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Nenonen posted:The brass casing has much larger surface area and contact with the chamber, so the bullet wouldn't imho matter that much. Unless you’re trying to bring the G11 back to life 
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Jul 12, 2023 17:50
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the yeti posted:Unless you’re trying to bring the G11 back to life A Clockwork Gunrange
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Jul 12, 2023 17:54
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Cyrano4747 posted:While lead is a LOT lighter than gold, the other issues are engineering ones and frankly being that dense isn't really an unattractive proposition. There are a lot of really interesting things you can do with small projectiles with a good ballistic coefficient, but tl;dr is that they're generally flatter shooting and often have a reputation for accuracy. Think German 8mm Mauser vs Swedish 6.5mm Mauser. That's a good apples to apples comparison because the cartridge lengths are basically the same (not EXACTLY but more or less) and the powder loads are at least ballpark similar. Thanks for this and the other effort posts! That was a really fascinating view into the gun world. Groda posted:Maybe stick to nuclear engineering... I have totally no idea what this is a reference to, sorry!
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Jul 12, 2023 18:20
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The only thing I know of involving gold and nuclear engineering was the fact that at the Manhattan Project, after they got a bunch of material samples to test with radiation, they wound up using the gold as a doorstop after they were finished testing with it.
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Jul 12, 2023 18:46
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Also the semi-related issue where the Manhattan project needed huge quantities of electromagnets for spectroscopy and isotope separation work, but as making them out of copper would have been too disruptive to other areas of war production, they made them out of silver instead. 12 million kilograms of silver.
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Jul 12, 2023 19:00
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Yes, it's like a lava lamp.
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They were just borrowing it from the US Treasury, they made sure to give it all back.
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Jul 12, 2023 19:09
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They returned it too. In theory you can make gold in a particle accelerator I think.
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Jul 12, 2023 19:09
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Nessus posted:They returned it too. I'm picturing some 15th c. Italian nobleman named Malicarius or something trying to build a cyclotron under his villa.
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Jul 12, 2023 19:12
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Nessus posted:They returned it too. I'm more familiar with using a gold-foil target, and some fraction of it being transmuted into (something other than gold).
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Jul 13, 2023 08:09
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The Lone Badger posted:I'm more familiar with using a gold-foil target, and some fraction of it being transmuted into (something other than gold). "Here's your, uh, gold bars back. Oh yeah they're lead now. Because science, it's a long story. Well, gotta go, see ya later!"
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Jul 13, 2023 08:21
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Nessus posted:They returned it too. I think the Soviets did this by accident at one point, in one of their reactors. The resulting transmuted gold was extremely radioactive.
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Jul 13, 2023 09:32
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In theory you can make any element in a particle accelerator, by mashing two atoms of lower atomic number together at high speed. In practice, eventually your two atoms will start experiencing radioactive decay before you can accelerate them enough to fuse together, so there is an upper limit. Unless the hypothetical "island of stability" actually exists...
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Jul 13, 2023 13:20
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TooMuchAbstraction posted:In theory you can make any element in a particle accelerator, by mashing two atoms of lower atomic number together at high speed. In practice, eventually your two atoms will start experiencing radioactive decay before you can accelerate them enough to fuse together, so there is an upper limit. Unless the hypothetical "island of stability" actually exists... The German novel Atomgewicht 500 had this island as a plot point, but since we've been closing in on an atomic weight of 500 with our growing number of artificial elements without the equally growing instability showing any signs of reversing, I'm guessing this mystical island either doesn't exist, or is at a plateau still far out of reach for modern particle accelerators
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Jul 13, 2023 14:27
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On gold and military history: James Franck and Max von Laue were two German physicists who won Nobel Prizes and also ardent anti-Nazis (Franck would work on the Manhattan Project after leaving Germany) and who both sent their gold medal prizes to Denmark to prevent the Nazis from getting their hands on them. When the Nazis invaded in 1940, George de Hevesy, a future Nobel winner himself, dissolved both medals in aqua regia and put the beaker on a shelf in his lab at the Bohr Insitute. The Nazis never figured it out and so after the war, de Hevesy finds that the beaker is still sitting there so he precipitates the gold out of solution and sent it to the Nobel Society in Sweden who recast both men's medals. Pre-nazi Germany was just packed with world famous scientists and some of the most brilliant and ground breaking theorists the world has ever seen, and who knows how much knowledge and understanding could've been advanced in that era had the Nazis never come to power. It's another thing they took from the human race. The 15 percent of German scientists who chose or were forced to flee Germany when the Nazis came to power represent nearly 2/3s of all German physics citations. zoux fucked around with this message at 14:41 on Jul 13, 2023 |
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Jul 13, 2023 14:38
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the ones who were able to flee were highly correlated with the ones who were actually good, iirc. there were only a few theorists who ended up believing in that crap, like teichmuller
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Jul 13, 2023 14:41
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bob dobbs is dead posted:the ones who were able to flee were highly correlated with the ones who were actually good, iirc. there were only a few great theorists who ended up believing in that crap, like teichmuller Franck and von Laue in particular were bravely outspoken against Nazism. But more I'm talking about having all those minds concentrated in one place, working together on peaceful scientific endeavors, rather than having to scatter across the globe. It's hardly the worst thing the Nazis took from humanity, but it bears mentioning.
