The Most Dangerous Rock in the World

[@notapplicable7292]

I knew of all these events but I hadn't actually ever heard exactly how the breakthrough was conceptualized. This was a really cool explanation.

[@WelchLabsVideo]

Thank you!

[@user-lp3cf5yn5b]

I didn't know the Japanese were working towards nukes too. I knew the Germans were, but not the Japanese.

[@Sniperboy5551]

@user-lp3cf5yn5b Probably because the Japanese didn’t get anywhere near as close as the US and Germans did

[@jnharton]

@@Sniperboy5551Which is probably just as well. Because it would have greatly increased the risk of nuclear weapons being used by all sides.

[@oahuhawaii2141]

@Sniperboy5551: The Japanese definitely had smart scientists, who understood the meaning of the latest research, and could try to repeat and even push the boundaries of nuclear physics at the time. However, they were limited by resources and communications of ideas, due to the war. Their government put nuclear research at a lower priority. After the war, some of their scientists went on to resume ground-breaking research in nuclear physics.

[@BoyProdigyX]

The stop-motion in this video is BRILLIANT!!! Not only looks great, but as a visual teaching aid, conveys the ideas perfectly!! Well done!!!

[@WelchLabsVideo]

THank you!

[@Steve_Plasma]

Yeeee

[@peteardGreatestRacist]

Thats a good comment

[@sorenkair]

its faked stop motion, they just took frames from a video to simulate the effect. the motion blur gives it away.

[@BoyProdigyX]

@@sorenkair oh yup. You're totally right! Simple yet effective 🤙🏽

[@tomcollins5112]

"But in their greed, the dwarfes dug deeper and deeper. Deeper than any before. And down there, they found something long forgotten. Something from another age of shadow and fire..."

[@midvightmirage]

From what is this? Also why did I think "deep rock galactic"?

[@tomcollins5112]

@@midvightmirageThis is from the Lord of the Rings series. In it, the dwarfs unleashed a monster.

[@JoeShmoism]

​@@tomcollins5112 It's more appropriate to say they woke a sleeping monster as the Balrog lived in the deep dark places and wasn't actually imprisoned.

[@someball.]

@@JoeShmoismI thought the dragon Smaugh made them flee, what did the Balrog do? Were these two separate dwarf states?

[@JoeShmoism]

@@someball. The Balrog was what the dwarves digging in moria woke up. It's the creature Gandolf fought at the bridge in moria. Smaug is the Dragon that drove the dwarves out of the lonely mountain then attacked the human settlement at lake town. 2 different creatures, 2 different stories, 2 different dwarven settlements.

[@g-mo7130]

That "alunimum" at 5:10 gave me a giggle. That's one way to solve the debate "aluminum vs aluminium"

[@kantetoast]

There is a debate? That would be horrific news for mankind.

[@maveritoburrito9415]

Right? I never knew it was ALL OF US saying it wrong.

[@maveritoburrito9415]

Yes, Americans say *ah-loo-mihn-uhm*, everyone else it seems says *al-ooh-min-yum*

[@ramsescampollo2506]

Alulimumum

[@thomasneal9291]

Standard chemical supply houses decided both pronunciations were correct literally decades ago. only fools fight about things already practically decided.

[@The_Joy_of_Physics]

This video feels like a work of art! I haven't seen such a beautiful physics, history video in quite some time. The subtle choices like writing on the slightly browned paper notes, old books, physical maps, and old calculator really immerse you in the time. Congrats on an amazing video!

[@WelchLabsVideo]

Thank so much!!

[@expchrist]

Agreed!

[@nicks8129]

+1

[@Science-Vlog]

it is a good video

[@thegeneralist7527]

The physics is interesting, but the history of the process of making the discovery itself I find makes it much altogether more interesting and meaningful.

[@Cytrillex]

You have an incredible ability to explain a complex topic very very concisely! This 13 minute video felt shorter than many other 13 minute videos I watch on this platform. I applaud you for also not shying away from showing the mathematics behind binding energy - you supported the math by breaking it down into components visually which was just great. Thank you so much for these high quality videos :)

[@WelchLabsVideo]

Thank you for the kind words and for watching!

