Friday, January 22, 2016

Manh(A)ttan

     So, I stumbled into this TV series, ostensibly set in Los Alamos during the Manhattan Project.  The critics raved about it; one even said something about a "pitch-perfect eye for period detail."

     I dispute that -- the frequently-seen spring-loaded boom light (Luxo L-1) isn't a total anachronism but "gooseneck" lamps were much more common at the time and you'll look in vain for a single example on someone's desk; and then there's the matter of bright-pastel foam-plastic hair rollers, referring to a meteor wiping out the dinosaurs* and so on and on -- but that's not my biggest objection.

     The story, you see, is a quite competently-told soap opera in a heavy science-becoming-engineering setting.  The actors are good in their roles, they're dressed well and, my quibbles aside, the sets and props are good.  It's just not the actual damn story of the development of the atomic bomb! And I'm not comfortable with that at all.  So far, I'm hanging on by telling myself it's an alternate-history tale, but the overall theme with the plucky underdogs of implosion standing up to arrogant frat-boys running the gun-type design is incredibly overplayed; the implosion-type was never disfavored and ran as a backup to the gun-type from the outset: the engineering was more difficult but the physics and chemistry were better, since plutonium was easier and quicker to come by than U-235. (With this last statement, I, too, am drinking the handwavium; it's that easy.  See below.†)

     So, we'll see.  Taken as fiction, Manh(A)ttan is not so bad.  As history?  Not just no but Hell no!

 P.S.: And the episode I watched last night managed to mis-tell the story of the neutron poisoning problem in the reactors at the Hanford site.  Um, make that completely mis-tell; I recognized bits from Fermi's actual experience at Hanford, from Richard Feynman's story of double-checking the gaseous diffusion uranium plant at Oak Ridge and found Chien-Shiung Wu's and Leona Woods' actual role in solving the problem split between three other and quite different characters. Oh, and a possible melt-down, which is odd, since xenon poisoning shuts down the chain reaction.  But it's all very exciting, in that alternate-history timeline where physics is different and Enrico Femi never existed.
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* Readers may not get how fractally wrong this is from my passing mention.  Luckily, Dr. Walter Alvarez can explain. While he was indeed instrumental in developing the Alvarez hypothesis, it also required the work of his geologist son, who was learning to walk, talk and not soil himself during the Manhattan Project. Oh, and they published it in 19-frikkin-80.  (If you like your science skillfully fictionalized, you'll find some of the elder Alvarez's other wartime work in Arthur C. Clarke's Glide Path.)

 † It's not quite that simple.  As the science turned into engineering, both the implosion and the gun-type bombs were designed around plutonium which was only screamin' difficult to get, rather than uranium-235 which was insanely hard to separate from U-238.  This decision was made early on, when there was less than a teaspoon of plutonium around (churned out in a cyclotron, it says here) and maybe not even that much U-235.  Work to produce both -- belt and suspenders! -- on a large scale was barely underway at Oak Ridge.  As reactor-produced plutonium started to be made -- slowly at first, with another big pile of problems to be solved (pun intentional) -- the isotopic composition of the stuff was substantially different to the first tiny samples.  The difference was such that it was a bit "hotter," and therefore more likely to start a chain reaction.  Good news?  Not for the gun design, which relies on rapid mechanical assembly of a critical mass: move the pieces together too slowly, and your bomb may fizzle, "burning" itself a little but not, in fact, exploding with much force.  And they were already moving slugs of dense radioactive metal about as fast as possible: there was no way to make the "gun" design work with the available plutonium.  On the other hand, the stuff would work fine in an implosion design.  At that point (April-June of 1944), the Manhattan Project swapped priorities; by July, implosion was the main focus and the gun-type, with the basic engineering either well-solved or relatively trivial (!) redesigned around U-235 and became the backup plan.  Meanwhile, gargantuan works at Oak Ridge produced a trickle of uranium 235: when "Little Boy" was dropped on Hiroshima, most of the world's then-available supply of U-235 was consumed.

8 comments:

New Jovian Thunderbolt said...

Dangit! SOME of use have paid attention to that era, prop people.

Guffaw in AZ said...

That's okay.
Watched Agent Carter (?) last night.
(And yes, I know it's based on a comic book and not a documentary.)
I do like most of the costumes and set decoration - but while everyone drinks to impunity, there isn't a ciggie to be seen!
I'm guessing Standards & Practices, again...

Hollywood.

gfa

Stingray said...

Finally, someone who wouldn't look at me funny for yelling at the screen during this one.

Ritchie said...

One blogger recently posted the analysis that the uranium gun design was a horribly unsafe weapon-for the users. Drop safe? Not really. AD/ND? Yeah, could happen.

Roberta X said...

Well....it wasn't inherently safe, but tests supposedly showed that it would take a 500 G impact to set the thing off by inertia. I'm not sure how easy that is to do when crashing a propeller-driven airplane but the Army Air Corps deemed it unlikely.

Other failure modes are less benign. Pilots were instructed to never ditch a plane carrying a Little Boy bomb in water, as the moderating effects of water would result in a crappy little reactor percolating happily away for quite some time. Gives a whole new meaning to "don't drink the water." And various mechanical failures might have resulted in varying levels of "fizzle," none of them good.

It's also inherently dirty. 141-some pounds of hot stuff in a Little Boy and only two (2) pounds of it undergo fission. Where's the rest? You're soaking in it!

It was a backup plan. After the end of WW II, they destroyed a lot of the documentation, thinking they'd never need more bombs of that design -- then had a bad scare when plutonium production hiccuped, hastily scraped together the info, and built a handful as a stopgap. You will find the story in the wikipedia article I linked to in this morning's edits.

igor said...

Nice to pick up a bit of history, from you, that is; not from the show. I worked at N-reactor from 80-88, and stayed at Hanford through 94. Being a young whipper-snapper, at the time, I paid no attention to the old guys, many of whom had been there since the war effort, and the stories that they could have told. Those stories would seem to be lost to history.

Where did you read about Fermi's experiences at Hanford? I don't recall that Feynman ever went up there.

Oh: Glide Path: novel or short? I don't recall it.

Roberta X said...

"Glide Path" is a novel: http://www.amazon.com/Glide-Path-Heart-Experimental-Technology/dp/0743475313/ref=sr_1_1?ie=UTF8&qid=1453605835&sr=8-1&keywords=glide+path

For whatever reason, even many Clarke fans aren't aware of it. Not his usual subject matter but IMO, one of his better novels and he gets the technology *right.*

Fermi at Hanford? Wikipedia and in the book, "The Atom People," by Leona Woods.

Richard Feynman was at the gaseous-diffusion plant at *Oak* *Ridge* when he found himself plowing through complex piping drawings, looking for problems and finding at least one by accident. Somehow the show transplanted that to the B reactor at Hanford. And added a concern for safety at a level and in a way that the "old-timers" you met would have sneered at: there was, after all, a war on.

There's actually a fair amount of Hanford history on the web and IIRC, some collected histories from both there and Oak Ridge.

batchainpuller said...

I found both seasons entertaining enough. They had an aerosol of authenticity sprayed on them. I kept thinking that this was like the Los Alamos version of "Rosencrantz & Guildenstern Are Dead", where the real drama is happening in the background while our lovable charters are stumbling around on center stage.

In 1980 I appreciated the mini-series "Oppenheimer" which ran on PBS/WGBH/BBC. I don't know how it would fare in 2016.