Speaker 1: So many of the problems facing humanity today come down
Speaker 1: to one basic issue. Power. Do you need to stay
Speaker 1: warm in the winter? Power solves that problem. Do you
Speaker 1: need to find shelter? Power makes it cheap and fast
Speaker 1: to make concrete or build structures. You need to drink
Speaker 1: some water. Electricity can turn seawater into drinking water if
Speaker 1: you have the power. You need to keep your food cold.
Speaker 1: Refrigeration requires power. You want to run a factory in
Speaker 1: manufacture clothing. Power you want to travel around your town
Speaker 1: or country. Power you want to grow food in the winter.
Speaker 1: Power power, power, power, power power. If we had a
Speaker 1: plentiful source of cheap power that didn't cause pollution or
Speaker 1: produce toxic waste, it would transform society. It would uplift
Speaker 1: the poor, It would make being human a completely different experience.
Speaker 1: And for a long time, fusion research has promised exactly that. Fusion,
Speaker 1: the process that powers the sun, doesn't need exotic heavy
Speaker 1: elements for fuel the way our nuclear plants do, and
Speaker 1: doesn't make deadly toxic waste. It doesn't produce climate impacting
Speaker 1: gases the way fossil fuels do, and it runs NonStop,
Speaker 1: unlike wind and solar, So it'd be great if we
Speaker 1: get fusion to work. Of course, fusion has been a
Speaker 1: few decades in the future, or an embarrassing number of
Speaker 1: decades now. But it turns out that there's another question looming.
Speaker 1: Before we solve the physics puzzles and make the technology work,
Speaker 1: there's a surprisingly difficult task of getting enough fuel that
Speaker 1: we can use to power those yet to be made
Speaker 1: fusion plants. So today on Daniel and Kelly's Extraordinary Universe,
Speaker 1: we'll be asking do we have enough fuel for fusion?
Speaker 2: Hello?
Speaker 3: I'm Kelly water Smith and I love power.
Speaker 1: Why that was awesome, Kylie? Toleeupguard there. Hi, I'm Daniel Whitson.
Speaker 1: I'm a particle physicist now, but as a youth I
Speaker 1: dreamed of being a plasma physicist, though not because I
Speaker 1: wanted power myself. So why because I wanted to bring
Speaker 1: power to the masses. I thought, Wow, fusion is the future.
Speaker 1: We're going to change the world. We're going to solve
Speaker 1: all the problems. Oh my gosh, it's going to be
Speaker 1: so exciting.
Speaker 3: And I find fusion that exciting as well. And we
Speaker 3: wrote about it a little bit for a book my
Speaker 3: husband and I wrote called Soonish. So I know a
Speaker 3: little bit more about fusion than you might expect from
Speaker 3: a parasitologist. But one of the things about fusion that
Speaker 3: I came across while doing my interviews is that everybody
Speaker 3: would be like, yeah, yeah, yeah, fusion. I know it's
Speaker 3: the power of the future, and it always will be,
Speaker 3: because it always feels like it's ten years out, no
Speaker 3: matter when you talk to people as ten years out.
Speaker 3: But I feel like I've been hearing some exciting fusion
Speaker 3: related news lately that makes the discussion we're going to
Speaker 3: have today like timely and relevant. So what is your
Speaker 3: sense how much longer till we have fusion?
Speaker 1: I know I'm gonna go on the record and predict
Speaker 1: when fusion will be commercially viable. We have a long
Speaker 1: way to go between now and fusion being a big
Speaker 1: part of how humans get power. We've also made a
Speaker 1: lot of progress, Like where we are today relative to
Speaker 1: where we were in the nineties when I was thinking
Speaker 1: about doing fusion research, like we are light years ahead
Speaker 1: of those nineties physicists, But I think we're also under
Speaker 1: selling how far we have to go. One of the
Speaker 1: things we're going to talk about on the podcast today
Speaker 1: is what you do after you make fusion work finding
Speaker 1: the fuel for it, and there are other technical problems
Speaker 1: that make it challenging to actually integrate fusion into our lives.
Speaker 1: But that's actually not the reason that I didn't become
Speaker 1: a plasma physicist. Why I didn't realize as a young
Speaker 1: scientist that you needed more than just the big questions
Speaker 1: of this field seem exciting, where the lofty goals of
Speaker 1: this project are worthwhile. To actually enjoy the work day
Speaker 1: to day, you need to have fun. And I didn't
Speaker 1: really like playing with vacuum chambers and lasers and all
Speaker 1: that kind of stuff day to day. I wasn't good
Speaker 1: at it. I didn't enjoy it, and we weren't bringing
Speaker 1: energy to the masses every single day. It doesn't really
Speaker 1: bother me these days in particle physics that I'm not
Speaker 1: discovering a new particle every day because I am having
Speaker 1: fun writing programs and solving little mental puzzles. I think
Speaker 1: a lot of people don't realize how important it is
Speaker 1: to actually enjoy the day to day grind of your science,
Speaker 1: not just the Nobel prize winning moments.
Speaker 3: I totally agree with you, so I for my PhD,
Speaker 3: I was doing some like molecular biology stuff, trying to
Speaker 3: figure out how a parasite that lived on the brain
Speaker 3: of a fish was manipulating its behavior.
Speaker 2: So I was measuring like hormones and neurotransmitters.
Speaker 3: And I hate pipets, and I thought i'd love them,
Speaker 3: Like I have friends who just like they're having like
Speaker 3: they're in the zone, man, listening to music, and there's
Speaker 3: one with the pipette and I.
Speaker 2: Just got angry.
Speaker 3: And so, yeah, no, you've got to love the day
Speaker 3: to day otherwise it's not going to work out.
Speaker 1: Yeah, and it's very personal. Some people love sitting in
Speaker 1: front of a computer all day long, and other people
Speaker 1: think that's not doing science. If you don't have a
Speaker 1: screwdriver in your hand, you're not feeling greasy at the
Speaker 1: end of the day, you're not doing science. But you know,
Speaker 1: everybody's got to find their bit. And the thing I
Speaker 1: love about science is that it takes all kinds. It
Speaker 1: takes computer nerds like me, and it takes screwdriver nerds,
Speaker 1: and it takes people who want to dive into dumb
Speaker 1: trucks full of smelly fish on a sunny day.
Speaker 2: I mean, I.
Speaker 3: Can't say I enjoyed that part either, but it was
Speaker 3: nice actually, you know, learning about new species of fish
Speaker 3: you find in Lake Eary.
