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By James Killus

There are reasons to suspect that science and engineering took a very different path over there: their limited understanding of nuclear weapons—they seem to think that nukes are roughly as easy to build as bottle rockets—suggests that nuclear fission may never have been developed on their timeline. – Twilight Zone by Gregory Cochran, on evidence that members of the Bush Administration are from a parallel universe.

Just how hard is it to build a nuke? And what is the smallest amount of plutonium needed to build one?

The smallest nuclear weapon ever designed was the Davy Crockett, aka the W54 warhead, weighing 51 pounds with a variable yield supposedly from 10 to 250 tons of TNT equivalent. It was the last weapon ever atmospheric-tested by the U.S. and in its two tests, (Little Feller I and II) it yielded 22 and 18 tons of explosive power. At those yields, however, the explosive power was pretty much unimportant compared to the radiation the blast produced, lethal to 50% of unshielded personnel at 400 meters, 100% lethal at 300 meters.

There’s not a lot of unclassified information about the actual design of the W54, but some conjectures can be made about it just from the nature of the nuclear chemistry involved. A “bare critical” mass of plutonium, for example, weighs roughly 10 kg, but a neutron reflector reduces this by maybe a factor of two. A uranium reflector/tamper can also increase yield because some fast fission will take place in the reflector itself (at the cost of a time delay in the return of the neutrons to the explosive core). Beryllium also multiplies neutrons, undergoing “light fission” on exposure to high-energy particles of any kind, including neutrons, to produce, well, more neutrons. This is also at the expense of slowing the neutrons and thus retarding the rapid increase in neutron population that make a bomb go ka-boom.

But slowing neutrons is called “moderation” and slower neutrons tend to react more easily with nuclei (have a higher capture cross section) than fast neutrons. This is a consequence of quantum mechanics, where fast particles have a more certain position than do slow ones. Think of the slow neutrons as being more “fuzzy,” virtually bigger, if you will. So if there is a nearby nucleus that is “sticky” for neutrons, a slow neutron is more likely to glom onto it.

That is pretty much the principle of nuclear reactors, where neutrons are slowed down to better react with the fissile elements in the reactor. A mass that is sub-critical for fast neutrons can be more than critical for slow neutrons.

The result is that, with a thick beryllium reflector, the critical mass of normal plutonium can be reduced to less than 20% of its “bare” critical number. The thickness of the reflector in the Davy Crockett was probably dictated by the limit that is reached when adding more reflector increases the overall mass of the design rather than reducing it.

The variable yield of the W54 looks like a signature of a variable fusion boost, but I’ve seen statements to the effect that D-T fusion doesn’t get going until you reach the 100 ton range, so the W54 may have had multiple fission core compositions. Still, the upper limit of the W54 is within the fusion boosting range, so a design modification could possibly have boosted its potential yield to a full kiloton.

A reasonable question arises, is the implied 2 kg core the minimum amount of plutonium (or U233, which has a bare critical mass of about 16 kg) that can be used to make a nuclear weapon, even one of such a low yield as the W54?
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Up until 1970 i used to celebrate Cinco de Mayo, the very merry month of May, with the rest of the Californios. After that, it became just another day in another month, a post-fourth of May acknowledgement of that dreadful moment in US History. Well in honor of all of those killed by our governments’ evils, i propose that we accept lists of the top-ten, alltime, worst, governmental administrations in world history. Bushco clearly has moved into the top spot in the US pantheon, but is it so horrible, so corrupt, so imperiously evil as to even garner a nod in the top-ten all time on the planet; and by what do we measure that dark force’s influence??? The candidates are nearly unlimited, even if we just stick to the 20th century. But buried deep in the minutiae of history’s dustbins and rubbish piles are some real winners spread across the continents. For example, i might consider Pizzaro more vile than Pinochet, but another would take Colombus over Cortez. Richelieu or Torquemada? I might consider Rove vastly more evil than either Bush or Cheney?? Go have fun with this one, while i research my fabulous ten and post later today.

I have been working on a film script to counter claims that the WAAGNFNP unfairly concentrates on nuclear destruction over other forms of apocalypse. A précis follows. [I have the idea pretty well fleshed out, but am looking for some help from readers on a few details.]

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Working title: Triumph of the Snark.

The movie, set in the indeterminate future, starts with an unnamed narrator (later in the movie we hear him referred to as “Doc”) describing the cynical and barren life that he lives in a cramped underground city: What would you do if you were stuck in one place and every day was exactly the same, and nothing that you did mattered? That about sums it up for me. There is nothing of beauty in this city, the residents (who sarcastically refer to themselves as Morlocks, and the city itself as Turgidsonville) are mean, spiteful, rude and condescending. Most spend their days online, trading acerbic barbs and ridiculing anyone who advances any positive agenda for change. A great catastrophic event in the past is hinted at, and the viewer at first assumes that it refers to some manner of nuclear, ecological, or epidemiological disaster. Instead, it is revealed that people were merely driven underground by their own perverse thoughts, their insistence that anything “nice” or “cheery” was bad - a “New Nihilism” had swept the world, sapping people’s will to live and reproduce, and leaving a small embittered remnant ensconced in their digitally-enabled tombs.

