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Bro... Your the reason why I'm gonna pass 11th grade chemistry, XD I wish you were my teacher, my teacher (miss roach) has no clue what she's doing, she messed up teaching us about moles (6.02*10^23) and reversed gamma, beta and alpha particles, she made alpha the strongest one and gamma the one stopped by paper.. So in short thanks for being smart bro :-)
+Robert McKinley We get taught about nuclear power mainly in physics, and I see where you're going. Although my teacher does not make stupid mistakes usually, he is slower at teaching than a snail and misses out on a lot of stuff. He doesn't challenge with his learning so I just bring my own work to class.
+Robert McKinley I had a math teacher like that last year. He would mix up EVERYTHING he taught. The only reason my friends and I passed is because RUclips videos and Khan Academy.
Comrade Stalin right? My teachers are always wasting time babbling about nonsense in their regular lives and it makes the whole thing like x1000 more difficult to understand
Although I'm a microbiology/immunology and pharmacology student I've always been fascinated with the more physical chemistry. Cheers for very interesting and well presented videos. It's good to take a break from working with plasmids. Lol
There has got to be a way to make fusion work. I think it’s an engineering problem of reaction confinement, which is why I’m doing my undergrad in Electrical Engineering and am planning on studying Plasma Physics in grad school with a focus on Nuclear Fusion. It’s in my view one of the five technologies that would be most impactful, which is why I want to dedicate my life to helping to figure it out. Love the videos John, keep them up.
I find it fascinating that E=mc^2 is so often associated with nuclear energy but not with say chemical energy. Those 420 tons of coal mentioned in the video, together with the O2 needed to burn it will be heavier than the CO2 and other stuff released by burning it by exactly the same amount as the mass defect of a mole of oxygen.
***** I'm pretty sure that's part of the reason. It's probably also because it's much easier to understand the usual explanation for chemical binding energy that looks at the valence electrons than it is to understand exactly what happens during nuclear fission or fusion. The video also acknowledges this by saying something like "well, it's complicated but here's an explanation that's easy to understand". So that in itself would have been fine. However, the video still puts it as if E=mc^2 somehow only applied to nuclear processes but not to chemical ones which I believe is a common misconception in physics.
***** Not only that, but when you do measure the mass defect, it really does not contribute much to understanding the chemical reaction. It is only useful to confirm Einstein's theory, which already had more than enough confirmation elsewhere.
I don't think I can thank you enough for all the help you've brought. The questions at the end were the cherry on top (they were exactly what I needed). Thank you so much and please keep doing this, you're saving an entire generation with their homework and stuff :)
heard that one before. also irrelevant to the video. try "nuclear fission. would be ironic in the sense that randomly place in a haiku, it does not make sense, and in relation to the video-if you didn't understand it- that's two humor points for you. also making an original ending would have spared you this response.
This is a bit difficult to say, but CrashCourse and SciShow just make me feel like I watching funny videos and studying and studying at the same time. I think when you have such an educational topic that is incredibly hard to do, so even when I had a great day, these RUclips channels are still the icing on the cake. Thanks Jack and Hank.
Thank you, CrashCourse! For the last week, I have been watching your General Chemistry videos (1-39) to help study/prepare for my PCAT (pharmacy standardized test). The last time I took Gen Chem 1 was three years ago (sophomore level of high school) and Gen Chem 2 was one year ago. Needless to say, I lost some of my notes along the way and had no good way to study for my test. So I thank you for making these videos to help me review and actually teach me some things I have never learned before. I love all of your videos and will eventually watch all of them. :) Yes, even the history ones probably even though I am not too fond of history simply because both you and your brother make learning very fun. :)
+Lance Corey he forgot to put the square sign over there........but if u check the value of c square,then it is equal to (3.0x10^8)^2 in hank's calculations..
Wow! I think I finally got the difference between the concepts and how a nuclear power plant and a nuclear bomb work!! By the way you are so inspiring by telling how this is the beginning and with enough effort anyone can be next big physicist... It’s a little for me though, but I’ll show it to my students!!!
This amazing video has inspired me to the answer of fission's disillusion. I believe the purpose of traveling into space is to begin scientific experimentation in the vacuum of space.... Thank you, Hank Green.
since you are correcting hank himself, I am assuming you know why the 'C' constant is the squared of the speed of light itself? why? please tell me dude. please
God is an atheist C is the speed of light. Because the conversion of mass to energy is an enormous factor, as even the smallest mass holds an enormous amount of energy.
It also would have made sense, when discussing the nuclear reaction that dominates the Sun's energy production, if he had mentioned that all those gamma rays are produced at or very near the core, so that they lose a lot of energy on their remarkably slow path to the surface of the sun, where the energy is finally released as mostly visible light. So no need to worry about gamma rays from the sun.
Okay, I'm missing something, at right around 8:00. Two atoms of hydrogen fuse together to form deuterium? Are we missing a proton? Does one of the protons lose some of its energy and positive electric charge in the form of a positron and become a neutron in the newly formed deuterium nucleus?
Err... The display of the calculation for E (@02:40) is missing the square for 3.0x10^8 m/s. Should be (3.0x10^8)^2). Your answer is correct, but the displayed equation is incorrect.
As far as I am aware the only current means of working against the heat of even laboratory fusion reactions (unfinished and non-stabilized) it with huge magnetic fields that repulse the oncoming kinetic particles an therefore prevent heat from transferring to the surrounding containment areas. Our problem is however that the energy we use to generate said magnetic field is more then the energy we get out of those test reactions.
On a positive note, if we were able to maintain said reactions for a specific duration, the energy output, assuming we are able to utilize most of the released energy, would allow us to maintain the magnetic field and still have excess.