Speaker 2: That was fun.
Speaker 1: So my number one piece of advice to like young
Speaker 1: scientists is to try a lot of different kinds of
Speaker 1: science because you can be excited about the big picture
Speaker 1: questions of cosmology or parasitology or geology, but if you
Speaker 1: don't enjoy the day to day work, you're not going
Speaker 1: to be inspired and creative because you're not having fun.
Speaker 1: And this can be really hard to tell in advance.
Speaker 1: So you got to dabble before you find your jam.
Speaker 3: Yeah, And it can be so hard to feel like
Speaker 3: you have time to dabble because I know, you get
Speaker 3: into grad school and you're like, I have to publish
Speaker 3: all the papers or you know, depending on what job
Speaker 3: you want. But I always tell students like, yes, dabble.
Speaker 3: My advisor was really good about encouraging me to dabble,
Speaker 3: and who knows where it would have ended up if
Speaker 3: I didn't dabble. Got a fun combo of things going on.
Speaker 1: But today we're not going to dabble. We're going to
Speaker 1: do one of our deep dives into a topic in
Speaker 1: physics to understand how fusion works, what we actually need
Speaker 1: to make fusion work, and where we can find that
Speaker 1: fuel if we even can.
Speaker 3: So when you sent me the idea for this topic,
Speaker 3: it kind of blew my mind because I thought we
Speaker 3: had plenty.
Speaker 2: Of fuel for funds all over the place.
Speaker 3: And so I'm personally very excited about this discussion because it,
Speaker 3: you know, I like discussions where the angle is something
Speaker 3: that really kind of throws me off, and I wasn't expecting.
Speaker 3: And so here we go, and let's see if our
Speaker 3: listeners were thrown off or not. And if you would
Speaker 3: like to be the people who answer the questions at
Speaker 3: the beginning of the podcast, please send us an email
Speaker 3: at questions at Danielankelly dot org and we'll send you
Speaker 3: the question. You can send us an audio file and
Speaker 3: then we'll put it on the show. All right, let's
Speaker 3: see what the listeners thought.
Speaker 4: I had no idea there was a fuel availability question
Speaker 4: for fusion, but from what I understand, it uses hydrogen
Speaker 4: and that's pretty much the most plentiful thing out there,
Speaker 4: So I would assume, no, there's not unless there's some
Speaker 4: challenge with making the hydrogen usable for fusion.
Speaker 5: To find fuel for fusion, we need only look to
Speaker 5: the universe. Hydrogen is the most abundant thing in the universe,
Speaker 5: so surely there's plenty of it in our rocks and
Speaker 5: water on Earth. And once we figure out fusion, we
Speaker 5: can probably just go to the local styles and suck
Speaker 5: them dry like a sci fi dystopian novel.
Speaker 6: I believe I've heard mentioned on the show that we
Speaker 6: do not have enough hydrogen to create fusion like the
Speaker 6: sun does. However, if we are talking about cold fusion,
Speaker 6: then I believe that we would have more than enough
Speaker 6: to accomplish this using seawater to pull the hydrogen from
Speaker 6: for that purpose.
Speaker 7: I think, is this a true question? Yeah, Well, hydrogen
Speaker 7: is the most abundant element in the universe, and plenty
Speaker 7: of hydrogen around, and that's what basically we're gonna be doing,
Speaker 7: is turning hydrogen and helium, you know, via our tokemac
Speaker 7: shape or whatever nuclear fusion reactor. So yeah, hydrogen would
Speaker 7: be very easy to come by. If I'm missing something,
Speaker 7: Am I missing something?
Speaker 2: I like that somebody else was like, is this a
Speaker 2: trick question?
Speaker 1: What I take away from this is everybody has heard
Speaker 1: the propaganda that fusion just requires hydrogen. Most of the
Speaker 1: universes hydrogen. Obviously, that's not a problem. Let's move on
Speaker 1: to the real stuff.
Speaker 2: I think we've all drank the hydrogen kool aid.
Speaker 1: Ooh, there's a new product we've unlocked, right there, hydrogen
Speaker 1: kool aid. I guess all kool aid contains hydrogen already, right,
Speaker 1: because it has water. But we could sell it as
Speaker 1: fancy kool aid.
Speaker 3: Yeah, no, absolutely. I mean, if people are buying bottled water,
Speaker 3: we can sell this too. And I buy a bottle
Speaker 3: of water sometype, So no judgment to the people who
Speaker 3: are buying it. Let's start at the basics. What is
Speaker 3: fusion and how does it work?
Speaker 1: Yeah, in order to understand the challenges for finding fuel
Speaker 1: for fusion, we have to understand how fusion works. And
Speaker 1: some of the details are actually really important, but the
Speaker 1: basics are that fusion is sticking protons together. We know
Speaker 1: that elements are defined by the number of protons in
Speaker 1: the nucleus. The reason we call hydrogen hydrogen is because
Speaker 1: it has one proton. The reason we call carbon carbon
Speaker 1: it's because there are six protons. Yeah, another proton, it's
Speaker 1: no longer carbon. This is my least like subject in
Speaker 1: science high school. Chemistry I'm currently now teaching my second
Speaker 1: child who's going through high school chemistry. But basically it's alchemy. Right.
Speaker 1: You can take elements, you can squeeze them together, you
Speaker 1: get a new element. Right. That would like blow the
Speaker 1: minds of people from the sixteen hundreds that we really
Speaker 1: can change elements from one to the other by squeezing
Speaker 1: their nuclei together and getting those protons to stick together.
Speaker 3: It's like magic because not only do you get something new,
Speaker 3: but you also get energy.
Speaker 1: Yeah.
Speaker 2: Yeah, and then you can try to capture it.
Speaker 1: Yeah, but it's not the kind of thing that protons
Speaker 1: like to do. Right, you have an hydrogen atom, it's
Speaker 1: a proton and an electron. The proton and electron attract
Speaker 1: each other because they're opposite charge, and so they fall
Speaker 1: into a stable pattern. Right, there's a bound state there
Speaker 1: of the electron of the proton neutral hydrogen. But if
Speaker 1: you're trying to take two protons together, like the nuclei
Speaker 1: of those hydrogens and squeeze them together, what happens, Well,
Speaker 1: they are like charges. They're both positively charged, so they resist. Right.
Speaker 1: It's like trying to put two North magnets near each other.
