So this is a topic I've seen hotly debated everywhere so let's see if I can get a once and for all answer:

Just how capable was the US of producing more atomic bombs if the first two were not enough? Were they not able to make any more, could muster a few, or go to full scale production or somewhere inbetween these?

Bit random, but what is the context of Oppenheimer's quote "I am become Death, the destroyer of worlds"? I always see it attached to the history of the development of the atomic bomb, and it's sort of entered our cultural lexicon.

Was any special paint used on the atomic bomb? yea, that's right, paint.

You mentioned in an answer already that the Manhattan Projecters failed miserably at catching spies, of which there were several.

• 1. Why?
• 2. What did the spies manage to get out? (the Soviets didn't test an atomic weapon until just over four years after Trinity)
• 3. This the one I'm most interested in: were all the spies ideological (presumably communist, but perhaps some nationalists as well)? Or were some just in it for the money?
• 4. Spies! Spies! Spies! Any other information that comes to your mind

I hope you've blocked off a lot of time for this because it's clearly become hugely popular already and it hasn't been up for even two hours... (which I think is great, because you know how much I enjoy reading what you write).

Was there any ever doubt (personal or otherwise) by the scientists leading the project that it would fail? What was to happen if (for any reason) it did so happen to fail; what there going to be any other tests?

Why werent Kyoto or Yokohama chosen as sites to drop one of the bombs? Wasn't it the intention of the USA to display to the Japanese just how much damage they could cause, thus forcing them to surrender? Because if mass damage was the intention, then these more populous cities would've been ideal targets.

Lastly, do you personally think the Japanese would have surrendered had the USA chosen incindiary bombs on these cities instead of going nuclear?

Edit: grammar

Hello! As an employee of the U.S. Department of Energy at the Hanford Nuclear Reservation Site, thank you for doing this AMA. The history here and at the other Manhattan sites is not only interesting but incredibly important historically. The only question I have at this point is 'Did they really have to make such a mess'? I mean really, we're still cleaning up today!

What was Einsteins reaction after Hiroshima and Nagasaki? Did it affect his future in any way?

How did the project approach secrecy in terms of making sure that workers wouldn't get a grasp of the overall project's goals?

It seems like an easy way to do this is compartmentalization: you do this thing over here, these other folks do their thing over there, few know the full picture; but presumably components of the project would have to mesh together to create the Gadget and the eventual bombs themselves.

Were people who had to connect certain parts of the project set at higher security clearances, with the highest reserved for the folks at top? Did they just not tell the guy driving parts from A to B what they were? And how did the project handle publicity/speculation/etc.?

I seem to remember Truman's committee poking into it until he was taken aside and given a quiet talking-to about not doing that, but that could just be a hazy incorrect anecdote I'm remembering.

I've once read that the US government hired a couple of physics professors to see if they could come up with the plans for an a-bomb based solely on the publicly released documents from the Manhattan Project and their academic knowledge. The resulting bomb that they came up had about the same power as Fat Man and Little Boy. Unfortunately, I can't find the source for this article and I'm not sure about its veracity.

I'm curious if you think that another country could build a nuclear weapon like the professors did -- based on public documents released by the US government.

I'd also like to know if you've read Eric Schlosser's book Command and Control. If so, what do you think about it?

Is "nuclear negligence" as active and dangerous as he states in his book?

I'm I interested in Los Alamos.

How did the logistics of secretly transporting experts and all the material to the isolated high desert work? Did local New Mexicans know something was up? What were the locals favorite theories to explain the hubbub? How secret was Los Alamos, really?

Thanks for doing this AMA!

Maybe a silly question, but here it goes.

If the war in Europe hadn't ended when it did, were there any plans for dropping an atomic bomb in that theater?

And since you brought it up, why did the German atomic program fizzle?

Hi! I've followed your blog and Reddit postings for a while now and I'm glad to see you do an AMA--hopefully this won't be the last.

1. Why was Jumbo suspended from a tower during Trinity? Also, according to what I've read, General Groves attempted to destroy Jumbo apparently because congress was displeased with its expense--is this true? What made Groves think that he'd avoid Congress's disdain for spending millions ($12/$142? million) on the device simply because he blew it up afterwards?

2. What happened to the lead lined sherman tanks used right after the Trinity test? I've seen much talk and speculation about this but no hard details. Apparently an old truck was excavated in 2011 from a trench at Los Alamos, but no tanks were found in the area.

3. The Trinity test site today is open to the public twice per year. Have you been? What do you think about the atmosphere at these events today? I've watched videos of tourists to these events, expecting something sombre, given that Trinity is a complimentary book-end to Hiroshima. Instead what I saw was...carnivalesque.

Before the Manhattan project, how widespread was knowledge of the theoretical possiblity of an atomic weapon among average, non-military scientists?

Was there knowledge that such power could be unleased, even if they didn't know it was being actively developed?

Did all of the scientists know that they were making a bomb? Did any of the scientists quit the project because of the moral implications?

Why the name Manhattan?

Was it just a random codename? Was it part of a series of projects also named after places? Maybe part of an alphabetical list? Is there a connection to NYC?