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Jul 13, 2023 14:44
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When it came to the big German scientists and engineers of that time, how many of them were full and enthusiastic supporters of the Nazi regime, and what happened to them after the war? Did the ones who were hardcore Nazis all get pardoned, or did any of them end up getting trials?
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Jul 13, 2023 17:14
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zoux posted:Franck and von Laue in particular were bravely outspoken against Nazism. But more I'm talking about having all those minds concentrated in one place, working together on peaceful scientific endeavors, rather than having to scatter across the globe. It's hardly the worst thing the Nazis took from humanity, but it bears mentioning. I mean, a lot of them did end up concentrated in one place... it's just that the place happened to be Los Alamos. And so not exactly peaceful scientific endeavors, but it wouldn't terribly surprise me to learn they may have gotten less work in some areas of physics done on Earth-2 without the enforced concentration on a single topic due to the war. One of the even-less-knowable counterfactuals, of course. Weren't the Soviets able to pretty rapidly figure out "the Americans are working on an atomic bomb" by just noticing how many Big Names stopped publishing in the open scientific literature when they were "invited" to Los Alamos? The spies helped too, obviously.
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Jul 13, 2023 17:17
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Timmy Age 6 posted:I mean, a lot of them did end up concentrated in one place... it's just that the place happened to be Los Alamos. And so not exactly peaceful scientific endeavors, but it wouldn't terribly surprise me to learn they may have gotten less work in some areas of physics done on Earth-2 without the enforced concentration on a single topic due to the war. One of the even-less-knowable counterfactuals, of course. The enrichment problem was so significant that I'm not sure what the development of an atomic bomb looks like without billions of dollars and the threat of the Nazis making their own driving it.
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Jul 13, 2023 17:20
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two fish posted:When it came to the big German scientists and engineers of that time, how many of them were full and enthusiastic supporters of the Nazi regime, and what happened to them after the war? Did the ones who were hardcore Nazis all get pardoned, or did any of them end up getting trials? A large number of them were captured and made to work for whichever country captured them. 1600 former Nazi scientists, engineers, and technicians were taken to the US in Operation Paperclip, and 2500 were taken to the Soviet Union in Operation Osoaviakhim. After the international tribunal at Nuremberg, the US had trials for doctors who committed inhumane experiments and chemists who developed poison gas, among others. The Doctors' Trial, the IG Farben Trial, and the RuSHA Trial. Several of the doctors were hanged for their personal involvement in crimes against humanity; the agricultural scientist who developed Generalplan Ost was sentenced to time served after three years' detention.
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Jul 13, 2023 17:28
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the fuckin journal paper dudes knew cuz so many peeps started subscriptions in los alamos. also a few preachers who got the only partially correct eschatological pamphlet in history
bob dobbs is dead fucked around with this message at 17:34 on Jul 13, 2023 |
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Jul 13, 2023 17:30
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bob dobbs is dead posted:also a few preachers who got the only partially correct eschatological pamphlet in history I knew about the sci-fi magazine (iirc it was that, not a journal which is lmao in its own right) but can you expand on this? Hadn't heard this one.
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Jul 13, 2023 17:35
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bob dobbs is dead posted:the fuckin journal paper dudes knew cuz so many peeps started subscriptions in los alamos. also a few preachers who got the only partially correct eschatological pamphlet in history I've heard about the sci-fi editor who noticed so many people changing their addresses to Los Alamos. Do you have any more information about the preachers?