[@simonmasters3295]

Yes echo that But the take out is the liquid drop model is "more real than imagined" (was that the quote?) and I think this is a learning point regarding how far physical analogies can be pushed... The development of "surface tension" is encouraged by the electron cloud (more pull toward the surface) and resisted by the proton-neutron ratio (more neutrons mean less push to the surface) ...so I was fascinated to see how these great scientists all refer to proton count, Z, (and ipso facto the electron count) in the formulae... ... There is surely some merit in a part two which takes the strong and weak nuclear forces (discovered I think after your timeline in this vide ends) and explaining how the nuclear oscillation water drop holds or does not hold under even more scrutiny? Thank you for a great video

[@NEKRWSPHERE]

How about supporting the thumbnail claim that implies that the thermonuclear weapons could "end all life on the planet" with mathematics? Or do I now need to make a video supported by math that demonstrates this idea to be utterly untrue, because otherwise researching topics like that in the scholarly and academic section is an impossible task for an average modern human? 🤔😏

[@frankathl1]

@@NEKRWSPHEREDo I need to point out that everything after the ‘because’ is a non sequitur?

[@NEKRWSPHERE]

1. You don't need to do anything you don't want to do, and everyone yourself included is entitled to one's (however uninformed) opinion. 2. Yes, you definitely had the need to ask me the question which you have already answered for me by asking it in the first place, and for which you didn't need my consent. It's hardly different than: " - Can I ask you a question? - You already have, haven't you?". So it's a bit funny to me that you'd choose to even mention formal logic. Are you certain you actually know what "non sequitur" is and whether it's even appropriate to mention in application to something lacking premises followed by a conclusion? Such as a joke? As for my part: I don't have to follow formal logic when making a joke, nor do I have to tie one to any of my premises directly. Nor is either a requirement, otherwise close to 50% of great humor would simply cease to exist altogether, which would be a very sad result, far more awful than me wasting over 5 minutes of my life on this video because of a deceitful thumbnail. @@frankathl1

[@EmissaryOfSmeagol]

The key takeaway from this video for me is a new and intuitive explanation for binding energy! A lot of times physics just sort of 'comes down to math' and it's hard to grasp what's really happening, but I feel a lot better about what binding energy is and where it comes from. Well done!

[@WelchLabsVideo]

Woohoo!

[@john-ic5pz]

unfortunately maths without a physical interpretation is masturbation... leading to infinite densities and zero volume objects...too much SciFi in the science.

[@thehellyousay]

Physics does not come down to math. Math is simply the most elegant language to describe physics.

[@kca698]

Its a one step calculation…. (rest masses are look up values)

[@EmissaryOfSmeagol]

@@kca698 brilliant reply good sir. I love it when I don't need to think about things and I can just look up a value from a table. Truly, an understanding is never required in such cases.

[@drewgatewood1864]

I want to thank you for absolutely taking me back to school, teaching me things I likely never would have learned. This was really cool, and great storytelling.

[@WelchLabsVideo]

Thank you!

[@dpeastman]

So glad you are back! You have a unique ability to explain complicated concepts in a way that is both understandable and engaging. And you do that without dumbing it down or just hand waving at the crucial points.

[@MrVvulf]

...which once again brings us back to Einstein: "If you can't explain it simply, you don't understand it well enough."

[@WelchLabsVideo]

Thank you!

[@sunkruhmhalaci2592]

I've enjoyed the theoretical side of physics for a decade, with it being one of my main interests. Even still, I've never ONCE heard nor seen such an intuitively encapsulated explanation of all these concepts, nor truly understood how the breakthroughs occurred. Combining the two with excellent visual representations, the historical ideas and individuals and their contributions, and so forth just... beautifully done. Absolutely beautifully done. You unpacked the math into how it works with the conceptual aspect that is so important to physics and yet so often ill-explained! This needs to be seen more! Keep up the great work!

[@WelchLabsVideo]

Thank you!!

[@FZs1]

I was introduced to your channel by 3Blue1Brown around 2 years ago. The imaginary numbers series was such an amazing and unique piece of art, it immediately got me subscribed! Only then did I realize that you had stopped making videos... Now that this showed up in my subscription feed, I couldn't believe my eyes. I wasn't disappointed by the quality and beauty of this video and am looking forward to the upcoming ones!

[@WelchLabsVideo]

Awesome thanks for watching!

[@reflective_shell]

Your storytelling of complicated topics from the history of science is really remarkable!

[@WelchLabsVideo]

Thank you!

[@Yotam1703]

Mannnn I missed you! Your series on complex numbers is what sparked my interest in math. Super stoked for this one.

[@WelchLabsVideo]

Awesome - hope you like it.

[@derekdai4849]

@@WelchLabsVideooh my gosh, I miss you so much. I was watching your videos in high school and you inspired me to major in Computer Science and I’m now a Tech startup owner. So happy to see you back!

[@engineering_guy]

Yessss!!! It was excellentt!!

