title
Nuclear Fusion Energy | Ian Hutchinson and Lex Fridman

description
Full episode with Ian Hutchinson (Jul 2020): https://www.youtube.com/watch?v=pDSEjaDCtOU Clips channel (Lex Clips): https://www.youtube.com/lexclips Main channel (Lex Fridman): https://www.youtube.com/lexfridman (more links below) Podcast full episodes playlist: https://www.youtube.com/playlist?list=PLrAXtmErZgOdP_8GztsuKi9nrraNbKKp4 Podcasts clips playlist: https://www.youtube.com/playlist?list=PLrAXtmErZgOeciFP3CBCIEElOJeitOr41 Podcast website: https://lexfridman.com/ai Podcast on Apple Podcasts (iTunes): https://apple.co/2lwqZIr Podcast on Spotify: https://spoti.fi/2nEwCF8 Podcast RSS: https://lexfridman.com/category/ai/feed/ Ian Hutchinson, a nuclear engineer and plasma physicist at MIT. He has made a number of important contributions in plasma physics including the magnetic confinement of plasmas seeking to enable fusion reactions, which is the energy source of the stars, to be used for practical energy production. Current nuclear reactors are based on fission as we discuss. Ian has also written on the philosophy of science and the relationship between science and religion. Subscribe to this YouTube channel or connect on: - Twitter: https://twitter.com/lexfridman - LinkedIn: https://www.linkedin.com/in/lexfridman - Facebook: https://www.facebook.com/lexfridman - Instagram: https://www.instagram.com/lexfridman - Medium: https://medium.com/@lexfridman - Support on Patreon: https://www.patreon.com/lexfridman

detail
{'title': 'Nuclear Fusion Energy | Ian Hutchinson and Lex Fridman', 'heatmap': [], 'summary': 'Nuclear fusion presents challenges due to the high energy impact needed, engineering hurdles, and the necessity for temperatures of tens of millions of degrees celsius; however, potential benefits include generating a million times more energy per unit mass than chemical reactions and reduced radioactivity compared to fission reactors.', 'chapters': [{'end': 281.298, 'segs': [{'end': 40.008, 'src': 'embed', 'start': 1.892, 'weight': 1, 'content': [{'end': 6.855, 'text': 'Maybe another distinction we want to try to get at is the difference between fission and fusion.', 'start': 1.892, 'duration': 4.963}, {'end': 10.036, 'text': 'So you mentioned fusion is the kind of reaction happening in the Sun.', 'start': 7.395, 'duration': 2.641}, {'end': 11.797, 'text': "So what's fission and what's fusion? Sure.", 'start': 10.176, 'duration': 1.621}, {'end': 19.481, 'text': 'Well, fission is taking heavy elements like uranium and breaking them up,', 'start': 12.717, 'duration': 6.764}, {'end': 23.803, 'text': 'and it turns out that that process of breaking up heavy elements releases energy.', 'start': 19.481, 'duration': 4.322}, {'end': 25.644, 'text': 'What does it mean to be a heavy element?', 'start': 24.083, 'duration': 1.561}, {'end': 40.008, 'text': 'it means that there are many nuclear particles in the nucleus itself, neutrons and protons in the nucleus itself, so that in the case of uranium,', 'start': 26.354, 'duration': 13.654}], 'summary': 'Fission breaks heavy elements like uranium, releasing energy. fusion occurs in the sun.', 'duration': 38.116, 'max_score': 1.892, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1892.jpg'}, {'end': 112.265, 'src': 'embed', 'start': 80.58, 'weight': 2, 'content': [{'end': 90.81, 'text': 'Deuterium has a proton and a neutron, and tritium has a proton and two neutrons, so it has a total of three nucleons in the nucleus.', 'start': 80.58, 'duration': 10.23}, {'end': 101.479, 'text': 'Well, taking light elements like isotopes of hydrogen and not breaking them up, but actually fusing them together,', 'start': 92.052, 'duration': 9.427}, {'end': 105.902, 'text': 'reacting them together to produce heavier elements, typically helium.', 'start': 101.479, 'duration': 4.423}, {'end': 112.265, 'text': 'Helium is a nucleus which has two protons and two neutrons.', 'start': 106.882, 'duration': 5.383}], 'summary': 'Fusing deuterium and tritium to produce helium with 3 nucleons in the nucleus.', 'duration': 31.685, 'max_score': 80.58, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk80580.jpg'}, {'end': 174.934, 'src': 'embed', 'start': 146.066, 'weight': 0, 'content': [{'end': 152.13, 'text': 'The energy released in a chemical reaction like that or the burning of coal or oil or whatever else,', 'start': 146.066, 'duration': 6.064}, {'end': 158.215, 'text': 'is about a million times less per unit mass than what is released in nuclear reactions.', 'start': 152.13, 'duration': 6.085}, {'end': 159.495, 'text': "But it's hard to do.", 'start': 158.735, 'duration': 0.76}, {'end': 164.239, 'text': 'It requires very high energy of impact.', 'start': 160.056, 'duration': 4.183}, {'end': 167.449, 'text': "And actually, it's very easy to understand why.", 'start': 165.287, 'duration': 2.162}, {'end': 174.934, 'text': "And that is that those two nuclei, if they're both, let's say hydrogen nuclei one is, let's say, deuterium, and the other is,", 'start': 167.549, 'duration': 7.385}], 'summary': 'Chemical reactions release a million times less energy than nuclear reactions, which require high energy of impact.', 'duration': 28.868, 'max_score': 146.066, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk146066.jpg'}, {'end': 218.583, 'src': 'embed', 'start': 191.068, 'weight': 3, 'content': [{'end': 196.453, 'text': 'the electric repulsion of the two nuclei from one another.', 'start': 191.068, 'duration': 5.385}, {'end': 205.98, 'text': 'And you have to get them extremely close to one another in order for the nuclear forces to overtake the electrical forces and actually form a new nucleus.', 'start': 196.873, 'duration': 9.107}, {'end': 212.311, 'text': 'And so one requires very high energies of impact in order for reactions to take place.', 'start': 206.881, 'duration': 5.43}, {'end': 218.583, 'text': 'And those high energies of impact correspond to very high temperatures of random motion.', 'start': 212.392, 