Cory Doctorow

There’s no red cape. But, then again, this was taken back in 2004:

Cory Doctorow in MiG goggles

Photo courtesty Windley (via, of course, a Creative Commons license)

Cory Doctorow was the guy who first convinced me to publish xkcd under a CC license, allowing people to share my comics freely. It’s easy to do and was one of the best decisions I’ve made. Check it out at CreativeCommons.org. If you want to learn more about the copyright debate, I recommend Lawrence Lessig’s book Free Culture, which is available online for — surprise — free. I read it as an audio book on a long car trip, but I recommend the text version — the audio book has a different reader for each chapter, and they’re of wildly varying quality.

MIT Programming Team

MIT has a BattleCode programming competition, (which reminds me of Robowar, the reason I didn’t have a high-school social life). This year, [at least] one of the teams was a group of xkcd readers — Nicole, Bobby, and Jessica. They are fun people who I actually had the pleasure of meeting briefly while visiting Boston a while back. Their team was called “If You Die in Canada, You Die in Real Life.”

They didn’t win the competition. But they did win “best team name”.

In which I lose the originals of the last three months of comics and the laptop I create them with.

I draw all my comics on paper, but I scan and process them on my lovely Fujitsu Lifebook P1510, a tiny hybrid tablet computer (it’s the size of a hardback book). I have high-resolution versions of all the comics, which I use for print versions and shirts and such. I used to save them to my Linux desktop, but recently I’ve been moving around a lot and I got in the habit of saving the comic files on my laptop. I’d gotten lazy about backing them up as I drew them, as evidenced by this exchange with the xkcd sysadmin last night:

18:02 <davean> Also, is [the high-res backup collection] up to date?

18:02 <xkcd> nope [Editor's note: here I was recognizing how guilty I should feel about this. I was answering casually because I knew both of us knew this was stupid and we didn't need to go over it again.]

18:02 <xkcd> I’m now sending in computer for repair

18:02 <xkcd> I’ll update the files when I back up the laptop later today

My laptop has had some hardware problems, so I was backing it up before I sent it in to Fujitsu to get it fixed. I was repartitioning my Linux desktop’s drive to make room for the files, and since that was taking a while I decided to go to sleep and finish the (months-overdue) backup when I woke up. Then, files nice and safe, I could send it to Fujitsu.

I slept in until about 1:25 PM. I’m a heavy sleeper, which explains why I didn’t wake up when, at 12:55 PM, someone forced opened a window to my apartment, came into my room, and stole my laptop off my desk within arm’s reach of where I was sleeping.

So, I have no laptop now. I think I can still manage to do comics on schedule (sans tablet screen or any sort of speed) via the cheap old XP machine I set up for that purpose during the repair. And I still have the pencil-and-ink copies of everything. But I do all the editing, arranging, coloring, etc. on the computer. The full versions of, for example, the recent kite comic, the Lisp comic, the Richard Stallman comic, and everything else since around New Year’s? Gone.

Nothing else was stolen except a little cash from my wallet. The police came and filed reports. There were a couple other burglaries in the complex on the same day. If it’s picked up they’ll call me, but I’m not holding my breath. If anyone sees it for sale on eBay, it’s a Fujitsu Lifebook P1510D with an extended battery pack, off-brand charger, and all the little logos removed. Sigh.

For the folks suggesting ways of tracking it online: my cryptography-geek security paranoia was canceled out by my laziness. I set up all sorts of ideas for dealing with stolen laptops, but never actually maintained them (after all, they were just paranoia). A year ago I bought wherethehellismylaptop.com, with the idea that every time it got online it could (securely) update the site with information about where it was and who was using it. But I never set that up. I have it automatically log in to a VPN, and I should be able to see it that way. But the VPN had stopped connecting a few weeks ago and I didn’t fix it. I’ll keep an eye out in case it phones home. I had also planned to make stickers that says “CONTAINS GPS, WILL BE TRACKED IF STOLEN,” (bluffing) but that’s part of my xkcd stickers plan that’s on a back burner right now.

Other than the comics, there’s not much that’s irreplaceable. But the laptop did contain assorted xkcd shipping records from last year (before I moved to the online system). Fortunately, there is no financial information about anyone (except me), but it did have the addresses I’ve shipped shirts to. And I had just removed the system passwords so the Fujitsu guys would be able to work on it. But I expect it’s just gonna be wiped and sold anyway. It was a mess — I’d be surprised if anyone else can use it.

And lastly, my roommates got me a RoboRaptor for Christmas, some sort of mini version of the popular toy you see everywhere. And I can’t help but notice that during the burglary it sat on the shelf and did nothing but watch. Fucking raptors. I guess it should have at least served as a reminder to never let ground-level windows go unsecured.

Fortunately, the place is a huge mess, so the thief didn’t spot my digital camera on the floor. It contains the results of a physics experiment involving 50 gallons of water and a parking deck that I’ll blag about later.

Edit: I know the lost data is my own damn fault, and it’s not so bad. I’m a lot more upset about the break-in while I was here and the loss of the laptop than the — rarely used — high-res comic files. I just want to share the awful irony that it was just when I was about to get back on track with backups that it happened.

I have also, in the past, been that obnoxious backup guy — the one who insists we back things up both here and here every six hours in case there’s a terrorist attack AND a tornado at the same time. So I feel even dumber about this.

