Metallurgist by day. Bad takes on🎬, good takes on☢️weapons & stockpile stewardship, fun at parties. Peace thru superior S&T. Prickly. All opinions my own.
I promised Matt he'd get a thread. $5 billion is a lot of money. Enough to upgrade a couple Big Stockpile Science facilities. NIF, LANSCE...but what if we could get something NEW? Enter MaRIE. A new tool to look at materials in all sorts of, ahem, "relevant conditions". (1/🧵)
@slip_trace
Opinion on the NIF?
Also… You have $5 billion to spend on science experiments that advance the national interests. What’s your plan and toward what ends?
Hello fellow Texans, is me, comrade Djason from Texas Oblast. I work at State Central Factory
#330
For Automotive Forgings Named After David Crockett just like many of you.
This is obviously a Russian. Only Russia talks about the value of a warm water port. Because the US as a whole has several and this has never been an issue for us.
>fire a salvo of ballistic missiles over Hawaii
This would be one way to finally find out if the USA has a launch on warning posture, lol, lmao
(PRC turbohawks continue to be one of the funniest demographics on this site)
Things China needs to do before 2026.
1️⃣Sail our carrier battle groups to Hawaii.
2️⃣Fire a salvo of ballistic missiles over Hawaii as our carrier group approaches.
3️⃣Scrap the "No First Use" nuclear weapon policy.
This will serve as China's Great White Fleet moment.
I've said it before and I will keep saying it. You guys get this stuff wrong because your field is allergic to domain knowledge. You think you can apply first principles econ reasoning to all topics, and you get huffy when the scientists and policy practitioners step in.
Plutonium Metallurgy, The Nuclear Stockpile, and You (a🧵)
All good effortposts should start with a hot take. Mine is that this diagram is one of the most important doodles in the entire national security world. Materials scientists rarely get to stake such bold claims, so, why?
@BradMossEsq
Or Vance appealed the most to Trump's vanity, rage, paranoia. The other possibles - Burgum, Youngkin, Rubio, certainly Haley - just don't have Vance's genuine lack of convictions, which permitted him to be exactly what Trump wanted.
Modern military turbofans are just crazy complex in design & supply chain. Can pursue autarky but it takes a long time to get results anywhere near what you can import. It took China 30 years (I'd argue they still aren't quite there). Turkey & India have been trying for decades.
@Emma_Pike_
You have got to stop wilfully misreading your opponents if you want to be taken seriously in your career. Outside the disarmament bubble, your reputation is going to be someone to ignore and not engage with, if this continues to be the level of debate you bring to the table.
@FahadMAlam
You'll be singing a different tune when Russia intervenes to defend the rights of ethnic Boomhauer accent havers against the HATO neonazi regime in Austin.
@peck_oh
It would be hard for me to believe this wouldn't prompt one of the more maximalist counterforce options on the oplan, joking aside. It would be a horrific tragedy for the Chinese people if some giga-hawk idiot managed to convince them to do this.
@UticaEric
@JamesRaxz
Been saying it for a couple years now. Musk is the weak link in a very important chain for DOD and I'm beyond concerned that nobody seems worried about it. If LM, Raytheon etc were run by unstable nutcases there would be congressional hearings.
Natsec people get so in the bubble that we forget that this "isn't normal", so here's the deal:
1) The military's job is to look and be ready to kill the country's enemies
2) "Lethality" is a natsec buzzword and using it in this speech is a screaming loud signal.
@michaeldweiss
@InsiderEng
@60Minutes
@derspiegel
Physics of undetectable, otherwise asymptomatic microwave-induced TBI don't pass much of a sniff test. If you're dumping enough energy into the head to burst blood vessels, you'd expect visible damage to the skin no? Myelin damage? Why no neuropathy in the external tissues?
If only the cheap FPV drone obsessed terminal GS-12s and their fellow magazine depth screeching retard cohort could see this. Sadly they have mostly blocked any of the few intelligent defense observers on this site.