I grew up in Manhattan, so I've always wondered.

there's this popular story that shockley and fisk at at&t had put together a working fission experiment and that that manhattan project crew basically wound up duplicating it independently. basically, i have three related questions:

• is this actually true, or is it some sort exaggeration or even myth?

• if true, did shockley and fisk's lack of inclusion delay the development of the bomb?

• and, lastly, shockley was known for being a racist and, perhaps, even a closet nazi sympathizer. did this factor into the decision to keep him away from the manhattan project?

sorry for smooshing three questions into one!

The Manhattan Project was an incredibly ambitious undertaking involving huge sums of money, a tremendous % of the nations scientific talent, and huge technological leaps. We got 600,000 people behind one idea and pushed with everything we had.

Do you think the US has another Manhattan Project in us? And if so, what do you think it should be?

Were the Japanese ever curious or suspicious about the cities that were spared conventional bombing, with the goal to nuke them 'fresh'?

Can you cover the process of transportation of the bombs? From upon completion all the way to the detonation sites in Japan? How did they keep it a secret? What steps were taken to ensure its secrecy and what routes did it take?

Thanks in advance.

Given the number of complete bombs that are still being regularly dug up 70 years later in London, Berlin and elsewhere: Was there any plan in place to cover the possibility of the bomb dropping and not exploding? (And so falling into enemy hands, albeit presumably damaged of course).

How much was known about the effects of nuclear fallout before the first detonation?

Do you have a favorite figure/character in the Manhattan project story - a particularly interesting scientist or official or something?

Did Oppenheimer use a Western or English style saddle?

Was there technology available at the start of the project that was not available in say 1930, or 1920? What I'm getting at is, theoretically if the funding was there when is the earliest that the project could have been completed? Sorry for bringing you into a realm of speculation.

How was the decision made about who should know what level of detail about the project, especially regarding politicians? Specifically, how much did Churchill and Stalin know, and what differences existed between their level of knowledge? Thanks for the AMA!

I grew up near Hanford, so I have some locally themed questions.

1. Where did the Project get its support personnel? Did the local populace just hear rumors that the government was had job openings in the desert and send in resumes? Was the Manhattan Project racially segregated? i.e. were non-white people allowed to work for it in a research or support capacity? If people of color did contribute, were they assigned separate but equal jobs and benefits?

2. There are currently a number of towns and cities around Hanford, such as Richland, Kennewick, and Pasco. Did these communities predate the Project, arise as a side effect of its shipping in thousands of support staff, or did they develop during Hanford's Cold War production era?

3. What kind of environmental consequences did Hanford's WW2 and Cold War activities have? i.e. did the water give me cancer and is the story about the radioactive rabbit true?

4. My high school mascots are a B-17 bomber and a mushroom cloud. What do you know about the history/perennial controversy behind this?

5. Have you been on the Hanford B Reactor tour? If yes, what was going through your head during and afterwards?

6. A story I heard is that a brilliant female scientist whose name escapes me worked on the Project at the insistence of Feynman or Szilard and over the sexist objections of everyone else in the Project. Apparently this caused a number of HR hiccups like having to build a separate office and restroom for her. Did this really happen? If yes, what was her career afterwards?

7. Another folktale: When the first sample of plutonium was produced at Hanford, the supervisor of the entire facility personally carried it in his briefcase to Los Alamos, traveling by commercial passenger rail. When he arrived a secretary offered to take his bag for him. He politely declined. saying that the contents was worth a billion dollars and he wanted to keep an eye on it. Did this actually happen, and was this really how they transported something as dangerous and valuable as plutonium?

8. Yet another anecdote: The DuPont engineering corporation was contracted to build and operate the Hanford site, with promises that they would be paid after the war. When the war ended the CEO refused all payment except for a single dollar bill, which he framed and displayed on the wall of the office. True story or patriotic legend? If true, did that decision bite DuPont on the ass later, and did the Hanford project occupy the entirety of the company's attention during the war?

My grandparents met and married while working in Oak Ridge (working there left them both a bit paranoid for the rest of their lives). I find the Manhattan Project fascinating, I just want to say thanks for the AMA!

Who are some notable scientists left out of the project and for what reason? Were there any interesting comments made by some of the scientists working on the project after the bombs were dropped?

What if either of the bombs dropped and failed to detonate? Was there a failsafe? Or would the impact detonate the bomb anyway?

Thanks so much for this very interesting AMA!

I supposedly had a family member that worked at Oak Ridge during the Manhattan Project. According to my family stories he died from complications that were likely related to the radiation he was exposed to while he was there.

Is there any information to suggest that it was common for the workers there, or with the MP in general, to have health complications from radiation they were exposed to? Also, are there any resources available that I could possibly find out his role in the project? I think that could be really neat.

What was the point of the Manhattan project. (Atomic weapons, of course) but... Why? We had the capability to decimate cities before the Manhattan project... Why was there a rush to get an atomic weapon that could do the things we were already capable of?

Like... All the money and man power that went into the Manhattan project could have been used to produce far more ordinance of destructive powers of a greater magnitude of little boy.

Do you know if there is a list of technologies and methodological innovations that were invented in the Manhattan Project? I'm thinking like Markov Chain Monte-Carlo, computer innovations, fabrication techniques, etc.