Doc’s job as an electrical engineer takes him to the surface on occasion to look after the power grid. The surface is a pleasant enough place - though it is evident that Doc himself is utterly unimpressed with it. There are a smattering of automated farms and mines providing raw materials for factories producing mass quantities of Mountain Dew, junk food, electronic components and other essentials. Working on the surface one winter day, Doc is drawn away from the solar grid he is repairing by a vision of a giant rabbit who tells him that “death will come from the sky” in 28 days, 6 hours, 42 minutes and 12 seconds. Following the vision causes him to miss being crushed by a falling jet engine that lands precisely where he had been working. Nearby he finds an injured teenager lying in the snow, mumbling Schlachthof Fünf over and over again. Doc brings him home, and although the boy can only remember his name - Donnie McLightly - he has a relentlessly cheerful nature which proves infectious. Inspired by the song Mr. Blue Sky from a CD Donnie finds in his pocket, he convinces Doc to help him form a club which he calls Electric Light Orchestra Illuminati (ELOI) club. Tapping a hidden, seething vein of optimism in Turgidsonville, the club soon grows in number, despite what seem to be self-limiting set of rules.

The first rule of ELOI club is that you do not blog about ELOI club.
The second rule of ELOI club is that you do not blog about ELOI club.
…
…
If this is your first day at ELOI club, you have to logoff and go topside.

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By peter ramus

Beowulf, still as yet the great Geat all these fifty years since Grendel, at last has at the dragon.

Locked in the narrow choices of a paragon, the fellow must go out, Beowulf, take on the beast that breaks and burns his people, put up against the incomprehensibly mighty foe what measure of strength and will to overcome is left him.

It is the man’s method to give full measure in this regard, paragon he is, however residual the powerful powers of one who’d mastered Grendel and his mom so long ago. Engage the worm? Contest it? Oh, yes, mustn’t he, being Beowulf yet?

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By Seattle

So I was listening to National Petroleum Radio as Oaktown Girl calls it the other day and heard the news that once again, the never-ending debate over abortion had been ratcheted up a notch due to a recent Supreme Court decision. Nothing sets my teeth grinding like that topic, except possibly driving behind very slow drivers from other nations on Beacon Ave. South in south Seattle when I’m late. I’m late a lot… But I digress.

The never-ending debate over our unwanted children is how I consider the abortion issue. Viability, pain thresholds, visible proof of life, murder, God, responsibility, God, did I mention teeth grinding? I feel the blood pressure rising in my temples just thinking about it - that happens way too much nowadays too - and I’ve come up with my own solution to the issue of our unwanted children. ‘Cause that’s what we’re talking about. Children their parents don’t want. We’ve got a lot of live ones in that category.
Not just in the US. It’s a global, human issue. Unwanted progeny.

Another National Petroleum Radio article a few days later described the living conditions of children in orphanages in Russia. Painful stuff, if you care about kids. Children left tied to cribs, fed, but not changed, not interacted with. Literally left to rot. Better off alive or dead? That’s the real question, isn’t it?
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By Zeus

It has been an interesting spectator sport watching candidates communicate their faith “approaches” in the political arena. Hillary Clinton seems committed to operating upon faith as a kind of demographic variable to be diplomatically embraced with the help of advisers. John Edwards is fairly typical of the liberal politician: Faith is personal, almost wholly personal, an attribute of both a stout and moral leader and a caring Christian man. No atheism or animosity to religion here, whewww, and none of the nasty side effects of authoritarian, conservative pseudo-Christian warmongering. Edwards is religion in its unthreatening glory– personal, friendly, earnest, and (innocuously?) virtuous. We can all dedicate ourselves to the nobler unifying issues, like healing the economic rift between the “two Americas”.

I won’t discuss the Republican candidates because I find them so sanctimonious, monolithic, and calculating as to be boring and strangely agnostic in their presentations.

Barack Obama, I find to be the most interesting, because his engagement of the action side of faith (organizing communities and confronting the injustice of racism) has presented challenges to the gauzy images that many Americans have come to expect from their religiosity. Patrick DeTemple has already discussed from a ground’s-eye view much about the political side of Obama in a recent post, so I won’t spend too much time there, but Obama serves as an interesting case study of a larger dynamic playing itself out on the political stage, a different kind of “triangulation” in which faith plays a kind of litmus role:

• The negotiation of the dialectical materialist and Marxism-influenced past of the 1960’s, and its own tensions between “opiate of the masses” secularism and liberation theology.

• The desire for a “mainstream” present in which conflicts and hard choices can be fluffed into non-existence or packaged into comfortable simulacra (think of oddly new-age flavored televangelism).

• And the opportunity (and challenges) of a progressive future in which faith might act as a verb, helping us to engage, rather than run from the unknown, and having us come to terms with injustice in the service of a renewed spiritual vision which both embraces diversity and empirical truth and points beyond it.

