There was an article referenced via Slashdot that mentioned that the USA forgot how to make “Fogbank”. Which is a material people can only basically speculate about.
Any ways, here are some articles about it and gives an idea of what obviously needs to be kept secret when it comes to weapons of this magnitude:
Also, As Bijou Drains has stated:
As I was once in the military I was involved in certain actions. Despite the fact that these actions were televised in real-time or that they are on Wikipedia… “I can not confirm or deny.”
The initiator provides a little squirt of neutrons at the moment the core reaches critical mass to kick off the chain reaction. Without an initiator a stray neutron from the environment will eventually start the reaction, but since you have a very tiny window of time before the whole assembly blows itself apart, you want to make sure the neutron cascade begins at exactly the right moment.
And, yes, I believe that initiator design is one of the things about making a bomb that is highly classified.
From the article in the NY Times this morning, he also offered to show them how to build a reactor to produce weapons grade plutonium. Reactors designed to produce plutonium for weapons are different than power reactors, because weapons grade plutonium needs to be almost pure PU-239. If the reaction is allowed to run too long, then the PU-239 picks up additional neutrons and becomes Pu-240, Pu-241 etc. To much contamination and it isn’t suitable for a bomb anymore. Weapons reactors have to shut down frequently to harvest the Pu-239.
Also note there is a lot of secret data on storing nuclear bombs. Apparently, due to the radioactivity, they mess themselves up in time. This is not an issue if you build one then blow it up relatively quickly but it is an issue if you plan to store the thing for years then hope to take it out of storage some years later and expect it to work.
The US and a few others know the ins-and-outs of this well from long experience. Others would have to find out the hard way too unless they stole the info so it is secret.
I used to work at the Department of Energy’s Mound Facility, where we built components for nuclear bombs. I now work for the Department of Defense, and some of my work is for MMIII systems and nuclear subs.
For the most part, the fundamental science and physics are not secret. The actual designs are we want to protect. We have spent billions of dollars developing these systems, and we don’t want this information to get in the hands of our enemies. Even seemingly mundane things like the dimensions of a copper wire are often classified.
As I’ve said before, the most engineered device ever built is a nuclear bomb. Few people can comprehend the amount of research, development, and testing that has been expended in this area.
The Wiki page also says that his research consisted of only publically available text but iirc he got a critical bit of info from a 3M technition regarding a material to intiate the implosion.
IIRC he was calling chemical manufacturers looking for explosives for an unspecified purpose, and one of the companies (maybe 3M) bragged that they made the explosives for US nuclear weapons.
I think I could probably comprehend it. I might be surprised and impressed, but even if it were expressed in scientific notation I think the figure would be understood.
Many other countries probably have the scientists and engineers to figure the details out eventually if they have the determination, time, and money… but wouldn’t it be a lot cheaper, faster, and easier to steal it?
How about using some reference material? think back to your college days, how often when working on a difficult problem would you have killed for a peak at the solution manual, even though you would have worked it out eventually?
Another thought is that, while the world’s elite probably have the knowledge, there are plenty of dangerous groups out there that don’t (and shouldn’t).
But no one today except maybe terrorist amateurs would bother with a multiton, low-yield fission device, if only because of how hard it would be to deliver. A would-be nuclear power would want something that can be delivered by missile or fighter-bomber. For another thing, if you can independently produce the fissionable material and solve the problems of building even a crude device, then you’ve already made enemies of the powers trying to prevent nuclear proliferation and you both need a stronger deterrent and have already done 3/4 of the work in producing a more sophisticated device.
In terms of miniaturized electronics, super-materials, and construction techniques, no. But they probably would have benefited from good computers. Many of the scientists in the Manahattan Project spent most of their time doing a lot of complicated math, with pencil, paper, and sliderules. The first plutonium bomb was an detonated with an implosion from conventional explosives, and there were questions about the reliability of the ignition process based on the available technology. The process of seperating Uranium and Plutonium isotopes for was difficult and required numerous machines and thousands of people to produce enough material for the first three bombs produced. But that part is still difficult, and one of the reasons that it is difficult to conceal the production of fissionable materials by nuclear wannabe countries.
The discussion reminds of one of the nuclear physicists I used to work with. He was a veteran of the Manhattan Project, and still did government research. He received instructions once for destroying some of the documents he kept in a government approved safe. He had a choice of several methods, but chose burning. He dumped the documents in a metal office wastebasket, took them out to the loading dock at the back of the building and ignited them. After following instructions to insure that the all the paper had been consumed, and the ashes stirred, he recruited help to roll a dumpster over to the loading dock, and kicked the wastebasket over to dump the contents. Apparently the instructions didn’t mention dousing the ashes with water, or waiting until all the embers were had gone cold. The contents of the dumpster caught on fire, and drew a visit from the fire department. During this time, he had left his safe open, and just like Feynman had described in his memoirs about Los Alamos, the dial had been left on the last number of the combination. I could have used that opportunity to start stealing nuclear secrets (like the ones still in the open safe even without figuring out the combination), but I was too busy laughing about the fire.