The importance of a China-Russia alliance in one picture.
By forming a united front, we can by-pass the biggest defense barrier of the US; The Pacific Ocean.
We can create a local superiority in the Bering Strait and start our liberation of North America.
Reviewing the simulations chapter in an old AIAA volume "Tactical Missile Warheads" (ed. Joseph Carleone) and there was a minor jump-scare in this citation.
Raytheon is getting off incredibly easy here. The more I read, just wow.
Their employees made trips to Lebanon, Iran & Russia with their work laptops, which contained restricted technical data on SM-3, SM-6, ESSM, F-15, F-18, F-22, F-35 & B-2. This harmed US national security.
@SwannMarcus89
Never ever let them forget that the CHAZ People's Security Forces shot more unarmed black boys in like 72 hours than Seattle PD had in years.
@mattkorda
@russianforces
The backlash has little to do with her gender and a lot to do with the content of the video. It's profoundly disingenuous to act as though the majority of the pushback in the comments is solely the result of sexism. Is that in there? Yes. But it's not most of it.
I don't give a flying fuck what kind of DEI politics or goofy academic theories you hold. But if you are this thoroughly opposed to the mission, you have no place in this organization. Not right now. Do not be a 5th columnist against our work.
@SwannMarcus89
Also... Not to be unkind, but do these people understand that the supply chains for HRT drugs will collapse pretty early in any revolution?
This is a fun question that I spent most of grad school pondering. Right now we are actually living through a step change in our understanding of the atomic & nanometer scale origins of material properties. This is spurred by computing power & our ability to see at the nanoscale.
I’ll ask this one publicly.
(Please understand, coming from someone who isn’t a physical scientist)
Is metallurgy destined for a series of incremental advances, or are revolutionary advances still possible in the future? And what does that look like? And mean?
You don't hate Greenpeace enough. I realize you're making a valiant effort, but it's simply impossible.
(The >100,000 deaths figure is global, not for the Philippines alone. Small caveat.)
Greenpeace and its allies just won a court case in the Philippines blocking Golden Rice from reaching millions of vitamin A-deficient young children. If this isn't a crime against humanity, I don't know what is. Avoidable deaths could total 100,000s. More:
@SwannMarcus89
This is why institutional tolerance for communists and (even moreso) anarchists has to be zero. They're not interested in participating in your feedback processes, politically they are actually not interested in being citizens in any recognizable way - literally just ignore them.
@ThrustWR
>try to start thread about hidden gem books
>no engagement
>shitpost about low effort Russian influence ops
>massive response
many such cases
I'm most qualified to talk materials selection although the challenges go far beyond that. Many know of the single crystal casting process for the most critical blades and static parts in the hot zone. This is one huge barrier (more later) but not the only material challenge.
2/ This crowded graph is the composition-temperature phase diagram for alloys of plutonium with gallium. The shaded-in section marked "δ" is essential to our ability to make thermonuclear bombs and to trust that they will still work after 40 years sitting in a hole in Wyoming.
Santa, for the 2026 World Cup I want B-21s, F-22s/-35s carrying yellow band AIM-260s, an E-4, an EA-37B blasting enough jamming ERP that you can feel it in your dental fillings, and fireworks delivered by ARRW.
Are you fucking kidding me? Just when you think the NYT can't sink any lower. What is the benefit for such wishy washy "humanizing" treatments of some of the worst war criminals of the modern age?
The inevitable inquest about the Secret Service's failure to secure a rooftop apparently just 125 meters away from their protectee's speech is going to be very interesting.
Obligatory and hopefully *stupefyingly obvious* disclaimer that everything in here can be found in unclassified and uncontrolled public facing journal publications and textbooks, and is not being assembled in a way which ought produce classification by compilation concerns.
It is bedtime for now; expect part 2 in the next couple days, covering corrosion behavior and a couple other things. A third part delving into electronic structure and the underlying physics of why plutonium is the way it is, after that.
