# Did Japan have an Atomic Bomb? **URL:** \ **Category:** Factual Questions\ **Created:** [February 14, 2014, 6:42pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354 "2014-02-14T18:42:45Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [February 15, 2014, 1:38am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/41 "2014-02-15T01:38:38Z")
> [@carnivorousplant](#): > > A guy nearly did it with a screwdriver. Tickling the dragon’s tail. > Slammed his hand between the two pieces of U-235 to keep them apart, and died of radiation poisoning. Plutonium, [actually](http://en.wikipedia.org/wiki/Tickling_the_dragon%27s_tail). And it was two guys, in two separate but roughly similar incidents. But that was just “criticality,” releasing a burst of radiation, and no explosive power. A far cry from sufficient to destroy a city. Fun fact regarding the scale of the Manhattan Project: Just _one_ of its sites, Oak Ridge, used _one seventh of the electricity produced in the United States_. Given that Japan’s “Index of War Production” was about 1/20th that of the US during the war, it’s doubtful they could have built a working bomb if we’d handed them the plans. The Manhattan Project was a gargantuan undertaking in every sense. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 15, 2014, 2:22am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/42 "2014-02-15T02:22:37Z")
> [@Sailboat](#): > > Plutonium, [actually](http://en.wikipedia.org/wiki/Tickling_the_dragon%27s_tail). And it was two guys, in two separate but roughly similar incidents. But that was just “criticality,” releasing a burst of radiation, and no explosive power. A far cry from sufficient to destroy a city. > > Fun fact regarding the scale of the Manhattan Project: Just _one_ of its sites, Oak Ridge, used _one seventh of the electricity produced in the United States_. Thanks, Sailboat. Something my Father told me when I was a kid. He took us on the great American vacation, from Arkansas to the Grand Canyon, and we went sideways to Oak Ridge in the 1960s. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [February 15, 2014, 2:33am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/43 "2014-02-15T02:33:29Z")
In August 1945, most of the German atom bomb program scientists were in American custody. When they were told about the Hiroshima bombing, they were dumbfounded. Their estimate was that Germany had been at least five years from developing a working bomb and they had assumed they were ahead of the Americas. Finding out America was so far ahead of Germany was such a surprise that their initial assumption was that it was a trick. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 15, 2014, 2:44am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/44 "2014-02-15T02:44:57Z")
> [@Little\_Nemo](#): > > In August 1945, most of the German atom bomb program scientists were in American custody. When they were told about the Hiroshima bombing, they were dumbfounded. Their estimate was that Germany had been at least five years from developing a working bomb and they had assumed they were ahead of the Americas. Finding out America was so far ahead of Germany was such a surprise that their initial assumption was that it was a trick. That was Heisenberg’s opinion. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [February 15, 2014, 3:03am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/45 "2014-02-15T03:03:24Z")
> [@carnivorousplant](#): > > That was Heisenberg’s opinion. Well, he was uncertain in principle… ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 15, 2014, 3:36am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/46 "2014-02-15T03:36:02Z")
> [@GIGObuster](#): > > Well, he was uncertain in principle… And this man wins the thread! 🙂 ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 15, 2014, 4:07am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/47 "2014-02-15T04:07:14Z")
Heisenberg was also the only scientist of note who even stayed in Germany. Not only were all the others in Allied custody, most of them actually defected, and were working on the American project. After the war, Heisenberg claimed to have been deliberately sabotaging the German project. No way to know if he was telling the truth, of course, but the Germans were far enough behind that it’s at least plausible. ---
**Author:** ![GythaOgg](https://avatars.discourse-cdn.com/v4/letter/g/49beb7/32.png) [@GythaOgg](https://boards.straightdope.com/u/GythaOgg)\ **Post date:** [February 15, 2014, 4:23am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/48 "2014-02-15T04:23:37Z")
> [@Sailboat](#): > > Plutonium, [actually](http://en.wikipedia.org/wiki/Tickling_the_dragon%27s_tail). And it was two guys, in two separate but roughly similar incidents. But that was just “criticality,” releasing a burst of radiation, and no explosive power. A far cry from sufficient to destroy a city. > > Fun fact regarding the scale of the Manhattan Project: Just _one_ of its sites, Oak Ridge, used _one seventh of the electricity produced in the United States_. > > Given that Japan’s “Index of War Production” was about 1/20th that of the US during the war, it’s doubtful they could have built a working bomb if we’d handed them the plans. The Manhattan Project was a gargantuan undertaking in every sense. Also, IIRC, the Manhattan Project also used \*practically all the silver in the United States Treasury \*- for the electromagnets at Oak Ridge. It was a MASSIVE undertaking of the sort it is hard to grasp even today. ---
