A few months before this happened Slokin did this 'trick' for Enrico Fermi. Fermi told Slokin that if he kept doing this this way he'd be dead inside a year..
The sad part to this is after it happened he turned to the scientists and said "well, I guess that's it". He knew what happened was his death sentence and there was no going back. He died of extreme radiation sickness/poisoning 9 days later. The hand he had used to pick up the demon core was completely burnt with irreversible damage and was decaying before he even died.
At the moment of supercriticality, you had a rapidly accelerating reaction - not nearly as rapidly as in a nuclear explosion ( a linear acceleration rather than an exponential one ), but when both blocks slipped, you basically had a dirty bomb spewing lethal radiation at extreme doses. Slotin was right at ground zero, plus he actually handled the beryllium shell with his bare hand. He got some insane exposure numbers and was dead within days. The two other close-in people were injured by the radiation but survived - at least until cancer took them out. The rest, AFAIK, lived normal lifespans and weren't permanently affected by the dose. Had Slotin not thought quickly and removed half the sphere, the reaction would have cotinued to accelerate, melting the core and spewing radioactivty enough to kill everyone in the room. He saved the lives of almost everyone there by sacrificing his own. That blue glow, BTW? That's called Cherenkov Radiation. it is a very complex phenomena that is present when huge numbers of high energy particles start stripping electrons off things and create a blue ionization glow. If you're *right next* to the reactor when you see that glow... heaven help you. Slotin knew exactly what it meant.
@@Klemheistthis is why I have no respect for people who say "nuclear [whatever] is perfectly safe!" It may be possible in theory to design a perfectly safe system, but add human beings to it - even as in this case, ones like Slotin who absolutely know the dangers - and shortcuts will be taken, mistakes will be made, and accidents will happen. People who don't accept that fact and just want to do it without considering and preparing for the consequences are a menace to society.
@@langdons2848 Its people like you that caused us to lose the best environmentally friendly fuel source we had. I don't think you understand a goddamn thing about nuclear energy.
@@Moritz558 Yep. He made a really reckless, careless mistake in not using the proper shims (which weren't a great failsafe to begin with). With just one screwdriver in place, he was toying with death and he and two others paid the price when he slipped up. It doesn't make him a hero that he went after the beryllium sphere with his bare hands, but at least he rectified his terrible mistake even at the cost of his own life.
Feynman told him to use the shims to avoid this very accident because he was the second guy to die doing this experiment. In reality, the sphere should have been stationary on top and they should have been lifting the bottom half up to do the experiment so if it slipped, the bottom half would fall away in a safe fashion. But this is the reason they don't do supercriticality experiments in this fashion anymore.
If you ever feel clumsy, just think of the whole team of scientists who thought manipulating deadly radioactive material with a screwdriver wedged between two surfaces was a great idea
The fact that they didn't manage to make a mechanical apparatus to safely and precisely control the experiment shows that they were truly scientists and not exactly engineers.
Slotin was warned repeatedly not to do what he was doing by hand, that proper equipment existed/would not be hard to devise and provision, but he liked showing off.
Thanks, I'll be more humble the next time my flathead slips off the head of a fastener. I've always cursed the things for it, but it really could be worse I suppose.
I know nothing about nuclear physics but I ended up here after reading about this on the BBC website a few days ago. It is based upon an actual event that took place at Los Alamos and caused the death of Louis Slotkin. I understand how dangerous radiation is. And while John Cusak, playing the unfortunate Dr. Slotkin is working from behind some sort of shielding material why are there so many other people there and why aren't all of them behind the shielding as well? This was very early in our experience making atomic weapons and to a degree they were making it up as they went along so they did things that would be unthinkable today. But this is an object lesson for all of us. When venturing into the unknown it is best to tread carefully.
It is a combination of two events. Those of Louis Slotin and Harry Daghlian, ironically both working on the same sphere of plutonium. Slotin did use the screwdriver and beryllium spheres to cause the reaction, but not the tungsten bricks. Slotin never grabbed the spheres to stop the critical reaction, but Daghlian did use his hand to grab the fallen tungsten brick. It really is a story that is almost stranger than fiction that the same exact sphere of plutonium killed two men in very similar ways in an identical experiment.
@@r.hudsonmadeo5745 Yes i had also heard of the death of Daghlian. And as you say it is ironic that both men died from exposure to radiation from the same core. Even more ironic both men died on the 21st of the month, Daghlian on August 21, 1945 and Slotkin 6 moths later on May 21 1946.