Regarding offers of donations — thank you, I appreciate the support. But I should be able to replace the laptop. I feel like if this is the worst problem you have, you’re doing okay, you know?

Edit #2:

(Thanks to Matthew.)

Large numbers

I mentioned an extremely large number in this comic, and then talked a little about comparing it to another large number in this blag post. But all the numbers discussed had a sense of arbitrariness to them. The xkcd number was just a function that grew rapidly plus a large argument. I’ve been thinking about it, and I want to construct a number that is not only mind-bogglingly large, but elegantly large. This is hard to define — the closest I can get is that it shouldn’t feel arbitrary.

Now, as some have pointed out, noncomputable functions like the Busy Beaver function can grow faster than any computable function. By my understanding, this just means they have a higher computational complexity — their values for a little bit may be smaller than a computable function, but you can never prove that, for sufficiently large arguments, a computable function is an upper bound to the sequence.

I decided I wanted to express the largest number I could in about 32 characters, something akin to the MIT big number duel. Here’s what I came up with:

H{F(n)}=F^n(n);H{H{H{H{BB(9)}}}}

In the first half (before the semicolon) I’m defining an operator H, which transforms a function F and an argument n into an n-level recursive call to itself (I’m using F^n() to refer to F(F(F( … recursed n times … ))) as in derivatives. That is, H{} represents the process of n-level recursion. Then I use this recursion several times on the Busy Beaver function until I run out of space. This isn’t just four recursions — each new H{} is a virtually infinite set of recursions, since it has as many levels as the result of the number in the level below it. As the seed, I picked 9 — the largest integer you can fit in a single digit.

I’m a lot happier with this number’s ‘bigness’ than I was with A(g_64, g_64). It feels bigger, in some hard-to-describe way (it also feels bigger in the easy-to-describe way: “>”). It uses a more fundamental idea of bigness It’s also, of course, noncomputable. However, you can stick the Ackermann function in place of the Busy Beaver function and get a number that is again much larger than the xkcd number.

So, anyone want to define an elegantly bigger number in about 32 characters, invoking reasonably standard notation and functions? I’m sure it’s possible — it’s not a well-defined contest, and I’m sure there are a lot of other tricks you can use. But at least I’m finally satisfied with my entry.

Edit: As a number of commenters have pointed out, my notation here is pretty bad.  I’m indeed using H{} more like a macro that acts on an expression than a transform that acts on a function, and this leads to difficulties in mixing the levels.  Fortunately, you guys have waded through the fog and understood what I was getting at :)

Here’s a slightly simplified expression that does the same thing and tacks in two extra recursions (so as to use the 32 characters).  It loses the generality I was going for, but it’s more compact and not ambiguous:

H(n)=BB^n(n);H(H(H(H(H(H(9))))))

Velociraptor Safety

I recently received a letter from Dr. Daniel Snyder, a paleontologist from Knox College, who wanted to share some theories on handling dromeosaurids:

Dear sir,

I have recently been introduced to your Web comic, and I write in great admiration. You have a keen mind and wit, as well as the artistic ability to convey them to the reader (me). Thank you, and keep up the efforts!

I notice that many of your comics revolve around people (including yourself) with a phobia of Velociraptor. This phobia revolves around Velociraptor overcoming some 70 million years of extinction and the geographic barriers between its home and yours, leaping out of the underbrush and/or through the kitchen, and doing unmentionable things to your innards with its teeth and claws.

I see little point in addressing the substance of your fears, as that’s perhaps best to someone more qualified to deal with the human mind. I hold a Ph. D. in vertebrate paleontology and am somewhat more qualified to address the symptoms. To wit, I would like to help you overcome your fears by successfully defending yourself against Velociraptor.

It is widely known in the field of agronomy (e.g., Avery, 2002) that birds are repulsed by methyl anthranilate, a natural compound found in many of the less sweet fruit varieties. Methyl anthranilate has been used (with some success) as a bird repellent on crops. Now, we know (e.g., Gauthier et al., 1988) that modern birds are descended from dinosaurian ancestors, of which one close relative was Velociraptor (ibid.). Much as lab rats respond to drugs like humans, it is entirely possible that Velociraptor will respond to methyl anthranilate as does the common crow or European starling.

Thus, I recommend you carry around a loaded SuperSoaker filled with Concord grape juice. Fresh-squeezed would be ideal, but from concentrate should be effective as well. This will not only have the theoretical asset of protecting you from Velociraptor, it will have the pragmatic asset of protecting you from thirst.

In appreciation of your Web comic efforts, I will happily waive my consultation fee.

Bibliography
Avery, M. L., 2002. Avian repellents. Pages 122-128 in J. R. Plimmer (ed), Encyclopedia of Agrochemicals. Volume 1. John Wiley & Sons, Hoboken, New Jersey, USA.

Gauthier, J., A. G. Kluge, and T. Rowe. 1988. Amniote phylogeny and the importance of fossils. Cladistics-the International Journal of the Willi Hennig Society, 4, pp.105-209.

Daniel Snyder, PhD
Knox College
K-52/x7846/dsnyder@knox.edu

Excellent!

And this makes me think of the can of shark repellent in that Batman movie. Maybe it wasn’t such a silly approach after all …

edit: By the way, as in all my comics, you can just read ‘velociraptor’ as referring not to the beagle-sized dinosaur, but rather as a generic term for whichever dromeosaurid most closely resembles the Jurassic Park animals.  That is, something between a deinonychus and a utahraptor.