I recommend the recent front page article in the New York Times on Obama to get a first hand look at this stormy love triangle. Obama was mentored by a scion of the 60’s, Jeremiah Wright, a pastor at Trinity Congregational in Chicago.
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Well, the frenzied fun of the Kentucky Derby Live Blogging pretty much blew out Open Thread (#6), so here’s a fresh one because there’s just so much going on this weekend - NBA and NHL playoffs, TC tells us there is LPGA action this weekend, a boxing match that is supposed to save boxing, and of course Paris Hilton possibly maybe actually doing jail time saving the corporate media from having to possibly maybe actually perform their duty to keep us informed of things that really matter.

A tip of the MOJ’s gavel to WAAGNFNP newcomer Ya Ya who not only picked the Derby winner, but picked it with authority. Maybe Ya Ya will resurface later this weekend when she reemerges from her Oscar De La Hoya-induced swoon.

Me, I’m missing a killer concert because I’m stuck inside with a horrible cold. So I rented a couple of movies. One is a Czech film, and the other is this one:

Which, can you believe, I still have not seen and it came out in 2000?

Live Blogging the Kentucky Derby!
Sat. 5/5/07 beginning one half hour before start time: 5:30pm Eastern, 2:30pm Pacific. Start time for the race is (I belive) 6:04pm Eastern, on televised on NBC.

[Hey Folks, I’m still fighting a bad cold, so there will be more links than writing here. But that’s OK because I’m not a writer anyway!]
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Tomorrow will be the 133rd running of the Kentucky Derby. How many of you know these names: Oliver Lewis, Jimmy Winkfield, or Isaac Murphy?

Oliver Lewis was the winning rider in the very first Kentucky Derby in 1875. He was also Black. In fact, African American jockeys dominated the sport in this country until the dawn of the 20th century:

From Tony McClean:

African-American jockeys rode 14 of 15 horses in that first Kentucky Derby. The horse racing sport was built with the talents of Blacks whose jobs typically included trainer, jockey, and owner.

From the Library of Congress’ review of the definitive Edward Hotaling book, Great Black Jockeys:

Decades before baseball player Jackie Robinson broke the color barrier to become the “first” black to play with whites in modern professional sports, black and white jockeys were competing alongside one another on racetracks such as Saratoga.

What happened? Again, from Tony McClean (part II of his article):

To no surprise, some white jockeys resented the choice mounts and big money earned by successful Black riders. Races became combative including several riots between Black and White jockeys in Chicago.

Isaac Murphy

By James Killus

A buddy of mine from the air biz used to work at Lawrence Livermore Labs, and he was once at a luncheon where Edward Teller was holding forth. Since there were several atmospheric scientists at that particular lunch, at one point Teller speculated on whether it would be possible to set up a series of nuclear explosions that would cause atmospheric particulates to precipitate out of the air.

My friend was a little nonplussed, because this was a truly loony idea. But after thinking about it for a while, he chalked it up to Teller having a little fun with his own reputation. He had, after all, basically invented the thermonuclear bomb, and had then spent much of his remaining career overseeing its refinement, and looking for some place to use it. From proposed massive canal building projects to attempts to get more natural gas out of geological formations, Teller always had that single tool that he was trying to use: the H-bomb.

Later, when we all heard about the Teller’s backing of the Strategic Defense Initiative (called “Star Wars” in the popular press), some of us immediately wondered, “Where’s the bomb?”

We learned soon enough about the proposed X-ray (or gamma ray) laser, which was supposed to be pumped by a thermonuclear explosion, so there you are and bob’s your uncle. I didn’t expect that to work, for technical reasons, and it didn’t.

SDI did not die with the gamma laser failure, however. We’ve had various debates about the feasibility of “hitting a bullet with a bullet” vs “smart rocks” or “brilliant pebbles,” (or “sentient sand” for all I know). In any case, there’s really no idea so lame that a DOD bureaucracy won’t champion it, but there are some things that generally don’t get said, so I’m going to say them here.

The fact is that there are certain paths of least resistance in engineering. Some ideas, no matter their soundness or unsoundness, will never happen, because something else that is technically easier will happen first. It’s important to know what it is that will happen first.
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By Dr. Free Ride

This week, I voted to ratify our new faculty contract with the California State University system. The negotiations for this contract were frustratingly unproductive until my faculty union organized a rolling strike that was planned as a set of two-day walkouts at each of the 23 campuses in the system. When strike dates were announced (and, we are told, with some serious political pressure behind the scenes to avert a strike that would have garnered national and international media coverage), the administration came back to the bargaining table with a contract the negotiating team deemed reasonably good. The vote this week should indicate whether the CSU faculty share that judgment (I’m betting they will).

The staggering thing to me is that we went almost two years without a contract before we could bring ourselves to the point where we were ready to strike.

I’ve been reflecting upon this, and it occurs to me that there are certain features of a good many faculty members that make it hard for us to embark easily on a job action. In honor of May Day, I’ll describe them here.

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