[@Hubris73]

Fantastically well written, well produced, and well performed video. In an era of utter slush on the platform, it is really exciting to run into an excellent channel you haven't seen before. Definitely earned a sub with this one!

[@OnTheRiver66]

I agree 100% ! This history and the science behind it is so well explained in this video that it should be shown in physics classes.

[@WelchLabsVideo]

Woohoo!

[@Cheeeesseee3678]

Indeed. Throw back appreciation to The Times editors for including the in-depth coverage of the discussions on "discoveries of the last quarter century of atomic transmutation" that took place between Rutherford, and others, at The British Association, 1933 - which Leo Szilard was so easily able to read in a daily newspaper. The full article can be read on The Times archive (£1 trial paywall) September 12, 1933 edition, search ref Rutherford. It's a fascinating read. Then insert your own comparison between the masses of pointless crap on KZbin and the dumbing down of the modern press

[@willoughby1888]

Nice going. I enjoyed this because you use words well and thoughtfully. I'm of boomer vintage and had to carefully consider as I listened so that I wouldn't get led away by "well, what if..."'s, but I muddled through good enough to not have any brain cells divide and then lose energy. Thanks, and "hello" from Maine. I'm just a tired old man who knows squat about the subject, but then I've never biked from Alaska to Argentina either. KZbin is any 'learning' or "lesson" I desire. I'm glad that I picked this one you presented to us.

[@notebene9791]

Richard Rhodes, the author of the book “The Making of the Atomic Bomb”, explains these findings using an exceptional expository methodology. The other two countries mentioned, Germany and Japan were no where near developing an atomic weapon, Uranium or Plutonium. The size and scope of the “Manhattan Project” was comparable to General Motors with everyone involved in the project living in a city specifically built to develop the atomic weapon. Great presentation.

[@LesCish]

An excellent source for us laypersons.

[@nidarizwi4020]

Ah Yes! "Curies in Paris". The infamous 20th Century song.

[@rvirzi]

I studied physics - mostly quantum. But I never heard such a detailed and clear explanation of how atomic energy was discovered - from a theory perspective. Such a fascinating video. Thank you.

[@ThePerfectRed]

4:54 I love how he "systematically bombarded every element with neutrons", knowing that when he succeeded the result would be a catastrophic explosion.

[@UnPuntoCircular]

This is wonderful Stephen! Absolutely loved it! I love when explanations go through the minds and the arguments of the time, instead of explaining what we know now. Seeing what these people saw at the time is a luxury nowadays. Thank you so much for this. It looks like it too so much time to produce.

[@WelchLabsVideo]

Awesome thank you for watching!

[@to_tire]

I can hardly believe what was accomplished at a time when electricity wasn't a widespread commodity. These people were amazing.

[@WelchLabsVideo]

I know right!?

[@pouya444]

Amazing. Hands down the best explanation of fission history and physics. Found the video randomly, immediately subscribed and looking forward to more of your content.

[@WelchLabsVideo]

Thank you!

[@brianparisien9262]

This is the first of your episodes that I've watched. I am now subscribed! I have to echo the positive comments in this thread. Brilliant explanations reinforced by simple yet intuitive graphics. Love the historical references, they provide a context for how huge discoveries evolve. Looking forward to exploring this channel! Thank-you!

[@WelchLabsVideo]

Thank you for the kind words and subsrcibing!

[@Usuiiichhi]

Welcome back mann. I have seen your complex number series two three times. It's my go to reference whenever I get confused about some topic and want a quick brush up. Added bonus is the fantastic visuals and narration.

[@WelchLabsVideo]

Awesome thank you

[@05degrees]

A month or so ago I was stuck reading an English Wikipedia article about Lise Meitner. It was fascinating (and sad too, because prejudices and all the politics making lives of people hard). Read it too, fellow commenters, it’s a tiny but surprisingly pretty layered window into history.

[@bramtheunissensciot2836]

I was doing the exact same thing yesterday, what a coincidence!

[@honkhonk8009]

Theres an english wikipedia article? Like UK mfs??

[@besticudcumupwith202]

...Otto Hahn was a p.o.s to Lise. He betrayed her to the natC's and took credit for HER work. He doesn't deserve the credit given to him in this video.

[@05degrees]

@@besticudcumupwith202 I don’t think this is the place to discuss that; but the issue doesn’t seem to be that simple as you state it, if we’re to believe in what’s in the article though; also it’s stated there that despite all the history Lise was friendly to him in the end. If I remember it right.

[@besticudcumupwith202]

@@05degrees ...Wikipedia has never been a good source for anything. From what I've read she had a thing for him, and didn't want to acknowledge and deal with his betrayals.

