I love the attitude of “well if this goes wrong I won’t have to worry about it”

George Kistiakowski was a truly colorful character. He was my dad’s research director at Harvard in the late 50’s/early 60’s. I grew up hearing stories of his exploits in the OSS and at Los Alamos. He had a feel for explosives that was uncanny in its accuracy. He once used plastique to rescue his home concrete mixer after a load cured inside of it. The explosion shattered the concrete without harming the mixer and the particles were simply poured out of the drum. A very colorful character who my father loved as man and mentor.

I used to drink beer regularly with a physicist from the Manhattan Project. He worked on detonation timing for the conventional explosives. He wanted to watch the bomb go off from one of the trenches but his boss said no way. After implacable badgering, his boss relented and declared, "OK but you'll be downwind!" He was the only physicist to witness the blast from a trench. He passed age 82 from MRSA infection after surgery. His name was Dick Davison.

Not only does Scott know his stuff, but he is also a great story teller.

Dentist drill makes perfect sense, they're air powered and run at about 400,000 rpm. But have practically zero torque. I used to demonstrate by engraving on a piece of steel and would then jab it onto the back of my hand whilst still running, where it would immediately stall. Same will happen if the dentist accidentally hits the gum or tongue, they're amazing from an engineering viewpoint. Other than the sound they make...

17:43 the idea of a camera plane flying over and practically turning on the sun for a split second and everyone being stunned is so funny to me😂😂 Would have never knew that existed without this video

The thing about the photography side was that the ultra fast gas switches were not used to fire the Xenon flash, which, for the technology of the time, was easy to do, using a simple high voltage pulse that ionised the gas in the Xenon flash tube at the cathode end. The big thing was they had to actually only fire the tube for a very brief period, so as to only have this very short burst of very bright light, so that the motion of the aircraft would not blur the image. Thus the need to develop a device that would be able to turn on very fast, and also handle a massive current pulse, so as to dump all the charge in the capacitor bank used to provide energy to light the flash tube, so as to drop the voltage across the flash tube (at this time it would be dropping from the 400V or so initial voltage, to the cut off point of around 60V, where the tube itself would start to slowly cut off due to the arc voltage being below the voltage needed to keep it on, slowly being in the order of tens of microseconds) to close to zero, and thus ensure it has a sharp cut off. Most devices at the time would either not last more than a single use, or would not have the fast response needed. This device was the original gas thyratron, and the need for fast ones meant they made them with a hydrogen gas fill, with early ones filled with neon being both slow, and too low an operate voltage. Hydrogen gave the needed high voltage stand off needed, and because it is light, it also ionised very fast, giving the very rapid current path build up, in the order of nanoseconds from fully off to fully on. This has led to them being now an export controlled device, and to this day an item that is still made, on the original tube lines, by some specialist companies in the USA, as the US military needs them for operational parts, and, because of the hydrogen gas fill being able to penetrate almost all seals with ease, a part that has a very limited shelf life of around 2 years, before you need to either replace or rebuild it. Neither are cheap either. You can test it at lower current, and do all your qualification at this level, as full power operation you only have around 5 uses, before it degrades to the point it is no longer usable. Selling them is ITAR restricted, as heavily as any part can be, because of the one use case, so there have been a few attempts to steal the technology. These days you still find it hard to get the same power delivery with small volume, it really is a part that is perfect in it's application. But you can do it, with modern high power semiconductors from specialist companies, with corresponding exotic semiconductor compounds, and prices that make the gold used to plate them the cheapest cost in production. Incidentally the bridge wires also underwent massive changes, from simple thin wires, to the modern ones, mass produced using semiconductor wafer processes, to make thin film metal alloy strips that are precisely controlled in shape, composition and dimension, so that all of them are as close to atomically identical as possible. The difference in timing between them is in the order of picoseconds, they are that identical.

The nice thing about being a bomb tech is that if anything goes wrong it will suddenly no longer be your problem.

For anyone wondering, high explosives are somewhat hard to detonate, you usually need another smaller explosion to set it off.

