Bombs and rockets – Page 38 – a sibilant intake of breath

Thermonuclear weapon design

A common misunderstanding about thermonuclear weapons (those that employ tritium-deuterium fusion as well as the fission of uranium or plutonium) is that most of the extra energy produced comes from fusion. In fact, the great majority comes from additional fission encouraged by neutrons produced by the fusion reaction. Each atom that undergoes fission generates 180 million electron volts (MeV) of energy, equivalent to 74 terajoules per kilogram. Tritium-deuterium fusion produces only 17.6 MeV per incident, though the materials that undergo fusion are far less massive than those that undergo fission.

The general functioning of a modern thermonuclear bomb (Teller-Ulam configuration) is something like the following:

A neutron generator bombards the plutonium pit of the primary (fission device).
Exploding-bridgewire or slapper detonators initiate the high explosive shell around the pit.
The pit is compressed to a supercritical density.
The pit undergoes nuclear fission, aided by the neutron reflecting properties of a shell made of beryllium, or a material with similar neutron-reflection properties.
The fission process in the primary is ‘boosted’ by the fusion of tritium-deuterium gas contained in a hollow chamber within the plutonium.
The x-rays produced by the primary are directed toward the secondary through an interphase material.
Within the secondary, heat and compression from the primary induce the production of tritium from lithium deuteride.
Tritium and deuterium fuse, producing energy and high-energy neutrons.
Those neutrons help induce fusion within a uranium-235 pit within the secondary (called the spark plug). Layers of uranium-235 may alternate with layers of lithium deuteride, and the whole secondary may be encased in a sphere of uranium-235 or 238. This tamper holds the secondary together during fission and fusion. Uranium-235 or 238 will also undergo fission in the presence of neutrons from fusion.

Throughout this process, the whole device is held together by a uranium-238 (depleted uranium) case. This is to ensure that the reactions proceed as far as possible before the whole physics package is blasted apart.

One important security feature can be built into the detonators that set off the explosive shell around the primary. By giving each detonator a fuse with a precisely set random delay, it is possible to ensure that only those who know the timing of each detonator can cause the bomb to explode as designed. If the detonators do not fire in a very precisely coordinated way, the result is likely to be the liquefaction of the plutonium core, followed by it being forced out of the casing as a fountain of liquid metal. Nasty as that would be, it is better than the unauthorized detonation of the weapon.

The detonators are also an important safety feature since their ability to cause very stable explosives to detonate means that the high explosive shell can be made of something that doesn’t detonate easily when exposed to shock or heat. That is an especially valuable feature in a world where bombs are sometimes held inside crashing planes, and where fires on submarines can prove impossible to control.

Slaughterhouse-Five

Kurt Vonnegut‘s Slaughterhouse-Five is a refreshing and enjoyable book, despite the often macabre subject matter. It reminds me strongly of both The Life of Pi, insofar as it refrains from interrogating its own fantasies, and Robert Heinlein’s Stranger in a Strange Land, due to the style of language and presentation of characters.

The book is mostly about an American named Billy Pilgrim who participates in the Second World War (though he never fights), witnesses the firebombing of Dresden, and subsequently becomes an optometrist. He either goes mad or genuinely begins to travel through time, experiencing his own life in a random series of vignettes. The story’s narration is unobtrusive, though it sometimes has a self-referential feeling. The language is clear, simple, and poignant.

Free will is a major topic of concern in the book. The aliens who Billy Pilgrim thinks he encounters are able to see back and forth through time, and believe that all actions necessarily unfold in a certain way. This leads to a kind of fatalism where the inevitability of war and death is somewhat tempered by the ability to experience the better periods prior to those things at will. Arguably, Pilgrim created this idea in his madness after being broken by war (or brain damaged in a plane crash). Possibly, Vonnegut is trying to satirize the idea that wars and actions are inevitable; that is certainly suggested by the way in which the end of the universe is described, as the inevitable result of a rocket fuel testing experiment conducted by Pilgrim’s aliens. Pilgrim’s overall haplessness – as well as the thoroughly unheroic portrayal of other soldiers – certainly counter some of the more common war myths of valour and meaningful sacrifice. The refrain of the whole book, usually following a brief description of some incident of death or cruelty, is simply: “So it goes.”

Appropriately enough, given how the narrative jumps around in time, my first experiences of the book came in the form of reading random bits and pieces every once in a while. It’s not an approach that I generally adopt with books, but it worked uniquely well with this one. Reading it straight through definitely gave more of an overall picture, but the book couple be chopped up and re-ordered in any number of ways without a new reader finding it at all suspicious.