Speaker 1: You know, they squirm and they slide and they try
Speaker 1: to avoid, and it's really hard to get them to
Speaker 1: actually touch. And the same thing happens with protons, which
Speaker 1: is why fusion is so hard. You can't just take
Speaker 1: hydrogen gas and watch it and see fusion happen, because
Speaker 1: those protons avoid each other.
Speaker 2: If you can't actually get them close enough, then they
Speaker 2: stop repelling.
Speaker 1: Right, Yeah, there are two things going on here at
Speaker 1: sort of a larger distance. The way hydrogen normally is. Basically,
Speaker 1: the electromagnet force repels the nucleid. They stay apart from
Speaker 1: each other. But if you get the protons close enough together,
Speaker 1: then they start to feel the strong nuclear force from
Speaker 1: inside them. And this is a little bit confusing because
Speaker 1: a proton is neutral in the strong nuclear force. So
Speaker 1: let's back up. We have a few fundamental forces in nature.
Speaker 1: You have electromagnetism, you have the strong nuclear force, the
Speaker 1: weak force, and gravity. Mostly it's electromagnetism that we talk
Speaker 1: about when we talk about elements and chemicals and bonds
Speaker 1: and all this kind of stuff, and it's those positive
Speaker 1: and negative charges that determine what sticks to each other
Speaker 1: and what repels. But these other forces are also powerful.
Speaker 1: In fact, the strong nuclear force is much much more
Speaker 1: powerful than electromagnetism, but mostly it's already neutralized. Like, a
Speaker 1: proton has quarks inside of it, and those quarks feel
Speaker 1: this strong nuclear force, but together all the quarks inside
Speaker 1: a proton are neutral, like they all add up to
Speaker 1: basically zero strong charge, which confusingly we call color. So
Speaker 1: a proton is neutral from the strong force and another
Speaker 1: done as neutral from the strong force. But if you
Speaker 1: bring them close enough together, then the quarks inside one
Speaker 1: start to feel the quarks inside the other, because like overall,
Speaker 1: on average, they're neutral. But if one of the quarks
Speaker 1: is sort of like near the edge of the proton,
Speaker 1: another one is near the edge, they will start to
Speaker 1: feel each other. So if you get them close enough together,
Speaker 1: that strong force attraction between the quarks inside the protons
Speaker 1: will take over and they will snap together and make
Speaker 1: a new nucleus.
Speaker 3: And what gives you the energy when that happens is
Speaker 3: it the snapping.
Speaker 1: If you put your ear really close to fusion, you
Speaker 1: can hear the snapping. It's amazing. It's just like pouring
Speaker 1: milk onto rice crispies.
Speaker 2: Oh what a pleasant experience.
Speaker 1: No, that part was a joke. It's a really good
Speaker 1: question where does the energy come from? And it's confusing
Speaker 1: because we have two forms of nuclear energy. We have fission,
Speaker 1: where you take really heavy elements and you break them
Speaker 1: up into lighter elements and you get energy. And then
Speaker 1: we have fusion, where you take lighter elements like hydrogen
Speaker 1: and you squeeze them together to make heavier elements and
Speaker 1: you get energy. And you might think, hold lot a second,
Speaker 1: isn't that cheating? How do you get energy in both directions?
Speaker 1: Making heavier stuff gets your energy, making lighter stuff gets
Speaker 1: your energy. Well, the answer is that those are very
Speaker 1: different configurations because if you start with anything heavier than iron,
Speaker 1: then making it lighter you get energy. If you start
Speaker 1: with anything lighter than iron, making it heavier, you get energy.
Speaker 1: If you take two uranium atoms, for example, and squeeze
Speaker 1: them together to something crazy super uranium, you don't get energy.
Speaker 1: And if you take two helium atoms and you break
Speaker 1: them apart, you don't get energy. So fusing light stuff
Speaker 1: together or breaking heavy stuff you get energy. And where
Speaker 1: does that energy come from? Well, in the case of fission,
Speaker 1: it comes from internal energy stored in the nucleus. It
Speaker 1: was like a spring that was compressed and it was
Speaker 1: bound up and you released it and the energy is released.
Speaker 1: In the case of the lighter stuff, it's a little
Speaker 1: bit more complicated. Basically, it was the energy of those
Speaker 1: hydrogen atoms and you could think of them as like
Speaker 1: flying around in space really really fast, and now they're stuck.
Speaker 1: They stuck together, and that where does the energy of
Speaker 1: their motion go. It gets kicked off as photons and
Speaker 1: other kinds of stuff. So they've sort of fallen into
Speaker 1: a lower energy state, a bound state together, and they've
Speaker 1: given up that energy when they do it. But that's
Speaker 1: very handwavy. The truth is, like it's really complicated in
Speaker 1: nuclear physics that we don't one hundred percent understand.
Speaker 3: Okay, so the lighter stuff is what you use for fusion.
Speaker 3: It must be harder to join things together than break
Speaker 3: things apart, because we already use fission in nuclear power plants.
Speaker 1: And because you're a parent and you know that, like
Speaker 1: breaking a glass is much much easier than putting it
Speaker 1: back together.
Speaker 2: Yeah, so much easier, So much easier, or a.
Speaker 1: Lego tower or something, Yes, exactly, it's pretty easy to
Speaker 1: have fusion happen. You just like have a nucleus, it
Speaker 1: wants to break apart. Like uranium is pretty unstable, you
Speaker 1: knock it with a neutron, it's just going to fall apart.
Speaker 1: It's not that complicated, but getting fusion to happen is
Speaker 1: hard because these protons will repel each other. Think of
Speaker 1: it like mini golf and you're trying to get the
Speaker 1: golf ball into the top of a volcano. If you
Speaker 1: get it right on the very middle, it's going to
Speaker 1: go to the top of volcano into the hole. But
Speaker 1: if you miss at all, it's just going to slide
Speaker 1: right back down the side. So to get these protons together,
Speaker 1: you have to have like the perfect shot, the right speed,
Speaker 1: the right direction. It's very unlikely for this to happen,
Speaker 1: even in like the Sun. Mostly protons avoid each other,
Speaker 1: even in the crazy high temperature, high density conditions of
Speaker 1: the Sun. The reason the Sun lasts so long is
Speaker 1: that fusion is very hard to do, and most of
Speaker 1: the Sun is not fusing.
Speaker 3: When we think about doing fusion on Earth, we're using hydrogen.
Speaker 3: As you said, why hydrogen and not carbon? Is it
Speaker 3: even harder to smooth together carbons because it's low enough
Speaker 3: in that like break them apart to get energy. Divide
Speaker 3: that you mentioned. So why hydrogen and not like carbon?