My favorite safety mechanisms that got built into modern nuclear weapons. They built the implosion soccer ball in slightly differently sized segments. Without a precisely timed electrical detonation any outside forces such as fire or bullets would not set off the bomb in the correct sequence to acheive critical mass. Further more you can add another layer of safety by encrypting the precise firing order for the explosive lenses. Grandpa was smart

Funny story about TNT. I was born in 1957 and had an interest in chemistry when I was in grade school, probably 4th through 6th grade at the time. I had a chemistry set and did all the examples in there, then I went to thrift stores and bought a bunch of chemistry books. This was in the early 60's and the books were mostly introductory college chemistry as taught during world war 2 as far as I could tell. They described reactions that would produce all sorts of explosives. I made gunpowder, thermite, nitrogen tri iodide, and other stuff. The TNT was a soaplike or waxy white stuff that could melt but could not be ignited by a fuse or hammer. My dad freaked. He explained that this was nothing like the burning stuff I had seen. Its hard to set off, but if you did, it would shatter the hammer head, even the tiny amount i thought would be safe. No parent went to the school and demanded those books be removed. Just sayin.

I met Doc Edgerton in 1976 in my freshman year at MIT. I was really impressed with his regular-guy attitude: I spent about 4 hours in his lab, ending after midnight, with just him and a fellow student. We had fun shooting cards in half with a rifle bullet and getting a flash picture of it. We played with all the original apparatus we've seen in the famous photographs like the milk crown, the water drops, etc. And he was having as much fun as we were, no pretensions at all. What a nice guy he was!

In the movie The Peacemaker, a teeny-tiny, 'backpack', implosion nuke is disabled at the end by the 'heroes' by prying off the cap of one of those 'soccer-ball' explosive segments. It went off as a teeny-tiny, 'dirty', chemical bomb rather than a 'nuke'.

If anybody doesn't know that yet, the author Richard Rhodes has a wonderful book "The Making of the Atomic Bomb" that has this story and many more. It's a wonderful, well-researched classic. Highly recommend.

In movies about the Manhattan project it fascinated me to hear the physicists talking about how difficult it is to make a nuclear bomb explode: the timings, the implosion, the precise geometric shapes of the explosives, etc.! Even though this is extremely complicated many people today still believe that a nuclear reactor can accidentally explode like a bomb!

21:30 to be fair, TNT isn't exactly looking for an excuse to just go off. If you give it an explosion, it'll join in without hesitation, but TNT really doesn't like to start explosions.

The implosion seems like trying to float water on top of gasoline, you might be able to do it with the surface tension but the slightest asymmetry or disturbance and and they instantly swap places

A number of years ago, I spent an evening with a distant cousin of mine and his wife in their chateau in Vail, CO (they were loaded. through the wife's family). When he found that I was an engineering student, he told me the story of his work on the Manhattan Project. I didn't drink back then, but he sure did, and he waxed poetic about the night before Trinity. A great many of the people who worked on it were recent graduates in physics; in other words, college boys. According to him, the crew they had hooking up the EBW firing harness consisted of recent college grads who drank their dinner nightly, and were three sheets to the wind while prepping the Gadget. He was pretty stewed himself while telling the story, and I've never been sure whether that added or took away from its credibility. But there were reckless college grads at Los Alamos: Harry Daghlian and Louis Slotin were both killed in separate prompt criticality tests of the same plutonium bomb pit, known these days as "the demon core". Slotin had supposedly been warned by Enrico Fermi that he would "be dead in a year" using the experimental procedure he employed. Decades later, a senior engineer from Rocketdyne told me of his visit to Los Alamos, where he observed some of the college kids setting up their own little nuclear reactors up in remote areas of the mountains, just to do their own experiments. You might do another video on something that is verifiable, namely the Ra-La experiments. Those were tests of the implosion system using radioactive lanthanum, which put out huge amounts of gamma rays, to image the implosion of a lead pit simulating the bomb's pit. They contaminated a lot of land, but solved the problem. Great video, as usual!

To put the spending in contrast, the U.S. spent roughly $3 billion on the Manhattan Project during the war. It spent roughly $3 billion to develop the B-29 Superfortress. It spent roughly $3 billion to develop the VT fuze. It spent about $30 billion on the strategic bombing campaign over Europe. This gives an idea of the scale of industrial and monetary resources the United States devoted to the war effort.

