Nuclear 101: How Nuclear Bombs Work Part 1/2
Vložit
- čas přidán 8. 06. 2024
- Lecture with Matthew Bunn, Associate Professor of Public Policy; Co-Principal Investigator, Project on Managing the Atom
Slides from the presentation are available here: belfercenter.org/files/HowNucl...
More information: belfercenter.org/MTA
September 10, 2013 - Věda a technologie
I get to listen to a lecture from one of the most prestigious universities in the world for free, and I can pause and rewind it at my whim. Think about that for a second...!
thanks for putting me on the NSA watchlist
MWB Gaming lol
Every American is on the NSA list. The Government is scared of us and collects all our data. Thank you Snowden. So if your hard drive crashes, just ask Obama for the back up. ;)
im not american im australian but i bet the NSA is still spying on me
also i think il have to purchase the backup from trump
obama would give it to me but trump would probably try to make me pay
MWB Gaming oh, Obama would make you pay, but TRUMP will make you pay with your daughter...
sorry for the bad joke if you actually HAVE a daughter....
lol no offense taken
trump would make me pay with both lol
I am a physicist and this is one of the clearest and well organised explanation to the layman and scientist on this topic - excellent presentation.
I am a chemist and this guy has no clue what is going on. Kinetic energy of fission products? Really? No mention of mass defect and the actual physics that is going on? This is disinformation pure and simple. I mean , he is an associate professor of public policy, associate! It shows. This man is in no way qualified to speak on this subject.
This professor is such a great speaker. Easy to understand even if you are not physics major.
Black SUV just pulled up next to my house.
kim was lit when his boys found this
What?..
Why am I mesmerized by this deadly apocalyptic subject?
Thanks James Cameron for an excellent 101 lecture.
No budget to steep, no sea to deep. That's who? It's him, James Cameron.
!?
Michael Corcoran Explains why his movies are loaded with bombs.
@Dan Kelly: It's a joke. Michael is saying Professor Bunn appears similar to James Cameron - and indeed there is a vague resemblance.
Dan Kelly:
A nuclear bomb took down the Titanic, and James Cameron attempted to tell the story with DiCaprio.
Can you imagine going back in time to WWII and telling people "you know that super secret tech you're all working on? Yeah... we call this CZcams"
my father was at Castle Bravo in 1954.
Never though I would get the basic understanding, well taught, not locked in explaining in complicated terms at all, so well delivered. Was always wondering how they can be sooo powerful, now that guessing can rest :P
A good portion of this info was in my course of study for a power reactor operator's license. Nice refresher.
If I wasn't on a list from all the other cap I watch.....I definitely am now
some dude haha yup. I’m a Feynman fan so naturally this pops in my feed.
I'm building a bomb for my dad for his birthday and I want it to be big. However my yield seems to be consistently below the 50 kiloton mark even when I use enough material for a 100k or so bomb. I've got the hollow sphere and the air gap and the explosive lenses mostly dialled in, but still I end up with this figure "8" blast pattern that is not very optimal Can you please help? I only have enough fissile material for two more bombs so I can really have only one more test before I make the present.
Use the fissile material for the remaining 2 bombs for 1 bomb.
You've got enough material for a 100kt explosion? Is that assuming the impossible efficiency of 100%, are are you assuming maximum possible efficiency of 33, but only getting 16%?
16% is pretty good. Are you using uranium or plutonium? Boosted or unboosted? Reflected or unreflected? Tamped or untamped? How precise is your neutron injection timing?
Some speculate that the yield of a nuclear bomb is dictated by the by its position in celestial space. So, it may fizzle or it may go BOOM.
56:35 Minor detail about hot air rising. I think he is mixing up cause and effect. You do not start with hot air rising and then colder air rushing in below to "prevent a vacuum". The hotter lighter air causes a lower pressure above the colder heavier air. This causes the cold air to be pushed up from its sides (as the side pressure around the cold air is higher than the pressure from above), which then in turn pushes the hot and lighter air upwards.