Overall, I really appreciated Vonnegut’s style and language. It shares many similarities with the early science fiction of Heinlein and Asimov: a crispness of language and compassionate voice. It makes me want to read more of his work.

Vozrozhdeniya Island

One disturbing consequence of the shrinking Aral Sea is that Vozrozhdeniya Island is now connected to the mainland. Between 1948 and 1991, the island was home to a secret Soviet biological weapons testing ground. Weaponized agents tested include anthrax, tularemia, brucellosis, the black plague, typhus, smallpox, and botulism. Animals on whom tests were conducted include horses, monkeys, sheep, donkeys, and rats.

The Aral Sea has essentially vanished because the Amu and Syr Rivers were redirected by the USSR to irrigate rice and cotton fields. Hopefully, the new connection between the disease island and the Kazakh and Uzbek coasts will not permit organisms to escape on rats or fleas, or criminal or terrorist groups to gain access to infectious materials.

In 2002, a team from the American Defense Threat Reduction Agency eliminated between 100 and 200 tonnes of anthrax, over a three month period.

Two perspectives on air power and insurgency

These two articles provide contrasting views on the use of air power by coalition forces in insurgency situations, such as those in Afghanistan and Iraq:

The first is much more personal, written by a woman who spent months living with soldiers in the Afghan valley where the campaign is ongoing. It does a good job of capturing the chaos and violence being endured by coalition soldiers, as well as the psychological toll of doing so. The second is more removed and – unsurprisingly – more straightforwardly critical.

Both do a good job of setting up questions about how to ethically, legally, and effectively use air power when fighting insurgent wars. At the end, it’s pretty clear that no unproblematically ‘good’ answers to them exist.

Space-related fatalities

I never appreciated just how hazardous spaceflight really was. Everyone knows about the Challenger, Columbia, and Apollo 13 disasters. Many people know about Apollo 1. I doubt anyone reading this is aware of all of these. Soyuz 23, for instance, crashed through the ice of Lake Tengiz and had the crew saved only through an elaborate underwater rescue. Apollo 12 was struck by lightning during launch and would have been destroyed if disabled computers in the crew compartment hadn’t had backups in the rocket itself.

Of the 439 people who have been strapped into a vehicle intended to eventually go into space, 22 (5%) have died as a result. American astronauts were statistically about four times as likely to die as their Soviet counterparts, though that is partly a result of how the large crew of the Space Shuttle means a catastrophic accident kills seven people. The Space Mirror Memorial in Florida commemorates Americans who have died in the space program; their cosmonaut contemporaries are buried in the Kremlin Wall Necropolis. No Russian has died in relation to space travel since the fall of the Soviet Union, so it is unclear how they would be memorialized now.

CIA given license to torture

President Bush vetoed legislation that would have forbidden the CIA from using certain torture techniques, such as simulated drowning. It seems a clear sign of what we have lost due to excessive concern about terrorism – the understanding that governments are the most dangerous entities in the world. While they generally lack the desire to cause mayhem that defines terrorist groups, the powers governments have are so vast that they can do great harm through simple ineptitude, or a failure to police the actions of their agents. Facilitating torture is an international crime, and for good reason. It is a shame that geopolitics ensures that none of America’s new generation of torturers will even find themselves on trial in The Hague.

Stopping this legislation ensures that a few more people will be tortured needlessly, in violation of international law and the kind of ethics that we are supposedly trying to defend from terrorism. Furthermore, I think it’s likely that decisions like this will be looked back on in thirty years time much as we now look back on using the CIA to arm Osama bin Laden and the Mujahideen in Afghanistan, or help keep Pinochet in power. In the long term and in purely geopolitical terms, it will prove to be an own-goal for the United States – further tarnishing its increasingly shaky reputation on human rights and emboldening governments like China and Sudan to treat the idea even more disdainfully.

This Michael Ignatieff article, which I have doubtless linked previously, does a very good job of treating the subject of torture ethics intelligently. Henry Shue has a less convincing argument.

Pessimism and the Future Leaders Survey

Increasingly, there seems to be a strong correlation between a young person’s level of education and their level of pessimism. Arguably, this is on account of the related correlation between education level and level of interest and engagement with current events. Somebody who never watches the news or picks up a newspaper just has less to worry about.