Thanks for the AMA, but I've always wondered, did the U.S.A really need to drop the atomic bombs?

Was it ever officially released as to what Asimov and Heinlein were doing with the Manhattan Project?

Hey, might be already answered in the thread, but I've always wondered how the general population came to find out about the existence of the bomb and their general reactions to it. Did people just start hearing rumors of some superweapon dropped on Japan? How did the information about this new technology get released to the public? What was their reaction to this information?

Thanks!

I'm so excited!

OK, could you explain a bit more about this picture? Seems like someone drove a Fat Man through a car wash..

http://blog.nuclearsecrecy.com/2011/11/28/you-dont-know-fat-man/

And q2. How does enrichment work? Is it really as simple and extreme as molten metal in centrifuges? That sounds like a very expensive wartime effort.

Were "Little Boy" and "Fat Man" especially made and customized to destroy Hirosima and Nagasaki or was there a whole arsenal of "Fat Mans" and "Little Boys"? If they were customized, can you tell what it was?

Why did they put the Manhattan Project in charge of both making the bombs and gathering intelligence on the German bomb effort? Why put those two things together at all? Scientists aren't spies...or, anyway, probably not very good ones, right?

How successful was the U.S. government in keeping knowledge of the Manhattan Project from the general public and what were the reasons for that success or lack thereof, in your opinion?

How large could such an operation even get with secrecy being feasible?

Those who were working on the project as laborers (so not the all-star cast of minds, but the factory grunts) I've heard had a remarkably short leash. What did they have available for fun on site, and what, if anything, was something they could 'get away with', for lack of better term?

Hopefully I will come up with a better question later, but how much science do you do? You are clearly familiar with the technical side of things, did you need to take a punch of chemistry and physics in undergrad/grad school?

EDIT: Better question, how has scholarship on the Project changed since the Cold War? Or perhaps more interestingly, how was the views on it changed by rash of nuclear war TV series in the 1980s (like The Day After)?

Also, how was the physical bomb transported to the Marianas, and was there any concern about that?

Were the Soviets working on anything similar to the atomic bomb during the development of Gadget, LB, and FM? And if so, was it due to information gathered from the US, or was it just coincidence?

EDIT: Also what was the UK's involvement, if any, in all of the production/research?

Cool, I just was wondering about this today: would US keep the project secret if it wasn't successful or wasn't needed? Were there preparations for a long-term secrecy cover, or for eventual release of information to the public?

And apart from hypothetical questions, how did release of information go in reality? Did US just announce "hey, we've been working on this thing for a while, and just released it to 200,000 beta testers"? Or did they hint at it beforehand? How much information about the bomb did US release and when?

Thanks for answering us! My question is: how close were the Axis Powers from creating their own nuclear weapons?

A light hearted question:

I've used you NUKEMAP many times to see the effects of dropping a nuclear device in the city where I live... Am I now on a government watch list?

Is it true that there was a Soviet mole among the top researchers and that we don't know which researcher it was? If so, when was it discovered that there had been a mole and what is known about them? If not, do you know how that myth started?

What work of the bomb was contracted out? I've heard of factories where workers only knew that they were working on something important and secret and, if asked what they did, were to say they "made the holes that go in donuts," or something to that effect.

Thanks.

What were the soviet involvement with the project in terms of espionage?

What happened to all of the waste that was produced in those old facilities? I'm guessing they might not have had all of the proper procedures developed before running all the tests or that the proper disposal might not have been fully developed during or after decommissioning the sites, or was it?

My grandparents worked on the Manhattan Project, for DuPont at Hanford. Like many involved in the project, they had no idea what they were working on. They got their tiny piece of the puzzle to work on, and didn't ask questions.

After the bombs were dropped and it was revealed to them, they were absolutely mortified. My mom says they felt horrible to have been part of something that caused so much death and destruction.

How common was their experience? Was there widespread "survivor guilt" (If I may co-opt that term) among Manhattan Project workers?

2 questions

As a by product of The Manhattan Project, did we get any breakthroughs for later use in Mathematics in ways unrelated to the Physics side of the Atomic bomb development?

How much freedom did the scientists at Los Alamos (and any of the other facilities) have? Was it run like an extension of the military in a very strict way and everyone had very specified roles they had to do, or did the scientists have some freedom in choosing where and what part of the project to work on?

Who made the decision to use the first and second atomic bombs on august 6th and 9th? I recently read that the decision was made on the ground at the time and the president had little to do with actually giving the go ahead.

I've recently finished Denise Kiernan's The Girls of Atomic City: The Untold Story of the Women Who Helped Win World War II and read Jennet Conant's 109 East Palace: Robert Oppenheimer and the Secret City of Los Alamos a few years ago. Enjoyed the oral/social history and behind-the-scenes perspectives on each. Is there a comparable book on Hanford?

Also: I've visited Trinity, Los Alamos, and Hanford. Is there anything to see at Oak Ridge that is open to tourists? A museum even? I'd like to complete the troika but it would require a specific trip as I'm nowhere near Tennessee any more.

This is the best ama I've read I think. This was awesome and I thank you for your time, detail, and depth. You are an amazing person. You made my evening.