'duration': 6.191}], 'summary': 'High energies needed for nuclear reactions due to electric repulsion', 'duration': 27.515, 'max_score': 191.068, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk191068.jpg'}], 'start': 1.892, 'title': 'Nuclear fusion challenges', 'summary': 'Explores the disparities between fission and fusion, with fission releasing energy by breaking heavy elements like uranium and fusion creating energy by fusing light elements like hydrogen isotopes. nuclear reactions release approximately a million times more energy per unit mass than chemical reactions, but achieving fusion is challenging due to the high energy of impact required. additionally, the chapter delves into the engineering challenges of nuclear fusion, emphasizing the need to overcome electric repulsion, high energies, and temperatures similar to those found in the sun to achieve ignition and create net energy.', 'chapters': [{'end': 112.265, 'start': 1.892, 'title': 'Fission vs fusion', 'summary': 'Explores the difference between fission and fusion, where fission involves breaking up heavy elements like uranium to release energy, and fusion entails fusing light elements like hydrogen isotopes to produce heavier elements, typically helium.', 'duration': 110.373, 'highlights': ['Fission involves breaking up heavy elements like uranium, releasing energy in the process.', 'Heavy elements like uranium have a large number of nucleons in the nucleus, with U-235 having 235 nucleons and U-238 having 238 nucleons.', 'Fusion entails reacting light elements like isotopes of hydrogen to produce heavier elements, typically helium with two protons and two neutrons.', 'Light elements like hydrogen isotopes have very few nucleons in the nucleus, with deuterium having a proton and a neutron, and tritium having a proton and two neutrons.']}, {'end': 167.449, 'start': 112.865, 'title': 'Nuclear reactions and energy release', 'summary': 'Discusses how nuclear reactions such as fusion and fission release approximately a million times more energy per unit mass than chemical reactions, powering the sun and stars, while being harder to achieve due to the very high energy of impact required.', 'duration': 54.584, 'highlights': ['Nuclear reactions like fusion and fission release approximately a million times more energy per unit mass than chemical reactions.', 'These reactions are what mostly powers the sun and stars.', 'Nuclear reactions require very high energy of impact, making them harder to achieve.']}, {'end': 281.298, 'start': 167.549, 'title': 'Nuclear fusion engineering challenges', 'summary': 'Explains that nuclear fusion reactions require overcoming electric repulsion to bring nuclei together, needing high energies and temperatures, similar to those found in the sun, to achieve ignition and create net energy.', 'duration': 113.749, 'highlights': ['Nuclear fusion reactions require overcoming electric repulsion between nuclei by getting them extremely close to form a new nucleus, needing high energies of impact and temperatures for reactions to take place.', 'The high energies of impact required for nuclear fusion reactions correspond to very high temperatures of random motion, similar to those found in the sun, making it possible to do something like that in the sun.', "Nature's fusion reactors, the stars, reach the point of ignition where they release more energy from reactions than they lose by radiation and transport to achieve net energy, similar to lighting a fire."]}], 'duration': 279.406, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1892.jpg', 'highlights': ['Nuclear reactions release approximately a million times more energy per unit mass than chemical reactions.', 'Fission involves breaking up heavy elements like uranium, releasing energy in the process.', 'Fusion entails reacting light elements like isotopes of hydrogen to produce heavier elements, typically helium with two protons and two neutrons.', 'Nuclear fusion reactions require overcoming electric repulsion between nuclei by getting them extremely close to form a new nucleus, needing high energies of impact and temperatures for reactions to take place.']}, {'end': 511.759, 'segs': [{'end': 366.096, 'src': 'embed', 'start': 309.246, 'weight': 0, 'content': [{'end': 314.349, 'text': "And that's what we've got to do on Earth if we're going to make fusion work on Earth.", 'start': 309.246, 'duration': 5.103}, {'end': 320.292, 'text': "But it's much harder to do on Earth than it is in a star,", 'start': 314.749, 'duration': 5.543}, {'end': 334.72, 'text': 'because we need temperatures of order tens of millions of degrees Celsius in order for the reactions to go fast enough to generate enough energy to keep it going.', 'start': 320.292, 'duration': 14.428}, {'end': 350.528, 'text': "And so if you've got something that's tens of millions of degrees Celsius and you want to keep it all together and keep the heat in long enough to have enough reactions taking place,", 'start': 338.622, 'duration': 11.906}, {'end': 352.429, 'text': "you can't just put it in a bottle.", 'start': 350.528, 'duration': 1.901}, {'end': 358.732, 'text': 'Plastic or glass, it would be gone in milliseconds.', 'start': 353.269, 'duration': 5.463}, {'end': 366.096, 'text': 'So you have to have some non-material mechanism of confining the plasma.', 'start': 358.752, 'duration': 7.344}], 'summary': 'Achieving fusion on earth requires temperatures of tens of millions of degrees celsius and a non-material mechanism of confining the plasma.', 'duration': 56.85, 'max_score': 309.246, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk309246.jpg'}, {'end': 444.143, 'src': 'embed', 'start': 388.48, 'weight': 2, 'content': [{'end': 399.946, 'text': 'But the mutual gravitational attraction of small objects is very weak compared with the electrical repulsion or any other force that you can think about,', 'start': 388.48, 'duration': 11.466}, {'end': 407.675, 'text': 'And so we need a stronger force to keep the plasma