Think about an air bubble under water. Water on the top of the bubble flows down on its sides and fills up the bottom of the bubble. The permanent movement of water from the top to the bottom makes the air rise up. There is no water rushing in from below to fill up any vacuum.
Trinity Slide @ 2:15 is not a picture of Trinity, but a picture of Shot Badger from the Upshot-Knothole series in 1953.
Fascinating. Great presentation.
so fascinating!!! i love learning about nuclear bombs!!
this vid just auto played when i was napping, just saying whomever might be spying on me lol
I grew up in the '60's and '70's, and while I missed the Civil Defense drills in schools, I had found a lot of books by the agencies in a landfill in the valley below our house, across the river from the US Naval Academy. Those books, plus reading "Triumph" by Philip Wylie, had me watching every contrail in the sky. Those neurosis-inducing nukes......
Test pilots would occasionally issue a sonic boom over the area, and one day a Harrier dropped in to hover over a parking lot at the Academy. The initial sonic boom and the subsequent roar had us running for cover..... like that does ANY good within ten miles of a nuke.
Thanks for sharing this extremely well-done lecture.
Very good lecture. Easy to understand.The science to make it explode is well known. Not exactly top secret. The means to do it is the hard part.
I personally loved this lecture, and the lecturer did a fantastic job explaining everything, I spend hours a day watching and listening to lectures about nuclear physics and explosives etc because they interest me alot, I wish New Zealand universities would offer a degree or diploma in nuclear physics or pyrotechnics and explosives, or even an online course, if they did do this I would be there first student
+SuperBking1340 One method is to observe the path of a charged particle as it collides with a neutral particle.
SuperBking1340 Good question, I'm not entirely sure.
SuperBking1340 Now that I think about it more, using the mass of the two given particles and the angle of recoil from the charged particle, it could be determined what direction the neutral particle rebounded in.
+SuperBking1340 good question, but unfortunately I don't know the answer to that, you would need to ask the people that assemble nuclear weapons for the answer to that
+mark lister Im from new zealand too and really enjoyed this lecture
I was at Trinity in 2007 - tourists took the last of the Trinitite glass from the ground a while back but you can still get some from collectors online.
Thanks a lot for the video. Very informative. That is one morbidly fascinating device
"All the energy and matter that has existed still exists. Matter does not create energy
of itself. The actions of matter enable energy to become manifest".
Dr. William Penney, the British scientist who developed the British nuclear weapons, had a permanent grin on. Look up a photo (any) of Dr. Penney and you can be sure he is flashing his toothy grin.
Maybe he was Stanley Kubrick's model for Dr. Strangelove. Penney was knighted for his contribution to the nuclear arms race.
Wonderful, it's absolutely right of what I was searching for. Thanks alot
Thanks for the upload
awesome video , i love learning about things like this
im gona look into seeing if you have any other lectures on different subject's
this kind of stuff is so fascinating to me
honestly had no idea it was so complicated and i enjoyed learning about how they use
this type of thing to produce regular power for people to use, or factory's ect.
agin awesome video !! thanks
Fascinating and wonderfully presented. Thanks.
Outstanding. Thank you.
Outstanding lecture.
great video! thanks for sharing!
He leaves the fun stuff out but a nice rendition of basics of old nuclear weapons design
Interestingly you can enrich uranium using photo activated uranium salt decomposition. You’ll have to guess the salts that this would work with.
This approach relies on the minute differences in the chemical properties of 238 and 235. It only needs recrystallisation equipment.
It’s not an economically viable method though.
Well done sir.
Many thanks for the lecture though I cannot imagine a situation where I'd need that type of knowledge. :)
thanks for sharing this. very clear explanation and it was very useful for me to understand.
I was looking at, like, a LEGO set for Nuclear Weapons on Amazon, but I couldn't find any. Do you think I'll have better luck on Craigs List?
Amazing video. Though obviously a very complex and chemistry / physics topic, professor Bunn does a fantastic job of explaining things clearly and in a simplified manner.
Great lecture
Fascinating! Thanks for the clear explanation.