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Jul 13, 2023 17:35
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Supposedly the editor of one of the big science fiction magazines (GALAXY or AMAZING STORIES or something) figured something was up when he noticed a whole bunch of his subscribers from Ithaca, NY and Princeton, NJ and other college towns had filed change of address requests to the same post office in some empty quarter of the New Mexico desert. e:f,b!
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Jul 13, 2023 17:37
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https://www.nytimes.com/2014/09/30/science/espionage-threatened-the-manhattan-project-declassified-report-says.html declassified 2014, so thats why its not common knowledge
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Jul 13, 2023 17:42
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yeah, both journal papers and the scifi dudes
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Jul 13, 2023 17:43
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bob dobbs is dead posted:https://www.nytimes.com/2014/09/30/science/espionage-threatened-the-manhattan-project-declassified-report-says.html Got a non-paywalled link?
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Jul 13, 2023 17:49
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https://archive.is/9miWr
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Jul 13, 2023 17:50
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two fish posted:When it came to the big German scientists and engineers of that time, how many of them were full and enthusiastic supporters of the Nazi regime, and what happened to them after the war? Did the ones who were hardcore Nazis all get pardoned, or did any of them end up getting trials? It's complicated https://www.youtube.com/watch?v=wuJZhT834Ss https://www.youtube.com/watch?v=L5WOnYB2-o8
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Jul 13, 2023 17:52
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Cyrano4747 posted:So does this mean we end up shooting really long bullets but with conventional weight:bore size ratios? Note that a projectile gets harder to spin-stabilize as length:diameter ratio increases, which is why modern anti-tank rounds are fin-stabilized. The higher the ratio the faster the spin rate necessary to keep precession to an acceptable amount, and your twist ratio would become absurd and eventually you'd exceed the tensile strength of your projectile (Gold's tensile strength is considerably higher than lead's but not as high as copper's). Quackles posted:I think the Soviets did this by accident at one point, in one of their reactors. It's been done on purpose, first with neutron bombardment of mercury. Au198 is used to treat prostate cancer but that isotope is just produced by neutron-bombardment of regular pure-strain gold. Phanatic fucked around with this message at 17:57 on Jul 13, 2023 |
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Jul 13, 2023 17:52
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Fangz posted:It's complicated Didn't Heisenberg make some incorrect decision that kneecapped the German A-bomb program from the start? I vaguely remember that detail but not what it was, maybe the wrong kind of enrichment? I know they were all about heavy water.
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Jul 13, 2023 17:53
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I think Heisenberg thought you’d need (reactor) quantities of Nukestoff to make a bomb.
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Jul 13, 2023 17:55
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Phanatic posted:Note that a projectile gets harder to spin-stabilize as length:diameter ratio increases, which is why modern anti-tank rounds are fin-stabilized. The higher the ratio the faster the spin rate necessary to keep precession to an acceptable amount, and your twist ratio would become absurd and eventually you'd exceed the tensile strength of your projectile (Gold's tensile strength is considerably higher than lead's but not as high as copper's). So what you're saying is in this alternate future we have 3mm fin stabilized discarding sleeve sabot gold rod firing swedish Mausers? I'm in.
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Jul 13, 2023 17:57
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This is your periodic reminder that the Nazis were picking on Heisenberg for practicing "jewish science" so heisenberg's mom called Himmler's mom (they knew each other) and made them stop it. And they did. Himmler told the SS to cut out harassing Heisenberg. Because his mom said so. No, really, this is a thing that happened.
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Jul 13, 2023 18:00
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Nessus posted:I think Heisenberg thought you’d need (reactor) quantities of Nukestoff to make a bomb. I know after the war he was like 'No way was I asking the Fuhrer for the actual money and manpower needed to make a bomb in 1942" but I always figured that was just sour grapes.