together, to confine it.', 'start': 400.966, 'duration': 6.709}, {'end': 417.778, 'text': 'And the predominant attempt at making fusion work on Earth is to use magnetic fields to confine the plasma.', 'start': 409.016, 'duration': 8.762}, {'end': 420.638, 'text': "And that's what I've worked on for much.", 'start': 418.538, 'duration': 2.1}, {'end': 433.1, 'text': 'essentially, most of my career is to understand how we can and how best we can confine these incredibly hot gases plasmas using magnetic fields,', 'start': 420.638, 'duration': 12.462}, {'end': 442.531, 'text': 'with the ultimate objective of releasing fusion energy on Earth and generating electricity with it and powering our society with it.', 'start': 433.1, 'duration': 9.431}, {'end': 444.143, 'text': 'Dumb question.', 'start': 443.463, 'duration': 0.68}], 'summary': 'Magnetic fields are used to confine hot gases for fusion, with the goal of generating electricity and powering society.', 'duration': 55.663, 'max_score': 388.48, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk388480.jpg'}, {'end': 501.815, 'src': 'embed', 'start': 471.376, 'weight': 3, 'content': [{'end': 479.043, 'text': "So, if we want to do it on Earth, where there's air, we want the plasma to consist of hydrogen isotopes or other things,", 'start': 471.376, 'duration': 7.667}, {'end': 480.164, 'text': "the things we're trying to react.", 'start': 479.043, 'duration': 1.121}, {'end': 488.091, 'text': 'And by the way, the density of those plasmas, at least in magnetic confinement fusion, is very low.', 'start': 480.824, 'duration': 7.267}, {'end': 492.795, 'text': "It's maybe a million times less than the density of air in this room.", 'start': 488.191, 'duration': 4.604}, {'end': 501.815, 'text': 'So in order for a fusion reactor like that to work, you have to keep all of the air out and just keep the plasma in.', 'start': 494.853, 'duration': 6.962}], 'summary': 'To achieve fusion on earth, low-density plasma must be maintained, a million times less dense than air.', 'duration': 30.439, 'max_score': 471.376, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk471376.jpg'}], 'start': 282.346, 'title': 'Challenges in nuclear fusion on earth', 'summary': 'Explains the challenges of achieving nuclear fusion on earth, requiring temperatures of tens of millions of degrees celsius and the need for a non-material mechanism to confine the plasma, with the plasma density being a million times less than the density of air in a room.', 'chapters': [{'end': 366.096, 'start': 282.346, 'title': 'Nuclear fusion challenges on earth', 'summary': 'Explains the challenges of achieving nuclear fusion on earth, requiring temperatures of tens of millions of degrees celsius and the need for a non-material mechanism to confine the plasma in order to keep the reactions going, which is much harder to achieve on earth than in a star.', 'duration': 83.75, 'highlights': ['Achieving nuclear fusion on Earth requires temperatures of tens of millions of degrees Celsius to generate enough energy to keep the reactions going.', 'A non-material mechanism is needed to confine the plasma in order to keep the heat in long enough for enough reactions to take place.', 'The difficulty of achieving nuclear fusion on Earth is highlighted by the need for a non-material mechanism to confine the plasma, as opposed to simply putting it in a bottle which would be gone in milliseconds.']}, {'end': 511.759, 'start': 367.179, 'title': 'Magnetic confinement fusion for energy generation', 'summary': 'Discusses how magnetic fields are utilized to confine incredibly hot gases plasmas for fusion reactions on earth, aiming to generate electricity and power society, with the plasma density being a million times less than the density of air in a room.', 'duration': 144.58, 'highlights': ['Magnetic fields are used to confine incredibly hot gases plasmas for fusion reactions on Earth. The predominant attempt at making fusion work on Earth is to use magnetic fields to confine the plasma.', 'The plasma density is a million times less than the density of air in a room. The density of those plasmas, at least in magnetic confinement fusion, is very low, maybe a million times less than the density of air in this room.', "The main purpose of the walls in a fusion reactor is to keep the atmosphere out. The main purpose of the walls is not to keep the plasma in, it's to keep the atmosphere out."]}], 'duration': 229.413, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk282346.jpg', 'highlights': ['Achieving nuclear fusion on Earth requires temperatures of tens of millions of degrees Celsius to generate enough energy.', 'A non-material mechanism is needed to confine the plasma in order to keep the heat in long enough for enough reactions to take place.', 'Magnetic fields are used to confine incredibly hot gases plasmas for fusion reactions on Earth.', 'The plasma density is a million times less than the density of air in a room.', 'The difficulty of achieving nuclear fusion on Earth is highlighted by the need for a non-material mechanism to confine the plasma.']