Thursday, January 26, 2006

Humanist among the Scientists

I have always been fascinated with science. In fact, in high school, I was very good at math and science. My teachers in those subjects were constantly encouraging me to pursue a career in science. I, however, wanted to be a poet. Even as I pursued my lucrative poetry career, though, I couldn't quite let go of science altogether. I wrote poems about asymptotes and red shifts. I went to talks about string theory.

For my dissertation, I'm venturing back into a little science by reading about graph theory. Now I couldn't replicate the experiments I'm reading about or expand on them, but I understand them for the most part. And I think it's very different way of looking at things--for me anyway. Most of the time, I don't think about science in any kind of concrete way. But to think about the fact that it underlies everything, including things that you wouldn't think it has anything to do with, is fascinating.

I'm reading Linked, which I highly recommend. In it, Barabasi describes the Internet as a scale-free network, that is, a network that contains highly-connected hubs rather than one where the connections are more evenly distributed. Last night I was reading the chapter where he discusses the failure rate of scale-free network. It turns out that failure isn't all that likely in a scale-free network if you eliminate nodes at random because it's more likely that a small node will be eliminated as opposed to a hub. In fact, small nodes fail on the internet all the time and we don't realize it's happened. Targeted attacks on the network, however, are likely to cause a scale-free network to fail pretty quickly. Attacks tend to target the hubs. When hubs go down, isolated islands are created; the network falls apart.

What this got me to thinking about, actually, was terrorist networks. If, as Barbasi suggests, scale-free networks can be observed even in social networks, and if terrorist networks are indeed an example of a social network, then there must be hubs, and bringing down those hubs would bring down the whole network. It doesn't strike me that this is the approach we're taking to combatting terrorism. Instead, we're using the "eliminate any random hub" approach. Or eliminate any random terrorist whom we found through a broad wiretapping program. And, as I discussed above, this doesn't cause the network as a whole to fail. What should we be doing? One, we should figure out who and/or where the hubs are. I suspect we know some of these, but I suspect there are many, many more we know nothing about. Two, we should eliminate those hubs. Seems simple, right? Well, unlike the Internet, where hubs are pretty visible, hubs in terrorist networks are not. Bin Laden must be a hub. Zarqawi is a hub. We have no idea where these people are. I also suspect that there are sub networks that are also scale-free. So there may be a worldwide terrorist network, but there's also one in Iraq, in Afganistan, in Pakistan, maybe one in the US, all of which may function somewhat independently. These smaller networks have their own hubs.

Surely, someone is working with this kind of theory as a way to combat terrorism. Although, this involves science and we know how the Bush administration feels about science.