**Author:** ![Keyzer\_Soza](https://avatars.discourse-cdn.com/v4/letter/k/a587f6/32.png) [@Keyzer\_Soza](https://boards.straightdope.com/u/Keyzer_Soza)\ **Post date:** [February 15, 2014, 4:38am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/49 "2014-02-15T04:38:25Z")
What a stupid fucking question. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [February 15, 2014, 5:18am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/50 "2014-02-15T05:18:47Z")
> [@Amateur\_Barbarian](#): > > While the understanding of how atomic weapons work is now widespread, it was NOT prior to the work of the 1940s. In fact, it has been postulated that the atom bomb was invented/developed only once, and all other iterations are copies of that design. Where the critical specifics weren’t passed along directly (by spies, to the Soviets, or by us, to England) it took only modest effort to fill in the details. Twice. The uranium and plutonium devices were of very different design and principle. > [@Amateur\_Barbarian](#): > > Good place to add my favorite comment from Luis Alvarez, which pops into my mind every time there’s a news story about the possibility of \*\*_DUN-DUN-DUNNNNNN!_ Plutonium! \*\*in the hands of terrorists or the like: > > “Detonating U-235 is a matter of dropping one chunk of it onto another. Detonating plutonium is one of the most difficult technical processes I know.” Herein lies the difference as I understand it. The uranium bomb is easy to make work if you’ve got the U-235, which requires massive efforts and zillions of centrifuges working simultaneously to make progress. This is what the gov’t of Iran has been up to. The plutonium bomb is quicker to get the fissile material (I have no idea how it is done), but damn near impossible to get it to explode correctly, which requires very precise engineering work that works correctly while hurtling toward the ground. The H bomb is even more complex, requiring (and again, I don’t know) at least one plutonium bomb (and probably a minimum of two) to explode in such a way as to force tritium (a kind of heavy hydrogen) to smush together at incredible speed and force. The first such device was the size of a house. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [February 15, 2014, 7:03am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/51 "2014-02-15T07:03:35Z")
**Moderator Warning** > [@Keyzer\_Soza](#): > > What a stupid fucking question. This is an official warning. Threadshitting is not permitted here. The next time you feel an urge to post something like this, either keep it to yourself or take it to the pit. ---
**Author:** ![Ranger\_Jeff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranger_jeff/32/2065_2.png) [@Ranger\_Jeff](https://boards.straightdope.com/u/Ranger_Jeff)\ **Post date:** [February 15, 2014, 8:59am UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/52 "2014-02-15T08:59:52Z")
The Kriegsmarine’s U-234’s last mission was to deliver some uranium oxide to Japan. It could have been used as part of a dirty bomb. [http://en.wikipedia.org/wiki/German\_submarine\_U-234](http://en.wikipedia.org/wiki/German_submarine_U-234) ---
**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\ **Post date:** [February 15, 2014, 3:37pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/53 "2014-02-15T15:37:10Z")
The rumours about a Japanese bomb detonation in Konan, Korea, possibly came about due to its role in the production of heavy water, which the US occupiers were unable to verify as the Soviets got there first. As to having a uranium bomb, [this](http://books.google.co.uk/books?id=MwD44jnjmmsC&pg=PA281&lpg=PA281&dq=japan+heavy+water&source=bl&ots=QSFVEBc_25&sig=hzuasoUAqb9yxl7JtpBAWDOSc24&hl=en&sa=X&ei=-YX_Up-xO8WthQeywYGYAQ&ved=0CFsQ6AEwBw#v=onepage&q=japan%20heavy%20water&f=false) book sums up Japanese progress towards it as _“…one failed and one uncompleted isotope separation experiment, a few vials of uranium hexafluoride, a sliver of metallic uranium and a few theoretical papers. No attempt was made to assemble a uranium pile.”_ A far cry from what fruits the Manhattan Project bore. The wiki on the [Japanese nuclear program](http://en.wikipedia.org/wiki/Japanese_nuclear_weapon_program#World_War_II) also quotes the above source on a Japanese Naval report;\* “It concluded in a report that while an atomic bomb was, in principle, feasible,\* “it would probably be difficult even for the United States to realize the application of atomic power during the war”.\* This caused the Navy to lose interest and to concentrate instead on research into radar.[11]”\* Kinda misjudged that one, lads. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [February 15, 2014, 3:55pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/54 "2014-02-15T15:55:44Z")
> [@Mr.Kobayashi](#): > > Kinda misjudged that one, lads. Nimitz made up for lost time, though. 🙂 ---
**Author:** ![cckerberos](https://avatars.discourse-cdn.com/v4/letter/c/f0a364/32.png) [@cckerberos](https://boards.straightdope.com/u/cckerberos)\ **Post date:** [February 15, 2014, 4:25pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/55 "2014-02-15T16:25:22Z")
> [@Mr.Kobayashi](#): > > Kinda misjudged that one, lads. Not at all 🙂 After all, it _was_ “difficult even for the United States” to create a bomb. And given their resources, radar was probably a much better place on which the Japanese navy to concentrate its efforts. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [February 15, 2014, 5:57pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/56 "2014-02-15T17:57:32Z")