}, {'end': 713.938, 'segs': [{'end': 536.814, 'src': 'embed', 'start': 512.578, 'weight': 1, 'content': [{'end': 524.505, 'text': "What we don't quite know how to do is to make a confinement device that's It isolates the plasma well enough so that it's able to keep itself burning with its own reaction.", 'start': 512.578, 'duration': 11.927}, {'end': 534.732, 'text': 'So maybe, can you talk about what a tokamak is? The Russian acronym from which the word tokamak is built just means toroidal magnetic chamber.', 'start': 524.986, 'duration': 9.746}, {'end': 536.814, 'text': "So it's a toroidal chamber.", 'start': 535.152, 'duration': 1.662}], 'summary': 'Challenges in creating a confinement device to sustain plasma burning in a tokamak, a toroidal chamber.', 'duration': 24.236, 'max_score': 512.578, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk512578.jpg'}, {'end': 614.769, 'src': 'embed', 'start': 564.713, 'weight': 0, 'content': [{'end': 575.72, 'text': "for making fusion energy work is one in which there's a very strong magnetic field the long way around the donut around the torus.", 'start': 564.713, 'duration': 11.007}, {'end': 583.769, 'text': "So you've got to imagine that there's this doughnut shape with an embedded magnetic field just going round and round the long way.", 'start': 577.026, 'duration': 6.743}, {'end': 598.216, 'text': "The big advantage of that is that plasma particles, when they're in the presence of a magnetic field, feel strong forces from the magnetic field,", 'start': 584.409, 'duration': 13.807}, {'end': 604.721, 'text': 'and those forces make the particles gyrate around the direction of the magnetic field line.', 'start': 598.216, 'duration': 6.505}, {'end': 614.769, 'text': "So basically the particles follow helical orbits, following like a spring that's directed along the magnetic field.", 'start': 605.442, 'duration': 9.327}], 'summary': 'Fusion energy relies on a strong magnetic field for plasma particles to gyrate, following helical orbits along the magnetic field lines.', 'duration': 50.056, 'max_score': 564.713, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk564713.jpg'}, {'end': 693.95, 'src': 'embed', 'start': 642.122, 'weight': 4, 'content': [{'end': 644.723, 'text': "It doesn't mean they're going to exit the chamber.", 'start': 642.122, 'duration': 2.601}, {'end': 656.357, 'text': "But if you just had a straight magnetic field, for example, coming from a Helmholtz coil or a bar magnet, then you'd have to have ends.", 'start': 645.324, 'duration': 11.033}, {'end': 663.442, 'text': 'It would come to the ends of the chamber somewhere and the particles would hit the ends and they would lose their energy.', 'start': 656.417, 'duration': 7.025}, {'end': 667.986, 'text': "So that's why it's toroidal and that's why we have a strong magnetic field.", 'start': 664.023, 'duration': 3.963}, {'end': 677.734, 'text': "It's providing a confinement against motion in the direction that would lead the particles to leave the chamber.", 'start': 668.026, 'duration': 9.708}, {'end': 684.182, 'text': "It turns out that Here we're getting a little bit technical, but it turns out that a toroidal field alone is not enough.", 'start': 678.094, 'duration': 6.088}, {'end': 689.827, 'text': 'And so you need more fields to produce true confinement of plasma.', 'start': 684.282, 'duration': 5.545}, {'end': 693.95, 'text': 'And we get those by passing a current as well through the plasma itself.', 'start': 689.867, 'duration': 4.083}], 'summary': 'A toroidal magnetic field provides confinement against particle motion, while additional fields are needed for true plasma confinement.', 'duration': 51.828, 'max_score': 642.122, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk642122.jpg'}], 'start': 512.578, 'title': 'Challenges in tokamak fusion', 'summary': 'Discusses challenges in creating a confinement device for plasma in a tokamak concept, utilizing a toroidal chamber with a strong magnetic field for potential fusion energy production and explaining plasma particle movement and confinement techniques.', 'chapters': [{'end': 583.769, 'start': 512.578, 'title': 'Tokamak fusion reactor', 'summary': 'Discusses the challenges of creating a confinement device for plasma to sustain its own reaction, focusing on the tokamak concept, which utilizes a toroidal chamber with a strong magnetic field for potential fusion energy production.', 'duration': 71.191, 'highlights': ['The tokamak concept utilizes a toroidal chamber with a strong magnetic field for potential fusion energy production.', 'A challenge in fusion energy is creating a confinement device for plasma to sustain its own reaction.', 'The Russian acronym for tokamak means toroidal magnetic chamber.']}, {'end': 667.986, 'start': 584.409, 'title': 'Plasma particle movement in a toroidal chamber', 'summary': 'Explains how plasma particles move in a toroidal chamber due to the presence of a strong magnetic field, causing them to follow helical orbits and preventing them from exiting the chamber.', 'duration': 83.577, 'highlights': ['Plasma particles gyrate around the direction of the magnetic field line, following helical orbits.', "Particles in a toroidal chamber can move very quickly along the magnetic field but can't move fast across it.", 'The toroidal shape of the magnetic field prevents particles from exiting the chamber, maintaining their energy.', 'A straight magnetic field would cause particles to hit the ends of the chamber and lose their energy.']}, {'end': 713.938, 'start': 668.026, 'title': 'Plasma confinement techniques', 'summary': 'Discusses the use of toroidal fields and passing current through plasma to achieve confinement, preventing particles from leaving the chamber, ultimately improving single particle orbits.', 'duration': 45.912, 'highlights': ['The use of toroidal field alone is not enough for true plasma confinement, requiring additional fields and passing current through the plasma.', 'Passing current through the plasma transforms field lines into larger helices, leading to improved confinement of particles and preventing them from leaving the chamber.']}], 'duration': 201.36, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk512578.jpg', 'highlights': ['The tokamak concept utilizes a toroidal chamber with a strong magnetic field for potential fusion energy production.', 'A challenge in fusion energy is creating a confinement device for plasma to sustain its own reaction.', 'The Russian acronym for tokamak means toroidal magnetic chamber.', 'Plasma particles gyrate around the direction of the magnetic field line, following helical orbits.', 'The toroidal shape of the magnetic field prevents particles from exiting the chamber, maintaining their energy.', 'Passing current through the plasma transforms field lines into larger helices, leading to improved confinement of particles and preventing them from leaving the chamber.']