YouSaid · the spoken record

Ian Hutchinson

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114
first
2020-07-29
most recent
2020-07-29
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1
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podcast

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  1. “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. So yes, there are other things, but those are things that are relatively easy. I mean, making a vacuum these days is technologically quite straightforward. We know how to do that, okay? What we don't quite know how to do is to make a confinement device that isolates the plasma well enough so that it's able to keep itself burning with its own reaction.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  2. “Well, actually, what we do need walls, those walls must be kept away from the plasma, because otherwise they'd be melted, or the plasma must be kept away from them inside of them. But the main purpose of the walls is not to keep the plasma in. It's to keep the atmosphere out. 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, the things we're trying to react. And by the way, the density of those plasmas, at least in magnetic confinement fusion, is very low. It's maybe a million times less than the density of air in this room.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  3. “And the predominant attempt at making fusion work on Earth is to use magnetic fields to confine the plasma. And that's what I've worked on for much 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 with the ultimate objective of releasing fusion energy on Earth and generating electricity with it and powering our society with it.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  4. “In the case of stars, that non material force is gravity. So gravity is what holds a star together. What holds the plasma in long enough for it to react and sustain itself by the fusion reactions? But on Earth, gravity is extremely weak. I mean, I don't mean to say we don't fall. Well, yes, we fall. 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 on Earth. And so we need a stronger force to keep the plasma together, to confine it.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  5. “And that's what we've got to do on earth if we're going to make fusion work on Earth. But it's much harder to do on Earth than it is, you know, in a star because we need temperatures of order tens of millions of degrees Celsius in order for the reactions to go fast enough to generate enough electricity to keep it or enough energy to keep it going. 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, you can't just put it in a bottle. Plastic or glass, it would be gone in milliseconds. So you have to have some non-material mechanism of Confining the plasma.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  6. “To keep themselves hot and hence keep the reactions going, that's chemical ignition. But what we need to do, what the stars do in order to generate nuclear fusion energy is they are ignited. They are generated enough energy to keep themselves hot.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  7. “Nature's fusion reactors are indeed the stars, and they are very hot in the center, and they reach the point where they release more energy from those reactions than they lose by radiation and transport to the surface and so forth. And that's a state of ignition. And that's what we have to achieve to give net energy. It's like lighting a fire. If you have a bundle of sticks and you hold a match up to it and you see smoke coming from the sticks, but you take the match away and the sticks just fizzle out, that's not, the reason they fizzled out is that, yes, they were burning. There was smoke coming from them, but they were not ignited. But if you are able to take the match away and they keep burning and they are generating enough heat,”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  8. “It requires very high energy of impact. And actually it's very easy to understand why, 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, let's say, tritium, they're both electrically charged. And they're positively charged. So like charges repel. Everyone knows that, right? basically to get them close enough together to react you have to overcome the repulsion, the electric repulsion of the two nuclei from one another. 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. And so one requires very high energies of impact in order for reactions to take place. And those high energies of impact correspond to Very high temperatures of random motion.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  9. “Well, taking light elements like isotopes of hydrogen and not breaking them up, but actually fusing them together, reacting them together to produce heavier elements, typically helium, okay, which is helium is a nucleus which has two protons and two neutrons. That also releases energy and that or reactions like that making heavier elements from lighter elements is what mostly powers the sun and stars, both fusion and fission release approximately a million times more energy per unit mass than chemical reactions. So chemical reaction means take hydrogen, take oxygen, react them together, let's say, and get water. That releases energy. The energy released in the... Chemical reaction like that, or the burning of coal or an oil or whatever else, is about a million times less per unit mass than what is released in nuclear reactions.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  10. “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, there are 92 protons in each nucleus and even more neutrons so that the total number of nucleons in the nucleus, nucleons is short for either a proton or a neutron, the total number, might be 235. That's U235, or it might be 238. That's U238. So those are heavy elements. Light elements, by contrast, have very few nucleons, protons or neutrons in the nucleus. Hydrogen is the lightest nucleus. It has one proton. They're actually slightly heavier forms of hydrogen, isotopes, deuterium. Has a proton and a neutron, and tritium has a proton and two neutrons, so it has total of three nucleons in the nucleus.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  11. “Well, fission is taking heavy elements like uranium and breaking them up. And it turns out that that process of breaking up heavy elements releases energy”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  12. “still electrically neutral, but a plasma conducts electricity, has all sorts of important properties that are associated with that separation. And that's what plasmas are all about. And the reason why my department is interested in plasma physics very strongly is because most things, well, for one thing, most things in the universe are plasma. The vast majority of matter in the universe is plasma, but most particularly stars and the sun are plasmas because they're very hot and it's only in very hot states that nuclear fusion reactions take place and we want to understand how to implement those kind of phenomena on Earth.”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  13. “Are essentially the fourth state of matter. So if you think about solid, liquid, gas, plasma is the fourth of those states of matter. And it's actually the state of matter which one reaches if one raises the temperature. So cold things like ice are solid. Liquids are hotter water. And if you heat water beyond 100 degrees Celsius, it becomes gas. Well, that's true of most substances. And plasma is a state of matter in which the electrons are unbound from the nuclei, so they become separated from the nuclei and can move separately. So we have positively charged nuclei, and we have negatively charged electrons, the net is...”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source

  14. “Nuclear physics is about the physics of the nucleus, and my department, Department of Nuclear Science and Engineering at MIT, is very concerned about all the interactions and reactions and consequences of things that go on in the nucleus, including nuclear energy, fission energy, which is the nuclear energy that we have already, and fusion energy, which is the energy source of the sun and stars, which we don't quite know how to turn into practical energy for humankind at the moment. That's what my research has mostly been aimed at. But plasmas”

    2020-07-29 · Lex Fridman Podcast · #112 – Ian Hutchinson: Nuclear Fusion, Plasma Physics, and Religion · IDENTIFIED FROM THE TRANSCRIPT · source