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"Nuclear Archaeology" Inspires Replica of Hiroshima's Little Boy
James Cho writes "Through a decade of painstaking reverse engineering, trucker John Coster-Mullen built the first accurate replica of the Hiroshima bomb. His work yielded a new history of the first nukes, 'Atom Bombs: The Top Secret Inside Story of Little Boy and Fat Man,' with historian Robert Norris saying, 'Nothing else in the Manhattan Project literature comes close.' Philip Morrison, one of the physicists who helped invent the bomb, deemed it 'a remarkable job.'"
*BOOM*
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How soon until homeland security shows up accusing him of terrorism?
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The guy went through declassified government documents to gather all the information he could find (including design information), and went from there. I don't think this is anything like reverse engineering.
If he "reverse engineered" the bomb, wouldn't it mean he put the design together based on blast data from known explosions of this particular device?
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While many people may exclaim that this information is 'dangerous' to be released in the public domain let me remind you of a few small details.
1) ANY high-school/college student should be able to tell you what the critical mass of U235/238 is.
2) Most handymen should be able to make atleast ONE method of creating a critical mass pile.
3) It takes a GOVERNMENT to build multiple copies and revisions and tests to make it bigger/better.
This information does not mean "the terrorists can now make a bomb!" This changes NOTHING that hasn't been known for 50+ years. I would rather live in a society that does not suffer a knee-jerk reaction everytime something unusual is expressed. If anybody knows if this place exists, let me know; I'll start packing.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
This is yet another example of things which, eight years ago, might have seemed merely odd, rather than somewhat unsettling.
How quaint the 20th Century already seems.
Mmmmmm... Bold, yet refreshing!
A working replica would be dangerous and surely illegal.
If I had a working replica of a nuclear bomb in my basement, I don't think I would give a rat's ass about whether it was dangerous or illegal.
If I did have a nuclear bomb, I would not have a problem.
Some other folks would have a problem.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
The Hiroshima bomb was a very simple "gun" design. Plenty of published info on it. It used a navy gun barrel cut down to size, a U235 doughnut target, a polonium initiator, and a U235 projectile. Mighty simple. Any chopper shop could build one, with the exception of getting the Polonium and U235.
This design was abandoned as it had many drawbacks-- it used about 8 times more U235 than absolutely necessary, there was a 7% chance of a fizzle, and there was no way to make it safe.
But it had the advantage that it was dead-simple and guaranteed to work, well 93% of the time.
Now if he made a replica of Fat Man, that would really be something.
There are a lot of stories that appear on /. in which I have absolutely no interest. (The same could be said by practically anyone here.) So you know what I do when one of those stories comes up on the front page? I don't click on it. Easy, simple solution -- let the people who do care about that particular story talk about it, and go find something I care about to read and comment on instead. Everybody wins. It's not that hard a concept to grasp.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
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One thing to keep in mind when you read statement such as "Destroy R. Worlds, former Director of Bomb Design at Los Alamos, said of Joe Amateur's work 'That's very well-done'" is this: reading between the lines of many interviews, articles, and books about and by former weaponeers they give out a lot of misleading, and/or misdirecting, information about how _exactly_ devices are built. They talk openly about the general principles and their scientific and political implications, but when the discussion/interview/chapter turns to the actual details of design, well, the replies turn a bit fuzzy or clever. I suspect that either by explicit training or shared values they give away very little and much of what they say would deliberately lead anyone following down the wrong path.
sPh
From the article: "Actually, he said, nothing about the bomb is secret. He smiled and added, 'The secret of the atomic bomb is how easy they are to make.'"
Actually, it is a pair of nested cylinders, and the rationale behind it is brilliant.
To get the biggest possible boom, you want to bring together the largest possible mass of fissile material. Problem: if you accumulate too large a mass, it starts a chain reaction on its own.
But if you form that mass into a ring shape, and make the hole in the ring large enough, you create extra surface area for neutrons to escape, but the gap is too big for them to have sufficient energy to split an atom on the other side of the gap.
For a given outer diameter (fixed by the inner diameter of the bomb casing) the maximum mass of fissile material is obtained with a cylinder whose height is determined by the mass on the "side" of the cylinder nox exceeding criticality. A mating cone shape results in a smaller usuable mass.
So why make the projectile hollow instead of shooting a slug into a hollow target? Because the sides of the gun barrel constrain the movement of the projectile and ensure that the mating surfaces are aligned.
It's actually, for such a "crude" design, brilliant engineering.
DG
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