}, {'end': 868.598, 'segs': [{'end': 776.607, 'src': 'embed', 'start': 736.599, 'weight': 1, 'content': [{'end': 739.32, 'text': "They'll be 100 million degrees Celsius or something.", 'start': 736.599, 'duration': 2.721}, {'end': 748.327, 'text': "So they're moving thermally with very large thermal energies in random directions, and they will collide with one another and have fusion reactions.", 'start': 739.941, 'duration': 8.386}, {'end': 752.75, 'text': 'When those fusion reactions take place, energy is released.', 'start': 749.427, 'duration': 3.323}, {'end': 755.432, 'text': 'Large amounts of energy is released in the form of particles.', 'start': 752.81, 'duration': 2.622}, {'end': 761.277, 'text': "One of the particles that's released is an alpha particle, which is also charged and it's also confined.", 'start': 756.314, 'duration': 4.963}, {'end': 767.801, 'text': 'And that alpha particle stays in the donut and heats the other particles that are in that donut.', 'start': 761.777, 'duration': 6.024}, {'end': 771.143, 'text': 'So it transfers its energy to those and it keeps them hot.', 'start': 768.141, 'duration': 3.002}, {'end': 776.607, 'text': "There's some leaking of heat all the time, a little bit of radiation, some transport and so forth.", 'start': 771.543, 'duration': 5.064}], 'summary': 'Fusion reactions release large amounts of energy, heating particles to 100 million degrees celsius, and causing alpha particles to transfer energy to keep particles hot.', 'duration': 40.008, 'max_score': 736.599, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk736599.jpg'}, {'end': 868.598, 'src': 'embed', 'start': 809.208, 'weight': 0, 'content': [{'end': 810.849, 'text': 'where do we stand on?', 'start': 809.208, 'duration': 1.641}, {'end': 815.03, 'text': 'uh, getting this thing to be, uh, something that actually works, that generates energy.', 'start': 810.849, 'duration': 4.181}, {'end': 826.62, 'text': 'yeah Well, there have been experiments that have generated net nuclear energies or nuclear powers in the vicinity of, you know,', 'start': 815.03, 'duration': 11.59}, {'end': 830.404, 'text': 'a few tens of megawatts for a few seconds.', 'start': 826.62, 'duration': 3.784}, {'end': 833.707, 'text': "So that's, you know, 10 megajoules.", 'start': 830.804, 'duration': 2.903}, {'end': 834.748, 'text': "That's not much energy.", 'start': 833.767, 'duration': 0.981}, {'end': 837.451, 'text': "It's a few donuts worth of energy.", 'start': 835.549, 'duration': 1.902}, {'end': 838.231, 'text': 'Okay Yeah.', 'start': 837.611, 'duration': 0.62}, {'end': 839.072, 'text': 'Literal donuts.', 'start': 838.532, 'duration': 0.54}, {'end': 840.413, 'text': 'Literal donuts.', 'start': 839.312, 'duration': 1.101}, {'end': 840.774, 'text': "That's right.", 'start': 840.433, 'duration': 0.341}, {'end': 849.83, 'text': 'But we have studied how well tokamaks can find plasmas.', 'start': 843.607, 'duration': 6.223}, {'end': 855.712, 'text': 'And so we now understand in rather great detail the way they work.', 'start': 849.91, 'duration': 5.802}, {'end': 866.057, 'text': "And we're able to predict what is going to be required in order to build a tokamak that becomes self-sustaining, that becomes essentially ignited,", 'start': 856.433, 'duration': 9.624}, {'end': 868.598, 'text': "or very so close to ignited that it doesn't matter.", 'start': 866.057, 'duration': 2.541}], 'summary': 'Experiments have generated net nuclear powers around few tens of megawatts for few seconds, equivalent to 10 megajoules, which is not much energy. however, there is a clear understanding of how tokamaks can find plasmas and predict the requirements for building a self-sustaining tokamak.', 'duration': 59.39, 'max_score': 809.208, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk809208.jpg'}], 'start': 714.419, 'title': 'Nuclear fusion energy generation', 'summary': 'Discusses the process of nuclear fusion energy generation, including the collision of particles, release of energy and particles, and the challenges in generating net nuclear powers, with experiments reaching a few tens of megawatts for a few seconds.', 'chapters': [{'end': 868.598, 'start': 714.419, 'title': 'Nuclear fusion energy generation', 'summary': 'Discusses the process of nuclear fusion energy generation, including the collision of particles, release of energy and particles, and the challenges in generating net nuclear powers, with experiments reaching a few tens of megawatts for a few seconds.', 'duration': 154.179, 'highlights': ['Experiments have generated net nuclear energies or nuclear powers in the vicinity of a few tens of megawatts for a few seconds, equivalent to 10 megajoules, providing insights into the challenges of generating nuclear powers (10 megajoules).', 'Particles in a fusion reactor, such as deuterons and tritons, collide with each other at temperatures reaching 100 million degrees Celsius, releasing large amounts of energy in the form of particles, including alpha particles and neutrons (100 million degrees Celsius).', 'The alpha particle released in the fusion reaction transfers energy to other particles in the donut, keeping them hot, while the neutron carries out four fifths of the fusion energy and needs to be captured in a blanket surrounding the chamber to generate energy (energy transfer and neutron capture).', 'Understanding of tokamaks and plasma confinement has advanced, allowing for the prediction of requirements to build a self-sustaining tokamak for nuclear fusion energy generation (tokamak plasma confinement and future requirements).']