#JackPosobiec
#CPAC
"I just wanted to say welcome to the end of democracy. We're here to overthrow it completely, we didn't get all the way there on January 6th, but we will endeavor to get rid of it and replace it with this right here, we'll replace it with this right here."
And people think I'M hawkish.
This is pretty maximalist stuff but frankly I want to paper this thread across every cubicle wall in my building. We are not in an era of "business as usual" and proposals which seem too shocking, too hard-nosed, might be just what the moment needs.
A good case for123 agreements with Russia and China. Hint: There isn’t one. Welcome to real competition signaling: Terminate them both, boost loadings on TIID5 at max yield per each a 8 warheads, fund and deploy SLCMs, accelerate Sentinel and fund real pit prod./1
One of the more eye-popping declassified docs I've ever encountered. Detailed performance characteristics for Minuteman III circa 1985, including reliability statistics and Pk assessments.
S/o
@ThrustWR
&
@John_A_Ridge
for putting this on my radar
7/ A diversion into unclassified nuclear weapon principles, since I think it helps to understand. Plutonium weapons are assumed to be implosion type devices. A hollow sphere of Pu is *uniformly* compressed very fast into a critical mass by precise application of high explosives.
4/ Most familiar engineering materials have two or three relevant crystal structures depending on temperature and composition. Plutonium has *six* at normal pressure, plus a seventh at very high pressure. Worse, the densities are very different and several are "uncooperative".
@peck_oh
Unless we had advance warning, I guess, and just... shot the missiles down? This would be a weird thing to respond to, if you knew in advance that it was bluster. Can't look weak domestically, can't let the PRC think they can do this with no response, but if it's just bluster...
14/ Radiation damage is complicated and out of scope for this thread (go read a textbook, I recommend Gary Was' personally), but we can make some gross generalizations. Energetic particles (neutrons, heavy ions and alphas) can knock atoms out of their positions in a crystal.
9/ This problem was realized in mid-1944 as Manhattan Project scientists grappled with scatter in their density measurements. Early Pu alloy design was largely trial and error; by chance it was discovered that Ga, Al and several other elements stabilize the delta phase.
3/ How? Why? Let's zoom out for a moment. Actually we will zoom in, to a magnification of about one million times the naked eye. Now we can see the arrangement of the atoms in a piece of plutonium, what we call the crystal structure. And for plutonium it's a bit of a mess.
12/ Problem solved right? Add 2% gallium and we're off to the races. This was true for a while. During the Cold War we tested *constantly* (just over 1000 total) and warheads were recycled relatively often. Then History Ended(tm), and we stopped testing. And this happened.
@GravitysRa1nbow
personally cannot wait for the BRVTHER PEOPLVS of the PLA and US armed forces to unite against the common enemy: the field grade officer
@BeijingPalmer
Personally I think the position she's staking out is likelier to lead to Pelagianism. Christological heresies are so passé, let's get some ponerological heresies in the mix.
13/ Show of hands, what do radioactive materials do over time? They age. They self-irradiate, which damages the material at the atomic scale. These defects, plus decay heat, can cause phase changes (like a very slow heat treat). They transmute, changing the composition slightly.
10/ The effect is pronounced. The retention of the delta phase to room temp in plutonium-gallium alloys improves our casting quality, our solid state processing (rolling, forging, hot pressing etc), and the mechanical properties of the final part.
17/ And now an important nuance. See, for most of the Cold War we thought that that lovely delta phase in Pu-Ga was stable at room temperature. Actually (as the Russians knew before us), delta Pu-Ga is *meta*stable. With the right "push", it will transform to the alpha phase.
6/ The delta phase in pure plutonium only exists above ~310° Celsius, and is not usually retained at room temperature even with fast quenching. The large density increase going from delta to alpha also causes extensive microcracking. For any practical purpose, pure Pu won't do.
@BretDevereaux
@BeijingPalmer
And then the band of wandering threats to the state monopoly on violence emancipated the peasantry and came up with a land-rights policy that neither produced reactionary backlash from the former aristocracy nor perpetuated peasantry in all but name! And Aaron Sorkin clapped.