Hanford is a messy, messy place. I live down river from it a bit. I've seen some old Soviet materials that show where they would strike (first strike, defensive strike, etc..). Hanford is up there as a main target, as are the dams on the Columbia River. So, I'd probably be toast. But, being that Hanford is still operational to an extent and is fairly dirty with it's waste from the past, if a nuclear weapon were to be detonated there, would the fallout cloud be a lot more dangerous (uplifting all that waste, etc.)? Depending on wind conditions, it seems like I'd be toast no matter what...

My granddad had his Ph.D. in chemistry from Auburn and was working in Pensacola, FL as a research chemist with the navy during WWII. He was actually asked to work on the Manhattan project but refused because he would have had to up and move across the country. I know this is vague, but what sort of work would he have done had he accepted the offer?

ninja edit: and if it helps, his work was primarily in organic chemistry pertaining to compound synthesis

This may be more of a question of morality, but I've heard a lot of accusations pitched at Truman for making the decision to drop the bomb on Japan at that stage of the war.

Do you have any opinions on that? Maybe this isn't the right venue for this question...

Two questions:

First, could you discuss the role of espionage in and around the Manhattan project? What were the reactions of Soviet intelligence? How much of the Soviet nuclear program was dependant on information gained through war-time espionage?

Second, could you discuss the British role in the Manhattan project? What did the trans-Atlantic politics look like? Was there a faction opposed to British involvement, who wanted a purely American Manhattan project?

Thanks.

What are your thoughts on Richard Rhodes' The Making of the Atomic Bomb? I think it is one of the best holistic accounts of the projects and a good starter book for history enthusiasts. What do you think?

Hello Alex! I would like to know if you can help me with something. I'm currently a high school senior in the International Bachelor Program at my school. For this program you need to do internal assements for most of your subjects. For my History Internal Assessment I did mine of the atomic bomb that struck Hiroshima and I would like to know if you would like to read it and give me recommdations. My pre-score on this has been 6/7. However, I would like to have an expert's opinion on it and you seem like the man who's most qualified.

Were there any scientists/workers that committed suicide as a result of their role in the Manhattan Project?

Why were two different bomb designs used?

How were the targets picked - Hiroshima & Nagasaki?

Did they really fear prior to testing that they would burn the atmosphere in an unstoppable chain reaction? Was there a real chance of that happening, and how did they statistically evaluate the probability of that potentially happening?

How long would it would have take to build and use a fourth and a fifth bomb?

How well did General Groves himself understand the science and engineering of the Project? Could he follow the equations? Was he abreast of the relevance of the smaller experiments that had to be conducted along the way, for example?

How did Oppenheimer and Groves manage to wrangle or coordinate team members on the project? I read an anecdote somewhere that many top notch scientists were unaccustomed to having to listen and learn from others, making it sound like a 'too many cooks in the kitchen' issue at times. In the anecdote, someone snubbed Oppenheimer because he didn't have a Nobel Prize. I think it was from the biography "American Prometheus."

I wanted to thank you for this AMA; one of life's great pleasures is to witness an expert expounding upon their field of expertise.

Who was the first person to say, "Hey, if general relativity is true, we can create this crazy ass bomb"? And any other info you can provide about that initial idea and how it developed in the early stages is appreciated.

A bunch of miscellaneous questions:

1. Is it true that the Germans were planning to put their bomb on a ship which would then self destruct in an an enemy port? If this is true, why did the Germans think the atomic bomb would be a best used as a naval weapon, rather than as part of an aerial or artillery weapon system? Did the Americans have an aerial weapon in mind from the start? Did they start planning other deployment systems or did that wait until the Cold War?

2. Is it true that American spies leaked fake scientific data to Germany suggesting that heavy water was the key to developing an atomic bomb? Did this misdirection significantly hamper the Germans? Which American intelligence organization was responsible for the operation? Did any Project scientists help author the fake data?

3. The Soviets thoroughly infiltrated the American atomic project. Did they monitor the German project to a similar extent? Did the Americans and British monitor the Germans? Did the Germans monitor the Americans? Did the Japan and Italy even know there was a nuclear meta-game happening in the background of the war?

4. How far did the German project get? How did their spending compare to that of the Americans? Where were they planning to perform their test detonation?

5. Is there any difference between the terms "atom bomb," "atomic bomb," "atomic weapon," and "nuclear weapon?" Is one more correct?

6. Who were the driving personalities behind the Manhattan project e.g. Roosevelt, Groves, Marshall, Churchill, Szilard, etc? Did it have any particular opponents among the Allies? Who were the analogous supporters and opponents of the German project? How closely did Stalin personally monitor the Manhattan Project? Did he give Soviet scientists updates on the American's progress?

7. Was Einstein offered a position in the Project? How much did he know about its progress?

8. Did the British provide any funding or personnel to the Project? Any other countries?

9. Were the potential economic applications of nuclear technology known during the project? Were there any attempts by the Project to develop nuclear energy alongside their weapons development program? If yes, were any of those designs incorporated into post-war technology?

10. What were the criteria for selecting the Project's locations? Secrecy? Existing infrastructure? Natural resources? Human capital? Safety for civilians?

Got any good Herb York stories?