Yap and the magnetic fields don'T contain the high energy neutrons which in turn are a huge problem for the reactor. (you know, fun stuff like inducing radioactivity in the reactor walls)
This was really well explained, kind sir! I'm a fan of nuclear chemistry and its possibilities and obstacles to break! Keep up those amazing videos! (:
This was such an inspiring video! I love how at the end, you said, "You've already taken the first step. It's now up to you how far you want to go. Maybe you'll write the next ... equation that'll take us to the next level!" I love that. The best thing is it's true! Hard work and determination!
Penny Lane already sort of covered this in their comments, but you made the same mistake most people who talk about nuclear chemistry make: E = mc^2 isn't the "source" or "cause" of the energy released in a nuclear reaction. It's an equation that tells you that the *result* of that reaction is going to involve a change of mass, because energy manifests itself as inertia/gravity. E = mc^2 gives us a way to measure the energy change, sure, but you got the causal arrow backwards (if a causal arrow can be drawn at all). The "cause" of nuclear binding energy is the strong nuclear force, of course.
What I don't understand is why fusion creates energy. In fission as small amount of mass is converted into energy, but in fusion energy needs to be poured in to create mass.
Chris P That is not right. Fusion releases energy if it occurs between elements lighter than iron. Fission releases energy if it occurs between elements heavier. So when you fuse two protons to get a deuteron, about 1% of the proton mass gets converted to kinetic energy of the deuteron.
The proton "mass" is just a measure of its energy. The deuteron "mass" is a measure of its energy. The energy released is simply equal and opposite the nuclear binding energy of deuterium, which is negative and which derives from quantum chromodynamics (the physics of the strong nuclear force). "Mass" never needs to enter into it except that it's easy to measure.
+OSUfirebird18 It's a theory of everything my child! Science has branches, but everything about it is very very connected like a string and time... Cheerio! :D
I agree with the other comments that these things are all closely connected, but nuclear chemistry in particular focuses on how one type of atom transforms into another. Nuclear chemistry might also cover the chemical techniques and properties of radioactive substances and how teh radiation and the change in element affects the chemical environment. Nuclear physics might for example more concentrate on that amounts of energy released, how to slow speed or confine a chain reaction. What are the fundemntal forces involved in the nucleus that give it is properties. What are the constituent parts of the nucleus. Is the study of fire physics or chemistry? Kind of depends on what you are studying about it. Its more of an emphasis rather than a distinction.
We have figured out how to control fusion reactions! and we are trying to generate energy with it! Look up Tokamaks or stelarators. We have done almost break even at the JET tokamak in England Q~0.7. ITER under construction in France would hopefully do 10 times as much energy for 30.minutes.
Bear in mind that if it takes 4.5 billion years to halve the number of nuclei in a sample, it will not take double the amount to go away completely, but rather take another 4.5 billion years to halve again... and again, and again, etc. This is why we say these things are basically always a problem, since just two half lives to get uranium a quarter of its previous size takes more time than the Earth has left to live, haha (because the Sun will run out of Hydrogen in about 6.5 billion years).
Researchers at Lockheed Martin in the USA are working on a compact fusion reactor. In 2014 they claimed a prototype will be running by 2019. This claim has been met with scepticism by some in the scientific community
At about 4:40, he says that when you hit a Uranium nucleus with a neutron, it splits. But this is only one of the possible outcomes. All the difficulties of reactor or bomb design require understanding that there are more possible outcomes, and how to optimize the desired outcome. For example, in a natural uranium reactor, you can use a 'heterogeneous' arrangement of moderator and fuel, which increases the probability of fission by slowing the neutrons down. But if you are building a breeder reactor, you may actually want faster neutrons, since they transmute more often. So splitting is one possible reaction, transmutation due to absorption of the neutron is another. Then there is scattering, which in turn can leave the nucleus in an excited state.
I so wish you would do an in-depth investigation of Thorium reactors and why we aren't converting to this technology. I mean, I know why...however it appears to be the perfect answer to our energy crisis and yet - nada. No one is working on it. Why? I'd love to learn more - but there is so little discussion on this topic. Bring us up to speed Hank. Would be an excellent video on Alternative Nuclear energy.
That would be a perfect topic for a future episode of SciShow. To sum up my knowledge of the subject - In the early days of nuclear research they had a few options as to the primary fuel but they chose uranium because the waste can be used for bombs. Since then it has been used simply because it is proven to work. Very few investors are willing to back a completely untested technology when it means putting up $10B+ up front.
***** Yes, but not untested - it has been tested and is safer and the half life is only like 100 years. The reason they don't convert is money - everything has been built to process Uranium and they just don't want to spend the millions necessary to retool everything for this safer, more efficient method of generating power. And it doesn't make weaponized uranium for bombs. - But we should be using Thorium reactors as they are not only much safer, but are also scalable - you can have a plant per each city or town and the fuel is found in dirt all over the world. It's just cheap ass greedy elite who don't want to lose a dime if they aren't forced to. But I'd like to hear more - it would be great to start a international dialogue about it as India and other developing countries could benefit greatly and there is no need to worry about bomb making.
you know how the Grinch's heart grew 4 sizes that one day? that just happened to my brain, this killed me, which means I'm god, or I'm a ghost... oh God I'm a ghos
Ok, but when two atoms fuse together, the energy that is produced holds the atom together. How can we use that energy if it is already in use to hold the nucleus of the atom together?
Why can the by products of the fission reaction not be used to generate more energy? it may not be as much but it seems like we sped up the half life of Uranium by smashing it with neutrons, can't we do this with the by products to not only make more energy but to accelerate the process of their stabilization?
Hey I'm confused, you said that the mass lost at 2:05 is the binding energy right? but then why would the individual protons and neutrons have more energy than when they are together, if when they are together they got that energy keeping them together?