A reset in relations with Russia requires a reset in Russian behavior. We wasted years giving them something for nothing and came out with very little to show for it.
🚨🚨🇺🇸🇺🇦🇷🇺 Politico is told by Biden Admin officials that they fear allowing Ukraine to launch long-range strikes on Russia will prevent the US from normalizing relations with Moscow in the future!
This is a bombshell piece with a lot of details on Ukraine's ongoing efforts to
8/ What if you explosively compress a pit made of brittle material? Or one full of cracks? The uniformity suffers; in a worst case, you might have so much inconsistency that the weapon "fizzles" and only some of the Pu participates in criticality.
11/ Why gallium and not plutonium-aluminum? Aluminum has undesirable alpha-capture transmutation behavior. Aluminum captures alpha particles from Pu-239 decay: the Al-27+a-->P-30+n reaction kicks off an extra neutron, which can tip the neutron economy in Pu towards a fizzle.
@Matt_Costlow
Wen Ho Lee is a minorly infamous case within the weapons world - he was indicted but acquitted in '99 for selling nuclear weapons data to the PRC while he worked at LANL, as part of the "how did China get W88 info" debacle.
21/ Those defects affect the rate of diffusion in the material, which affects RIS behavior...see what I mean? Esteemed LANL metallurgist (and onetime lab director) Sig Hecker called plutonium "a physicist's dream and a metallurgist's nightmare" for a reason.
5/ "Uncooperative"? Crystals with low symmetry tend to be brittle, and indeed the alpha and beta phases of plutonium are normally brittle. Contrast with the face-centered cubic structure of the delta phase: very ductile, almost the same as aluminum in fact.
18/ At room temperature, the kinetics (rate) for this transformation are so slow that we've never seen it in real weapons material. But it *can* happen, and we don't fully know how this will play out as the oldest weapons in the stockpile approach 50 years old.
Engine performance scales with temperature and (usually) stresses on rotating parts, plus weight reduction. Overall system performance from military POV includes reliability, which is where established (US, some EU... really no one else) engines outcompete you beyond fairness.
@Support
You won't do anything about the mobs of terrorists, sanctions violating Russian armament suppliers, or your own boss' crippling amphetamine dependency but you have time for this? pls fix
15/ This damage produces lasting defects. Point defects are a missing atom or an atom where there shouldn't be one (vacancies and interstitials respectively). Dislocations are line defects; think of a line of point defects in a row.
I have to say I find it a little head-scratching that Jacobsen's book is the post the leading arms control advocates want to hang the movement's hat on. Its easily discredited factual inaccuracies and over-reliance on controversial figures like Ted Postol makes it an easy target.
Here’s another review of
@AnnieJacobsen
’s new book Nuclear War: A Scenario. Given how much coverage she’s getting - and how much time nuclear advocates are spending discrediting it - she has clearly hit a nerve about nuclear fears in our time.
Sorry but this is a pretty shit take. SpaceX could be revolutionizing launch infrastructure exactly as well as they currently are, while not flouting simple environmental protections. It is a conscious leadership decision to cut corners and act like they're above the law.
Shot: successful Starship launch, maybe the most impressive industrial accomplishment of the century, set to revolutionize humanity's relationship with space as it exponentially reduces the cost of launch
Chaser: NYT: but you broke a few dozen eggs!
20/ For instance, Pu self-heats by decay heat; Pu-238 enriched alloys heat more. We know that radiation-induced defects will anneal themselves out at some temperature dependent rate. Is the rate of defect generation and annihilation the same in enriched and weapons-grade Pu?
Making fun of these weirdos aside, I would love to know - is this a "bit" aimed at gullible Western 5th columnists, is it just bored social media trolling or is there a real hawkish youth cadre in the ranks? Are we gonna have to worry about PLA Curtis Lemay for the next 40 years?