What were some of the psychological effects around those who worked on the project, and who delivered the payload? Urban legend has it that one of the pilots of the mission killed himself later, but Paul Tibbets, who dropped Little Boy, is said to have died with no regrets. Charles Sweeney, pilot who dropped Fat Man, is said to have some controversial assertions about the Nagasaki mission but ultimately defended it.

Were there any cases where the technicians, scientists, or officers and servicemen saw this as not just another mission?

Thank you so much for your answers. Very interesting topic. You have displayed an enormous amount of knowledge about your subject,so congratulations on that.

My question is if there was any meaningful opposition to the decision to drop the bombs within the US government. I understand that firebombing and other war-time practices aimed at civilians were incredibly damaging, but did no one oppose the use of nuclear weapons, particularly after the first bombing? Did they ever consider the hypothesis of dropping the bomb right next to a city, so as to display the magnitude of its power but avoid the incredible death toll?

How does the Manhattan Project compare to other major govt. programs in terms of spending / impact on national debt, total man-hours, etc? I'm thinking things like the space race (culminating in the Apollo Program), or the capital injections / quantitative easing following the 2008 economic crisis, or maybe even all the nuclear weapon spending post-WW2.

I'm an Engineer and have done a fair bit of work involving civil nuclear reactors. You probably know that an emergency shutdown of a reactor is often called SCRAM, which according to a prof. I used to know comes from a mechanism at Chicago Pile 1, where a man would cut a rope, dropping the control rods into the core. Therefore the acronym is "Safety Cut Rope Axe Man" or similar. How much of this is true? I suspect not very much.

To what extent was Feynman a nuisance by his hobby of opening the locks at Los Alamos? In other words, was he ever threaten to be written up or something because of this?

Hopefully I'm not too late. I've been reading a lot of news articles recently that Russia (and Putin in particular) seem to be rewriting Cold War era rules on the use of nuclear weapons. Specifically, statements by Putin indicate that Russia is increasingly willing to use nuclear weapons, disregarding the concept of MAD 1 2 3.

What do you make of the current security climate regarding Russia's nuclear weapons? On a scale from "nuclear weapons don't exist yet" to "Cuban missile crisis," how are nuclear tensions between the US and Russia today?

What was the logic in shipping the bombs by ship and not by plane?

How close was Japan to surrendering before the bombs were dropped, and, maybe more importantly, what was the perception of their readiness to surrender by leaders at the Manhattan Project?

Being so knowledgeable about something that the government most likely wants to keep secret, have you ever been contacted by someone high up in government and been politely asked to keep quiet?

I have a grandfather who may have had a role in the project. My mother (b 1945) grew up in NM and he was an engineer on all kinds of secret projects later. Non-top secret, too, like Skylab and space shuttle. My mother never really tried to find out what he was doing at that time, though, and he passed away 20+ years ago.

Is there any way to find out names of people and work they were involved with?

How long it took for the japanese government to perceive that they were struck by a new kind of weapon?

They were aware it was a atomic bomb?

The western propaganda about the bomb started as soon as the bomb exploded?

They (the government in Tokyo) had, right away, full comprehension about its destructive power?

The post-explosion landscape of H&N were much different than the most bombed cities in europe during WWII?

The problems of radiation in the site was perceived by the japanese government right away?

A couple questions:

1. Why did the management put up with Edward Teller's reluctance to do the work assigned to him for so long? Was he simply so smart that an uncooperative Teller was better than no Teller? Or did they want to see if his fusion ideas developed? Or was it something else entirely?

2. Not totally on topic, but what do you think happened at the infamous Bohr-Heisenberg meeting in Copenhagen?

How do you remember all of this in such detail? Do you have an exceptional memory, or do you have an enormous stack of notes in front of you?

How easy would it be to look up a person's involvement in the project? Apparently my grandfather had some involvement, but I don't know in what capacity.

How large was Feynman's role in the project and do you believe that his involvement had a profound impact on his future work in quantum electrodynamics?

What is your favorite course to teach? Will it be available in the spring?

How many People actualy knew about the project? How many actualy knew what they where building? and how many worked on it?

What was the reaction of prominent people and large populations to weapons of this power? Is Stalin on record on this topic, what about average citizens of various countries?

To how much of an extent was President Truman kept in the loop about the project and did he have all the information necessary/required when he made the decision to drop the bomb? In addition to this, who gave the "all-clear" to the pilots over the comms on the actual days?

Hey, a Stevens guy! God that place killed me.

I'm sorry to crash late to the party, but if you allow me to stretch the topic a bit. What's your expert opinion on the Vela incident (https://en.wikipedia.org/wiki/Vela_Incident)? Was that actually a nuclear test at all, or what was it? And whatever it was, who was responsible for it? Are there any specific future dates (for example classification expiry dates) when we might learn more?

Please ignore if it's already been asked (I just saw this and can't read the whole thing now).

Regarding spying on the Manhattan Project. To what extent was it penetrated by the Soviets (and non-Soviets), and how did they place their spies in the Project? Was is a calculated move to get spies into this project or did they just spy everywhere and happen to hit paydirt here?

Thanks!

Was there ever any effort to disguise the fact that many prominent nuclear physicists had suddenly disappeared and stopped publishing?