+Trexap Humanguard It doesn't take energy to keep them together - it takes energy to keep them apart! It's just like chemistry where covalent bonds forming is exothermic and covalent bonds breaking is endothermic. I think you're confusing forces; the electrostatic repulsion forces them away from eachother, but the strong nuclear force is magnitudes more powerful that pull them together. The problem is getting them close enough that the strong nuclear force's short lasso has any effect at all (which either happen entirely by chance like in the sun called quantum tunneling, or at extreme temperatures/pressures). That's the activation energy needed to kick start the process.
I'm looking forward to the next generation of nuclear reactors that are better able to manage the fuel and are largely self-buffering, and can even use old nuclear waste as new fuel!
Assuming that A. You can make it work B. You can make it less expensive C. Companies funding it won't lose billions trying to figure it out. (Think about General Public Utilities losing billions after the Three Mile Island incident. Take away the meltdown scare but keep everything else the same, that's the big scare for investors.)
gizmodo.com/5990383/the-future-of-nuclear-power-runs-on-the-waste-of-our-nuclear-past Most of the research into how to make this kind of reactor was done decades ago by the US government. They're becoming cost effective BECAUSE of the amount of waste traditional reactors have accumulated over time.
TechLaboratories I'm not talking about initial costs, although they would still be high. www.energyfromthorium.com/pdf/lidsky1983FusionTrouble.pdf Pages 9 and 10.
The Creeper Awesome article! Thanks for sharing! And I agree with you, (and MIT) that a fusion reactor is currently far more costly than we can imagine. But what I'm talking about is the molten salt fission reactor, which can use the existing nuclear waste 'stockpiles' as source fuels, and can be designed to be self regulating and with safeguards against accidental release of radioactive material, at a higher cost than current nuclear power yes, but only marginally. Current fission processes leave large amounts of energy in the nuclear waste that they produce, and if these could be reclaimed, or better used, it's more cost effective for everyone in the long run. After the initial outlay of building such a plant, it's longevity comes from a next-to-nothing cost for additional fuel, which is in rich supply, and without the ability to create enriched Uranium or Plutonium for atomic warfare.
Recommendations for watching crash course: 1. Take notes when you watch the video 2. Pause the video and replay if you don't understand something 3. Set the speed to 0.75. This makes it much easier to understand
If I recall correctly they build a fusion plant that makes as much energy as is needed to sustain itself for short periods of time, so there is progress I guess
I went to a physics symposium thing at cambridge and there I was told that either fusion doesnt actually produce that much energy or it isn't efficient or something like that, its just produces so much energy in stars and stuff because they're so big so there's so much fusion taking place. But if you just got like a little bit of the sun say, it wouldnt actually produce that much energy. Idk though, it was just something I was told
You are lacking a context here that you may have failed to catch. Fusion energy doesn't produce as much energy in comparison to what? The stars? That's a given. But fusion energy when compared to burning of coal, fossil fuels, solar panels and various green energies, it is much more powerful, efficient and cleaner with a near limitless fuel source in the form of hydrogen where our planet is stuffed full of.
It isn't efficient at the moment as we input more energy (and money) into kick starting fusion, than the energy output of the whole process. For example the hydrogen bomb uses a fission reaction to start the fusion of hydrogen.
I’m a laser plasma physicist, I often work with the fusion community. Firstly, note on the micro scale fusion is always very efficient. About a million times more energy is released per fusion reaction then a chemical reaction. I can think of two possible reason why they said this. 1: Lawson criterion (ρR > 1 g/cm²) of the sun being achieved by a very large R value. This means that the fusion reactions are spread out over a large radius (the core of the sun). Thus if you grabbed a few kilograms of the sun’s core and counted the number of fusion reactions you’d find there were only a few. No where near avogadro's number. But since the sun’s core is so big and it takes a million years for one photon to escape the sun, it doesn’t need to have a lot of reactions per kilogram to sustain itself. This is not the case in really big stars (90 solar masses). Big stars burn their fuel much faster. That’s why there life span is in millions of years while our sun’s life span is in billions. 2: The inefficiency in regards to our current attempts at power generation. This inefficiency is due to something called ignition, or rather our failure to achieve ignition. Ignition in fusion works very similar to ignition in your car. Ignition is a chain reaction as Hank just explained. Lets use the car analogy. In your car the spark plug triggers the combustion reaction. The energy released near the spark plug is transferred (heat) to the gas molecules of hydrocarbons and oxygen. The energy allows the two molecules to overcome their energy barrier and combine in a chemical reaction, but only near the spark plug. The rest of the gas remains too cold to react. However the gas near the spark plug that did react release energy into it’s neighboring gas, This energy triggers another layer around the first gas to undergo combustion. This is how the chain reaction gets started. There is an expanding layer of combustion radiating out (burn wave) from the spark plug, sustaining itself off it’s own energy output. At least until it runs out of gas to burn. This self sustaining expanding burn wave is called ignition. If ignition didn’t happen the spark plug would have to drive the reaction of the entire gas, not just a small initial bit to trigger the burn wave. This would take way more energy than you would get out of the total combustion, negative efficiency. Fusion ignition works the same way. For instance in inertial fusion the “spark plug” is a laser. However since we have never achieved ignition in a power plant scheme we have to drive the entire reaction with the laser, thus it is negative efficient. We have achieved ignition in thermonuclear bombs or hydrogen bombs. The hydrogen in the name refers to the fusion of hydrogen. Which is why the energy release is so great despite being relatively small. The “spark plug” in hydrogen bombs is a fission bomb, very uncontrollable. That is way there is no limit to how big a nuclear bombs can be. The fusion reaction can always be used to trigger another layer of fusion. Just add a little fuel to get a big effect. Whenever you achieved ignition it is very efficient, approximately a million times more so than chemical power plants such as coal or natural gas. Which is why we want to do it in the lab so badly.