16/ The generation and motion of these defects can cause chemical inhomogeneity on short scales (nanometers to microns), or "radiation-induced segregation". RIS in Pu causes some rejection of Ga into a Pu3Ga precipitate; drop the Ga content and the delta phase gets less stable.
If you're in your 20s-30s and your circle isn't discussing:
Intercritical annealing
Extended deterrence
The Third Offset
Conventional counterforce
Shock Hugoniots
Proliferated space constellations
Electron microscopy
You need to get a new circle. Your network is your net worth.
The tweet in question was pretty obnoxious & this whole affair encapsulates a trend I've noticed for years (and my mentors have noticed for decades before). The anti nuclear crowd can say whatever nasty, slanderous things they like, but if we say one word back we're the assholes.
Quick disclaimer:
I make it a point not to be disrespectful or get personal first. However, I also believe in matching the energy I receive.
If you accuse the employees of NATO's Nuclear Policy Directorate of being into "planning war crimes and killing millions," I feel
Also since today's ✨ discourse ✨ is about the lack of civility lately in Defense Twitter, I think it's very funny that Mike of all people gets on his high horse about how rude the college kiddos are when he's basically Patient Zero for being abrasive for the sake of it.
25/ We don't have a solid handle on how bubbles change the mechanical behavior yet. From the accel'd aging study we know there is some strengthening (Δσ_ys up to 120 MPa!) from aging but mechanisms unclear. Can imagine consequences for M&S etc. Hit thread limit, pt 2 to follow...
23/ The alpha decay of Pu-239 to U-235 and a helium nucleus fills the lattice with He atoms. Helium has near zero solubility in solid metals, so it tends to cluster and eventually form small bubbles. In conjunction with vacancy defects, this causes the metal to swell.
On my knees begging and pleading conventional force understanders to have nuke opinions even a quarter as smart as their conventional force opinions (this is not one of them)
broke: gravity bomb B61-13 are destabilizing because something something Obama promised
woke: gravity bomb B61-13 are destabilizing because the lack of standoff decreases the survivability of the NATO sharing DCA fleet and thereby undermines our extended deterrent credibility
The US Pentagon pursuing a type of nuclear weapon called a gravity bomb "is a troubling development for many reasons," writes Stephen Young of
@UCSUSA
.
Read more below:
19/ An accelerated aging study with 238-enriched Pu at LLNL suggests that we should be okay out to the 90 year mark. Are the accelerated aging studies representative of aging in real conditions? I'm not so sure. There are so many factors to disentangle. So many coupled behaviors.
Advanced superalloys for strength and long lifespan at high temperature require advanced processing. Those single crystal castings are made by, last I counted, 10ish countries. (🇹🇷&🇮🇳 aren't quite there). The specialized furnaces for the castings? 4 or 5 countries.
24/ How much swelling? A few tenths of a percent, at most. The model estimates below jive with the LLNL accelerated aging experiment. Not a huge amount, but as you can see the upper bound runs away with time and could become trouble in the future. (It does eventually saturate.)
22/ Fortunately, it looks like the composition changes from nuclear transmutation don't really affect the chemical stability of the material on any time scale we've measured yet. But there is one composition effect that really does matter: helium generation.
Breaking exclusive: The US and Germany foiled a Russian plot to assassinate the chief executive of the powerful German arms manufacturer Rheinmetall, which has been producing shells and equipment for Ukraine. with
@KatieBoLillis
@fpleitgenCNN
@QuincyInst
Whose victory terms do you favor? I mean we all already know where your paychecks come from, but let's have some honesty (and frankly, some long overdue FARA registrations.)
Reading Joshi's snippets I was like ???? But cracking open the full report I actually agree. The part this quote elides is that they're not comparing targets on an apples to apples basis. The point is that precision conventional attack can kill targets of strategic value...(1/x)
This is fascinating: "Advanced conventional warfare [i.e. precision] dramatically expands the “crossfade” domain wherein conventional strikes may have a greater risk of triggering general nuclear war than nuclear strikes."