@@r.hudsonmadeo5745 Also fascinating that it was a core that was destined to have been dropped on Tokyo if Japan had not surrended. The story of the demon core is remarkable. And shows along with other events what little margin for error one has when doing this kind of things. It also shows how complacent you can get about anything. I know that from my time in a chemistry lab where I did not treat very very toxic chemicals with the respect that they were due.
@@jimbonacum8917 Slotin was warned about his experiments, that he is violating safety rules. That metal around is not shielding, but reflector. When material is spontanuosly decay, emits some free neutrons, that escape. Reflector is bouncing this free neutrons back to material, causing more decays. So it is producing more neutrons, more energy. Thats supercritical state. Released energy and radiation level jumps crazy. They knew it, but who cares safty rules.
Inverse square law. Doubling the distance from the radiation source will decrease the radiation by a factor of 4. The reason why he had people in the room mark their positions was so that later they could estimate how much radiation each person received. The reason he had people remove metal was because the radiation source released neutrons, which can transform other atoms into radioactive isotopes. This is called neutron activation. The source also released gamma rays, but those don’t make other atoms radioactive (except in extreme circumstances that wouldn’t apply here). Using the amount of neutron activation created in the metal it could be helpful to determine how big of a neutron flux (how much they got sprayed with) each person received. So a person could still be relatively close but not receive a lethal dose simply by being twice as far away. Slotin died in 9 days. The next closest person got radiation sickness, but survived 20 more years. Everyone else in the room was unaffected.
It is truly surreal that Slokin and other highly educated physicists performed a similar maneuver to what is depicted here. Slokin melted alive, burned lethally by radiation for his recklessness.
@@TransoceanicOutreach Actually, when you suffer severe radiation poisoning, the effect is essentially melting while alive. 'Dissolving' might be a better word than melt, but you're basically falling apart and - in cases - liquifying.
guy's name was Slotin, not Slotkin. As noted by others, it took place after the end of WWII, but this core killed another scientist in a very similar manner earlier. And no, the procedure was not necessary. Slotin was showing the others how this stupidly dangerous procedure, knows as "tickling the dragon's tail" is performed.
Apparently, Italian physicist Enrico Fermi had warned the scientists at Los Alamos not to use a screwdriver and recommended a separate tool that was supposedly safer and more stable.
Louis was best friends with Harry Dhaglian Jr and was on comforting him on his death bed when he passed from doing essentially the same thing slotin died doing
The difference between a scientific experimenter and a careful engineer. One is often daring, even reckless, and unperturbed about unknown risks. The other sees their role as precision and caution in the name of safety and efficiency
I mean what did he expect using a freaking flathead screwdriver? This was known as "tickling the dragon's tail" as far as the screwdriver is concerned, because they knew it was dangerous and did it anyway. Personally, I would have preferred some type of mechanism similar to the caliper-like device that he is shown using...but affixed to the shell and keeping it separated. Twisting a long screw would keep it from opening or closing too fast.
@@Spaceflightlover2010 shims where supposed to be used and where present to be used but they where taken out so they can push the system closer to the critical state. It was just a guy chasing glory which led them to throw out every precaution out the window
This is what is the scary part of this scene to me. We've got some of the best scientists in the country playing around with the heart of an atom bomb in such a rinky dink fashion like they're working on a water heater.
@@dergunter1237I believe it, but it seems so far-fetched. I was only a mechanic, but did occasionally fabricate things like flanges -- I know my way around a straight edge and feeler gauge. They could have had shims at thin as 0.002" which, unless you're a watchmaker, would be thinner than a flathead screwdriver.
@@Spartan536 I suppose it's arguable. They both have lasting effect that still exist today. I think the whoopsie in Chernobyl could have been mitigated without the aforementioned mountain of lies. And Ego. And Beaurocracy. Goddamn imagine being one of those people who just threw themselves at fixing it knowing they were shortening their lives. The one dude that was forced to look in the reactor. I would have told them to shoot me now. I don't know if that was dramatized or not, but no. Shoot me now and it'll be faster.
@@singh2702 1 person received lethal those, 2 people had radiation related illnesses later in life, rest of them lived normal lives. It depends on how close you are you it. Inverse square law.
@Cattleclysmic In conclusion, when you see that bright flash you are on the clock 👍 don't try and sugar coat it. These men were tryna find out how far criticallity can be reached with no protection.
@@CattleclysmicBut the blue flash also signaled that “criticality” or a nuclear reaction had begun. If nobody had separated the sphere it would have resulted in a meltdown that would have killed them all.