After my rather unfortunate rant on the last video I feel I need to address that one too. Well, keeping it short - this one is factually much better than the last one. In fact, I couldn't catch any obvious faults (unlike the last one). So there, this video is good. I'm still mad at them, though, for calling it chemistry. This is not chemistry, it's physics! I know the lines are blurred and we step on each other's toes all the time and I've not complained much when they ventured into physics in the past (the ideal gas laws are not chemistry, guys). But... we need to draw the line somewhere. And we teach students that chemistry stops with the electron shells, the nucleus in chemistry is just treated as a given and questions about it are forwarded to physicists. Next thing you know they'll be doing quark chemistry.
Well is sort of found a error but it was more a such a minor side note that it not really worth mentioning. (But I will do it anyway. Fusion reactors have a tendency to produce some radioactive martial due to transformation coursed by neutron radiation. This only very slight and easily managed. Especially compared to what you standard Fission reactor puts out in terms of radioactive waste.) I really think this was a great episode and hopefully people will start to go deeper in to nuclear chemistry being inspired by this. I feel one of the greatest dangers with nuclear power is not the power it self, but the general ignorance of the public and politicians in the matter.
The division between physics and chemistry is pretty artificial, though. While calling nuclear physics chemistry seems a bit of a stretch it does involve transmutation of elements which sounds like a pretty big deal to a chemist. Electron shells and so on aren't necessarily chemistry either since they're relevant to quantum mechanics, lasers, x-ray production etc. And Hank's video on silicon touched on geology and electronics, which aren't chemistry or physics!
I found no significant errors from Hank's side either; the only error I could see was that Kr was described as having 35 protons instead of 36 in the animation, but this is probably just a typo from Thought Café's side.
and besides chemistry is mostly far cooler than physics...except for the stuff we want to steal for our own. Nuclear physics is now ours, mwa ha ha. (although you can keep gas laws, they definitely fall into the 'uncool physics' category) Obviously all in jest though, don't take this too seriously .
i have a question about fission. if in a atom of an unstable isotope of uranium bombarded with a neutron. why dose this cause the separation of the nucleus if the nucleus is held together with the binding energy of the "strong nuclear force" which is at its strongest when neutrons are bound to protons to my knowledge as surely this would increase the strength of forces holding the atom nucleus together ?
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The internet needs more of this kind of content.
true
+J.M. Studios pretty cool stuff. i didnt understand much of it but still..
Can you cover Rap God?
He's not that fast, unless he practices
Martin Ducharme hehe
You should find Benedict Cumberbatch instead for that.
4:42 "Yes, krypton is real thing". LOL I loved that line.
Bro... Your the reason why I'm gonna pass 11th grade chemistry, XD I wish you were my teacher, my teacher (miss roach) has no clue what she's doing, she messed up teaching us about moles (6.02*10^23) and reversed gamma, beta and alpha particles, she made alpha the strongest one and gamma the one stopped by paper.. So in short thanks for being smart bro :-)
+Robert McKinley We get taught about nuclear power mainly in physics, and I see where you're going. Although my teacher does not make stupid mistakes usually, he is slower at teaching than a snail and misses out on a lot of stuff. He doesn't challenge with his learning so I just bring my own work to class.
+Robert McKinley I had a math teacher like that last year. He would mix up EVERYTHING he taught. The only reason my friends and I passed is because RUclips videos and Khan Academy.
+Robert McKinley Does CC chemistry have structural diagram drawing?
+Robert McKinley hes currently the reason im passing my general chem II class in college.
I love ur teacher 😂😂
Bro, you taught me more in 10 minutes than my teacher in a double class(1h 20 minutes)! Thanks for being smart.
Why am I spending an hour in class barely getting this information when I can get it here in a few minutes
Comrade Stalin right? My teachers are always wasting time babbling about nonsense in their regular lives and it makes the whole thing like x1000 more difficult to understand
Although I'm a microbiology/immunology and pharmacology student I've always been fascinated with the more physical chemistry. Cheers for very interesting and well presented videos. It's good to take a break from working with plasmids. Lol
Thank you so much! This really helped clear up my conFUSION about nuclear energy
What a joke!!!!!! love it
It's amazing that you can speak that fast and fluently without tongue twisting. It's sure takes a lot of rehearsing and practice.
Hands down, one of my favorite, if not my favorite video explaining how nuclear energy works.
There has got to be a way to make fusion work. I think it’s an engineering problem of reaction confinement, which is why I’m doing my undergrad in Electrical Engineering and am planning on studying Plasma Physics in grad school with a focus on Nuclear Fusion. It’s in my view one of the five technologies that would be most impactful, which is why I want to dedicate my life to helping to figure it out. Love the videos John, keep them up.
I find it fascinating that E=mc^2 is so often associated with nuclear energy but not with say chemical energy. Those 420 tons of coal mentioned in the video, together with the O2 needed to burn it will be heavier than the CO2 and other stuff released by burning it by exactly the same amount as the mass defect of a mole of oxygen.
***** I'm pretty sure that's part of the reason. It's probably also because it's much easier to understand the usual explanation for chemical binding energy that looks at the valence electrons than it is to understand exactly what happens during nuclear fission or fusion.
The video also acknowledges this by saying something like "well, it's complicated but here's an explanation that's easy to understand". So that in itself would have been fine. However, the video still puts it as if E=mc^2 somehow only applied to nuclear processes but not to chemical ones which I believe is a common misconception in physics.
Penny Lane see this is why I like the new comment system...things like this :)
@kyle386 Oh so bored today
***** Not only that, but when you do measure the mass defect, it really does not contribute much to understanding the chemical reaction. It is only useful to confirm Einstein's theory, which already had more than enough confirmation elsewhere.
SpectatorAlius Why would it explain anything less in the chemical than in the nuclear case?