[@colin2utube]

This is the first of your video's I've stumbled across and I really appreciated the clarity, and pacing with which you were able to deliver a complex subject (even down to the colour coding of the formulae which was familiar to my background in programming !). Excellent.

[@WelchLabsVideo]

Awesome!

[@xChinky123x]

Fantastic video. Its completely incomprehensible how creative these scientists working with just numbers and observations must be to come up with theories without access to our advanced labs and understanding

[@WelchLabsVideo]

I know right!

[@1495978707]

As a physics student, we honestly use stuff like computers as enough of a crutch that our ability to just pop stuff off the top of our head is not so good as it used to be. And for modern discoveries, this use of computers is often mandatory, because of the insane complexity of the integrals in particle physics, or of many body quantum systems in condensed matter/material science, etc

[@sergeysmyshlyaev9716]

0:03 - the stone is called "Pitchblende" It's remarkable, that at the very beginning of the video the the name of the stone is pronounced, but not displayed on the screen, while the mine name is displayed. I suppose it's because the audience would pause, google the name, read Wikipedia, and then close the video.

[@THarSul]

that was the most concise and easy to understand explanation of nuclear fission i've ever encountered, well done.

[@WelchLabsVideo]

Thank you!

[@marcelma]

I just watched this episode again: It is just incredibly well done. Your approach to step by step show the thinking, errors and break throughs of the time and to assign those steps to the people involved makes science SOOOO much more understandable than the usual result and success reporting we find in our text books. And I immensely enjoy your "show the instruments / documents available and produced at the time" approach. The amount of useful context you create takes all those bits and pieces of the puzzle that have floated through my mind since decades, rattles them thoroughly and when they settle - wow - there's a real picture! Was it there all the time? Why didn't I see it before?

[@xypnox]

Great intro to radioactivity mired by one of the worst clickbait titles.

[@abdullahalam2088]

Fantastic video! You have a way of simply explaining complex topics without dumbing them down too much. The presentation style is a breath of fresh air. Really enjoyed the progression of the science with the historical context. Instant sub.

[@RFC3514]

5:08 - Okay, "aluminium" is fine, "aluminum" is borderline acceptable, but... "alunamum" is starting to get silly.

[@fhoenixellis9397]

i was hoping somebody else noticed that! i was appalled

[@stephenhicks826]

An excellent video. Thank you. You seem to have forgotten 'Tube Alloys'. In March 1940 at the University of Birmingham, England while working under Marcus Oliphant an Australian Physicist, Rudolf Peierls and Otto Robert Frisch co-wrote a memorandum explaining that a small mass of pure uranium-235 could be used to produce a chain reaction in a bomb with the power of thousands of tons of TNT. It was this memorandum that started British research into the Nuclear Bomb under the code name 'Tube Alloys'. The contents of the 'memorandum' were made known to the USA during the course of WW2 along with details of other technologies such as the cavity magnetron and the proximity fuse just to name a couple.

[@kapoorh]

I am not a science student, but mostly understood, sort of, what you described. But more than that I appreciate the amount of work you put into creating this video. Good work!! Thanks and cheers!

[@WelchLabsVideo]

THank you!

[@jwestney2859]

5:45 Lise Meitner. She is one of the amazing people that figured out how atoms work. Remarkable person. Remarkable woman!

[@mohammedhardi7891]

I'm really excited to see back. Loved your complex numbers series and can wait to watch what next you'll publish

[@WelchLabsVideo]

Thank you!

[@jwestney2859]

5:48 Irene Joliot-Curie. She is just one of the women that helped figure out how atoms work. Remarkable people. Remarkable women!

[@npgatech7]

I don't think people who watch these videos understand how much effort goes into making them. They have no clue. Kudos man.

[@alexs3973]

seems like that one took him 4 years to make 😉

[@adamsfusion]

I love the way this concept was explored. I remember in school being told "the facts" about the events that lead to the discovery of fission, but it was today that I learned that the scientists were far more creative. _That_ is what I wish was exposed more in general education. I've never thought of the nucleus of an atom like a wobbly raindrop before.

[@GianmarioScotti]

Lise Meitner deserved the Nobel prize.

[@enque01]

This was without a doubt the BEST summary and explanation of not only the history of the discovery, but the nature of the phenomenon itself. And I'm 40 years old and have watched ALL the documentaries available.

[@HebaruSan]

5:08 - Have to admit I've never heard it pronounced alunimum before

[@christopherlatham4254]

Sounds like he morphed the British pronunciation Aluminium with the American Aluminum.