I thought I knew ALL the Manhattan Project trivia! I didn't know ANY of this (and, outside of the demon core hoopla and the failed dress code, this is easily one of my favorites)! Thanks so much, Scott! Everyone and their dog is putting out Oppenheimer videos right now... thanks for not being the same crap in a different nuclear pile (heh. "Fissile Pile" would be an awesome name for a band.)!

In the video clip of the scientists working on Trinity in the tent, you can see Louis Slotin (wearing sunglasses). He would end up dying while conducting experiments one the later cores that were meant to be dropped on other parts of Japan if they didn't surrender. Those experiments involved handling the core with a screwdriver. One day, the screwdriver slipped...

BTW, the guilds say to watch movies and stuff until they call for specific boycotts, so everyone can Barbenheimer it up without guilt!

Interesting piece of Manhattan Project trivia I was not aware of. The other thing that I doubt most folks are aware of is developing the B-29 was more expensive then the Manhattan Project.

The people on strike made a point of saying not to stop watching movies.

Fun fact about TNT, one reason several countries did not start using it in until after ww1 was that it was quite difficult to get it to explode. It cannot burn to detonation, so would be pretty riskfree to drill in.

In case anyone is planning on showing solidarity with the writers and actors, they actually want people to go watch these movies because it shows the studios how valuable writers and actors are.

I used to work at MIT, and one of my fond memories is going to a Doc Edgerton lecture in the mid '80's. Later on, I helped his son Robert who was doing a short-term experiment in one of the buildings associated with the Edgerton Laboratory. A wonderful time, honored to interact with such people.

An entire town full of physicists and nobody thought of thermal expansion ahead of time

I hope you saw "Fat Man and Little Boy" 1989 starring Paul Newman as Groves and Dwight Schultz as Oppenheimer. That film centered on them at Los Alamos and the Trinity test. The only gripe I had was the depiction of one of the Criticality accidents with the "Demon Core" which didn't happen till after the Nagasaki mission.Two older flicks were "The Beginning or the End" 1947 B&W and was highly fictionalized as it was just 2yrs after the fact but did portray the Hiroshima mission. Also "Above & Beyond" 1952 B&W which centered on Col. Paul Tibbets who commanded the group to fly the B-29's and he flew the 1st bombing of Hiroshima.

I love how you get a physics, engineering and history lesson all in one.

So so interesting - I've previously read large parts of what you described, but you really brought it all together for me.

Nice deep dive, I especially enjoyed the spark gap initiator! Thanks to you and your team Scott. Cheers!

Ahh, nuclear physics, always a delight

Similar to the drilling into blocks of high explosives. Supposedly a bomb tech said that he was more concerned about disarming small devices rather than large ones because in the event of an issue the small ones would really hurt but the large devices would suddenly not be his problem anymore

Scott, That was a really good one! No rehash of the same ol' same ol' but a completely new insight of the difficulties that had to be overcome. Thanks.

One of my professors in grad school in the early 70s had worked at DuPont during the war, developing the high explosives that were used. At the time, he only knew it was for better explosives for conventional bombs.

For those uninitiated, probably, the definitive book on the Manhattan Project is "The Making of the Atomic Bomb," by Richard Rhodes. Thanks , Scott.

I enjoy all of your videos, but this one I enjoyed immensely. Thank you Scott.

I would highly recommend reading "The Making of the Atomic Bomb" by Richard Rhodes for deep dive into the full history of the Manhattan Project.

after WWII Edward Teller was pushing for the hydrogen bomb but it was too demanding to do the math for so it got pushed back (that changed when the Russians tested their first nuke). Von Neuman was bought in to help solve this problem and a big part of the reason we have computers today at all is because thermo-nuclear weapons would be impossible to build without those computations

Hmm it's less important that the detonator be quick, than it have a low variance. It doesn't really matter if it takes milliseconds to trigger, as long as they ALL TRIGGER at the same time

So the Manhattan Project scientists set off the world's first dirty bomb before the Trinity explosion...😂 My late grandfather was a freight conductor on the Southern Pacific railroad who worked on the "Golden State" route (El Paso, TX to Tucumcari, NM) , and was working when the Trinity detonation happened, he saw the flash from it. The powers that be fed false information to the local papers the next morning, and it was reported as an ammunition depot explosion

This video is so much better than all the other videos I’ve seen on this topic, so much more detail! I Love that you made this video.