I am just interested in how everything works together
Fantastic very interesting. This speaker is well worth the effort to listen to. And is so close to perfect as far as keeping every sentence riveting
If he can just drop the habit of saying O.K , OK , OK , It's to many oks .
He is so interesting I had to persevere, but please play it back and note how often you say ok.
Then note how the flow sounds so more interesting when you use far less ok.
This is in no way intended to offend, you are well worth the time.
In fact I will both like and share.
Keep it up you are great , in fact so riveting and interesting , you don't need the ok , ok.
Thank you I found your technical explanation perfect
OK.
Warm regards Grant
Makes me wish i went to college... Great talk. Very interesting!
Gone fission...
great video
Very Interesting, i like your class online, i send you greetings!
Very good video.
Great video. Great lecture. Is there a similar on nuclear power?
Great information, very informative. Lecture is off the chain, you know you are in the presence of a expert. On the other hand what horrible reality these devices have created. So sad and depressing. So much engineering in the wrong direction. One love y'all.
CVbeats to be fair more people wouldve died if they didnt bomb hiroshima and nagasaki vs an invasion of japan, the lesser of two evils if you will
@39:38 are you referring to gamma ray detection only? If so, are you stating that cat litter emits a higher count rate (combined Th, U, and P) than *unshielded* enriched Uranium?
Very good teacher.
This is a great professor.
21:15 it's so badass when someone says "that's classified" one day I hope to be able to say it.
Love it when he said "people" instead of scientists.
Makes us feel like we belong to the same human beings.
Where can we download the blueprints for 3D printing?
So I starting watching this a couple of days ago and heard him suggest The Making of the Atomic Bomb by Richard Rhodes. I finished it and yes it is a page turner. and yes it is very good. If you are interested in history of science you will enjoy this book. the book tells the history of nuclear physics not just an account of los alamos.
Great explanation. I enjoyed a lot, thank You. God Bless peaceful countries and lovely people.
Nothing new really, except the breakdown on what's hardest to achieve.
Was just looking for a short and sweet answer to fill my curiosity, like modern marvels. Good presentation though.
well done ,now everyone got ideas about how to made accelerated nuclear bomb , please continue your favor and give more ideas where to get the materials from ! i think we can buy it from the black market of weapons ready rockets with nu warhead !
l love i like this documental exelent job teacher
is it me or he make it sound simple? even i would of used bigger words :/ this man as a gift
This science made 1sec an eternity of time
and don't forget to watch the 1963 movie "Dr Strangelove, or ..." Still a great and important story.
Did they invite Iranian nuclear scientists and reps of the Guards of Islamic Revolution to this exciting lecture?
+Al Johnson Da.
No but your racism was
This level of understanding of the thermonuke is trivial. However, it was only arrived at after 40 years of experimentation and testing, which might lead you to the clue that a lot is unsaid here. Go read Clancy's "The Sum of All Fears" to put yourself to sleep.
+YELLING ARNOLD (IS EVERYWHERE) Got anything better than that?
eatenbytheweasel americans
If that whole putting the dueterium into the pit to cause a fusion reaction at the same time as the fission isn't the classified part, I wanna know what the classified part is.
Miniaturisation. The smallest fission bombs in the US arsenal are literally the size of a football. The smallest high-yield fusion bombs are smaller than the fission bombs other nations have.
I find it interesting that a few Manhattan project physicist theorized before the first test that the chain reaction would not stop leading to the end of the planet.
We hear about other countries who we don't want to have them, but the truth is the knowledge on how to is easily available, and is taught to students in school....yes even students from other countries no restrictions other than the general admission to the school.
Very informative.
Thank you
Nice video
Thanks profe. I like how easy you made me understand. Profe stay calm I won't make bombs :-). I'll make a new material none nuclear explosive much said a very steady material I just want to be able to flow out and absorb the energy from this type of reaction. I'll keep watching your videos please keep us learning.