}], 'duration': 154.179, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk714419.jpg', 'highlights': ['Experiments have generated net nuclear energies or nuclear powers in the vicinity of a few tens of megawatts for a few seconds, equivalent to 10 megajoules, providing insights into the challenges of generating nuclear powers (10 megajoules).', 'Particles in a fusion reactor, such as deuterons and tritons, collide with each other at temperatures reaching 100 million degrees Celsius, releasing large amounts of energy in the form of particles, including alpha particles and neutrons (100 million degrees Celsius).', 'Understanding of tokamaks and plasma confinement has advanced, allowing for the prediction of requirements to build a self-sustaining tokamak for nuclear fusion energy generation (tokamak plasma confinement and future requirements).', 'The alpha particle released in the fusion reaction transfers energy to other particles in the donut, keeping them hot, while the neutron carries out four fifths of the fusion energy and needs to be captured in a blanket surrounding the chamber to generate energy (energy transfer and neutron capture).']}, {'end': 1442.152, 'segs': [{'end': 928.393, 'src': 'embed', 'start': 899.175, 'weight': 0, 'content': [{'end': 907.725, 'text': "it's called eater i-t-e-r, which means the way, or just means the international tokamak experimental reactor, if you like.", 'start': 899.175, 'duration': 8.55}, {'end': 922.247, 'text': 'um, And that experiment is designed to reach this burning plasma state and to generate about 500 megawatts of fusion power for hundreds of seconds at a time.', 'start': 907.725, 'duration': 14.522}, {'end': 924.91, 'text': "It'll still only be an experiment.", 'start': 922.407, 'duration': 2.503}, {'end': 928.393, 'text': "It won't put electricity on the grid or anything like that.", 'start': 925.51, 'duration': 2.883}], 'summary': "The iter experiment aims to reach a burning plasma state and generate 500 megawatts of fusion power for hundreds of seconds, but it won't provide electricity to the grid.", 'duration': 29.218, 'max_score': 899.175, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk899175.jpg'}, {'end': 982.116, 'src': 'embed', 'start': 947.285, 'weight': 2, 'content': [{'end': 956.91, 'text': 'But it will be the first demonstration on Earth of a controlled fusion reaction for a long time period.', 'start': 947.285, 'duration': 9.625}, {'end': 968.451, 'text': "Is that exciting to you? It's been an objective that has in many ways motivated my entire career and the career of many people like me in the field.", 'start': 956.93, 'duration': 11.521}, {'end': 982.116, 'text': "I have to admit, though, that one of the problems with ITER is that it's an extremely big and expensive and long time to build experiment.", 'start': 971.221, 'duration': 10.895}], 'summary': 'First earth demo of controlled fusion reaction, a long-term objective for iter, though big, expensive, and time-consuming.', 'duration': 34.831, 'max_score': 947.285, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk947285.jpg'}, {'end': 1093.944, 'src': 'embed', 'start': 1062.309, 'weight': 1, 'content': [{'end': 1068.284, 'text': 'Look, I absolutely think that fusion research is Completely justified.', 'start': 1062.309, 'duration': 5.975}, {'end': 1072.027, 'text': 'In fact, we should be spending more time and effort on it than we currently do.', 'start': 1068.344, 'duration': 3.683}, {'end': 1080.473, 'text': "But it isn't going to be a magic bullet that somehow solves all the problems of energy.", 'start': 1072.928, 'duration': 7.545}, {'end': 1085.097, 'text': "By the way, that's a generic statement you can make about any energy source, in my view.", 'start': 1080.714, 'duration': 4.383}, {'end': 1093.944, 'text': "I think it's a grave mistake to think that science of any sort is suddenly going to find a magic bullet for meeting all the energy needs of society,", 'start': 1085.517, 'duration': 8.427}], 'summary': 'Fusion research justified, not a magic bullet for all energy needs.', 'duration': 31.635, 'max_score': 1062.309, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1062309.jpg'}, {'end': 1345.31, 'src': 'embed', 'start': 1314.059, 'weight': 3, 'content': [{'end': 1320.543, 'text': "fission does have some drawbacks and they're, and they're largely to do with four main areas.", 'start': 1314.059, 'duration': 6.484}, {'end': 1328.726, 'text': 'One is do we have enough uranium or other fissile fuels to supply our energy needs for a long time?', 'start': 1321.544, 'duration': 7.182}, {'end': 1342.109, 'text': 'The answer to that is we know we have enough uranium to support fission energy worldwide for thousands of years, but maybe not for millions of years,', 'start': 1329.126, 'duration': 12.983}, {'end': 1345.31, 'text': "okay?. So that's resources.", 'start': 1342.109, 'duration': 3.201}], 'summary': 'Fission energy can be sustained for thousands of years with current uranium resources, but may not be viable for millions of years.', 'duration': 31.251, 'max_score': 1314.059, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1314059.jpg'}, {'end': 1410.212, 'src': 'embed', 'start': 1378.875, 'weight': 4, 'content': [{'end': 1389.067, 'text': "There's a problem of safety beyond that, and that is that in fission, it's hard to turn the reactor off.", 'start': 1378.875, 'duration': 10.192}, {'end': 1397.194, 'text': 'When you stop the nuclear reactions, there is still a lot of heat being liberated from the fission products.', 'start': 1389.567, 'duration': 7.627}, {'end': 1401.216, 'text': 'And that is actually what the problem was at Fukushima.', 'start': 1397.594, 'duration': 3.622}, {'end': 1407.6, 'text': 'The Fukushima reactors were shut down the moment that the earthquake took place.', 'start': 1401.676, 'duration': 5.924}, {'end': 1410.212, 'text': 'And they were shut down safely.', 'start': 1408.891, 'duration': 1.321}], 'summary': 'Fukushima reactors shut down safely after earthquake, but heat from fission products remained a safety concern.', 'duration': 31.337, 'max_score': 1378.875, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1378875.jpg'}], 'start': 870.559, 'title': 'Fusion research and the future of fusion and fission energy', 'summary': 'Discusses the iter project aiming to generate 500 megawatts of fusion