Speaker 1: Yeah, great question. Well, yeah, you get more energy from
Speaker 1: fusing hydrogen together than helium. You get less and less
Speaker 1: energy as you go up, and when you get to
Speaker 1: iron you get no energy and then it turns over
Speaker 1: and it costs energy to fuse them. So hydrogen fusion
Speaker 1: give you the most energy, and hydrogen is the easiest
Speaker 1: to combine and also requires lower temperatures. That's really the key. Like,
Speaker 1: to fuse helium together, you have to be even hotter
Speaker 1: than fusing hydrogen, and to fuse carbon together, you got
Speaker 1: to be even hotter. And fuse neon together, you got
Speaker 1: to be even hotter. That's why out there in the universe,
Speaker 1: some stars are big enough to make iron, but most
Speaker 1: of them aren't. Most of them will die out after
Speaker 1: the make helium or carbon and they never get hot
Speaker 1: enough to fuse that carbon together. It just stays there
Speaker 1: inert until the star dies. So the key is temperature.
Speaker 1: If you can get super duper hot and super duper dense,
Speaker 1: yeah you can fuse and make iron, but that's like
Speaker 1: elite stars, only some of those can make that. So
Speaker 1: here on Earth, where we're like doing a little baby fusion.
Speaker 1: We start with the first easiest steps, Like we have
Speaker 1: made fusion work here on Earth. We have fusion bombs.
Speaker 1: It's not great, it's how wonderful that we can do it.
Speaker 1: But fusion bombs start with a fission reaction, so it's
Speaker 1: like a classic atomic bomb, which then creates the necessary
Speaker 1: conditions for fusion and you get a massive release of energy.
Speaker 1: So a hydrogen bomb, for example, is a fusion bomb.
Speaker 1: So we know the physics, we know we can make
Speaker 1: it happen. The challenge is creating the conditions to make
Speaker 1: it happen long term, so you can keep pouring fuel
Speaker 1: in and keep getting energy out. And to do that
Speaker 1: you really have to get things hot or dense, or
Speaker 1: do it all really really quickly before it disperses.
Speaker 2: That sounds hard.
Speaker 3: I'm feeling like, if you to kick off this reaction,
Speaker 3: you need a fission bomb that doesn't bode super well
Speaker 3: for ability to contain it and use it to like
Speaker 3: power toasters. And so before we jump into how do
Speaker 3: you contain those conditions so that you can make power
Speaker 3: and send it out onto the grid, We're going to
Speaker 3: take a quick break, all.
Speaker 2: Right, We're back.
Speaker 3: So we've discussed how hydrogen bombs use fission to create
Speaker 3: the kind of conditions that you need for fusion to happen.
Speaker 3: But since we don't want to be setting off nuclear
Speaker 3: bombs and neighborhoods, how are we trying to create the
Speaker 3: conditions for fusion in a and friendlier ways.
Speaker 1: So, if you want fusion to happen, the critical things
Speaker 1: are temperature, density, and time. Like if you can make
Speaker 1: your protons really really hot, meaning they're going really really
Speaker 1: fast and they're more likely to overcome this electromagnetic repulsion
Speaker 1: and fuse together, to get close enough to fuse together.
Speaker 1: Another trick is density, because the more protons you have
Speaker 1: jammed in there, the more they can't avoid each other
Speaker 1: and will eventually fuse. And then there's time. The longer
Speaker 1: you can maintain this hot, dense soup of protons, the
Speaker 1: more likely you are to get fusion going. And so
Speaker 1: basically we try all these different strategies. Like out in
Speaker 1: the universe, the stars use gravity. They're like, Okay, if
Speaker 1: we just get enough hydrogen together, it'll have enough mass.
Speaker 1: That is, the gravity is going to do the job
Speaker 1: for us, and it's going to make things hot it's
Speaker 1: going to make things dense, and it's going to trap
Speaker 1: it there forever. So starts sort of have it easy
Speaker 1: because they went big, and here on Earth we can't
Speaker 1: go that big. We can't just use gravity. So one
Speaker 1: classic strategy is to use magnets instead of using gravity
Speaker 1: to create the conditions where all the hydrogen gets squeezed together.
Speaker 1: What if we use magnets because magnets can bend the
Speaker 1: path of charged particles, Like that's basically what a magnetic
Speaker 1: field is. You have an electron flying through space, you
Speaker 1: put a magnet near it, it will bend the path
Speaker 1: of the electron. So now imagine you have a plasma
Speaker 1: which is basically just charged particles. You take hydrogen, heat
Speaker 1: it up, so the protons electrons are now flying free.
Speaker 1: It's a gas that has electric charge, and that means
Speaker 1: that you could use a magnetic bottle to contain it.
Speaker 1: So the classic strategy is basically a donut. Get the
Speaker 1: plasma moving in a doughnut and use magnets to keep
Speaker 1: bending it. It's like a racetrack and just zooms around
Speaker 1: and around and around. You have this hot, flaming plasma
Speaker 1: contained in a magnetic bottle and nothing has to touch it, right,
Speaker 1: You don't need something which can withstand three thousand calvin.
Speaker 1: So magnetized fusion is like heat it and then try
Speaker 1: to contain it in a bottle and keep it there
Speaker 1: long enough that you get some fusion going.
Speaker 3: And so my brain has lost track of the names
Speaker 3: of some of the projects, but I think there's the
Speaker 3: biggest international project. Is this delicious doughnut shape doing the
Speaker 3: magnetized confinement fusion, right, And that's EATER, I think. And
Speaker 3: what does that acronym stand for.
Speaker 1: What is EATER stand for? It stands for International Thermonuclear
Speaker 1: Energy Reactor. No, I just made that up.
Speaker 3: Well, I was convinced you said it with the right
Speaker 3: level of confidence, and I was in.
Speaker 1: No, EATER actually stands for International Thermonuclear Experimental Reactor, so
Speaker 1: I was pretty close. But you're right. The EATER is
Speaker 1: sort of the big Mama version of the classic strategy,
Speaker 1: which we call a tokomac. And the Russians were leaders
Speaker 1: in this for many years, and so a lot of
Speaker 1: the words in this field come from Russian, so I
Speaker 1: don't actually understand the origin of the word tokmac. But
Speaker 1: it's basically a magnetic donut and as you said, magnetically
Speaker 1: confined fusion. And the challenge is keeping it there and
Speaker 1: keeping it hot. Because plasmas are crazy. It's really hard
Speaker 1: to keep them stable. And as people watch them, they're
Speaker 1: all sorts of like fluid dynamics that's going on. So
Speaker 1: you have like electromagnetism with all these charges, and you
Speaker 1: have all the issues of like liquids and keeping things
Speaker 1: flowing without creating vortices and turbulence, and it's very unstable.