> [@cckerberos](#): > > Not at all 🙂 > > After all, it _was_ “difficult even for the United States” to create a bomb. And given their resources, radar was probably a much better place on which the Japanese navy to concentrate its efforts. Yamamoto was probably one of the few Japanese general staff to have a good idea how many orders of magnitude the US industrial capacity eclipsed that of Japan, and even he may have underestimated the US capacity for war, his estimate having not included the US making Germany the first priority. The US wound up defeating Japan as a definite second priority to defeating Germany within a few months of defeating Germany. > [@Ranger\_Jeff](#): > > The Kriegsmarine’s U-234’s last mission was to deliver some uranium oxide to Japan. It could have been used as part of a dirty bomb. > > [http://en.wikipedia.org/wiki/German\_submarine\_U-234](http://en.wikipedia.org/wiki/German_submarine_U-234) This was doomed to fail as the submarine should have been named the U-235. One proton off and the whole project sinks. ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 15, 2014, 6:03pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/57 "2014-02-15T18:03:49Z")
> [@The\_Second\_Stone](#): > > Twice. The uranium and plutonium devices were of very different design and principle. I concede the point, but it’s like the difference between a piston engine and a Wankel rotary… exactly the same effect at the core (heh heh) of each. Point being that there is no evidence that anyone, not even the Soviets, independently re-invented any part of the process. The atom bomb was invented once (for certain double values of once) an once only. The Soviets may have done more genuine “invention” in creating their thermonuclear weapons, starting with no more than evidence that it could be done. ---
**Author:** ![cckerberos](https://avatars.discourse-cdn.com/v4/letter/c/f0a364/32.png) [@cckerberos](https://boards.straightdope.com/u/cckerberos)\ **Post date:** [February 15, 2014, 6:21pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/58 "2014-02-15T18:21:37Z")
> [@The\_Second\_Stone](#): > > Yamamoto was probably one of the few Japanese general staff to have a good idea how many orders of magnitude the US industrial capacity eclipsed that of Japan, and even he may have underestimated the US capacity for war, his estimate having not included the US making Germany the first priority. The US wound up defeating Japan as a definite second priority to defeating Germany within a few months of defeating Germany. I don’t know about that… I think that Japanese overconfidence in the lead up to Pearl Harbor gets highly exaggerated. Most of the general staff were aware that Japan didn’t really have much of a chance. They decided to go to war not because they thought they could win, but because they viewed fighting and losing as preferable to just submitting. ---
**Author:** ![The\_Second\_Stone](https://avatars.discourse-cdn.com/v4/letter/t/bbe5ce/32.png) [@The\_Second\_Stone](https://boards.straightdope.com/u/The_Second_Stone)\ **Post date:** [February 15, 2014, 6:50pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/59 "2014-02-15T18:50:22Z")
> [@Amateur\_Barbarian](#): > > I concede the point, but it’s like the difference between a piston engine and a Wankel rotary… exactly the same effect at the core (heh heh) of each. > > Point being that there is no evidence that anyone, not even the Soviets, independently re-invented any part of the process. The atom bomb was invented once (for certain double values of once) an once only. > > The Soviets may have done more genuine “invention” in creating their thermonuclear weapons, starting with no more than evidence that it could be done. think more of the difference between a piston engine and a jet engine. The plutonium device requires that multiple explosive charges go off at a very precise time in a very precise way. The uranium device requires you shoot one uranium charge down a barrel at another charge, which is comparatively simple. The builders were so confident the uranium method would work they didn’t test it, and scientists and engineers love to test stuff. Confidence and uranium 235 is very hard to come by and refine. ---
**Author:** ![Philliam](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/philliam/32/3011_2.png) [@Philliam](https://boards.straightdope.com/u/Philliam)\ **Post date:** [February 15, 2014, 7:07pm UTC](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354/60 "2014-02-15T19:07:36Z")
For those interested in the subject in depth (also addressing most of the questions asked here), try: > **[The Making of the Atomic Bomb](https://en.wikipedia.org/wiki/The_Making_of_the_Atomic_Bomb)** > > The Making of the Atomic Bomb is a contemporary history book written by the American journalist and historian Richard Rhodes, first published by Simon & Schuster in 1987. It won the Pulitzer Prize for General Non-Fiction, the National Book Award for Nonfiction, and a National Book Critics Circle Award. The narrative covers people and events from early 20th century discoveries leading to the science of nuclear fission, the Manhattan Project, and the atomic bombings of Hiroshima and Nagasa Praise... [Previous page](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354.md?page=2) [Next page](https://boards.straightdope.com/t/did-japan-have-an-atomic-bomb/681354.md?page=4)