[@Scott_Buchanan]

It took 3 tries to read that right 😂

[@satchice9102]

The details about the forces in the nucleus is beautiful. I've never seen it explained to that level of detail before with the water drop model and coulomb forces. Normally it's just "neutron hits uranium nucleus, there's a chance the nucleus split into a nucleus of Krypton and Baruim". Your level of detail with oscillations and surface area made the model of why it does, much more interesting.

[@WelchLabsVideo]

Thank you!

[@Finnnicus]

Quality better than ever! i love the yellowed paper, are they the original articles?

[@tsites1]

The Rockwell calculator shown in the last part of your video is a real classic. It was my first calculator way back in the mid 1970's. It had a large easy to read cold cathode vacuum fluorescent display (much better than the tiny dim red LEDs on most). It also had a square root function and a memory register, features only found on much more expensive Texas Instruments or HP calculators at the time.

[@nanamacapagal8342]

Absolutely love how the new series is turning out! Just in time for Oppenheimer on cinema, actually

[@WelchLabsVideo]

I know right!

[@stratfanstl]

A phenomenal and concise summary of the physics of the atom and weapon design. I happen to be re-reading Richard Rhodes' classic book The Making of the Atomic Bomb which goes through all of this background in great detail and this video condenses the first 80+ pages into 13 minutes. Well done. Subscribed.

[@covariance5446]

Very cool to have this video available for us to watch less than a month before the Christopher Nolan directed (2023) film Oppenheimer is to be released! I think this will help myself (and others) appreciate said movie (though it was already a very interesting topic). I also learned a lot more than I remember learning about the topic back in high school and my undergrad years (though I only ever took an intro physics, an intro chemistry, and an organic chemistry course).

[@WelchLabsVideo]

Yeah! I'm really excited for oppenheimer!

[@a64738]

The Oppenhimer movie was a huge dissapointment... Half the 3 hour long film was about his court hearing about his communist connections. Rest was a confusing mess jumping around in time with no warning so you never did know what time it was, what was happening, and why it was happening...

[@nathanlaughton9971]

Dude your videos are SO good! You're up there with other youtube greats like Veritasium and Smarter Every Day in my opinion. So glad to see you back making videos. I still love your series on imaginary numbers, which is how I learned about your channel in the first place. In fact, I sent that video to a student of mine earlier today after he said "Ugh, I hated imaginary numbers in Algebra II." Thanks for making the world a smarter place to live!

[@WelchLabsVideo]

Amazing thanks for the kind words

[@Finkelthusiast]

What an amazing presentation! The stop motion animations of the nucleus were awesome. I would love to see a similar presentation the development of qcd. I think your combination of presenting the history as well as technical matter would lend well to the story.

[@WelchLabsVideo]

Will add to my list of potential topics!

[@MoLewis57]

I read my Dad's copy of George Gamow's book "One Two Three... Infinity" as a kid ( in the early '80s ) and loved it. Before watching this video, I had no idea he has done such important scientific work.

[@NoNTr1v1aL]

He's back!!! Let's goooooo!!!

[@WelchLabsVideo]

Let's gooooo!

[@Thelearninglouge]

Let’s gooooooooooooooooooooooooooooooy4yyeuy37y3gsvhcvhsgzjfhdvgchebjcbci dhf3y*dndkehieg2i

[@areitu]

Admittedly, I resisted clicking on the video but I'm so glad I did and now I've subscribed! This is one of the most understandable and approachable videos I've ever seen on the discoveries that led to fission and on how it works

[@SanePerson1]

Becquerel did an accidental control experiment that he probably should have designed from the outset. Excellent video: it puts across the basics of the physics of nuclear stability and fission from a fascinating historical perspective.

[@WelchLabsVideo]

Thank you!

[@dylancope]

I love the way you make the content into a story. You did a great job weaving together the physics and the people.

[@WelchLabsVideo]

THank you!

[@vergeltung75]

Oh man it ended too soon. I would love to watch you go over the Manhatten project, atomic research and advancements in WW2, current discoveries.... In short I just loved this and I want more! I went to subscribe and discovered I already am. I wonder if the algorithm dropped you from my feed?

[@WelchLabsVideo]

More on the way 😁

[@greggweber9967]

12:56 also Britain and their Tube Alloy?

[@supreetsahu1964]

It's amazing how much insight we can get even from defunct models

[@bloodvue]

A spherical cow on a flat plane in a place with no air.. you use the best models that work at the scale you are using for the granularity you can work with. Most people use the first three numbers of pi until they start thinking orbital mechanics.