power, facing challenges including cost and delayed operation until 2025. it also explores the potential of fusion and fission energy, emphasizing the need for continued research and development, focusing on environmental impact and safety concerns.', 'chapters': [{'end': 1008.169, 'start': 870.559, 'title': 'Fusion research: iter and the quest for controlled fusion', 'summary': 'Discusses the international fusion research project iter, which aims to achieve a burning plasma state and generate about 500 megawatts of fusion power for hundreds of seconds, but faces challenges such as cost, time to build, and delayed operation until 2025.', 'duration': 137.61, 'highlights': ['ITER aims to generate about 500 megawatts of fusion power for hundreds of seconds at a time The ITER experiment is designed to reach a burning plasma state and generate about 500 megawatts of fusion power for hundreds of seconds at a time.', "ITER won't come into operation until about 2025 Despite being built for 10 years and designed for 30 years, ITER won't come into operation until about 2025, causing disappointment and delay in achieving a burning fusion reaction.", "Challenges with ITER include being extremely big, expensive, and long time to build One of the problems with ITER is that it's an extremely big, expensive, and long time to build experiment, posing challenges in terms of cost and construction time."]}, {'end': 1442.152, 'start': 1008.569, 'title': 'Future of fusion and fission energy', 'summary': 'Discusses the potential of fusion and fission energy, highlighting the challenges and advantages of both, emphasizing the importance of nuclear power and the need for continued research and development in the field, with a focus on environmental impact and safety concerns.', 'duration': 433.583, 'highlights': ['Fusion research is important but not a magic bullet for solving all energy problems. The speaker emphasizes that while fusion research is justified and worthwhile, it is not a panacea for solving all energy needs or societal challenges.', 'Fission energy has advantages, such as being CO2 emissions free, but poses challenges related to safety and waste management. The chapter discusses how fission energy is CO2 emissions free and important for meeting energy challenges, but also highlights challenges related to safety concerns, waste management, and resource availability.', 'Safety concerns and challenges related to fission energy include issues with turning reactors off and managing after heat. The safety concerns with fission energy include the difficulty of turning off reactors, managing after heat, and the potential for environmental contamination in the event of accidents.']}], 'duration': 571.593, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk870559.jpg', 'highlights': ['ITER aims to generate about 500 megawatts of fusion power for hundreds of seconds at a time', 'Fusion research is important but not a magic bullet for solving all energy problems', 'Challenges with ITER include being extremely big, expensive, and long time to build', 'Fission energy has advantages, such as being CO2 emissions free, but poses challenges related to safety and waste management', 'Safety concerns and challenges related to fission energy include issues with turning reactors off and managing after heat']}, {'end': 1643.313, 'segs': [{'end': 1520.008, 'src': 'embed', 'start': 1470.524, 'weight': 0, 'content': [{'end': 1475.487, 'text': 'Fusion has major advantages in respect of all of those problems.', 'start': 1470.524, 'duration': 4.963}, {'end': 1480.428, 'text': 'It has more longer term fuel resources.', 'start': 1475.567, 'duration': 4.861}, {'end': 1484.669, 'text': 'It has far more benign waste issues.', 'start': 1481.108, 'duration': 3.561}, {'end': 1491.631, 'text': 'The radioactivity from fusion reactions is at least 100 times less than it is from fission reactions.', 'start': 1485.39, 'duration': 6.241}, {'end': 1497.073, 'text': 'It has essentially none of this after heat problem,', 'start': 1492.452, 'duration': 4.621}, {'end': 1503.815, 'text': "because it doesn't produce fission products that are highly radioactive and generating their own heat when it's turned off.", 'start': 1497.073, 'duration': 6.742}, {'end': 1507.138, 'text': 'In fact, the hard part of fusion is turning it on, not turning it off.', 'start': 1504.215, 'duration': 2.923}, {'end': 1514.884, 'text': "And finally, you don't need the same fission technology to make fusion work.", 'start': 1508.879, 'duration': 6.005}, {'end': 1520.008, 'text': "And so it's got terrific advantages from the point of view of proliferation control.", 'start': 1514.944, 'duration': 5.064}], 'summary': 'Fusion offers longer term fuel resources, less radioactivity, and no proliferation risk compared to fission.', 'duration': 49.484, 'max_score': 1470.524, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1470524.jpg'}, {'end': 1566.023, 'src': 'embed', 'start': 1542.956, 'weight': 4, 'content': [{'end': 1552.578, 'text': 'Fukushima actually is, I think in many ways, often overstated as a disaster, because after all, nobody was killed by the reactors, essentially, zero.', 'start': 1542.956, 'duration': 9.622}, {'end': 1566.023, 'text': "And that's in the context of a disaster, a tsunami that killed between 15 and 20,000 people more or less instantaneously.", 'start': 1554.799, 'duration': 11.224}], 'summary': "Fukushima disaster: reactors didn't cause deaths, while tsunami killed 15-20,000", 'duration': 23.067, 'max_score': 1542.956, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1542956.jpg'}, {'end': 1643.313, 'src': 'embed', 'start': 1601.537, 'weight': 5, 'content': [{'end': 1602.077, 'text': 'And I think..', 'start': 1601.537, 'duration': 0.54}, {'end': 1608.479, 'text': 'From everything I understand, nuclear energy, fission-based energy, goes into that category.', 'start': 1602.657, 'duration': 5.822}, {'end': 1611.82, 'text': "It's one of the safest, one, of the cleanest