the people placing these bets are likely to find that they’ve badly misunderstood how the internet and political organizing actually work — but it is at least a little slimy.

And it probably doesn’t merit much policy attention.  These documents are membership drives, not legislative programs.  Though it is interesting to see the net bloc — which (to the extent one can speak about it monolithically at all) seems to style itself as post-partisan — begin to be inevitably absorbed into the world’s existing ideological camps.