Speaker 1: Once you get like something spinning in a little vortex forming,
Speaker 1: you have electric charges in the mix, and then the
Speaker 1: whole thing just spins out of control and collapses. So
Speaker 1: mostly the last few decades have been spent trying to
Speaker 1: keep these plasmas calm, get them hot, get them spinning,
Speaker 1: keep them going for long enough that you can put
Speaker 1: fuel in there. It will fuse, and then the energy
Speaker 1: from that fusion will keep the plasma hot. So this
Speaker 1: is called ignition. It's like when you're trying to start
Speaker 1: a fire, right, It's first it's really hard to get
Speaker 1: that log going. Once you've got a hot logo, you
Speaker 1: can throw anything in there and it's just going to
Speaker 1: baby burn. Right. So the trick is getting this plasma
Speaker 1: hot enough that it sustains itself.
Speaker 3: I am really bad at starting fires. Another reason it
Speaker 3: not be stuck with me in the apocalypse. Okay, so,
Speaker 3: if I'm remembering my fusion stuff correctly, what you want
Speaker 3: is to pass break even. And break even is the
Speaker 3: point where the energy that you put in to get
Speaker 3: this really complicated system going matches the energy that the
Speaker 3: system outputs. And ideally then you get way past that
Speaker 3: because now you can start powering new things. Has any
Speaker 3: tokamac hit break even?
Speaker 1: It depends on exactly how you do the accounting from
Speaker 1: a commercial perspective. No, if you account like how much
Speaker 1: it costs to run the whole thing, including like the
Speaker 1: facility and the electronics and everything, then nobody has hit
Speaker 1: break even. If you're really creative with your accounting where
Speaker 1: you're like, I'm only going to account the actual energy
Speaker 1: I spent that went into the plasma or something, then
Speaker 1: there are some places that have achieved break even briefly, right,
Speaker 1: So briefly is the key there, Like they have put
Speaker 1: in fuel and it has fused and it has released energy.
Speaker 1: They have not captured that energy. Like, it's not like
Speaker 1: they turn that into electricity. That's a whole other issue
Speaker 1: for like, what do you do with his energy? How
Speaker 1: do you capture it and efficiently turn it into electricity. Nobody's
Speaker 1: done that even but we have achieved fusion with tokeomacs,
Speaker 1: and the idea is that this eater, this huge reactor,
Speaker 1: is going to scale it up and solve all these
Speaker 1: problems because these tokemacs actually get better as they get bigger,
Speaker 1: because their volume grows more quickly than your surface area.
Speaker 1: It's the reason that like an elephant has to cool
Speaker 1: itself with its big ears, is because there's so much
Speaker 1: meat inside and so much less surface area that it's
Speaker 1: hard to keep it cool. Well, that actually works in
Speaker 1: the benefit of plasmas. As they get bigger, they don't
Speaker 1: cool down as easily, and so there's like a hot,
Speaker 1: dense core the center that stays fusing. So that's why Eater,
Speaker 1: which is like twelve meters high, this massive doughnut. All
Speaker 1: the projections are that it will hit break even and
Speaker 1: actually generate power. Of course, it's taking like decades to
Speaker 1: build and zillions of dollars, so whether it's commercial it's
Speaker 1: another question, but it's sort of tried and true.
Speaker 2: Okay, Yeah, that's what I was wondering.
Speaker 3: If it's that expensive, is it really going to be
Speaker 3: feasible to like PLoP one of these in you know,
Speaker 3: every state to power stuff. But you know, I guess
Speaker 3: you get better at it and then you can get
Speaker 3: economies of scale and stuff like that.
Speaker 1: But okay, you could just build them in space. Everything's
Speaker 1: easier in space, right Kelly.
Speaker 2: Oh my gosh, yeah great.
Speaker 3: Where is the We need to find an angel investor
Speaker 3: for you, because you, I think are onto something.
Speaker 1: Everybody should invest in my fusion AI crypto startup.
Speaker 2: That's all the words. You've got this.
Speaker 3: I get all the monies, right, well, I helped you
Speaker 3: think about it, so I get half the monies. Okay,
Speaker 3: so we've done. Okay, so magnetized fusion, this is clear.
Speaker 3: The tokemacs are clearly the most delicious way to think
Speaker 3: about fusion. But maybe the most epic way to think
Speaker 3: about fusion is the laser version. And so how does
Speaker 3: the laser version work?
Speaker 1: The laser version says, let's give up on keeping the
Speaker 1: fusion going for a long time. Instead, let's go for
Speaker 1: super high density like this, have really brief fusion, but
Speaker 1: make it really good because we have high density because
Speaker 1: fusion happens more rapidly at higher densities, Like as you
Speaker 1: squeeze those stars together and the cores get hot, you
Speaker 1: get more fusion faster. This is why like big stars
Speaker 1: burn out faster in the universe than slow stars. They
Speaker 1: have more fuel, but they burn hotter. The fusion happens
Speaker 1: more rapidly. They burn out in a few brilliant million years,
Speaker 1: whereas small stars can burn for like billions or trillions
Speaker 1: of years. The idea of laser fusion, sometimes called inertial
Speaker 1: confinement fusion, is you just take a pellet of fuel
Speaker 1: and you zap it with intense lasers, like one hundred
Speaker 1: and ninety six lasers from all directions. It's like super
Speaker 1: futuristic and awesome looking. And if you zap it from
Speaker 1: all sides simultaneously, basically the outer layer explodes, which compresses
Speaker 1: the whole pellet, and then you get the density you
Speaker 1: need for fusion. So you have this shockwave. It's like
Speaker 1: a mini supernova. The shockwave travels inwards at like three
Speaker 1: hundred and fifty kilometers per second. We're talking these tiny
Speaker 1: little pellets in this super fast shockwave, and this fuel
Speaker 1: goes from like the density of water, you know, one
Speaker 1: gram per middle liter, to one hundred times the density
Speaker 1: of lead, and that's where the fusion happens.
Speaker 3: That this method works at all kind of blows my
Speaker 3: mind because anything that requires like incredible amounts of coordination.