20:38 I can't believe you resisted saying "went off with a bang"

I was expecting «Drill safe» this time :). Thanks Scott.

Great story telling Scott. I am fascinated by the technology and the minds who created something out of nothing. Thank you, please tell us more!

Thanks Scott! I always had visions of all this high tech (there was plenty of that) stuff going on with the “gadget” but to hear that some guy is sitting around with a dental drill and drilling holes into a block of high explosives is just🤯!

This was extremely interesting. You are an outstanding communicator. Thank you.

Fascinating! I had heard of the Jumbo container, but was told that it was some random container they had dragged in to see how powerful the bomb was up close. Your explanation makes much more sense. A successful nuke going off inside Jumbo would be interesting. I didn't catch it if you said it, but all those cables looping around the outside of the bomb were the same length. The signal to the detonators had to arrive simultaneously, and the length of travel affected the timing. (Or so I heard.)

Best video you've done in a while! Thanks Scott

Fascinating insights not offered elsewhere, Scott! Thank you!

I am a HUGE atomic history buff/fan/infinitely interested. I have NEVER heard of the 200ton Jumbo device. Keep it up Mr.Manley, as always, great stuff!

Scott, you’re amazing storyteller… you’re always going to such great details! Wow… 👍 I hope one day you get to go into space you deserve it! God bless and best regards, Greg / Ft. Lauderdale Fl.

Long time fan, Scott Good luck catching views off Barbenheimer weekend!

Thank you for a great explanation of the implosion system and the trigger mechanism. Fascinating history!

Excellent Scott!!! I learned a lot! 👍🏻👍🏻👍🏻

Scott has a way of weaving a tale that makes us believe we are there, much appreciated! Thank you!

This video didn’t disappoint. I’ve been reading about this stuff for years - this really lays it out well

Scott, that was a great recap and explanation of the Trinity Test in NM. Small correction however as “Jumbo” was not made on site, it was hauled there after it was made. Also FYI 2 times a year you can tour both the actual test levels cation and the McDonald farmhouse that was used to do some of the preliminary work nearby the test site. it is very interesting to see firsthand. Keep up the great work!

Terrific explanation, one of your best

Always bringing us new gems out of what we thought we knew pretty well.

Scott - once again a masterful demonstration of accurate knowledge, clearly presented. I have no compunctions sending folks to your site for great expositions with a minimum of fluff! DKB, physicist

Scott, great video! Thanks for sharing!

I thought I knew almost all the history and detail of the engineering solutions and physics of nuclear weapons available in the public domain. I was wrong. You taught me a whole bunch more and reignited my curiosity. Cheers, ma man!

The "Gadget" looks like it would have fit in just fine backstage at an early rock concert🎸🥁🎙️☢️💣💥✌️

Wow, with Veritasium's video the other day about Oppenheimer the man, and now this, we are getting spoiled for atomic goodness 🤘

fascinating info .. thanks for putting this out there!

An explosion creating an implosion to result in the mother of all explosions.🤯

Those krytron triggers were also used in high-end xerox copiers. I bought one a while back on eBay, just for fun.

Great episode with plenty of unusual details. Thank you, Scott.

Very interesting! With a couple of details I didn't know. Thanks Scott!

A late friend of mine's grandfather worked in the metallurgical lab for the Manhattan Project. He later made halfway decent money coming up with a process for producing metal halide salts for lightbulbs and such, until the CCP stole their patented methodology. When I was in my early twenties, I got to go to their lab a couple times. I would've loved to work at a place like that. Machine shop, glass blowing shop, other lab spaces. I regret not asking my buddy's dad (who still worked there after his father-in-law retired) more seriously about a job. Could've learned so much in a place like that.

Little Man, the bomb dropped on Hiroshima, was also the test shot for the gun method, since the designers figured that it was sure to work.

I always admire your research on the topics!

"well if it goes wrong I won't have to worry about it" is such an Oceangate move...

For anyone who's wondering the unions representing writers and actors have asked people not to boycott current pieces of art that are coming out/ already completed. Among other reasons it emphasises the difference good actors and writers make - people have been encouraged to see the Oppenheimer movie specifically in recent posts.

"Shadow Makers", Dwight Shultz (Mad Murdoch) & Paul Newman, Covers alot of what you talked about Scott & it is a really good film. Even covered the fact that they got the BRITS in to resolve the implosion failure

Exzellent content and presentation! Thanks a lot, Scott!