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Jul 13, 2023 18:01
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Also gently caress Heisenberg. I've got some sympathy for people who were stuck there because no one wanted to let them immigrate. I'll even throw out a fig leaf that maybe this applies to lower level academics. Like, I dunno, being the junior assistant graduate student in charge of mopping up the heavy water might not be enough for the US or UK to want to let you in (I mean, even so probably good enough ,but we're being generous for the sake of argument). But if you're big enough that your name is still featured in textbooks because of a principle or a constant or something? Yeah, you could have gotten out and if you stayed it was because you decided to stay. And if you decided to stay and keep working for the Nazis: gently caress you. edit: I'll even extend this to Planck. He's a bit more sympathetic because he clearly didn't think things were as bad as they were, and he did try to help Jewish colleagues, but at the end of the day he kept his position even after he knew for a fact that it was untenable. It's rough being almost 80 and going into exile abroad. In the end he at least resigned his position before the war. So it's kind of a softer gently caress you, but a gently caress you none the less. Cyrano4747 fucked around with this message at 18:07 on Jul 13, 2023 |
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Jul 13, 2023 18:03
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zoux posted:Didn't Heisenberg make some incorrect decision that kneecapped the German A-bomb program from the start? I vaguely remember that detail but not what it was, maybe the wrong kind of enrichment? I know they were all about heavy water. Heisenberg seriously miscalculated the critical mass of uranium. His goof was basically to use a random-walk model: Sphere of pure U235, neutron in the center flying off in some direction towards the surface of the sphere. After some mean path length, it'll smack into a uranium nucleus and cause a fission, releasing two neutrons flying off in some random direction. So he basically asked "We need some number n of neutron-doublings to get a bomb, we take mean path length as a given, what radius sphere do we need to get n doublings?" and came up with an answer like "our sphere needs to be a meter in radius," which is *tons* of uranium. Here's a good explanation of the problems with this approach and how the Allies did it instead: https://www.cantorsparadise.com/how-one-miscalculation-stopped-nazi-germany-from-developing-the-atomic-bomb-3305b442cabc https://www.cantorsparadise.com/derivation-of-the-neutron-diffusion-equation-64087afbdd20 https://www.cantorsparadise.com/solving-the-neutron-diffusion-equation-and-calculating-the-critical-mass-of-uranium-cf90cc3bd16f Phanatic fucked around with this message at 18:12 on Jul 13, 2023 |
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Jul 13, 2023 18:08
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Phanatic posted:Heisenberg seriously miscalculated the critical mass of uranium. Ah, thanks, I'll check these out.
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Jul 13, 2023 18:13
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FMguru posted:Supposedly the editor of one of the big science fiction magazines (GALAXY or AMAZING STORIES or something) figured something was up when he noticed a whole bunch of his subscribers from Ithaca, NY and Princeton, NJ and other college towns had filed change of address requests to the same post office in some empty quarter of the New Mexico desert. Related, here's a science fiction fan claiming to have deduced the Manhattan Project from the news blackout on uranium. I don't quite believe it, but the broad strokes are plausible: quote:In the first edition of Willy Ley's book Rockets and Space Travel, he said he didn't see how Uranium-235 could possibly be applied to rocketry. This was before the A-bomb. I wrote him a castigating letter — me, a 15-year-old kid arguing with the great expert — saying of course you could apply atomic energy to space flight. Willy wrote me back saying he could not comment because the military wasn't allowing anyone to talk about U-235. I linked that with the fact that I hadn't been able to find any recent information on U-235. In 1939, everyone had been talking about it freely. I notice you've got the facsimile edition of the July 1939 Astounding in your bookcase there. The editorial is about U-235 and atomic energy. Suddenly in 1940 — boing! — all references to U-235 disappeared from the journals. Yet I knew they couldn't have just lost interest. My natural speculation was that a military project was afoot and, considering the complete silence, I assumed it must be a realistic, practical military project. They weren't thinking of using U-235 in the Third World War; they were planning to use it in the Second! I argued this with my friend Bruce Knight. I was saying there must be a secret atomic bomb project and we're going to drop an A-bomb on the Japanese very soon. He pooh-poohed me. We argued until three in the morning. The next day, while I was mowing my lawn, Bruce came down the street white-faced. "Guess what," he said. "What?" "You won the argument." "What?" "They've just dropped an A-bomb on Japan!"
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Jul 13, 2023 18:19
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My grandpa was at summer camp in 1945 and was messing with the radio trying to find music. One of the other guys had the dial and grandpa Nessus said wait wait turn it back! Why? It’s some news report. I heard them say atomic bomb, I wanna find out who won the war!
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Jul 13, 2023 18:24
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