At 15:00 when he's talking about 2/3s critical mass inriched uramium. Is he talking about uranium that's being compressed by an explosion making it completely hypothetical? Or is he saying that if you swing 2 pieces of uranium 235 at each other that there will be a small deadly explosion even before you could hit them together?! Fascinating and good to know if your ever handling nuclear bomb cores.
This lecturer is brilliant. I'd bet he could make "how paint dries" an interesting topic :) Thanks for the video Belfer Center.
Well that was interesting.
well presented
I know someone who has 125 MG of 55% enriched Uranium and want to know what YIELD that would have?
thanks
Why is the CIA following me
Amazing! :D
Watching this and repeatedly hearing about the astronomical orders of magnitude of heat and pressure that is released in these reactions, I wonder if we could harness this power to mimic the natural processes which create petroleum. Any thoughts about that?
Great lecture! Except the actual process where the energy is transferred from the primary to the secondary (31:00) is not exactly right. The actual process is the ablation of the surface of the secondary, from high energy X-rays filling the bomb case, exploding it inward. It's not the radiation pressure. The surface is rapidly heated and ablates away, propelling the material inward to compress the secondary.
If you want to get technical, wouldn't it be the mass and radiation transferred from the primary to the secondary?
Eric Wesson tellar-ulam
Bryan Carter Even if you assert that what you said is correct, the radiation pressure is what starts the main reaction in the secondary. A distinction without a difference.
if we are getting technical, it was radiation pressure. all momentum is carried by photons
False. radiation pressure results from the kinetic energy of the photons (yes, photons, despite having mass, have an energy associated with them). Ablation pressure is a different mechanism.
this is amazing
If we could get to Pluto... We can get all the plutonium we'll ever need !!!💥💫🌐
Anyone familiar with the phenomena of the Ocean water around a Nuclear detonation turning temporarily black? .... I read about it years ago but am unable to find any info anywhere on the net, .... would greatly appreciate any help ... cheers
+getorfmalawn Its called a "slick". I think it does not actually turn black. When the hyper-sonic shock wave travels thru the water the surface becomes a little smoother thus not reflecting light as well. Right behind that shock wave is the one traveling slightly slower thru the air. Where the air wave meets the surface of the water it creates an effect call "cracking". It disturbs the surface of the "slick" and causes it to then appear white.
Cheers Tyler ...I since posting found the term "slick" mentioned in Wiki of all places .... Ive been thinking the phenomena is connected to the property of water to form a temporary "Lattice" through its H-bond network,... acting similar to a Black Body type absorber .....temporarily negating reflection ... you're explanation is not entirely excluded in that process, ( speculative as it is) with the tremendous energy compressing the molecules into forming the lattice .... interesting stuff thanks again for your reply mate
+getorfmalawn It looks like i spoke too soon on the "cracking" too. It appears that the cracking happens before the air pressure gets there. I assume the cracking is the result of the "slick energy" being released from the lattice as it decompresses. Can you expand on that?
excellent lecture!
This came up on my recommended list...
Great video+speaker...even for an average IQ guy like me-
Just the fact that you underestimate yourself is a sign of a higher IQ. Plus I don't think average IQ blokes Care about this stuff. They are watching Britney Spears videos.
Not to mention look how many people have watched pt 1 vs pt 2. I bet most of the numbers who started pt1 never finished Pt1 let alone pt2.
I'm 15 minutes in, and realized , D.C. Current is relevant!
Modern Nuclear Chemistry by Seaborg ... is very useful also ... shake at 10ns is essentially one fission cycle ... 12 ns is one k-meson time ... if you have a doubling every shake ... it does not take long to release a lot of energy ...
Thanks
Wouldn't plutonium 238 be great for nuclear powerplants since it generates heat and therefore be great in a steam turbine?
You're correct... Plutonium 238 is used as a heat source in very long-range exploring spacecraft (Voyager, etc). There's a special material that gives off electricity if one side is cold and the other hot, so one side is heated by the Pu -238, and the other side radiates heat off into outer space, at around 400 below zero F.
Fission > fusion > fission > fusion > fission and in the end = huge boom and giant fireball and whole city gone in just one second.