I don't think I can thank you enough for all the help you've brought. The questions at the end were the cherry on top (they were exactly what I needed). Thank you so much and please keep doing this, you're saving an entire generation with their homework and stuff :)
Amazing explanation. Its potential is enormous, we just need to use it in the right way
Never expected to see Commander Shepard in a CrashCourse video..... I love this.....
Great new studio.
I can't say Chemistry makes sense to me, but Crash Course is the best channel on You Tube for general knowledge.
I got to say, you are my favorite chem person I like watching on here. Keep up the GREAT work!
haikus are easy
but sometimes they don't make sense
refrigerator
heard that one before. also irrelevant to the video. try "nuclear fission. would be ironic in the sense that randomly place in a haiku, it does not make sense, and in relation to the video-if you didn't understand it- that's two humor points for you. also making an original ending would have spared you this response.
Geez, let this human enjoy his humor!
Huh, it's almost like
energy IS mass and force...
I mean quantum flux.
I cannot thank the crash course crew enough! These videos are awesome!
Nuclear engineer in training. Glad to see someone is trying to explain to the general public the basics of nuclear chemistry. --Thanks
Haha love the mass defect animation.
This is a bit difficult to say, but CrashCourse and SciShow just make me feel like I watching funny videos and studying and studying at the same time. I think when you have such an educational topic that is incredibly hard to do, so even when I had a great day, these RUclips channels are still the icing on the cake.
Thanks Jack and Hank.
4:11 is very closely linked to the evolution of the most massive stars, that drop-off after Fe is why supernovae occur.
Thank you so much for these courses, people like you are having a positive impact on humanity.
Cmon' Hank lets stretch for Organic Chemistry before the year ends!
Thank you, CrashCourse! For the last week, I have been watching your General Chemistry videos (1-39) to help study/prepare for my PCAT (pharmacy standardized test). The last time I took Gen Chem 1 was three years ago (sophomore level of high school) and Gen Chem 2 was one year ago. Needless to say, I lost some of my notes along the way and had no good way to study for my test. So I thank you for making these videos to help me review and actually teach me some things I have never learned before. I love all of your videos and will eventually watch all of them. :) Yes, even the history ones probably even though I am not too fond of history simply because both you and your brother make learning very fun. :)
At 2:40 in Nuclear Chemistry part 2, you didn't square the constant.
+Lance Corey he forgot to put the square sign over there........but if u check the value of c square,then it is equal to (3.0x10^8)^2 in hank's calculations..
Before, people say fusion energy is impossible to contain
Now, people say screw you we found out how
2:15 Mass effect reference! Ayyy lmao
thanks Hank Green, I hope everything is going well for you right now
If you want to learn more about the nuclear bombs, I have a video in my channel explaining what happens when a nuclear bomb explodes...
Great channel :)
Wow! I think I finally got the difference between the concepts and how a nuclear power plant and a nuclear bomb work!! By the way you are so inspiring by telling how this is the beginning and with enough effort anyone can be next big physicist... It’s a little for me though, but I’ll show it to my students!!!
Oh cool. This is what Homer Simpson does.
FrankGarrett316 lol.. who knew he was actually smart
This amazing video has inspired me to the answer of fission's disillusion. I believe the purpose of traveling into space is to begin scientific experimentation in the vacuum of space.... Thank you, Hank Green.
You mentioned at 6:54 that it produces krypton and bromine, it should be krypton and barium.
Actually 6:50 ish
since you are correcting hank himself, I am assuming you know why the 'C' constant is the squared of the speed of light itself? why? please tell me dude. please
God is an atheist C is the speed of light. Because the conversion of mass to energy is an enormous factor, as even the smallest mass holds an enormous amount of energy.
but why speed of light as the factor why squared and why cant any other constant be used?
God is an atheist Don't ask me, ask Einstein
So with a nuclear fission reactor, you could have a really awesome power plant and a balloon factory at the same time!
Best comment! Haha!
*fusion
Do crash course quantum physics/mechanics!
Me being the sad person i am would actually watch all of it. Please do!
OnlineDater69 Watch SciShow, Hank talks about Quantum Mechanics
CC physics #43
It also would have made sense, when discussing the nuclear reaction that dominates the Sun's energy production, if he had mentioned that all those gamma rays are produced at or very near the core, so that they lose a lot of energy on their remarkably slow path to the surface of the sun, where the energy is finally released as mostly visible light. So no need to worry about gamma rays from the sun.
At 4:49 isn’t krypton atomic number 36, not 35; the reaction doesn’t even add up with 35 there
your right
Defiantly the best chemistry episode I've watched
Error at 2:40
He has forgotten to square the speed of light. The result checks out though.
Okay, I'm missing something, at right around 8:00. Two atoms of hydrogen fuse together to form deuterium? Are we missing a proton? Does one of the protons lose some of its energy and positive electric charge in the form of a positron and become a neutron in the newly formed deuterium nucleus?
Err... The display of the calculation for E (@02:40) is missing the square for 3.0x10^8 m/s. Should be (3.0x10^8)^2). Your answer is correct, but the displayed equation is incorrect.
Slow clap
As far as I am aware the only current means of working against the heat of even laboratory fusion reactions (unfinished and non-stabilized) it with huge magnetic fields that repulse the oncoming kinetic particles an therefore prevent heat from transferring to the surrounding containment areas. Our problem is however that the energy we use to generate said magnetic field is more then the energy we get out of those test reactions.
On a positive note, if we were able to maintain said reactions for a specific duration, the energy output, assuming we are able to utilize most of the released energy, would allow us to maintain the magnetic field and still have excess.
Also Beam-Beam confinement
Yap and the magnetic fields don'T contain the high energy neutrons which in turn are a huge problem for the reactor. (you know, fun stuff like inducing radioactivity in the reactor walls)
ProFoxMike We can only hope that one day, soon than later, we can produce a stabilized nuclear reactor.
So what happens to all the electrons during fusion and fission?