Speaker 3: Like I think about my family and there's just four
Speaker 3: of us, and I'll be like, we all need to
Speaker 3: meet at the same place in fifteen minutes, and nobody's
Speaker 3: there at the right time. But somehow you're getting like
Speaker 3: all of these lasers to sort of time up and
Speaker 3: shoot the same exact tiny spot at the It's kind
Speaker 3: of amazing to me that the coordination problem here has
Speaker 3: been solved or is working on being solved.
Speaker 1: Well, it turns out electronics are more reliable than children.
Speaker 2: Yeah, I guess that's not surprising.
Speaker 1: Yeah, But the whole thing happens in like ten to
Speaker 1: thirty nanosecond time period. It's super fast, and the reason
Speaker 1: it works is like you're squeezing the fuel by huge factor,
Speaker 1: so you're not containing it for very long because now
Speaker 1: it's super tiny, but the density goes up much more
Speaker 1: quickly than you're losing seeing the time, and the fusion
Speaker 1: goes up with the density. It's another one of these
Speaker 1: dimensional arguments, like if you squeeze things down by a
Speaker 1: factor of ten, it lasts for ten times less long.
Speaker 1: But the density goes up by a factor of ten cubed,
Speaker 1: as does the fusion. So higher density also means the
Speaker 1: heat is not lost, like the alpha particles that you're
Speaker 1: creating in this fusion don't escape. And so the calculation
Speaker 1: suggests this should actually work. And in the last few
Speaker 1: years they made huge progress and the National Ignition Facility,
Speaker 1: Lawrence Livermore National Lab, actually made this work and like,
Speaker 1: got fusion happen from these little pellets?
Speaker 2: Whoo? And so do you blast the pellets with the lasers?
Speaker 3: And then how so we were talking about how you
Speaker 3: want this reaction to keep going and take more time
Speaker 3: so that you're getting more energy out of it. Do
Speaker 3: you just keep blasting pellets over and over and over
Speaker 3: and over again or do you blast once and that
Speaker 3: gets something going?
Speaker 2: And then you contain that yes.
Speaker 1: So basically each pellet is a one shot operation. And
Speaker 1: if this ever were to work, you zap the pellet,
Speaker 1: you get the fusion, replace it with new pellet, zappit
Speaker 1: get fusion. This approach is giving up on time, right,
Speaker 1: the magnetic confinement is saying, let's try to keep this
Speaker 1: going as long as possible so it builds on itself.
Speaker 1: Here they've given up on that, and they're like, let's
Speaker 1: just have a rapid series of fusion, each one independen,
Speaker 1: so don't benefit from the previous one. You start from
Speaker 1: scratch with a new pellet every time. But it means
Speaker 1: you have to have these pellets and you have to
Speaker 1: prepare them. They're these like tiny little fragile dots of
Speaker 1: special hydrogen and they're not cheap to make.
Speaker 3: All right, So some economic problems that also need to
Speaker 3: be solved. But is that the two ways to do
Speaker 3: it or is there a third way?
Speaker 1: Those are the two main ways, magnetic confinement or inertial confinement,
Speaker 1: basically like magnets or lasers. These days, there's lots of
Speaker 1: clever ideas out there in the business world, and you
Speaker 1: start to see startups coming up with their own idea
Speaker 1: for fusion. They're like, these big government funded ideas are
Speaker 1: too slow and too conservative. I have my billion dollar
Speaker 1: fusion idea. And so there are some companies out there
Speaker 1: that have private funding that are working on variations of this.
Speaker 1: Like there's a company called Commonwealth Fusion, and their idea is,
Speaker 1: you don't need to make your magnetic confinement so big,
Speaker 1: you just make the magnets more powerful. So they're using
Speaker 1: like super conducting magnets to make like a smaller version
Speaker 1: of eater that they think also is going to work.
Speaker 1: And those are serious scientists, Like these guys know what
Speaker 1: they're doing. They publish academic papers, they have real money.
Speaker 1: This could really work. And then there are other crazier ideas.
Speaker 1: There's one here in southern California called tri Alpha Energy
Speaker 1: where they have a plasma which is contained magnetically and
Speaker 1: then they shoot a particle beam into it because they
Speaker 1: think they can make this like special resonance coil happen
Speaker 1: where it like spins in a certain way that makes
Speaker 1: magnetic fields that help stabilize it instead of destabilizing it.
Speaker 1: The basic idea for that whole company was created by
Speaker 1: a professor here at UC Irvine a few decades ago,
Speaker 1: and so a lot of people believe that that could
Speaker 1: really work. Then there's the one Sam Altman is funding
Speaker 1: Helion Energy, and they're using some combination of these two
Speaker 1: ideas lasers and magnets simultaneously. But the bottom line is
Speaker 1: that all these differ and approaches all use the same fuel.
Speaker 1: It's all hydrogen, and it's all the special version of
Speaker 1: hydrogen that you need. In every case. The challenge is
Speaker 1: getting the high temperature, maintaining the high temperature, or creating
Speaker 1: that high density to make fusion happen. But it turns
Speaker 1: out that doing fusion with pure hydrogen, like the kind
Speaker 1: that most of the universe is made out of, is
Speaker 1: actually much much harder than doing it with special fancy hydrogen.
Speaker 3: Tell me about this special fancy hydrogen. Am I going
Speaker 3: to like try to capture it in a locket?
Speaker 2: Is it that kind of fancy? What does it look like?
Speaker 1: Yeah, give it to your partner on their birthday. So
Speaker 1: we heard at the top a lot of people thought, well,
Speaker 1: fusion is great because the inputs are hydrogen, and hydrogen
Speaker 1: is everywhere, and it's true that most of the universe
Speaker 1: is hydrogen. Like way back in the beginning of the universe,
Speaker 1: things were still cooling down. You had protons and electrons
Speaker 1: flying around mostly that just cooled into hydrogen. Very briefly,
Speaker 1: there were the conditions to make heavier elements a little
Speaker 1: bit of helium was made, but mostly from the beginning
Speaker 1: of the universe was hydrogen. And stars have come along
Speaker 1: and fused a bunch of stuff to make heavier stuff,
Speaker 1: so that it's me and you and lava and kittens
Speaker 1: and all that stuff. And we have iron now, but
Speaker 1: that's still a tiny fraction of the universe. Most of
Speaker 1: the universe is still hydrogen. So this seems great. We
Speaker 1: have a power source which requires a fuel, which is
Speaker 1: most of the universe. How could it be any better? Right?
