4 ms·

The more I read about the Manhattan Project, the more I become convinced that if it were not for the Manhattan Project, we might not have nuclear weapons even n

The more I read about the Manhattan Project, the more I become convinced that if it were not for the Manhattan Project, we might not have nuclear weapons even now. There were a bunch of things that came together perfectly. 1) A bunch of intellectuals of the higher caliber that could be brought into a single location. A lot of this had to do with the rise of Nazism which led to a lot of these high powered intellectuals fleeing Germany and Eastern Europe for the US. 2) A bunch of money that could be poured into the project. At that time, the USA was completely committed to using every resource it had to win WWII. 3) Convince all those intellectuals that working on creating the most destructive weapon ever was a good thing. If there was ever a "good war" in the history of the world, it was the war against Hitler. I think almost everyone in the West understood at that time that stopping Hitler was of the highest moral imperative and that massive amounts of violence was the only way to stop him. Even with all this, people like Oppenheimer had their doubts. (Of course this would end up being used, not against Hitler and the Germans but against the Japanese). 4) The theoretic foundations for all this work were just laid a few decades before. This could not have happened before then. I don't see such a convergence of factors happening afterward. I don't think you could get the top 100 leading scientists together to build a superweapon now. If it were not for the Manhattan Project, I think it is likely that we would still be living in a nuclear weapon free world. Though, if that is a good thing or a bad thing with respect to great power wars, I am uncertain.

acidburnNSA 5y ago
It's almost a certainty that at least enriched U-235 gun-type weapons would be made regardless of the Manhattan Project as the relatively simple technology of uranium enrichment came online. It's almost literally a cannon shooting a U-235 bullet into a U-235 sphere welded to the end of the cannon. Given the pure material (which you can make by spinning natural uranium in a tube), it's basically easy. Heck, the Manhattan Project people didn't even bother testing it like they did with the far more complex plutonium implosion device (Trinity).
- stan_rogers 5y ago
  The outer part was the projectile; the slug was the target. Making it the other way around - the way most of us always assumed it would have worked - would have forced the ring into criticality. So it is an easy concept, but the first guess is almost bound to be the wrong one.
  - dtgriscom 5y ago
    Interesting: citation?
    - int0x2e 5y ago
      https://en.wikipedia.org/wiki/Gun-type_fission_weapon https://en.wikipedia.org/wiki/Gun-type_fission_weapon Look at the diagram on the right - it's the cylinder that's the target.
  - deleted 5y ago
    [deleted]
  - wrycoder 5y ago
    Where did you hear that? It seems to me that the only thing that matters is the relative speed of the two components. Was the ring much lower mass than the core? Edit: it was more. Nonetheless, accelerating the ring had advantages, according to WP! I didn’t know that.
    - stan_rogers 5y ago
      It's not the mass per se, but the need for the thing to be contained at the target end. If the ring is already at the target end, you have a relatively large mass of enriched uranium surrounded by a neutron reflector. That's not going to make things go bang, but it is enough to be rather exciting. By sitting the core cylinder in the middle of the containment vessel with a gap around it and filling that gap with the ring on firing, nothing goes critical until it's supposed to go supercritical. (The ring is carried on a sort of sabot.)
- 5y ago
ProjectArcturis 5y ago
Then you'd probably have had the US and USSR go to war sometime in the 50s or 60s, and we'd probably have built the A bomb then.
dragonwriter 5y ago
> I don't see such a convergence of factors happening afterward. I don't think you could get the top 100 leading scientists together to build a superweapon now. It wouldn't have taken the top scientists a generation later, with advancements in all the related fields diffusing through the scientific community, even without those strictly depend on thr Manhattan Project and nuclear weapons, abd without the political context created by Hiroshima and Nagasaki, the first use might well have been by a nation with dozens of devices available, and no reason for restraint in using them.
CheezeIt 5y ago
The Soviets were going to do it in a few years anyway. Maybe it would not be as quickly as they got it done. Japan even had a wisp of a program. Everybody knew that an atom bomb program was a thing to do. At the barest minimum, we would still develop nuclear reactors, and then plutonium would get discovered, and it’s easy to manufacture and purify (compared to U-235), and the bomb is just a matter of time.
UncleOxidant 5y ago
> A lot of this had to do with the rise of Nazism which led to a lot of these high powered intellectuals fleeing Germany and Eastern Europe for the US. The Nazis managed to drive out a large portion of Europe's best scientists & mathematicians (Von Neumann, Einstein, Gödel [eventually... it took him a while to realize how bad things were] just to name a few). Most of which ended up in the US or the UK. Which in turn meant that in WWII Nazi Germany was at something of a scientific disadvantage without realizing it was of their own making. Add to this the Nazi critique of of what they called "Jewish science" - things like relativity, quantum mechanics, even Gödel incompleteness theorem got this label - did not allow them free inquiry into many of these areas.
- TedDoesntTalk 5y ago
  To add to this, the USA was lucky enough to hustle a bunch of Nazi scientists out of Germany and into the US just AFTER the war, too. Werner Von Braun comes to mind, but there were others. Von Braun did not give a shit about Nazi philosophy and only wanted money so he could build and test his rockets. That’s what we promised him to get him to come to to the USA. But as I recall, there was a “secret” operation created with the singular goal of getting Nazi scientists out of Germany and to the US in ‘45 and ‘46 before the British or Soviets could recruit or just plain kidnap them. EDIT: Operation Paperclip https://en.m.wikipedia.org/wiki/Operation_Paperclip https://en.m.wikipedia.org/wiki/Operation_Paperclip
  - colinb 5y ago
    https://www.youtube.com/watch?v=QEJ9HrZq7Ro https://www.youtube.com/watch?v=QEJ9HrZq7Ro
abraae 5y ago
It's also possible that if it wasn't for the Manhattan project, there would have been nuclear armageddon in the 50s or 60s. The bomb arrived at a time when the US and Russia were allies. They were focused on winning the war. By the time they started snarling at each other in earnest, the Russians had the bomb (1949) and detente had been established. WWII gave us a smooth glide path to both superpowers having the bomb and MAD doctrine was established. If instead the bomb had arrived say in the 60s, there would have been an entirely different political landscape. Perhaps even more bitter than the cold war. If one side had then got the bomb, just when they were at each other's throats, they could well have used it.
deleted 5y ago
[deleted]
foobarian 5y ago
> 1) A bunch of intellectuals of the higher caliber that could be brought into a single location. A lot of this had to do with the rise of Nazism which led to a lot of these high powered intellectuals fleeing Germany and Eastern Europe for the US. It's amusing that this is very much like how the bomb worked. Take fissile material and bring it all together into the same place at the exact same moment so that a chain reaction can occur :-)
- effie 5y ago
  That's a very interesting observation!
twoodfin 5y ago
I think that’s unlikely, and what that confluence of factors produced was speed rather than any otherwise undiscoverable knowledge. “A Manhattan Project for X” (cancer, renewable energy, quantum computing, …) is a common political refrain, but misses what made the original successful: The scientists had a pretty good idea what was possible and how one might do it. The devil was in the details but the picture was, in outline, quite clear, if enough money were spent and the right brains harnessed. Now, one might argue that speed still made a world-historical difference: Because the weapon was made in time to be used in the current conflict, we did not have to wait until the next conflict to fully understand its significance, at which point it might have been too late.