@@RidgeR5 And yet he was plenty times more brilliant than any of us commenting here. Maybe this kind of thing just isn't for you. The man who invented penicillin injected himself with it first, Marie Curie the famous radiologist died of radiation poisoning because she played around with all her radioactive elements without much concern for safety, even the madlads at the CIA would take massive acid (LSD) hits themselves before they started experimenting on homeless people, soldiers and prisoners.
@@RidgeR5 also to be fair, poking a fission bomb with a screwdriver in a shack was sort of the culture. this accident happened in 1946. the postwar-era was...interesting. in 1950 we literally gave functional miniature reactors with real Uranium-238 to children as an alternative to a "Chemistry set": en.wikipedia.org/wiki/Gilbert_U-238_Atomic_Energy_Laboratory
@@nighttrain1236 you’re all absolutely right he wasn’t USING the ID portion, but if you look closely you do see a thin “tail” on the back, that is the Inner Dimension portion that would’ve been used.
It’s a pity they messed with historical records for the sake of drama. The criticality accident that fatally dosed Michael Merriman occurred on May 21, 1946, well after the timeline of the Hiroshima bombing.
@@jeffwads That was the name of the character in the movie. In fact, two different people were killed in two accidents in the same way by the same core. It came to be known as the demon core. Harry Daghlian was killed in 1945 and Louis Slotin in 1946. The demon core was melted down in 1946 and reused in other cores.
Similar in Chernobyl the popular HBO miniseries. They depict a helicopter crashing in the show at a time earlier than the real accident. A helicopter did crash but it was much later. Anyhow, I guess it's worth showing because it conveys how severe and catastrophic the conditions are, even if they distort the timeline for dramatic effect. It's good that people know about Slotkin.
@@patrickdezenzio4988 Yes. Watch very carefully in the show, and you can see that is depicted. It's hard to see because it's so far away, but the helicopter in the show hits what looks like cables or a crane, and you can see the rotors break apart first then it falls. The TV show does a pretty good job, though liberties are taken
And apparently that parts not made up. Every account I've heard is he was very matter of fact about it and then dedicated his remaining time to documentation and dying.
The sad thing about this event is it didn't happen during the development of the first two bombs used in the war as portrayed in this movie. It happened in 1946 but was really dramatic so the movie producers shoe horned it into this movie.
@@samurphy They weren't convincing enough. The Japanese government did not understand what had happened. It was the destruction and rout of the Kwantung Army in Manchuria by the Soviet Red Army that convinced the Japanese that the war must be ended now. Japan knew it had lost after Guadalcanal and Iwo Jima. It had lost air superiority over the home islands and even it's littoral defence forces were inneffective.
I've read about this incident before. When I watched the series "Travelers" I instantly knew that David was dead the moment the two halves of the bomb closed.
Some non-obvious details: When the moment of criticality occurs the core would be in what is known as a "prompt critical" state. Importantly, this differs from supercriticality where there is a high neutron/fission multiplication factor between generations. In a supercritical state you would get a fission explosion due to the rapid escalation of energy levels on nanosecond time scales (one "shake" is about 10 nanoseconds, that's roughly the time between generations in a fission bomb core, in 1 microsecond that can grow to more than enough energy to vaporize the bomb, or at least blow it apart in a "fizzile"). However, that doesn't happen here because there are rapid negative feedback mechanisms that keep the core right on the line of criticality and limit the energy release. One mechanism is doppler broadening, as the core heats up the relative velocity of neutrons and nuclei broadens out of the "sweet spot" where criticality occurred. Another is just thermal expansion of the core and the neutron reflector material, both of which are better at doing their jobs at higher densities. In small research reactors this effect is used intentionally where the core will be pulsed in a prompt critical state which will only last a moment before reaction rates fall due to those natural negative feedback mechanisms, providing ample time for the control rods to move into place. As a side note, if you're wondering how similar things play out in a power reactor, they tend to rely on a combination of both delayed neutrons from fission products as well as negative feedback from interactions with the moderator, making it possible for well designed reactors to be easily controllable. The blue glow depicted here is often said to be from Cherenkov radiation but it was actually just from regular ionization of the air.
Imagine being smart enough to know how to make an atomic bomb and dumb enough to use a standard screwdriver to carry out this test, screwing up ROYALLY, and then having then having the presence of mind to tell everyone to mark where they were standing when it happened. Humans. 🤦♂️
Theoretically, once the beryllium spheres are fully separated from via the screw driver wedges, it is safe to simply pick up the beryllium sphere. The actual one used by Slotin had a thumbhole in it for him to gab and he only used one screwdriver and his hand holding the beryllium. I say, "theoretically" because you wouldn't catch me doing this experiment.