Speaker 1: And often you hear fusion's fuel described as abundant, virtually inexhaustible,
Speaker 1: and equally accessible to everyone. So this seems amazing, right,
Speaker 1: And we have like oceans of water water has filled
Speaker 1: with hydrogen. So in principle this sounds great, but as
Speaker 1: always with science and with commercializing science, the details are
Speaker 1: important because it turns out that fusion is hard to
Speaker 1: do with sort of vanilla hydrogen. You have this two protons,
Speaker 1: you us squeeze them together. You can do it, but
Speaker 1: it's gotta be really hot or really dense. It turns
Speaker 1: out it's a lot easier to make it happen if
Speaker 1: one of those protons has a neutron friend along. For
Speaker 1: the ride. So if you have hydrogen, but you add
Speaker 1: a neutron to the nucleus, so now the nucleus is
Speaker 1: like a proton and a neutron. It's still hydrogen, right,
Speaker 1: It's still just one proton, but now it has a
Speaker 1: neutron friend, and that makes it a lot easier to
Speaker 1: squish together with another proton because the neutron helps mediate it.
Speaker 1: Neutrons make nuclei more stable. They're neutral. They don't play
Speaker 1: a role electromagnetically, but for the same reason, like they
Speaker 1: have quarks inside of them, and those quarks have the
Speaker 1: strong force that neutrons help things happen. And so it
Speaker 1: turns out that using deuterium, which is what we call hydrogen,
Speaker 1: with an extra neutron, makes fusion a lot easier. It
Speaker 1: can happen at lower densities, it can happen at lower temperatures.
Speaker 3: So how many hydrogen protons have neutron friends? How often
Speaker 3: does that happen? I hope they're not lonely that often.
Speaker 1: So not very often. It turns out that out there
Speaker 1: in the universe, one in about sixty five hundred hydrogen
Speaker 1: atoms has the neutron friends. So deuterium is not very common,
Speaker 1: but deuterium is actually not even the best source. What
Speaker 1: we really want for fuel for fusion is something called tritium.
Speaker 1: So deuterium we call deuterium, has that prefix in it
Speaker 1: from Latin, which tells so there are two particles in
Speaker 1: the nucleus, the proton and the neutron. Tritium is if
Speaker 1: you have a proton with two neutron friends, that's tritium
Speaker 1: and tritium. Deuterium fusion together is like the best. If
Speaker 1: you have deuterium and tritium, you got like two protons
Speaker 1: three neutrons to help out. This thing is the easiest
Speaker 1: to make happen. So a lot of the fusion that
Speaker 1: we've succeeded to do here on Earth, what we talked
Speaker 1: about for the ignition facility, those pellets have deuterium and
Speaker 1: tritium in them, and the tokamax also use deterium and
Speaker 1: tritium for fuel. So even to make it work here
Speaker 1: on Earth, we've relied on doing it the easy way,
Speaker 1: which means using these rare special kinds of hydrogen.
Speaker 3: So why wouldn't tritium and tritium be even easier than
Speaker 3: deuterium and tritium.
Speaker 1: Tritium tritium, you can make that work also, I think
Speaker 1: deuterium and tritium work better. This is complicated stuff like
Speaker 1: getting the neutrons to play along and how that all happens.
Speaker 1: You know, there's a lot of complicated strong force interactions
Speaker 1: that we still don't understand. We still don't really understand
Speaker 1: what makes a nucleus stable. This is a really cool
Speaker 1: theory about the shell model, about how these things slide
Speaker 1: into each other, sort of like electrons. How you want
Speaker 1: to fill orbitals and make them complete to make something inert,
Speaker 1: and in the same way you want like the same
Speaker 1: number of protons and neutrons they like complete shells. Anyway,
Speaker 1: the short answer is it's very complicated. But there's one
Speaker 1: other fuel we can use to make fusion easier than
Speaker 1: like vanilla hydrogen, and that's actually a form of helium
Speaker 1: called helium three. Helium is two protons, but it's actually
Speaker 1: not even stable that way. Like you have just two protons,
Speaker 1: they will not stay together. You need neutrons to hold
Speaker 1: that guy together. So if you add a neutron, you
Speaker 1: can have something called helium three. So it's two protons
Speaker 1: and a neutron, and this is a lot of the
Speaker 1: fusion that happens in the sun. For example, helium three
Speaker 1: fusion produces helium four and hydrogen, and it's actually great
Speaker 1: for fusion because it's low temperature, it produces a lot
Speaker 1: of energy. It doesn't produce dangerous neutrons which can fly
Speaker 1: through everything and kill people, and so helium three fusion
Speaker 1: is fantastic. So the bottom line is vanilla hydrogen hard
Speaker 1: to fuse with. You need really high temperatures and pressures.
Speaker 1: Heavy hydrogen or helium three are the best. That's what
Speaker 1: we really need to do fusion.
Speaker 3: So two different questions. First, you talked about the neutrons
Speaker 3: shooting out and killing people. This whole process still has
Speaker 3: less like radioactive waste and danger than fission, right, but
Speaker 3: with hydrogen you still have some rogue stuff you gotta
Speaker 3: worry about.
Speaker 1: Well, you don't have the byproducts in the same way.
Speaker 1: Like when you start from big messy radioactive nuclear like
Speaker 1: uranium or plutonium, they're going to break down into big, messy,
Speaker 1: poisonous stuff. And that's the problem with fission fusion. You
Speaker 1: start with hydrogen, which is basically innocuous, and you make helium,
Speaker 1: which like ya makes you talk like a squirrel, so
Speaker 1: there's no like dangerous byproducts that way. But sometimes when
Speaker 1: the energy comes out, it doesn't come out in the
Speaker 1: form of photons like light that you can just gather,
Speaker 1: comes out in the form of really high speed neutrons
Speaker 1: that are ejected in these processes, and neutrons are bad,
Speaker 1: like if you heard of a neutron bomb. Neutron bombs
Speaker 1: kill people, and they do it without destroying a lot
Speaker 1: of the buildings. It's really terrifying because neutrons don't have
Speaker 1: a charge, so they can fly through a lot of material,
Speaker 1: but if they fly through your body, they like tear
Speaker 1: your delicate biological machinery to shreds, and so neutron bombs
Speaker 1: really insidious, which means if you're going to like capture
Speaker 1: the energy from some of these reactions, you need a
Speaker 1: way to like capture these neutrons and slow them down
Speaker 1: and extract their energy. But they're also going to end
Speaker 1: up irradiating your facility, so you will produce irradiated materials,
Speaker 1: like your fusion reactor will become irradiated. It's not as
Speaker 1: bad as what fission makes, and some people argue, hey,
Speaker 1: even fission isn't that bad, but it's not true that
Speaker 1: fusion produces like no dangerous radiation.