[@hubbletrubble7875]

2:59 Great video! I couldn't help but notice, though, that there's an error. That's lithium-6, rather than the Lithium-7 needed to form two alpha particles w/ a proton

[@ThatSkiFreak]

I already know the vague beats of this story and information, but I still enjoyed this. Honestly, an amazingly well-made video, love the visual style!

[@WelchLabsVideo]

Thank you!

[@williamford8566]

Outstanding! I am a Ph.D. physicist. Didn't learn much science history in school, but started reading on my own. I'm more interested in medieval science. This is simply an outstanding video. Love how she came ip with her world changing idea sitting on a log in the snow!

[@philc2729]

What a phenomenal presentation with stop-motion animation. Really well done!

[@WelchLabsVideo]

Thank you!

[@ronaldgarrison8478]

12:55 I know this is a nit, but those are the present-day boundaries of Germany, not the ones in the Thirties.

[@_jalmon_8482]

what music is used in the first 33 seconds and again at 1:13 seconds, I've heard the melody before but I cant put a name on it!

[@therunthroughthrgarden]

Erik Satie - Gnossienne No. 1

[@beyondfubar]

The other guy is correct, but no. 5 is amazing.

[@awkwardmonkee]

If you’ve seen the movie Chocolat with Johnny Depp, it’s part of the soundtrack and might be where you’ve heard it

[@Diamonddavej]

Becquerel and his laboratory assistant, Louis-René Matout, were examining a recently discovered highly phosphorescent uranium salt, not metal, Potassium Uranyl Sulfate. The remarkably fluorescent compound fascinated scientists who wanted to understand how its fluorescence worked. Several scientists, including Becquerel, Charles Henri and Gaston Niewenglowski worked on the uranium salt and other fluorescent compounds in 1896. Also, Henri Poincaré hypothesised that its fluorescence might also include X-Rays, recently discovered by Wilhelm Röntgen. In order to test Poincaré's theory, Becquerel asked Matout to place the uranium salt on photographic film, sealed inside two sheets of lightproof paper, out in the noon Sun to see if its fluorescence included invisible light (X-Rays). These experiments were a success, the film was exposed, it seemed to confirm X-rays were generated just as Poincaré predicted. They also repeated the experiment with an aluminium sheet, again the film was exposed. Then the weather turned cloudy, so they left the experiment for a few days. Matout or Becquerel put the Uranium salt in a drawer, and by chance or by intention (we do not know) it was placed on top of a plate of photographic film. After a few days of poor weather, Becquerel thought the plates were ruined and he told Matout to throw them away, but Matout decided to develop the film plates anyway. To their shock the uranium salt exposed a sheet of film without sunlight. They realised energy, radiation, was emanating from the uranium itself. "Becquerel, he told me, envisaged an experiment to check if elements like uranium had the property of producing light by fluorescence under the influence of solar rays. To this end, he instructed Matout senior to prepare photographic plates containing a uranium salt under the opaque paper, and to expose the plates to the Sun. Unfortunately, for three days the Sun did not show at all, and Becquerel told Matout to throw away the plates and to prepare new ones, which he did. But, before throwing away the old plates, Matout had the idea of developing them, and he saw the effects of uranium on them." - Matout's son, in 1969. Becquerel failed to acknowledge the part played by Matout in his papers and lectures, it was customary at the time not to mention one's laboratory assistant, so no slight was intended. It wasn't until decades later that historians discovered the correct sequence of events via Becquerel and Matout's correspondence and notebooks, and Matout's son. Matout was not upset over not being mentioned, they collaborated on other many experiments. Without the accident of placing the uranium salt on a sheet of film in a drawer and Matout's decision to develop the film, THEY would not nave discovered radioactivity.

[@FoodNCheese]

I'm so happy you're back and into such a fun topic. So excited to see more. Why does uranium always tend to split into krypton and barium as opposed to two more equally massed nuclei? I'm guessing it has something to do with the oscillations of the nucleus (harmonics?) and the energy of the bombarding neutron, but I'm curious why krypton and barium are the two predominant. I noticed that the ratio of the atomic numbers of krypton/barium are around 1.5, so my guess is that maybe the nucleus oscillates between two states where each end is around 1.5x bigger than the other. Great video!

[@isbestlizard]

It's interesting to think about, perhaps for nucleuses that need less of a nudge from a neutron, they split into two roughly equally sized daughter products, but for more stable nucleuses, the extra energy has to be higher to cause more extreme oscillations, and the nucleus breaks at the extreme of that oscillation. I bet Plutonium fissions into, on average, more equally sized elements as it's less stable?