@@r.hudsonmadeo5745 Two or three quarters taped together, taped to the edge so if he slipped, they wouldn't touch. But that's something I wouldn't trust either. I'm not genius (134, 6 points shy) but I'm damn blessed with the common sense to never mess with anything dangerous without proper failsafe equipment. Especially the guts of an atomic bomb. No matter what, he died a hero that gave his life for his country.
They were scientists. Did none of them ever think to reverse the setup? Have one half of a sphere suspended upside down and then the other half underneath with the guy holding a screwdriver pushing it upwards towards the first sphere from below. That way if someone fudges with the screwdriver, for instance when some lame drops their coffee mug and startles him, the sphere that person is manipulating upwards simply falls away FROM the other half. Not downwards onto it...
Apparently that was suggested and they rejected the idea. At which point I would assess whether or not they should be allowed near plasticine, let alone plutonium.
OK after watching the scene God knows how many times, I have to ask the question: why the fuck did they not build a rig for this thing? An entire compound full of engineers, scientist, and tinkerers, and no one thought to create a system in which one could safely lower 1/2 of the sphere towards the other, safely? When was dangerous items ever created in there fiddling around with it with a couple of screwdrivers? I thought these guys were supposed to be smart.
There were supposed to be stop-blocks and safety measures to prevent this but the character cusack is based on often disregarded them. They used to call the guy “the nuclear cowboy.”
The point of this experiment vs. the risk involved just amazes me. People love to think they're in control...until they're not. They should've brought the other half of the sphere up from the bottom so human error would stop it automatically rather than set it off.
Isn't it really impossible to get a manipulator that can be studied, carefully lowered, carefully raised, to study the critical mass for this. But you also need a protected room with a thick lead wall. In the USSR, the laboratory was specially studied by the laboratory and a manipulator and an excitation sensor were carried out there
A screwdriver? I'm assuming a group of engineers who built the bomb could design a better setup. Maybe a screwdriver that is 10ft. long and allows you to stand behind a lead curtain.
@@ItalianoYMexicanoaccording to other comments there were safety rules/protocols which he ignored, the guy portrayed here was called a nuclear cowboy, and warned even before the accident that he would be dead inside a year.
I think the main issue was the design of the experiment itself, they would've been fine if he wouldn't have used freaking screwdrivers to prevent supercriticality.
@@Teddy_Bass well it should since they are playing with fire and it kills when they screw up with these games on the bright side your learning why safety rules exist
"Yeah, I fix my Dad's car engine when it breaks down. And I took a few physics courses at the annex. How hard could it be?" - Not QUITE as reckless as the actual physicists who fucked around and found out by basically playing catch bare-handed with nuclear baseballs. But close.
I hate to call this a benefit because it was a tragedy but because of this incident we had for the first time detailed notes and symptomology for radiation sickness. Radiation is way outside my field but I would imagine that what was learned in this accident saved many lives afterwards or at least gave future patients of this a better chance of survival.
there are no better chances for survival... nothing to learn here... you are either lucky or not depending on how much exposed you are... lucky being being dying from cancer a few years down the line... besides, I think Marie Curie had already done enough by the time this guy decided to play with fate
At the moment of supercriticality, you had a rapidly accelerating reaction - not nearly as rapidly as in a nuclear explosion ( a linear acceleration rather than an exponential one ), but when both blocks slipped, you basically had a dirty bomb spewing lethal radiation at extreme doses. Slotin was right at ground zero, plus he actually handled the beryllium shell with his bare hand. He got some insane exposure numbers and was dead within days. The two other close-in people were injured by the radiation but survived - at least until cancer took them out. The rest, AFAIK, lived normal lifespans and weren't permanently affected by the Had Slotin not thought quickly and removed half the sphere, the reaction would have cotinued to accelerate, melting the core and spewing radioactivty enough to kill everyone in the room. He saved the lives of almost everyone there by sacrificing his own. That blue glow, BTW? That's called Cherenkov Radiation. it is a very complex phenomena that is present when huge numbers of high energy particles start stripping electrons off things and create a blue ionization glow. If you're right next to the reactor when you see that glow... heaven help
What amazes me is that he had a pair of calipers. In about ten minutes I could spot weld a couple of thin metal plates to the calipers and use them to accurately gap that core. Two plates on the jaws and a way to attach the screwdriver to the thumb wheel would have saved his life AND gave accurate reading with the caliper. I mean come on man, billions were spent and they couldn't have come up with a safer solution?