EDIT: To clarify, was there ever a counter-intelligence effort to try and keep an enemy from reading American physics journals and filling in the blanks of what was suddenly not being spoken of?

I'm finding this quite fascinating! Thanks for your efforts.

Can you tell about use of silver ingots from the US Treasury in the Oak Ridge enrichment work? Was that something where Stimson could just tell [Treasury Secretary] Henry Morgenthau "it's for the war effort; don't worry about it?"

Two questions, if you manage to make it back to this thread to answer them.

1. I live right outside of Oak Ridge, Tennessee but have never done any physical looking around for interesting areas of historical interest. What are some good areas of historic interest I should be sure to visit at some point? Of course, many areas are still off-limits, and I'm not wanting to get on any lists, or really cause myself a headache, so nothing that I'd need prior permission to visit.

2. I have read City Behind A Fence: Oak Ridge, Tennessee, 1942-1946 by Charles W. Johnson and Charles O. Jackson and loved its focus on the civilian side of the Manhattan project. Has a similar work been written about the Los Alamos site? Have more works with similar focus been written about Oak Ridge that do not just cover the same information? (Also, feel free to give your opinion of City Behind a Fence)

This is of huge historical interest to me. I have been studying the Cold War as a lay person for years now. Here are my questions:

1. How does Project Paperclip tie into the Manhattan Project, if at all? Were there German scientists secretly helping the US, or are there instances where the OSS was able to make gains on the German atomic program?

2. What was the psychological impact on the vast number of employees who worked for the project when they saw the attack on Japan and realized that they had been part of it? Short vs. long term opinions.

3. With the power of today's bombs, is it likely that they would destroy the entire planet if a few were ever used?

4. How is current nuclear bomb testing carried out? Space?

I could really ask a lot more, but I'm going to head over to your blog and read what everyone else has written. Thanks!

Wasn't there a large underground lab complex built somewhere around the University of Chicago? There's not much mention of it. How did that fit into the Manhattan Project?

What was the management structure inside the development lab?

Were there ever concerns during the discovery process that they would stumble across something truly catastrophic and destroy far more than they intended, either amongst the scientists or non-scientists who knew of the project? I'm thinking along the lines of some of the concerns from less informed people about CERN turning the Earth into a black hole. Was there anything of that nature during the process of discovering the atomic bomb?

As a Canadian I've heard a couple offhand remarks from teachers about the role of Canada in the Manhattan Project and they've varied anywhere from minimal involvement to the primary uranium and plutonium source, so I was wondering if you could answer: How much of a role did Canada play in the Manhattan Project? How much of the work took place in Canadian facilities?

Seeing as it is now a major issue:

Were the disposal procedures at Hanford adequate to the best of the scientists abilities and knowledge?

Did any of the scientist or officer involved ever left the project for moral reasons? I would imagine that some ethical concerns were raised, would those doubting the humanity of the project ever punished?

I can't imagine the US being thrilled at the idea of letting go someone with so much knowledge on such a project.

My Great Grandfather helped work on the Manhattan project and I have several copies of patents and his signed appreciation letter from the president on display at my grandparents house. I loved hearing about all the work that went into it and the level of secrecy he was held to. Thank you for doing this AMA!

I have been through every single document in my library about Leo Szilard. (And that's a lot of documents! We have a lot of his papers. I love my job!)

I think because of this, I have a pretty one-sided view of the man. A lot of it was his correspondence with others. He was the one talking in most of these documents.

Mostly what I want to know is what you think about him! I try to talk about him with my friends, but they aren't down.

How did other people view him? In your research, is he painted as a good guy or a bad guy? I know Leslie Groves HATED HIM. Have you ever encounter anything of that nature?

Come to UCSD and look at his papers! You'll get a kick out of them! His stuff that has been declassified is seriously a trip.

Have you read Joseph Masco's work Nuclear Borderlands: The Manhattan Project in Post-Cold War New Mexico? If so, what are your thoughts?

How close were the Germans to developing the bomb? And if it is known, or if there's a time estimate, how much longer would it have taken after the US developed and used the bomb for the Germans to develop it?

What, if any, was the role played by The University of Chicago in this project? As a former student there, I've heard many apocryphal stories on the subject, so I'm really curious to know. Thanks in advance.

This question is late to the party, but if you happen to see it, can you comment on the quality of the High Energy Weapons Archive run by Carey Sublette at http://nuclearweaponarchive.org as a historical and technical source?

What were the worst case scenarios of how the Manhattan Project could have failed? What contingencies were prepared and what countermeasures implemented?

1. Were there plans to cover-up, continue, or re-purpose the project in the event of the Allies losing the war? Was there a plan for what to do if the Allies won before the bomb was ready?

2. Would it have been scientifically possible for the project to fail in a spectacular and catastrophic fashion e.g. a Chernobyl-esque meltdown or a nuclear explosion? Was their a possibility for an less dramatic but equally crippling disaster like an irreparable machine component fusing together irreparably? Were these potential fail states known at the time or only in hindsight?

3. How did the Project's security forces react to leaks? Leave them unsubstantiated and hope they went away? Find the leak and obtain silence through coercion? Bribery? Imprisonment? Killing?