[@GNelke]

Good thinking

[@WelchLabsVideo]

If i remember correctly it's not always Ba and Kr.

[@AllanWhite]

Watching "Oppenheimer" this weekend, the question came up: what if the US had simply decided not to pursue a nuclear weapons program? This video (towards the end) explains why - once fission was discovered - it was probably inevitable. Really enjoy the style and approach to explaining these concepts. The historical props used really take it over the top.

[@ireoluwaTH]

A preview of 'Oppenheimer' on my favorite KZbin channel... Someone get the popcorn!!!

[@WelchLabsVideo]

Woohoo!

[@fascialrufaie]

Finally, you came back. I wanted so badly to see the self driving car series finished.

[@xbzq]

5:10 Alunimum! And again at 5:13

[@KamikazeMedias]

Propably the only channel on science topics that pronounces Maria Skłodowska's full name - or at least tries to. As a Polish man, for that, You got a sub.

[@Ihsees91]

If anybody is interested in even more details, I can only recommend the book "Making of the atomic b..." by Richard Rhodes. Be warned though, it is quite a long read...

[@WelchLabsVideo]

Rhodes is the GOAT

[@Corialtavi]

I found in the early nineties a book on Radioactivity by Earnest Rutherford from about the turn of the twentieth century in a charity shop. I took it home to read and it really helped me understand a little more where they were at that time. It was written in easy to understand terms as no one had invented new terms for things & he just described what happened in different experiments. The book disappeared with other cherished books when I was moving through different rented accommodation. Really wish it had not been (I presume) stolen as I would have loved to have re-read it once more.

[@WelchLabsVideo]

Oh man that sounds awesome!

[@loveinc.7438]

5:09 Alunimum huh?

[@NathanHarrison7]

I was familiar with this history; but watching this video, and the wonderful analog graphics, really brought it home. Thank you very much. Subscribed.

[@edlabonte7773]

Minor nitpick. It should be “This was an entirely new phenomenon.” Not phenomena. Phenomena is plural, phenomenon is singular.

[@lernerleben]

I recognise that background music from the Connections series of doccos by James Burke. Anyone know what it is?

[@edwardnedharvey8019]

@5:20 I noticed you say "alunimum" aloo-nim-um, not "aluminum" aloo-min-um or "aluminium" aloo-min-ee-um

[@JethroCramp]

The visuals in this presentation are brilliant. A lot of high-quality work has made this breathtakingly easy to follow.

[@ROFLance]

I was expecting a Dwayne Johnson documentary, but I was not disappointed.

[@sushiburps]

So great to see you back, can’t wait for more.

[@WelchLabsVideo]

Thank you!

[@TheT0nedude]

It's time to use it, this world has gone batshit crazy. The species is beyond saving.

[@MrPojopojo]

It is really strange that a few party tricks and an interesting phenomenon with glowing rocks eventually, through continued research, managed to produce the most devastating weapons in history. Its hard to imagine what someone would think if they were told about it, holding that glowing vial of radium.

[@karhukivi]

First error at 0:29 - Becquerel placed pieces of uranium ore, not metal on photographic plates. I stopped there because a scientific presentation has to be accurate, not sensational. Thumbs down.

[@swainscheps]

Don’t be a party pooper. What’s sensational about this? He notes it’s technically a salt, but what’s being studied is the underlying metallic element.

[@karhukivi]

@@swainscheps For the same reason people think mercury is dangerous and understand that to mean mercury metal, which is not poisonous. It is the compounds of mercury and its vapour which are dangerous Furthermore, it is the trace elements in the uranium ore that produce most of the radioactivity, not the element uranium alone. Facts have to be correct in science, otherwise it degenerates into emotional fiction.

[@karhukivi]

@@swainscheps And as for "the most dangerous rock in the world" that is definitely sensational clickbait! The arsenic minerals realgar and orpiment are probably more dangerous as handling them transfers enough arsenic to your fingers to kill you if you licked them.

[@Pepesmall]

This must be trolling or a joke or else that's the funniest thing I've ever heard

[@Femefatal]

I entered the Naval Nuclear power program back in the 90's and learned about reactor Theory and the function of Nuclear fission. Of course we also had to learn about the history of Marie Currie and all the others listed in this video, but how you laid out the timeline of everything was exceptionally well done. Thank you Machinist Mate 2nd class Naval Nuclear Power School, Orlando Fl. Nuclear Prototype A1W, Idaho National Engineering Laboratory USS Long Beach CGN-9

[@coneburger9081]

im gonna eated it 😋😋😋

[@vishalkumar040393]

After so long. Happy to see you back. Please keep the posting.

