> The source of the error, Coster-Mullen recognized, was an assumption that every (male) researcher who studied the subject had made about the relation between projectile and target. These scholars had apparently been unable to conceive of an arrangement other than a “missionary position” bomb, in which a solid male projectile penetrated a vessel-like female target. But Coster-Mullen realized that a female-superior arrangement—in which a hollow projectile slammed down on top of a stationary cylinder of highly enriched uranium—yielded the correct size and mass.
Does anyone understand what point is being made here? I don't understand how which piece is the projectile would make a difference in the overall size/geometry. All else equal, I would think it would be easier if the lighter, simpler piece were the projectile. Accelerating a cone/cylinder without breaking/damaging it seems a lot easier than accelerating the complementary shape.
Then again, I'm male, so I guess I'm just not capable of imagining the "female superior" design...
"shooting a mass of uranium down a barrel into another mass of uranium to form a supercritical mass."
My guess is that the person who first said that didn't intend for the metaphor/description to be taken quite as literally as everyone ended up taking it. (Or they meant to mislead.)
Hypothetically, if you read "into" as crash/collision and not "in to"/inside of, you start to see how a generic description could be ambiguous. Run this (or a similar story) through a few iterations of the telephone game and draft revisions by journalists/editors (that somehow all seem to graduate without ever taking a single sophomore level technical writing course), and a description becomes a misunderstood metaphor becomes a fact. Somewhere along the way, the word "bullet" gets thrown in, and then no one "un-see" the visual.
That's my take. That and the author of tfa is trying way too hard to make a big a deal out of it being a "gendered" thing, when it's not.
This is the problem. Why are they trying to shoehorn male or female dominance here? The whole thing is not only unpleasant to read, but also confusing.
A cylindrical barrel is being fit over a fixed centre pin, rather than a pin inserted into a barrel.
Makes sense when you realise that the moving component is inside of a similarly cylindrical bomb casing and that no fancy and complicated sabot and/or rail arrangement are required to keep it aligned and centered with the fixed pin.
Most DC charging plugs work the same way for the same reason.
With the gun-type bomb, suppose the final critical assembly has a 2"-diameter "male" part in a 3"-diameter formerly hollow ball. If the 2"-diameter "male" part were in a 3"-diameter barrel then, indeed, some mechanism would be needed to stabilize it. But I see no fundamental reason that the barrel needs to be 3" in diameter -- couldn't the "male" part just as easily be a projectile in a narrower barrel?
(I made up the 2" and 3" numbers.)
On the breech end, you insert a large "hollow point" slug of the rest of the critical mass. (an empty ice cream cone, open end first) The hole in the middle helps keep the neutron flux low, for now. Following this slug is the cordite explosive which will push the slug down the barrel at great speed.
The charge is set off, the slug rushes down the barrel, and gets wedged against the sides, in the process it breaks the neutron initiator, crushing it, and setting off a rush of neutrons, into the now complete, supercritical mass. The temperatures and pressures in the gun barrel begin to rise exponentially as the chain reaction takes off, within microseconds it is just the inertia of the barrel that helps keep things in place, the melting and even vaporization temperatures have been passed, but the contents have yet to disassemble completely, the chain reaction reaches its peak as the temperature climbs past 50,000,000 degrees, and then everything spreads outwards, 7/10ths of a gram of mass (the weight of about 3 rain drops) has been converted to energy, yielding the explosive yield equivalent of 15,000 tons of TNT.
If I want good prose, I read the the Cabinet Magazine which is far superior in writing, curtness and straightforwardness while not affecting the charming and poetical aspects of writing.
Furthermore, New Yorker has inappropriate political and social undertones that is very offputting - they don't belong here and but its beat into place. Any informed reader would see through it. If you enjoy that sort of a thing, great but it's not my thing even if I agree with the underlying message.
Just look at the title, manages to demean and belittle an entire industry that is entirely required for a functioning economy and society.
Y'all wonder why blue collar America thinks we're stuck up entitled pricks? Maybe it's because we are.
What is not often pointed out is that he managed to reason his way into understanding to various points, and the process of doing so revealed information that is otherwise still classified.
As a teen in Las Vegas in the 70's we could "feel" the underground tests, and I was always fascinated by the test site. I even managed to snag a summer internship there (inadvertently[1]) when I was in college.
I know folks who worked at Sandia and Lawrence Livermore who found the book fairly remarkable.
[1] The job offer was for the contractor facility in Las Vegas but my clearance had not come through so they bused me to an unclassified facility at the test site to do the work.
For example, even if "everyone" knows how fast an SR-71 can fly, that number is still classified. And if you have a clearance you can't talk about it because it is classified and you know its classified. So it is illegal for you to talk about its top speed. This is another good reason to avoid getting a government clearance if it can be avoided.
https://en.wikipedia.org/wiki/Demon_core
For me, it shows how hard it is to internalize dangers of a technology one is working with daily. How hard it is to trade convenience for security.
He binds and ships them himself as far as I can tell.
I thought the plutonium core was one piece and the explosives compressed it, making the same mass critical due to increased density.
While other responses have explained it was not, I thought I should point out that any sphere, even if a single piece, will always have at least two hemispheres, iow, a sphere having two hemispheres does not imply it is more than one piece. When you leaned of the Earth's northern and southern hemispheres, did you wonder if it was more than one piece?