I do enjoy these videos, learned alot again. Also interesting is that Brando Herrera did a video about the US having broken arrow incidents in north Carolina in the cold war during operation chrome dome.

Hats off to you for supporting the artists who are striking for their fair share of the profits from their creative work. 👍🏽

Incredible how Scott not only finds out all these untere details, but also manages to tell them in a way that it makes a compelling story!

Some of your best work ever, well done Sir!

I too have not seen the movie. But I did see segments of a program about Oppenheimer. That program spent about 7 seconds on the topic which you detailed in this 20min video. That is the kind of details I enjoy about videos like this. Thanks for sharing.

It’s mind blowing (pun kind of intended) to see vacuum tubes in the electronics package!

What I want to know is, was the photo flash plane ever used in war?! I had never heard of it!

WOW!!!....what a video...thanks Scott🤯...cheers from Scotland😁

The two bombs used were a uranium bomb and a plutonium bomb. "Little Boy", used on Hiroshima, was a uranium bomb that used the "gun" system that would get the critical mass to explode. That was easy. They didn't need to test it. "Fat Man", used on Nagasaki, was a plutonium bomb. Plutonium doesn't chain react like uranium, so they had to use the implosion process. So that's the system they tested at Trinity.

Wow! Fascinating. I have visited the Trinity Site, and my father worked in various nuclear weapons programs. He met Oppy and Einstein, and took a class from Linus Pauling. I asked him who he thought was the smartest person he ever met- he didn't equivocate- "Linus Pauling".

excellent presentation Scott (as usual)

Scott. You are always explaining what we want to hear!

I’m curious how much of this technical detail will be in the movie.

In 2018 and 2019 there was an exhibit about the Manhattan Project at the National Building Museum in Washington DC. Part of the exhibit talked about the technical parts, but the majority of the exhibit was about the logistics. The amazing photographs on display showed the magnitude of the project from a people standpoint that is mind boggling. Scott mentioned at 4:30 that it involved standing up a whole new set of industries. It really was, it wasn’t just scientists and engineers needed, it was everything. A whole new industry, created completely in secret, and scattered over more than a dozen different project sites around the country. The main concentration was more than 125,000 people who lived in three cities that had been built from scratch, and in total secrecy in Oak Ridge, Tennessee, Los Alamos, New Mexico, and Hanford, Washington. Without using the W and L words that our friends at YT don’t like, you can see some of the photos from the exhibit called Secret Cities - The Architecture and Planning of the Manhattan Project. There is also a brief video about the exhibit. You can find all of this by going to the place that we go to for this type of thing, and looking for that exhibit name at the National Building Museum. On their little corner of that place that we like to go to for these type of things they have a nice little write up about it.

Love the video, thanks for making it :)

Pretty fascinating history indeed! Thanks, Scott! 😃 Stay safe there with your family! 🖖😊

I had some relatives on my mom's side who worked for the Schaefer Pen Company in Ft. Madison, IA. That plant made some parts for the Manhattan Project. Also, my dad, who was in the Navy during WW2 was attending Signal School at the University of Chicago during that time. While there, he got to meet Albert Einstein and he stood guard duty at Soldier Field when the first controlled chain reaction took place. A guy who became his best friend was an Electrical Engineering student who had some involvement with the early RADAR development (he later went on to work for Motorola and became the head field rep in the state of Iowa, and encouraged my interest in electronics; I went on to be an Electronics Technician in the Navy, then eventually working my way through college to get my degrees in Computer and Electrical Engineering). I wonder how many other people have been similarly encouraged by folks who were associated with such projects...

Apparently he used a Dremel tool (or it's equivalent) to drill in and fill the voids in the explosive. So tell the story about how one of the first the bombs was assembled wrong on Tinian island, and could have gone off and caused a bit of a mess while it was being fixed.

if the movie is releasing then what does it matter if the writers are on strike ? other than you being busy , which one can understand . Love your content and always have for years and years!

Thank you Scott - that was very educational.

Thanks Scott, A nice story to start my Thursday!

the strikers HAVE NOT CALLED FOR A BOYCOTT!!! GO SEE THE MOVIES, IT HELPS THE STRIKERS!!!