My question is related to the events immediately after the Trinity Test.

After the unfortunate death of Harry Daghlian, did the government or anyone in charge consider attempting to weaponize the event that killed him?

In other words, were there ever any plans to create a "bomb" that would simply emit an enormous amount of radiation to kill anyone in the area while leaving infrastructure and such untouched?

Two things:

1. Go Bears!

2. That article in the New Yorker was really, really cool.

Now for my question, hopefully you can reach it at some point. There were over 1,000 nuclear tests, your article said. But why so many tests? What exactly were these tests (broadly speaking) looking for?

I've heard that some scientists expressed fear that Trinity may ignite Earth's atmosphere leading to an apocolypse. Did the leaders of the project and the government just roll the dice on that one, or were they 100% certain that the Earth's atmosphere would not ignite?

How did the UK and Canada contribute?

Thanks.

At the time of development, how aware were they of the dangers of radiation? Were any workers/scientists/soldiers exposed to dangerous levels of radiation (deliberately or accidentally)?

Could you explain the "controversy" (I put it in quotations because i've only ever seen it brought up on Reddit) about the US allegedly stealing the research done by British scientists in the Tube Alloys program?

I was always told in school that the Manhattan Project was very compartmentalized so that the overall goal of the project (to create the bomb) was not known by anyone working on the project except for Einstein, Oppenheimer, and Fermi.

My question: How much information did each team of scientist know about the bomb while working on it? Did a lot of them know they were working towards making a WMD or were they in the dark due to the compartmentalization?

Hi, thank you for doing this ama. The Atomic Age is my favorite subject to teach but I have always wondered, is the mechanism to detonate a hydrogen bomb still classified? I told my students last year that it was but I thought I would ask an expert!

You occasionally hear about fears the scientists had of igniting the atmosphere. Was this ever actually a real thing, or was it just anti-'irresponsible warmonger nuclear bomb scientist' rhetoric?

If it ever was a real fear, how far up the chain of command did the possibility go before the decision was made to go ahead anyway?

Hi! To what extent did Britain contribute to the bomb, and why did it take them another four years to make their own?

I've read a little on nickel from Wales that was needed for the process of making the bomb. Why Wales, and what was it for?

Hey thanks for doing this. I may be too late but just noticed the thread. I'm told that my great grandfather James Marshall was at one point in charge of the Manhattan project. I was hoping you could shed some light on what he actually contributed and why he was relieved (fired) before its completion.

My question is about how the Manhattan Project was understood by the general public in the immediate post-war period.

In 1946, how much information about this program would be known to the general public? The existence of nuclear weapons is a given, but would your Average Joe know of the existence of Hanford, Oak Ridge, or Los Alamos? Would they know the names of prominent physicists who worked on the project? Was the use of both Plutonium and Hightly Enriched Uranium identified to the public?

What sort of discussions were there within the federal government about whether parts of the program should remain secret?

Finally, did the Soviet nuclear test in 1949 result in further disclosures about the US wartime program, on the rationale that secrecy was less vital now that the Soviets had gained the technology?

What happened to the Japanese government in the three days between the bombs? Was there any talk of surrender after the Hiroshima bombing? Also, would the US government continue to bomb Japanese cities with nuclear weapons if there was no surrender?

Did the pilots that actually dropped the bombs ever come out with any grievances towards doing so? Did they know exactly what they were dropping and what would happen?

I was looking into the scope of the project and it looked like we had industries all over the US making the required products for the tests and later bombs. How did we keep anything substantial from leaking? Were everyday people just so far removed that they assumed what they were manufacturing was nothing special? Or was the war effort so engrained that people were more than willing to keep quiet?

What do you think of the Rush song Manhattan Project?

How exactly were the Soviets able to infiltrate the Manhattan Project and remain hidden so well?

How much did the public know about it? If nothing about the project, were they even aware that something like the bomb might be possible (before it was used)?

Had the war continued in Europe, would any of the weapons been used there? If so, what were the potential targets?

You mean the 3 nuclear tests? Seriously, were the last two necessary?

Not about the A-bomb, but what's your take on the Teller vs Ulam fight over the hydrogen bomb (radiation implosion) idea?

According to some documentaries, the soviets had spies inside Los Alamos, they supposedly knew about the correct detonation of the test bombs. My question is, how deep was the infiltration by the Russians (militar level, rank, etc) and for how long where the russians among the people involved in the project.

I follow you on twitter! What's the coolest thing your expertise/consulting has gotten you into?

Is there any literature/studies regarding cancer rates of troops who witnessed Trinity? They always replay the test footage on TV with troops in bunkers/trenches. Were scientists aware of the risk of radiation poisoning beyond the initial blast zone? Were the troops who witnessed Trinity used as unknowing test subjects?

Hi! thanks for doing this AMA. Two questions:

-Were there any specific hardware/equipment advantages that researchers at LANL had that were not available at other public or private research projects, either domestic or abroad? For example, did they have superior computing power, or more advanced centrifuges?

-When discussing the benefits of the space program in the 60's people often point to "direct descendants" of the technology discovered in the program that wound its way into average citizens' everyday life. Are there similar "descendants" that had their discovery within the Manhattan Project?