[@scifisyko]

Can’t quite pronounce Aluminum there? ;)

[@saraking7398]

Great video but can’t you please tell me what piano song is playing toward the beginning of the video? I’ve heard it before and my brain is going to explode if I don’t figure it out 😵‍💫

[@am-per-e]

Gnossiennes: 1. Lent in gymnopedie by Erik Satie

[@benjamincarnell2590]

STOP USING SATIE I FEEL LIKE I'M GOING INSANE

[@FloridaManMatty]

Gymnopedie is the perfect piece for this. Well done.

[@chyldstudios]

I am reading "The Making of the Atomic Bomb" by Richard Rhodes, and this video helps clear up some of the material. Wonderful use of simple animations to illustrate fusion.

[@varunahlawat9013]

You've nailed these videos. This became my favorite yt channel now! I love physics and just began reading L.D. Landau's "Course of Theoretical Physics"(I'm currently at volume1). I've heard great things about Russian engineers, physicists and mathematicians.

[@johnmiranda2307]

Outstanding!! Thank you, esp for the oscillation aspect. That’s not usually included, probably for simplicity. In any event, what I suggest and ask you to investigate is electron(ic) energy, tapping energy from electrons that spin perpetually (or the Universe would collapse.) It starts with the lowly, everyday spark. In the 80’s, Dr. Hal Puthoff asked the late Ken Shoulders to help him at SLAC to determine why electrons in the traces did not appear uniformly, but they were clumped together in “bundles.” Fast forward a few years and the two scientists concluded that more energy is released than is required to release it when electrons at the tip of a spark inductor, eg, a spark plug, are compressed beyond the Coulomb Barrier into “condensed charge clusters” that emerge from the spark. Here’s the secret sauce, as told to me directly by Ken Shoulders at a conference in 2003. These bundles are: 1) EXTREMELY energetic and 2) EXTREMELY short lived. So, that means if one of these bundles has enough energy to knock a proton out of the nucleus of an adjacent atom, an enormous amount of binding energy is released as the proton leaves the nucleus and the atom transmutes into a different atom. Sidebar: According to Ken, this side effect of such a brief longevity accounts for how physically localized these nuclear transformations are occurring. The studied “localized domain of impact” accounts for the common byproducts of cold fusion experiments, eg clusters of tin, nickel, copper, appear BOTH on AND below the surface, indicating a nuclear process, not a chemical one. So, how do these electrons in charge clusters get compressed beyond the Coulomb Barrier? Resonance in the crystalline structure of the metal compresses some number of electrons beyond the Coulomb Barrier. Now, the question neither Puthoff, nor Shoulders ever addressed, much less answered, is “what happens when these clusters lose their energy? Do the clustered electrons come BACK ACROSS the Coulomb Barrier?” I believe they unveiled only one direction of this process. If I’m not mistaken, condensed charge clusters have been included in mainstream Physics for 30 years or so. Shoulders once calculated that the energy of a charged cluster equalled about 26,000,000 degrees, hot enough to be on the surface of the sun. However, the time of life is so short, only a minuscule amount of that energy reaches us. No radiation. Just light. My guess is that what we humans see when we see a bright, white spark, is an “infinitesimal” amount of binding energy. How can you tap the energy of a “spinning” electron w/o slowing it down? We’re talking about the energy of electrons as they are compressed into the universe beyond the Coulomb Barrier and, IMHO, what happens when they cross back into the universe ruled by the Coulomb Barrier. Break that code and you can probably end up building your own UFOs. …..end of xmission.

[@peterweicker77]

Science, personalities and historical context conveyed with speed and clarity in a cinematic style. This is great stuff.

[@etmax1]

This was an exceptionally well presented subject, giving historical context as well as all of the necessary technical details, Thank you

[@WelchLabsVideo]

Thank you!

[@jameswatkins7763]

Wow... This is probably the best math history video I've ever seen. I can tell a lot of work went into this. Great balance of high information throughput by infographic and pacing. It stays interesting while also deep diving into math. My mind is blown, you've done the impossible.

[@2639263926392639]

As someone nearing exasperation point with society.... thank crunchie there are these tiny corners of worthwhile, informative and engaging content. Dont suppose you'd consider being the minister for education?

[@thegeneralist7527]

Well told story with an extremely clear explanation of the nuclear physics involved. Serendipity favored Becquerel. A good illustration of why you always need a control in any experiment, and why you also need a control with any model. Good luck with the control in the model.