acidburnNSA 5y ago

It's almost a certainty that at least enriched U-235 gun-type weapons would be made regardless of the Manhattan Project as the relatively simple technology of uranium enrichment came online. It's almost literally a cannon shooting a U-235 bullet into a U-235 sphere welded to the end of the cannon. Given the pure material (which you can make by spinning natural uranium in a tube), it's basically easy. Heck, the Manhattan Project people didn't even bother testing it like they did with the far more complex plutonium implosion device (Trinity).

stan_rogers 5y ago
The outer part was the projectile; the slug was the target. Making it the other way around - the way most of us always assumed it would have worked - would have forced the ring into criticality. So it is an easy concept, but the first guess is almost bound to be the wrong one.
- dtgriscom 5y ago
  Interesting: citation?
  - int0x2e 5y ago
    https://en.wikipedia.org/wiki/Gun-type_fission_weapon https://en.wikipedia.org/wiki/Gun-type_fission_weapon Look at the diagram on the right - it's the cylinder that's the target.
- deleted 5y ago
  [deleted]
- wrycoder 5y ago
  Where did you hear that? It seems to me that the only thing that matters is the relative speed of the two components. Was the ring much lower mass than the core? Edit: it was more. Nonetheless, accelerating the ring had advantages, according to WP! I didn’t know that.
  - stan_rogers 5y ago
    It's not the mass per se, but the need for the thing to be contained at the target end. If the ring is already at the target end, you have a relatively large mass of enriched uranium surrounded by a neutron reflector. That's not going to make things go bang, but it is enough to be rather exciting. By sitting the core cylinder in the middle of the containment vessel with a gap around it and filling that gap with the ring on firing, nothing goes critical until it's supposed to go supercritical. (The ring is carried on a sort of sabot.)
5y ago