4:43 if so, then Superman must be real. 😂
This was really well explained, kind sir! I'm a fan of nuclear chemistry and its possibilities and obstacles to break! Keep up those amazing videos! (:
i honestly find Hank really cute :)
This was such an inspiring video! I love how at the end, you said, "You've already taken the first step. It's now up to you how far you want to go. Maybe you'll write the next ... equation that'll take us to the next level!" I love that. The best thing is it's true! Hard work and determination!
Carolina Crown 2013 e= mc^2
I just love the shirt Einstein is wearing
burn 420 metric tons of 420 blaze it
SuperSamSquared 69th comment like
If we work out the logistics of fusion reactions, would we be able to use the hazardous waste created by fission to fuel fusion reactions?
The sound effects are so cute! 4:35
Very inspiring! Just what I need before applying to Chemical Engineering bachelor program this summer
Penny Lane already sort of covered this in their comments, but you made the same mistake most people who talk about nuclear chemistry make: E = mc^2 isn't the "source" or "cause" of the energy released in a nuclear reaction. It's an equation that tells you that the *result* of that reaction is going to involve a change of mass, because energy manifests itself as inertia/gravity. E = mc^2 gives us a way to measure the energy change, sure, but you got the causal arrow backwards (if a causal arrow can be drawn at all).
The "cause" of nuclear binding energy is the strong nuclear force, of course.
@thomas353 Hi it's been a long time.....yes I'm still modeling part time
What I don't understand is why fusion creates energy. In fission as small amount of mass is converted into energy, but in fusion energy needs to be poured in to create mass.
Chris P That is not right. Fusion releases energy if it occurs between elements lighter than iron. Fission releases energy if it occurs between elements heavier.
So when you fuse two protons to get a deuteron, about 1% of the proton mass gets converted to kinetic energy of the deuteron.
The proton "mass" is just a measure of its energy. The deuteron "mass" is a measure of its energy. The energy released is simply equal and opposite the nuclear binding energy of deuterium, which is negative and which derives from quantum chromodynamics (the physics of the strong nuclear force).
"Mass" never needs to enter into it except that it's easy to measure.
*****
That's because they're light :D
This man is the reason why I’m passing High school
I'm curious, where do you draw the line between nuclear chemistry and nuclear physics, or heck even the realm of quantum mechanics?
you can't, they get combined very oftrn. the same way physics ans chemistry overlap
+OSUfirebird18 It's a theory of everything my child! Science has branches, but everything about it is very very connected like a string and time... Cheerio! :D
I agree with the other comments that these things are all closely connected, but nuclear chemistry in particular focuses on how one type of atom transforms into another.
Nuclear chemistry might also cover the chemical techniques and properties of radioactive substances and how teh radiation and the change in element affects the chemical environment.
Nuclear physics might for example more concentrate on that amounts of energy released, how to slow speed or confine a chain reaction. What are the fundemntal forces involved in the nucleus that give it is properties. What are the constituent parts of the nucleus.
Is the study of fire physics or chemistry? Kind of depends on what you are studying about it. Its more of an emphasis rather than a distinction.
what would happen if a fusion reaction is done inside a hard material like diamond with an absolute zero temperature?
At around 6:50, you said Uranium-235 splits up into Krypton and Bromine but it should be Barium
+Ahnaf An-Nafee yaa man actually it was a mistake by them...but its okk ...it happens
exactly
2:40 There is missing the square on the speed of light term!
Something so complicated, explained so easily....starting with the radioactive decay video.Thanks
We have figured out how to control fusion reactions! and we are trying to generate energy with it! Look up Tokamaks or stelarators. We have done almost break even at the JET tokamak in England Q~0.7. ITER under construction in France would hopefully do 10 times as much energy for 30.minutes.
There is a mistake in the nuclear equation of uranium fission.
Atomic number of Kr is 36.
Missed the squared on the equation at 2:35.
The half-life of Uranium-235 is 4.5 billion years
whats a half-life its in my paper and i have no clue what the hell it is!!!
MegaHazzaBee
Its the time it takes for an element's radiation emission to decrease by half.
+Jamie Williamson awesome thank you very much x
MegaHazzaBee
thats alright
Bear in mind that if it takes 4.5 billion years to halve the number of nuclei in a sample, it will not take double the amount to go away completely, but rather take another 4.5 billion years to halve again... and again, and again, etc.
This is why we say these things are basically always a problem, since just two half lives to get uranium a quarter of its previous size takes more time than the Earth has left to live, haha (because the Sun will run out of Hydrogen in about 6.5 billion years).
2:11 Commander Shepherd from Mass Effect makes an appearance!
There is progress in fusion reaction, an institution in Europe (France I thought) is developing a technique using lasers to fuse hydrogen.
Researchers at Lockheed Martin in the USA are working on a compact fusion reactor. In 2014 they claimed a prototype will be running by 2019. This claim has been met with scepticism by some in the scientific community
WOW!
Seems you only touched on fast breeder reactors. I hope you can do a show about molten salt reactors. More specifically, LFTR.
"Now I am become Death, the destroyer of worlds." (Oppenheimer)
At about 4:40, he says that when you hit a Uranium nucleus with a neutron, it splits. But this is only one of the possible outcomes. All the difficulties of reactor or bomb design require understanding that there are more possible outcomes, and how to optimize the desired outcome. For example, in a natural uranium reactor, you can use a 'heterogeneous' arrangement of moderator and fuel, which increases the probability of fission by slowing the neutrons down. But if you are building a breeder reactor, you may actually want faster neutrons, since they transmute more often.
So splitting is one possible reaction, transmutation due to absorption of the neutron is another. Then there is scattering, which in turn can leave the nucleus in an excited state.