Two questions: how much work was done on the theoretical side toward a fusion bomb before the end of the war? My understanding it they figured out the theoretical physics pretty early on and most of the work was actually on the practical engineering side, which left the theoretical staff to move on to the next generation of weapons.

2nd question: what was the level of work on getting thing like the Zippe Centrifuge done on the German side? I know they were way off base on the theoretical end of things (BTW why?), but were more advanced at refining ideas than the US was with gasseous diffusion as an enrichment method.

Bonus question: do you ever get nervous about researching this stuff online, like it would trigger the NSA to start checking you out?

Crazy sam weissman's office was right next to mine. When it was finally cleared out I was able to snag some pretty cool punched tape reels from the trash. I've always wondered what information they contained .

Did the scientists working on the project foresee the future use of their research as a source of peaceful energy use, or was their research only focused on the military aspect of the project?

Do you know anything about Wayne Buckles Nottingham? He was my great grandfather and he worked on it on the Administrative side I think. He was a professor at MIT if that helps you.

Is there any truth to the statement that the bombs were unnecessary for Japan's surrender? I've somewhat regularly heard that the Japanese government had already made up their minds before the bombs even fell, and that the bombs were specifically used to see what kind of damage they would REALLY do.

I still remember that, among others, one elementary and one high school teacher of mine were a big supporter of this theory.

Hi! I work on the music team for the TV show "Manhattan" on WGN, and I was wondering how accurate the show's handling of Oppenheimer is. In the show he is portrayed as more of an overseer / administrator. He isn't really showed to be involved the 'hands-on' sciencing of developing the bomb, which is strange to me since his famous quote always led me to believe that he was in the trenches, perhaps leading the effort in more of an on-the-ground way. Is this accurate?

What did people think of Richard Feynman's antics? Especially when it came to safe hacking

I was a nuclear engineering major in undergrad and worked at Los Alamos for a couple summers. I watched the first season of Manh(a)ttan and enjoyed it a lot, but found that some it seemed historically and scientifically inaccurate. What were your overall thoughts on the accuracy of the first season and how much did they follow your advice when you consulted on the second season?

Thanks for doing this AMA! I always enjoy your posts on here and your blog!

just wanted to say - thanks for all the great reading material here and on your blog!

Thanks for the AMA, always enjoyed reading your blog. My question this: I've recently finished "Critical Assembly" and was wondering if there is a list of documents from the Manhattan project which are still classified after all these years. Do you think that's any hope for a comprensive declassification of old documents? I don't think something can be keept secret from the public for more than 70 years. Thanks again!

Thank you for this fascinating AMA.

I read in Max Hasting's superb "Retribution" that Truman essentially never gave an actual order to drop the bombs...that so much treasure and effort had been expended that it was simply assumed that yep, they'd be used. Does your research bear that out?

Also, given the immense destruction already visited on Japan with things like Operation Meetinghouse and other lesser examples of the fire bombing campaign, did Little Boy and Fat Man's awesome power SEEM awesome to Truman and the rest of the country?

Came to the thread late, so I just want to thank you for all the great answers!

Really enjoying this ama. Thank you for doing it!

Now for my question. It's not a scientific, but I'm curious. Have you read any of Jonathan Hickman's Manhattan Projects? It focuses on the historical figures of that time and asks the question: "What would happen if the Manhattan Project never ended?" I think you'd get a kick out of it.

Anyway, thanks again!

I've been reading The Emperor of All Maladies by Siddhartha Mukherjee lately. He discusses how in the mid-40's American scientists were transitioning from open-ended research to targeted, 'programmatic research', and cites a New York Times article from August 7th (the day after Hiroshima) that posited "University professors who are opposed to organizing, planning and directing research after the manner of industrial laboratories... have something to think about now."

So my question is, was the methodology used at Los Alamos significantly different from contemporary research, or was the research just more focused and a teensy bit more urgent?

Also, while I've got your eyeballs, any recommendations for good books on the subject?

This will be an opinion question, but i think you might find it interesting.

Given what you know about the stories behind the project, the money, the politics, both governmental and international, the people, the knowledge, the science as well as the social and ethical matters behind it, and given what you know of the status of the world as it currently exists, i have this question for you:

Do you think, given enough pressure to commit and 'do it, with the force and hopes of humanity behind it', could we actually survive past an extinction-level event through sheer preparation, determination, manpower and science? Think, say, Interstellar.

This may be an off-shoot question, but i'd love to hear your thoughts on it.

Honest answer: Why? and why did the US go to such extreme measures with Hiroshima? At what point did it go beyond defending the country to pushing the boundaries of science?

Is it possible that Little Boy as a name was a reference to Barnes Wallis' Tall Boy bomb?

What exactly was Feynman's improved method for the computations? He mentions that his system allowed them to do more than one calculation at once but doesn't say how.

How close was the British "Tube Alloys" project, as a proportion of the completed Manhattan project? Could the British have completed it alone?

I've read that after the bombing of Hiroshima, Japanese scientists investigating the site concluded (correctly) that the United States did not have the resources to construct an additional uranium-based nuclear weapon. This informed the decision to not surrender until the (plutonium based) bombing of Nagasaki.

Can you speak on why the US decided to drop the uranium bomb first?