Iran is currently working on obtaining fissionable uranium which can be used for nuclear weapons. This is presenting something of a thorny issue for our current Simian-in-Chief, whose approval rating is dipping perilously close to single digits over his mismanagement of the botched and ultimately pointless war in Iraq. We currently lack the political capital and the military and financial resources to mount any kind of overt action in Iran, wishful thinking of the pro-war Far Right aside. None of this is news to anyone who’s not been living under a bridge for the past four years or so.

There’s some good news and some bad news in this situation, none of which has anything to do with American politics or the situation in Iraq. The good news is the part that says “Iran is currently working on obtaining fissionable uranium which can be used for nuclear weapons.” This is good news because, more than fifty years after Word War II, it still requires a major committed effort on the part of an entire nation to obtain fissionable uranium which can be used for nuclear weapons. The bad news is generic programmable nanotech assemblers. The good news is that these don’t exist yet. The bad news is that they will.

The process of enriching uranium is delicate, costly, complex, and fiddly. The Reader’s Digest Condensed Version is this: Uranium occurs in nature in two isotopes, U-235 and U-238. The difference is the number of neutrons in the atomic nucleus of the uranium atoms. U-238 has three more neutrons in the nucleus than U-235 does.

The vast majority of the uranium in nature is U-238. U-235 is quite scarce, making up just over one-half of one percent of the uranium you can dig up out of the ground. For various complicated reasons that have to do with Science and are beyond the scope of this post, U-238 doesn’t go boom. In order to be useful to people who want to make things go boom, uranium needs to be “enriched,” meaning that the percentage of U-235–the kind that does go boom–needs to be increased.

This process is really, really, really hard to do. Essentially, you take your uranium and combine it with fluorine to form a gas called uranium hexafluoride. You then put this gas into a special centrifuge and you spin it really, really fast for a really, really long time. A tiny percentage of the U-235, which is just oh such a little bit lighter (by the weight of three neutrons) than U-238, ends up at the top. Then you take some of the gas out of the bottom, where it’s more U-238, and put the remaining gas into a second centrifuge, which you spin really, really fast for a really, really long time. You keep doing this over and over and over again for months, and you’re left with a little bit of enriched uranium hexafluoride, which you take the fluorine atoms off of to end up with uranium.

The centrifuges are complicated and difficult to make, even if you’re an entire country. The process is so delicate that if one of your workers sneezes while it’s happening, the whole shebang gets all mixed up again and you have to start over. Even with billions of dollars on hand and the resources and will of an entire nation behind you, making nuclear bombs is tough to do.

There is this notion that once a nation acquires nuclear weapons and realizes how destructive these things are, that nation tends to become very, very reluctant to use them. In the history of the world, only two have been used in war. There are historians who will argue that the existence of nuclear weapons has likely averted a third world war; these weapons are so bad that nobody really wants to use them, so nations that have them tend to think twice about getting into shooting matches with other nations that have them.

Of course, this assumes people are reasonable. This is often, but not always, the case. Witness 1 for the prosecution: Kim Jong Il, the poster boy for “deranged psychopaths,” who just so happens to be the leader of North Korea, a nation which just so happens to have nukes.

I tend to think the notion that nuclear weapons have a calming effect on countries is a historical artifact, because they’re so hard to make that only highly industrialized, rationalist nations get them first. There is a correlation between countries with stable, rational governments,and countries which are wealthy and industrialized.

Don’t look at me like that. Compared to Kim Jong Il, Josef Stalin is a model of reason and rationality. And George W.’s administration didn’t invent the Bomb. Had all our nation’s leaders been like W, we would never have become a First World nation to begin with, and we may still not be a First World nation by the time he leaves office. Half a trillion dollars drained out of the nation’s economy to finance a war against a paltry and largely unmilitarized Third World country…but I digress.

The point is, making nuclear bombs is tough and expensive, even for entire nations. Your next door Al Qaeda cell isn’t going to get one any time soon, wishful thinking of the pro-war Far Right aside.

But hold on. Things are getting better.

Nanotechnology is a cutting-edge new technology that offers the promise of doing for manufacturing, medicine, and materials engineering what electronics did for computation. Right now, human technology is barbaric and primitive almost beyond reason. We like to think that we’re high-tech, but we’re not. The process by which we make things has hardly changed since flint knives and bearskins. We take a piece of something, we whack off all the bits that don’t look like what we want, until we get what we do want. Today the whacking is done by computer-controlled, automated CNC milling equipment instead of with a big rock, but essentially it’s the same. Our processes for making stuff are better, but our basic techniques have scarcely changed.

The Holy Grail of manufacturing nanotech is the universal programmable assembler, a hypothetical device that makes stuff the way the cells in your body made you–at an atomic scale, one molecule at a time. The theory is simple: you take a bunch of little programmable machines, each of which is the size of a couple dozen molecules or so, and you program them with what you want to make. Then you give them some carbon, iron, or whatever, and they make that thing for you from the ground up, one molecule at a time. It’s the ultimate dream manufacturing technique; if you can conceive it, you can make it. (Of course you don’t want to make stuff literally one molecule at a time; when I say a “bunch” of assemblers, I mean like “a few billion.”)

It’s less farfetched than it sounds. Read Engines of Creation. Go ahead; I’ll wait.

You back? Cool stuff, right? Radical longevity, effortless and cheap manufacturing that doesn’t pollute or deplete natural resources, personalized cancer cures that cost less than a low-end Dell desktop. The advent of nanotechnology will arguably change human civilization more than the advent of agriculture did.

If we live that long, that is. You see, nanotech offers the promise of building stuff on a molecular level. Nanotech assemblers manipulate matter on the level of individual molecules. Forget that complicated, tedious mucking about with expensive and finicky centrifuges and uranium hexafluoride; dissolve your uranium in hydrogen peroxide and sodium hydroxide, stir in some nano devices that sort out the U-235 bits from the U-238 bits, and wait. Enriching uranium is removed from the realm of entire nations and brought down to the level where anyone who’s having a bad hair day can do it.

If he can get the uranium to begin with, of course. It’s not like you can buy it at the corner grocery. But we’re a clever species; someone will figure out how to solve that problem. 🙂