A recent British survey has produced some numbers that support the pessimism hypothesis. The Future Leaders Survey polled 25,000 applicants to British universities. The findings demonstrate a widespread anticipation of a worsening world:

Asked about likely outcomes for humanity by 2032, the responses are gloomy to say the least. Nine out of 10 surveyed think Africa will still be starving and oil will be prohibitively expensive, and eight in 10 expect more terrorism and the effects of climate change to be hitting hard. Inequality within the U.K. and between rich and poor nations will have worsened, according to around 70 percent of those surveyed. Half expect nuclear weapons will have been used again and that the U.S. will still be in Iraq.

16% of respondents said that they expected humanity to go extinct within a century; 78% of respondents said that could only be avoided through radical lifestyle changes. Admittedly, these are people who are just starting out at university, so it doesn’t demonstrate much about the linkage between education and pessimism. It would be quite interesting to have the same group re-polled in four years time. It would not surprise me if they were significantly more dispirited the second time.

One has to wonder whether this makes today’s society an aberration. Surely, history has been full of people who never really expected the world to change, one way or the other. Periods of history have also included large numbers of people believing that big improvements were possible or even inevitable. I am not sure if the kind of apocalyptic feeling spreading through the most influential segments of the most powerful states has much precedent. One can only speculate about what the long-term consequences might be.

Big picture uncertainty

Climate change policy focuses on constant attempts to make guesses about the future: about economic development in rich states and poor, about patterns of technological evolution, about climatic responses to radiative forcing caused by changes in the gas mixture of the atmosphere. One cannot always evade the feeling that too many uncertainties are being layered. Consider, for instance, the possibility that hydrocarbon fuels will peak in world output within the next few decades. If that happened, most of our ‘business as usual’ economic projections would be badly wrong.

An even more ominous consideration relates to global conflict. When the world is generally doing well, it is devilishly hard to convince states to reduce their greenhouse gas emissions for the universal good. Imagine how hard it would be in a geopolitical environment based around rising tensions and the growing expectation of great power war. We make projections for 2100 without acknowledging that making it from now to then without such a war would be a historical aberration.

In the end, I suppose, cynicism does us little good. The vast majority of ordinary people – and of powerful people – will not believe in the disastrous potential consequences of climate change until they start to manifest themselves visibly. As such, agonizing about them just makes you more marginal to the debate that exists among those not kept awake by fear about the possibility for self-amplifying positive feedbacks in the climate system. We must do the best we can, avoid confusing engagement with the mainstream debate with genuine complacency, and hope that humanity possesses more wisdom than it has ever demonstrated before.

Natural gas and Russian politics

The results of the election in Russia yesterday are not surprising, though they are part of a very worrisome overall trend. Bolstered by high energy prices and strategic overstretch on the part of the United States, Russia is regaining some of its nastier old habits. Of course, it is unreasonable and unacceptable to hope that Russia will remain as powerless as it has been since the fall of the Soviet Union. As much as is the case with China, the question of how a powerful Russia will return to geopolitics is an interesting and somewhat frightening one.

Europe’s vulnerability to Russian control of natural gas supplies has been well demonstrated of late. Poorer Central European states are potentially even worse off in the medium term, if Russia manages to build pipelines that go around them. Turning off the heat in Kiev is unlikely when it means doing the same in Berlin. Being able to do the first without the second would further worsen the strategic situation presented to the states in the middle. I expect they are feeling pretty nervous right now, given how generally spineless NATO and the EU have been recently in the face of Russian bullying.

Hopefully, concerns about access to gas will help to advance the drive towards renewable energy in Western Europe, eventually reducing the economic vulnerability of those states to Russian machinations. Such an outcome would have positive consequences in relation to the state of the global environment, and may embolden Europe’s democracies in relation to an increasingly assertive and unapologetically totalitarian Russia.

Robert Gates posturing on missile defence

Everybody has probably heard about how the United States shot down a supposedly dangerous satellite with a ship-based kinetic kill interceptor. Now, US Secretary of Defence Robert Gates is saying that this proves missile defence works. Of course, this is absurd. Satellites follow very predictable orbits. As such, it is pretty easy to hit them with missiles. Commanders won’t have that advantage when trying to shoot down the incoming missiles of their enemies: especially since those missiles will often employ physical or electronic countermeasures.

It is also worthwhile to consider what they would be saying if this test had failed: “Of course, downing an ailing satellite is completely different from missile defence! The fact that this test didn’t succeed in no way suggests that America’s $12.8 billion per year missile program is ineffective, nor that missile defence technologies aren’t worthy of billions more taxpayer dollars.”

It’s a good thing Canada never bought into the idea.