Amazing. Its just amazing how smart are some people.
Awesome lecture thank you.
That first slide is not a picture of the Trinity test. It is from a Nevada Test Site test in the 1950's.
21:01 what are they?!?! Now im curious... Very much so
now we know.... wish we can make more useful usage of this stuffs.
The graphite control rods in a reactor are what control the neutron reflections right? Pulling out the control rods causes the reaction to accelerate, while inserting them blocks the netrons, slowing the reaction? In the case of Chernobyl the control rods were all pulled out over accelerating the reaction, neutrons everywhere, then all control rods were quickly inserted back in, in a state of panic, but doing so caused the control rods to actually become reflectors, there were too many neutrons already about that, then excessive hydrogen gas was created, and thus only making the meltdown of the reactor, also explode. Can anyone comment on my understanding?
+SwingingChoke No. Graphite is a good moderator, better than water. Control rods are made of materials like cadmium and hafnium that have large cross sections for absorbing neutrons at desired energies. Inserting them blocks neutrons. Inserting graphite rods, which are not control rods, moderates the neutrons (slows them down without absorbing them), slow neutrons fission uranium-235 or Pu-239 more readily, which speeds up the reaction.
Chernobyl was a graphite-moderated reactor with light water cooling. Water is also a decent moderator a poor neutron absorber. If it ever gets hot enough that steam bubbles form in the reactor, neutrons zip across those steam bubbles and hit graphite, which is a better moderator than regular light water in that it doesn't absorb as many neutrons; that means, if it boils in the reactor, the reactivity increases. The water is operating as a "liquid control rod" that is never supposed to be removed.
Among the fission products, there are isotopes which absorb neutrons readily. The most important one of these is xenon-135. This isotope is a neutron-hungry monster. When you start a reactor up, there is no xenon-135 because it has all decayed. Over a few hours it will build up in the reactor, decreasing the reactivity. It reaches an equilibrium when it is being destroyed as fast as it is created.
In the Chernobyl reactor they had been operating at full power, creating a lot of iodine-135, which decays into xenon-135.
As they ramped the power down, they eventually had trouble maintaining the right level of reactivity because xenon-135 was being formed from decaying iodine-135 faster than they were burning it off, so they manually removed control rods to maintain the reactor to keep it running. Eventually the xenon-135 burned off, which increased reactivity, which increased power, which burned off xenon-135 faster, which increased reactivity. When they noticed the power unexpectedly and rapidly increasing; from low levels towards normal levels; they SCRAMed the reactor to shut it down.
The control rods were tipped with graphite, which is not a control rod, but prevents water from entering the channels were the control rods are withdrawn, giving even more control. The control rods had been withdrawn so far, manually, that water had entered these channels. The water is essentially acting like a weak, liquid control rod in these channels when present. As they insert the control rods graphite tip first to try to shut down the reaction, they push this water out of the channel with the graphite tip, replacing water with an excellent graphite moderator. This made the power increase rapidly far beyond what the reactor could take. Things overheated, broke, warped and they could not get the control rods more than about a third of the way in before they got stuck.
From mathematical simulation and witness accounts it is believed that the power was about 30 GW thermal when the first steam explosion happened (ten times normal; 3 GW thermal -> 1 GW electric), lifting a 2000 ton steel plate, and after that the excursion continued (less water) until the second more serious explosion dispersed the core so that it was no longer critical. The second explosion can have been caused by several different candidates, e.g. hydrogen from hot zirconium in steam, or hydrogen and carbon monoxide from hot graphite or prompt criticality, equaling about 10 tonnes of TNT in explosive force.
Thank you, I appreciate the clarification for me. I have a great understanding now.
That photograph at 2:20 is of the - Badger shot of Operation Upshot-Knothole in 1953 and NOT of the Trinity Test as Bunn suggests! Just look the pictures up yourself, if you don't believe me.
IIRC, the heavy metal Beryllium is used as the tamper.
Beryllium is not a heavy metal, it's the second lightest metal. Also it's not used as a tamper, but as a neutron scatterer.