Genro wrote:“ I would really like to see a bomb physicist do a calculation----“ 18 Dec 2003 04:02
Who wrote that ?
With out at least some comprehension of science this sort of rubbish gets printed and believed by many.
‘Gauges at the top and bottom of the column, intended to measure a difference in pressure - showing that separation was taking place - indicated no difference at all.’
The Making of the Atomic Bomb. Richard Rhodes.
The less said about Wilcox’s books the better they are considered a joke in physics.
Here is a thought, if Japan had had the industrial and financial muscle that America had at the time, the atomic bomb would probably have been made in half the time and at half the cost and with the need of brains from Europe.
Do you ever just, you know, answer a direct question, directly? You should try it sometime, it's quite refreshing.
As near as I can determine---and it's difficult with you and your evident passive aggression, because most of what you say comes out sideways---your repeated "novelist" comment is intended as a smear against Wilcox. Which, again, has absolutely zero---nothing whatosever---to do with the issue that was being discussed and about which I asked you: YOUR STATEMENT, which YOU CLAIM was directly from Nishina, that he had achieved 10% enrichment in the small quantities of uranium with which he was working at the Riken.
Seeing as how you seem to identify quite strongly with Japan, my guess is that you are echoing a comment made ca. 1985 by a prominent Japanese citizen in response to Wilcox's book: "He's just a novelist". If this is what you think, here's a suggestion for you: Why don't you just say so in so many words, and then list for us the specific passages in Secret War
that you believe "...are considered a joke in physics" and why? Along the way maybe you'll also tell us why Wilcox is wrong in other ways, ie, journalistically and historically. And I'll go a step further, not that I expect a straight answer from you: have you ever actually read Secret War
? If I had to guess, my guess would be that you have not. Most of the mouthiest critics of Wilcox whom I have encountered have never read his book, a truly curious phenomenon if there ever was one. But, maybe you're the exception to this trend.
To answer your question directly, a courtesy that you do not return to me, here is my entire quote from 12 years ago:
"I would really like to see a bomb physicist do a calculation of the explosive force of a fission bomb with a slower compression speed, so we would know once and for all what kind of yield the Japanese weapon would actually have had---again, assuming they did not do any further refinement of their warhead design after 1943, an unlikely proposition, it seems to me. Unless the Nishina interview took place in 1943 and the warhead design was done later; the Japan Times article does not specify this."
As I have already stated repeatedly, for public consumption, on the internet---both in this thread and elsewhere---and under my own name, I was making that statement based on the text of two (2) articles I used as sources for my article. These were the BBC News website piece, "Atomic Plans Returned to Japan" and the Japan Times piece, "Japan's A-Bomb Goal Still A Long Way off in '45". Both of these, but particularly the BBC article, claimed that the information in the Kuroda Papers was sufficiently detailed to constitute a bomb design; the BBC piece outright called this a "blueprint" and stated that the result would have been "a weaker weapon". While I am---obviously---not a nuclear physicist, I do know that in a gun type weapon it is necessary to ram the two subcritical pieces of fissile material together at a sufficiently high speed to ensure a detonation and not a fizzle. The Japan Times piece said that Nishina had made a calculation error such that he thought the two uranium components would detonate if they came together in 1/20th to 1/30th of a second and not the 1/200th to 1/300th that is really necessary. Alright, you are claiming not only that this is incorrect from an engineering standpoint but also, apparently, that the Kuroda Papers don't say that at all, and that Nishina did not make the calculation error that the article said he did. I'm assuming you can see for yourself that I was relying on these articles for accuracy and that if they are not accurate in these details, then obviously and as a direct result, some of what I wrote in my piece (and elsewhere) is mistaken as well.
In short, if I am in fact mistaken in what I wrote because these two articles are themselves mistaken, hey, let's get it straight so that the historical record will be set straight. That's the only agenda I have here.
Now, let's try a final time to put some direct questions to you to see if you will give straight answers.
QUESTION ONE: Did Nishina, in fact, achieve 10% enrichment, or not? Yes, or no?
I repeat: You state upthread that it was Yoshio Nishina himself who stated, in the Tonizo Report(s), that he had achieved 10% enrichment in small quantities of uranium at his Riken thermal diffusion pilot plant. And yet, in the post immediately above this one, you quote Richard Rhodes (one of the very few American writers who has ever seriously investigated the WWII Japanese atomic bomb projects) as stating that Nishina's apparatus did not achieve ANY enrichment. At what point was Nishina saying (according to you) that he HAD achieved 10% enrichment, and at what point is Rhodes saying he HAD NOT? At the end of the Riken project in April 1945? When Nishina was kicked to the curb in 1944? When? And which of these two contradictory statements is correct, and how do you know that?
QUESTION TWO: Do you believe that Japan was in fact trying to build atomic bombs in WWII? Yes, or no?
QUESTION THREE: Since what I wrote on the subject was "rubbish", why don't you, the presumed expert, enlighten us all on the REAL bomb physics of a gun-type atomic fission bomb?
Just how fast do the two subcritical HEU pieces have to come together in order to detonate? Is there a specific threshold that will always result in a fizzle if the speed of the bullet into the target is below that threshold, or do other factors such as the purity of the HEU and the size and shape of the target affect the potential detonation?
Here is a thought, if Japan had had the industrial and financial muscle that America had at the time, the atomic bomb would probably have been made in half the time and at half the cost and with (sic) the need of brains from Europe.
QUESTION FOUR: I presume you meant to say, "...WITHOUT the need of brains from Europe"?
As though Japanese science developed completely independently of Europe. Oh, wait: it didn't? Oh, that's right. Nishina studied under Niels Bohr, and Arakatsu under Albert Einstein. Oops. Nishina also benefited greatly from his relationship with the American physicist Ernest Lawrence, who despite being edgy-muh-kated entirely in inferior US institutions somehow managed to, you know, invent the cyclotron. But he was the exception in terms of his formal studies. The fact is, nearly every
major nuclear weapons physicist in the world of that era was educated in part or in whole in Germany. But you just couldn't help yourself, and had to get in another gratuitous anti-American dig. Jolly good for you, Genro. By the way, the US - Allied effort under Oppenheimer would almost certainly have been able to build its gun-type U-235 bomb, Little Boy, with little or no help from exiled continental European scientists. Where those people were of the most direct and comprehensive aid to the Americans was in the Fat Man plutonium implosion bomb. Like the US, Japan was also trying to build the much less sophisticated gun-type weapon, but nevertheless their science---such is your clear and petulant implication---was superior to the US. It just wasn't fair, I guess, that the Americans---drat the luck!!!---just happened to have all that industrial capacity and manufacturing power lying around, and of course none of that had anything to do with their success, you see. They just dumb-lucked their way into an atomic bomb, since we all know, don't we, Precious, that all Americans are idiots.
Some are, of course. But not in this case.