ProjectArcturis 5y ago

Then you'd probably have had the US and USSR go to war sometime in the 50s or 60s, and we'd probably have built the A bomb then.

dragonwriter 5y ago

> I don't see such a convergence of factors happening afterward. I don't think you could get the top 100 leading scientists together to build a superweapon now. It wouldn't have taken the top scientists a generation later, with advancements in all the related fields diffusing through the scientific community, even without those strictly depend on thr Manhattan Project and nuclear weapons, abd without the political context created by Hiroshima and Nagasaki, the first use might well have been by a nation with dozens of devices available, and no reason for restraint in using them.

CheezeIt 5y ago

The Soviets were going to do it in a few years anyway. Maybe it would not be as quickly as they got it done. Japan even had a wisp of a program. Everybody knew that an atom bomb program was a thing to do. At the barest minimum, we would still develop nuclear reactors, and then plutonium would get discovered, and it’s easy to manufacture and purify (compared to U-235), and the bomb is just a matter of time.

UncleOxidant 5y ago

> A lot of this had to do with the rise of Nazism which led to a lot of these high powered intellectuals fleeing Germany and Eastern Europe for the US. The Nazis managed to drive out a large portion of Europe's best scientists & mathematicians (Von Neumann, Einstein, Gödel [eventually... it took him a while to realize how bad things were] just to name a few). Most of which ended up in the US or the UK. Which in turn meant that in WWII Nazi Germany was at something of a scientific disadvantage without realizing it was of their own making. Add to this the Nazi critique of of what they called "Jewish science" - things like relativity, quantum mechanics, even Gödel incompleteness theorem got this label - did not allow them free inquiry into many of these areas.

TedDoesntTalk 5y ago
To add to this, the USA was lucky enough to hustle a bunch of Nazi scientists out of Germany and into the US just AFTER the war, too. Werner Von Braun comes to mind, but there were others. Von Braun did not give a shit about Nazi philosophy and only wanted money so he could build and test his rockets. That’s what we promised him to get him to come to to the USA. But as I recall, there was a “secret” operation created with the singular goal of getting Nazi scientists out of Germany and to the US in ‘45 and ‘46 before the British or Soviets could recruit or just plain kidnap them. EDIT: Operation Paperclip https://en.m.wikipedia.org/wiki/Operation_Paperclip https://en.m.wikipedia.org/wiki/Operation_Paperclip
- colinb 5y ago
  https://www.youtube.com/watch?v=QEJ9HrZq7Ro https://www.youtube.com/watch?v=QEJ9HrZq7Ro

abraae 5y ago

It's also possible that if it wasn't for the Manhattan project, there would have been nuclear armageddon in the 50s or 60s. The bomb arrived at a time when the US and Russia were allies. They were focused on winning the war. By the time they started snarling at each other in earnest, the Russians had the bomb (1949) and detente had been established. WWII gave us a smooth glide path to both superpowers having the bomb and MAD doctrine was established. If instead the bomb had arrived say in the 60s, there would have been an entirely different political landscape. Perhaps even more bitter than the cold war. If one side had then got the bomb, just when they were at each other's throats, they could well have used it.

deleted 5y ago

[deleted]

foobarian 5y ago

> 1) A bunch of intellectuals of the higher caliber that could be brought into a single location. A lot of this had to do with the rise of Nazism which led to a lot of these high powered intellectuals fleeing Germany and Eastern Europe for the US. It's amusing that this is very much like how the bomb worked. Take fissile material and bring it all together into the same place at the exact same moment so that a chain reaction can occur :-)

effie 5y ago
That's a very interesting observation!

twoodfin 5y ago

I think that’s unlikely, and what that confluence of factors produced was speed rather than any otherwise undiscoverable knowledge. “A Manhattan Project for X” (cancer, renewable energy, quantum computing, …) is a common political refrain, but misses what made the original successful: The scientists had a pretty good idea what was possible and how one might do it. The devil was in the details but the picture was, in outline, quite clear, if enough money were spent and the right brains harnessed. Now, one might argue that speed still made a world-historical difference: Because the weapon was made in time to be used in the current conflict, we did not have to wait until the next conflict to fully understand its significance, at which point it might have been too late.