Thanks a lot bro! you really help me pass my IGCSE LMAOO
I so wish you would do an in-depth investigation of Thorium reactors and why we aren't converting to this technology. I mean, I know why...however it appears to be the perfect answer to our energy crisis and yet - nada. No one is working on it. Why? I'd love to learn more - but there is so little discussion on this topic. Bring us up to speed Hank. Would be an excellent video on Alternative Nuclear energy.
That would be a perfect topic for a future episode of SciShow.
To sum up my knowledge of the subject - In the early days of nuclear research they had a few options as to the primary fuel but they chose uranium because the waste can be used for bombs. Since then it has been used simply because it is proven to work. Very few investors are willing to back a completely untested technology when it means putting up $10B+ up front.
*****
Yes, but not untested - it has been tested and is safer and the half life is only like 100 years. The reason they don't convert is money - everything has been built to process Uranium and they just don't want to spend the millions necessary to retool everything for this safer, more efficient method of generating power. And it doesn't make weaponized uranium for bombs. - But we should be using Thorium reactors as they are not only much safer, but are also scalable - you can have a plant per each city or town and the fuel is found in dirt all over the world. It's just cheap ass greedy elite who don't want to lose a dime if they aren't forced to. But I'd like to hear more - it would be great to start a international dialogue about it as India and other developing countries could benefit greatly and there is no need to worry about bomb making.
Nexus2Eden You know those same reasons might be used when/if fusion power ever becomes commercially viable.
you know how the Grinch's heart grew 4 sizes that one day? that just happened to my brain, this killed me, which means I'm god, or I'm a ghost... oh God I'm a ghos
CrachCourse - Thank you so much for this educational video :). It helped me a ton for my exam. I thank you and i owe you a lot :).
Are you going to talk about Thorium generated power? Maybe comparing it with Uranium and Plutonium ones? :)
and how much more badass the name throium is over poussy plutonium, and uranusum
Haha, the Hikus are easy, but sometimes they don't make sense, refrigerator t-shirt. I love that shirt. Great video too!
Now to put a fusion reactor in my chest like Tony Stark!
Thank you this will really help my project, and I will make sure to reference you
2:39
Squared, mind you. =P
+Mohammed Zaid Nop! he distributed the square in: the speed of light is 3.00*10^6 m/s, if you square it, it's 3.00*10^8 as written. hehe :p
Baptiste Bauer
Yeah, right! ;P
*****
He meant it as a joke
Ok, but when two atoms fuse together, the energy that is produced holds the atom together. How can we use that energy if it is already in use to hold the nucleus of the atom together?
the c was not squared...
did you say bromine instead of barium at 6:55 or is it unrelated to the equation at 4:46?
Am I the only one that got a ad for help with Chemistry?
Why can the by products of the fission reaction not be used to generate more energy? it may not be as much but it seems like we sped up the half life of Uranium by smashing it with neutrons, can't we do this with the by products to not only make more energy but to accelerate the process of their stabilization?
Isn't the equation E=(mc^2)^2 + (pc)^2
For the equation starting at 4:43, shouldn't the Krypton's atomic number be 36 instead of 35?
You're right. Bromine is 35.
Thorium is the answer! look it up.
Hey I'm confused, you said that the mass lost at 2:05 is the binding energy right? but then why would the individual protons and neutrons have more energy than when they are together, if when they are together they got that energy keeping them together?
+Trexap Humanguard It doesn't take energy to keep them together - it takes energy to keep them apart! It's just like chemistry where covalent bonds forming is exothermic and covalent bonds breaking is endothermic.
I think you're confusing forces; the electrostatic repulsion forces them away from eachother, but the strong nuclear force is magnitudes more powerful that pull them together.
The problem is getting them close enough that the strong nuclear force's short lasso has any effect at all (which either happen entirely by chance like in the sun called quantum tunneling, or at extreme temperatures/pressures). That's the activation energy needed to kick start the process.
I'm looking forward to the next generation of nuclear reactors that are better able to manage the fuel and are largely self-buffering, and can even use old nuclear waste as new fuel!
Assuming that A. You can make it work
B. You can make it less expensive
C. Companies funding it won't lose billions trying to figure it out. (Think about General Public Utilities losing billions after the Three Mile Island incident. Take away the meltdown scare but keep everything else the same, that's the big scare for investors.)
gizmodo.com/5990383/the-future-of-nuclear-power-runs-on-the-waste-of-our-nuclear-past
Most of the research into how to make this kind of reactor was done decades ago by the US government. They're becoming cost effective BECAUSE of the amount of waste traditional reactors have accumulated over time.
TechLaboratories I'm not talking about initial costs, although they would still be high.
www.energyfromthorium.com/pdf/lidsky1983FusionTrouble.pdf Pages 9 and 10.
The Creeper Awesome article! Thanks for sharing! And I agree with you, (and MIT) that a fusion reactor is currently far more costly than we can imagine. But what I'm talking about is the molten salt fission reactor, which can use the existing nuclear waste 'stockpiles' as source fuels, and can be designed to be self regulating and with safeguards against accidental release of radioactive material, at a higher cost than current nuclear power yes, but only marginally. Current fission processes leave large amounts of energy in the nuclear waste that they produce, and if these could be reclaimed, or better used, it's more cost effective for everyone in the long run. After the initial outlay of building such a plant, it's longevity comes from a next-to-nothing cost for additional fuel, which is in rich supply, and without the ability to create enriched Uranium or Plutonium for atomic warfare.
TechLaboratories From what I know of that, that is still purely theoretical.
Recommendations for watching crash course:
1. Take notes when you watch the video
2. Pause the video and replay if you don't understand something
3. Set the speed to 0.75. This makes it much easier to understand
E^2=M^2 * C^4 + P^2 * C^2
Is the actual full equation.