Well,That mark position thing is quite critical. At least he did that part. This was before people know anything about nuclear in general, just like kids in the 60s might hold some liquid mercury in their hands before.
How come everybody is misspelling his name on this particular comment section? And don't praise slotin for "sacrificing himself", he caused the accident in the first place with his stupidity.
They make it look like it was an experiment that they all had to do exactly like that and under those unsafe conditions. Slotin had been told on multiple occassions that conducting that demonstration with the demon core would cost him his life. He called it, "flicking the dragon's tail". His death should be an example, to not let pride, boastfulness and egotism be a factor in taking precautions with dealing with radioactive materials.
Nope, that was the second incident. This is supposed to depict the first, but even still, the first incident with what would become known as the demon core occurred on 21 Aug 1945, 6 days after the Japanese surrender. They took a bunch of liberties with this film. Still a good watch though.
@@PopulismIsForBottomFeeders so, it involved Harry Daghlian, not Louis Slotin ... I have not watched the film, but from the clips it seems that the scene is temporally misplaced ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AQ0P7R9CfCY.html
@@yallowrosa Well... when I said they took a bunch of liberties with the historical accuracy. In short, John Cusak's character doesn't exist exactly. He's a composite of 2 or 3 people. But as I said, it **is** a pretty good '90s film in spite of the divergence from total accuracy. Also kinda funny that it's effectively a portrayal of first atomic weapons program being led by Murdoch from the A-Team.
@fahQ8869 But apparently, the first incident involved a brick that fell on top of the core. The sphere slipped down on the core in the second incident. Both happened after the war, not during as depicted in thr movie.
Even with screwdivers couldnt they just put some distancers should it fall like that to not close? I researched a bit about it they used distancers on 3 sides and he tried to get rid of one with the screwdiver. That resulted in the heavy berillium ball to cause a vibration that moved the other two away and thus the thing happened
I am gonna have to see this Movie. I looked into the actually events of the Demon Core and they are fascinating but also sad when the 2 incidents Killed People.
@PORRRIDGE_GUN it sounds ridiculous to you. It sounds funny to me. But we both know the language in different country's are weird to anyone, not from there. Still, Fat Man and Little Boy has its meaning to the bomb s
As far as Slotin’s portrayed reaction here, smart. As far as his tail tickling of the dragon, not smart at all. This experiment had already cost another man his life.
this is why exponential is such dangerous concept if occur in real world. human brain does not comprehend that on basic instinct level and our safety and well-being is driven by instincts. This is why we need rules and strictly obey them, when we are dealing with phenomena which is described by exponential.
Imagine being in that moment at 1:36, you KNOW FOR SURE you're going die horrifically. If that was me, I'd have run outside, found an MP, tried to take his weapon to shoot myself with it
@@nycot107 I read. We all end up dead. So either you didn't understand that they iddn't die from this incident, or you said something completely useless. Neither is a good look.
Honestly, it’s sad it happened, but if your using a screw driver as your method of separation, you deserved this. How can someone so smart be so stupid?
US Military "This ball of uranium has already killed people, we named it the demon core, please be careful with it" US Scientist (pokes it with a screw driver)
There are a lot of people involved in that era who had absolutely no idea of what they were playing with. The story goes that John Wayne was shooting the movie Genghis Khan in the desert right next to a site where they had been doing nuclear testing. As if that wasn't bad enough when they finished shooting on location and had to do some extra shots in the studio, they actually went out to the site and imported a few tons of dirt from the area just so that it would match on camera. Just about everybody who worked at that location wound up dying of cancer including Mr Wayne himself. They hadnt quite figured out the rules about nuclear fallout and radioactive Half-Life yet... Or if they have they just forgot to mention it to Hollywood when giving them permission to shoot there.
While most of what you say is true, the story that everyone who worked on that movie died of cancer from the radiation is an urban myth. It was never radioactive enough when they were out there to do what that story claims.
@@RedSiegfried Statistically though, the cast and crew do seem to have had significantly higher cancer rates. 220 people, 91 cancers and 46 deaths in the period from 1955 to 1980. The radiation was from the HARRY test, part of Operation Upshot-Knothole, (UK#9) and was one of the dirtiest tests in terms of fallout in US continental testing. Due to a sudden change in wind direction the fallout was scattered well outside the Yucca Flats testing area. It is believed the name of the character 'Dirty Harry' played by Clint Eastwood was some form of homage or protest