forms of energy.", 'start': 1608.799, 'duration': 3.021}, {'end': 1620.463, 'text': 'and yet the PR whoever does the PR for nuclear energy has a hard job ahead of them at the moment.', 'start': 1611.82, 'duration': 8.643}, {'end': 1623.504, 'text': 'Well, I think part of that is their association with nuclear weapons.', 'start': 1620.703, 'duration': 2.801}, {'end': 1629.266, 'text': "Because when you say the word nuclear, people don't instantly think about nuclear energy, they think about nuclear weapons.", 'start': 1624.064, 'duration': 5.202}, {'end': 1635.349, 'text': 'And so there is perhaps a natural tendency to do that.', 'start': 1630.506, 'duration': 4.843}, {'end': 1636.469, 'text': 'But yes, I agree with you.', 'start': 1635.389, 'duration': 1.08}, {'end': 1643.313, 'text': 'People are very poor at estimating risks and they react emotionally, not rationally in most of these situations.', 'start': 1636.549, 'duration': 6.764}], 'summary': "Nuclear energy, though safe and clean, faces pr challenges due to its association with nuclear weapons, impacting people's perception and risk assessment.", 'duration': 41.776, 'max_score': 1601.537, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1601537.jpg'}], 'start': 1442.552, 'title': 'Advantages of fusion over fission and reassessing fukushima disaster and nuclear energy', 'summary': "Discusses the benefits of fusion over fission reactors, including longer-term fuel resources, reduced radioactivity, and proliferation control. it also emphasizes the overestimation of the fukushima disaster, the safety of fission energy, the public's irrational fear of nuclear energy, and its association with weapons.", 'chapters': [{'end': 1542.156, 'start': 1442.552, 'title': 'Advantages of fusion over fission', 'summary': 'Discusses the advantages of fusion over fission reactors, highlighting the longer-term fuel resources, significantly reduced radioactivity, absence of after-heat problem, and proliferation control.', 'duration': 99.604, 'highlights': ['Fusion has more longer-term fuel resources compared to fission.', 'The radioactivity from fusion reactions is at least 100 times less than it is from fission reactions.', "Fusion doesn't produce fission products that are highly radioactive and generating their own heat when it's turned off.", 'Fusion technology has terrific advantages from the point of view of proliferation control.']}, {'end': 1643.313, 'start': 1542.956, 'title': 'Reassessing fukushima disaster and nuclear energy', 'summary': "Highlights the overestimation of the fukushima disaster, the safety of fission energy despite zero deaths from the reactors, the public's irrational fear of nuclear energy due to poor risk estimation, and the association of nuclear energy with weapons.", 'duration': 100.357, 'highlights': ['Fukushima disaster is often overstated, with zero deaths from the reactors, in contrast to the tsunami that killed between 15 and 20,000 people. The Fukushima disaster is often overstated as nobody was killed by the reactors, which contrasts with the tsunami that killed between 15 and 20,000 people.', 'Fission energy is considered one of the safest and cleanest forms of energy despite public fear and poor risk estimation. Despite public fear and poor risk estimation, fission energy is considered one of the safest and cleanest forms of energy.', "The public's fear of nuclear energy is driven by emotional reactions and poor risk estimation. The public's fear of nuclear energy is driven by emotional reactions and poor risk estimation, rather than rational assessment.", "The association of nuclear energy with nuclear weapons affects public perception and creates challenges for nuclear energy PR. The association of nuclear energy with nuclear weapons affects public perception and creates challenges for nuclear energy PR, contributing to the public's fear."]}], 'duration': 200.761, 'thumbnail': 'https://coursnap.oss-ap-southeast-1.aliyuncs.com/video-capture/HT9YRGSSyNk/pics/HT9YRGSSyNk1442552.jpg', 'highlights': ['Fusion has more longer-term fuel resources compared to fission.', 'The radioactivity from fusion reactions is at least 100 times less than it is from fission reactions.', "Fusion doesn't produce fission products that are highly radioactive and generating their own heat when it's turned off.", 'Fusion technology has terrific advantages from the point of view of proliferation control.', 'Fukushima disaster is often overstated, with zero deaths from the reactors, in contrast to the tsunami that killed between 15 and 20,000 people.', 'Fission energy is considered one of the safest and cleanest forms of energy despite public fear and poor risk estimation.', "The public's fear of nuclear energy is driven by emotional reactions and poor risk estimation.", 'The association of nuclear energy with nuclear weapons affects public perception and creates challenges for nuclear energy PR.']}], 'highlights': ['Nuclear fusion reactions require overcoming electric repulsion between nuclei by getting them extremely close to form a new nucleus, needing high energies of impact and temperatures for reactions to take place.', 'Achieving nuclear fusion on Earth requires temperatures of tens of millions of degrees Celsius to generate enough energy.', 'The tokamak concept utilizes a toroidal chamber with a strong magnetic field for potential fusion energy production.', 'Experiments have generated net nuclear energies or nuclear powers in the vicinity of a few tens of megawatts for a few seconds, equivalent to 10 megajoules, providing insights into the challenges of generating nuclear powers (10 megajoules).', 'ITER aims to generate about 500 megawatts of fusion power for hundreds of seconds at a time', 'Fusion has more longer-term fuel resources compared to fission.', 'The radioactivity from fusion reactions is at least 100 times less than it is from fission reactions.', 'Fusion technology has terrific advantages from the point of view of proliferation control.']}