If I recall correctly they build a fusion plant that makes as much energy as is needed to sustain itself for short periods of time, so there is progress I guess
HBO's Chernobyl brought me here ...again
I went to a physics symposium thing at cambridge and there I was told that either fusion doesnt actually produce that much energy or it isn't efficient or something like that, its just produces so much energy in stars and stuff because they're so big so there's so much fusion taking place. But if you just got like a little bit of the sun say, it wouldnt actually produce that much energy. Idk though, it was just something I was told
You are lacking a context here that you may have failed to catch.
Fusion energy doesn't produce as much energy in comparison to what? The stars? That's a given.
But fusion energy when compared to burning of coal, fossil fuels, solar panels and various green energies, it is much more powerful, efficient and cleaner with a near limitless fuel source in the form of hydrogen where our planet is stuffed full of.
It isn't efficient at the moment as we input more energy (and money) into kick starting fusion, than the energy output of the whole process.
For example the hydrogen bomb uses a fission reaction to start the fusion of hydrogen.
I’m a laser plasma physicist, I often work with the fusion community. Firstly, note on the micro scale fusion is always very efficient. About a million times more energy is released per fusion reaction then a chemical reaction. I can think of two possible reason why they said this.
1: Lawson criterion (ρR > 1 g/cm²) of the sun being achieved by a very large R value. This means that the fusion reactions are spread out over a large radius (the core of the sun). Thus if you grabbed a few kilograms of the sun’s core and counted the number of fusion reactions you’d find there were only a few. No where near avogadro's number. But since the sun’s core is so big and it takes a million years for one photon to escape the sun, it doesn’t need to have a lot of reactions per kilogram to sustain itself. This is not the case in really big stars (90 solar masses). Big stars burn their fuel much faster. That’s why there life span is in millions of years while our sun’s life span is in billions.
2: The inefficiency in regards to our current attempts at power generation. This inefficiency is due to something called ignition, or rather our failure to achieve ignition. Ignition in fusion works very similar to ignition in your car. Ignition is a chain reaction as Hank just explained. Lets use the car analogy. In your car the spark plug triggers the combustion reaction. The energy released near the spark plug is transferred (heat) to the gas molecules of hydrocarbons and oxygen. The energy allows the two molecules to overcome their energy barrier and combine in a chemical reaction, but only near the spark plug. The rest of the gas remains too cold to react. However the gas near the spark plug that did react release energy into it’s neighboring gas, This energy triggers another layer around the first gas to undergo combustion. This is how the chain reaction gets started. There is an expanding layer of combustion radiating out (burn wave) from the spark plug, sustaining itself off it’s own energy output. At least until it runs out of gas to burn. This self sustaining expanding burn wave is called ignition. If ignition didn’t happen the spark plug would have to drive the reaction of the entire gas, not just a small initial bit to trigger the burn wave. This would take way more energy than you would get out of the total combustion, negative efficiency. Fusion ignition works the same way. For instance in inertial fusion the “spark plug” is a laser. However since we have never achieved ignition in a power plant scheme we have to drive the entire reaction with the laser, thus it is negative efficient. We have achieved ignition in thermonuclear bombs or hydrogen bombs. The hydrogen in the name refers to the fusion of hydrogen. Which is why the energy release is so great despite being relatively small. The “spark plug” in hydrogen bombs is a fission bomb, very uncontrollable. That is way there is no limit to how big a nuclear bombs can be. The fusion reaction can always be used to trigger another layer of fusion. Just add a little fuel to get a big effect. Whenever you achieved ignition it is very efficient, approximately a million times more so than chemical power plants such as coal or natural gas. Which is why we want to do it in the lab so badly.
After my rather unfortunate rant on the last video I feel I need to address that one too. Well, keeping it short - this one is factually much better than the last one. In fact, I couldn't catch any obvious faults (unlike the last one). So there, this video is good.
I'm still mad at them, though, for calling it chemistry. This is not chemistry, it's physics! I know the lines are blurred and we step on each other's toes all the time and I've not complained much when they ventured into physics in the past (the ideal gas laws are not chemistry, guys). But... we need to draw the line somewhere. And we teach students that chemistry stops with the electron shells, the nucleus in chemistry is just treated as a given and questions about it are forwarded to physicists. Next thing you know they'll be doing quark chemistry.
Dunno why you are complaining. Quark chemistry sounds AWESOME!!!
Well is sort of found a error but it was more a such a minor side note that it not really worth mentioning.
(But I will do it anyway. Fusion reactors have a tendency to produce some radioactive martial due to transformation coursed by neutron radiation. This only very slight and easily managed. Especially compared to what you standard Fission reactor puts out in terms of radioactive waste.)
I really think this was a great episode and hopefully people will start to go deeper in to nuclear chemistry being inspired by this. I feel one of the greatest dangers with nuclear power is not the power it self, but the general ignorance of the public and politicians in the matter.
The division between physics and chemistry is pretty artificial, though. While calling nuclear physics chemistry seems a bit of a stretch it does involve transmutation of elements which sounds like a pretty big deal to a chemist. Electron shells and so on aren't necessarily chemistry either since they're relevant to quantum mechanics, lasers, x-ray production etc. And Hank's video on silicon touched on geology and electronics, which aren't chemistry or physics!
I found no significant errors from Hank's side either; the only error I could see was that Kr was described as having 35 protons instead of 36 in the animation, but this is probably just a typo from Thought Café's side.
and besides chemistry is mostly far cooler than physics...except for the stuff we want to steal for our own. Nuclear physics is now ours, mwa ha ha. (although you can keep gas laws, they definitely fall into the 'uncool physics' category)
Obviously all in jest though, don't take this too seriously .
i have a question about fission. if in a atom of an unstable isotope of uranium bombarded with a neutron. why dose this cause the separation of the nucleus if the nucleus is held together with the binding energy of the "strong nuclear force" which is at its strongest when neutrons are bound to protons to my knowledge as surely this would increase the strength of forces holding the atom nucleus together ?
My head hurts :(