Speaker 3: At all, But would it produce no dangerous radiation at
Speaker 3: all if you use helium three?
Speaker 1: Yeah, there are no neutrons that'll come out if you
Speaker 1: just use helium three, So that's nice. It comes out
Speaker 1: in terms of photons, and you can capture the energy
Speaker 1: more easily. And I'll say that like, in almost none
Speaker 1: of these fusion efforts have people really spent significant time
Speaker 1: figuring out how to capture this energy. It's mostly like
Speaker 1: how to make the energy, how to like actually turn
Speaker 1: that energy into electricity and factoring and that inefficiency and
Speaker 1: the difficulty is not even like really begun. People are
Speaker 1: just still working on step one, which is like get
Speaker 1: fusion happen, And they were like, oh, we'll figure that out.
Speaker 1: That's an engineering problem, but like the whole thing is
Speaker 1: an engineering problem.
Speaker 2: It's engineering problem stacked on top of each other.
Speaker 1: Really exactly.
Speaker 3: Let's take a break and then we're going to talk
Speaker 3: a little bit about how and where we find these
Speaker 3: things on Earth. Okay, we're back, and first I actually
Speaker 3: want to start with another helium three question for Daniel,
Speaker 3: because I'm kind of obsessed with helium three. So my
Speaker 3: question is, I think you mentioned that most of the
Speaker 3: reactors that are running today are using like deuterium and tritium.
Speaker 3: If that creates some radioactive waste and doesn't work as
Speaker 3: well as helium three, why aren't we using more helium
Speaker 3: three in reactors right now?
Speaker 1: Yeah, great question. Well, the answer is that helium three
Speaker 1: is rare. You know, we don't have a lot of it,
Speaker 1: as we'll talk about it in a minute. I'm sure
Speaker 1: like there's some on the Moon, but there's really not
Speaker 1: a whole lot here on Earth, and so it's easier
Speaker 1: to find tritium and deterium. And this is a lesson
Speaker 1: that like the easier the source of fuel, the more
Speaker 1: likely you are to use in your research and define
Speaker 1: practical solutions. And so there's a whole chain here that's
Speaker 1: required to make fusion actually change the way our lives work.
Speaker 1: And there's a step in the middle there, like assuming
Speaker 1: you have all the fuel and a way to capture
Speaker 1: the energy, get fusion to work, and that's like where
Speaker 1: the physics is. So people have focused on that, but
Speaker 1: you got to make the whole chain work, and there've
Speaker 1: been discussions about like how to do step two, which
Speaker 1: is like a have to give fusion work, capture the energy,
Speaker 1: but not enough. I think about step zero, which is
Speaker 1: like have the fuel on hand to actually get this going.
Speaker 1: And so you need sources of deterium and tritium and
Speaker 1: helium three to make this practical.
Speaker 2: So where do we get those now?
Speaker 1: So deterium we find in seawater, because water is like
Speaker 1: one in sixty five hundred atoms zero point zero one
Speaker 1: five percent is just naturally deterium. It was like made
Speaker 1: in the early universe, you know, when these protons were
Speaker 1: cooling and sometimes they came together and one became a neutron.
Speaker 1: This beta decay and inverse beta decay and all this stuff.
Speaker 1: And so some like fraction of hydrogen is just heavy
Speaker 1: hydrogen which makes heavy water, and so we can filter
Speaker 1: it out. And India is actually the leading producer of
Speaker 1: this stuff. You start with water and you isolate it,
Speaker 1: use all sorts of like chemistry tricks because deterium is heavier, right,
Speaker 1: and so centrifuges and all sorts of other stuff centrifuges
Speaker 1: and complicated distillers, et cetera. But you got to filter
Speaker 1: it out of seawater and so it's not like you
Speaker 1: can just scoop up water or gather hydrogen and you
Speaker 1: have fuel. Your fuel is like one sixty five hundredth
Speaker 1: part of the hydrogen that you've gathered. So that's not easy.
Speaker 1: It's like a whole production chain that you need.
Speaker 3: So if we could make that process easier. There's loads
Speaker 3: of seawater, so there'd probably be enough deuterium to run
Speaker 3: fusion for generations, presumably, Is that fair to mm hmm.
Speaker 1: Yeah, deterium is probably solvable. There's lots of sea water
Speaker 1: and so there's lots of heavy water out there. It's
Speaker 1: just not as accessible as people think. And it's going
Speaker 1: to cost energy, you know, so you're gonna have to
Speaker 1: factor this in. It's gonna be a huge cost upfront.
Speaker 1: You're gonna sink energy in to get your fuel out.
Speaker 1: It's not as easy as like I can scoop up
Speaker 1: hydrogen and I'm there. And also deterium is not enough,
Speaker 1: Like if you just ran these reactors on deterium, we
Speaker 1: couldn't make that work. You really need the tritium to
Speaker 1: make these reactions happen, and tritium much more complicated than deterium. Unfortunately.
Speaker 2: All Right, tell us about that, how much more complicated?
Speaker 1: Well, the problem is deterium is naturally stable like hydrogen,
Speaker 1: as a proton and neutron, it'll hang out forever. A
Speaker 1: lot of that is billions of years old, but tritium
Speaker 1: is not a proton and two neutrons in there. That
Speaker 1: falls apart. The half life is only like twelve and
Speaker 1: a half years. So even if the universe made a
Speaker 1: bunch of tritium, it's like all gone now naturally, And
Speaker 1: if you make it, you can't like store it for
Speaker 1: a long time. It's just like your bottle of tritium
Speaker 1: just turns into deterium naturally, and so on. Earth is
Speaker 1: like a very tiny amount in the atmosphere made constantly
Speaker 1: by cosmic rays. Particles from space common hit a piece
Speaker 1: of the atmosphere, and sometimes tritium is made just like
Speaker 1: by chance, one of a thousand things that can happen.
Speaker 1: But mostly we get tritium by manufacturing it here on
Speaker 1: Earth by shooting neutrons at lithium.
Speaker 3: Okay, so that sounds like we're talking about typical nuclear
Speaker 3: fission reactors, right, So this is a byproduct of that.
Speaker 1: Neutrons are a byproduct of fission. And they are byproduct diffusion.
Speaker 1: So this is actually a little bit promising because you
Speaker 1: can imagine like a fusion reactor that pumps out neutrons.
Speaker 1: Then you surround that with a lithium blanket, and the
Speaker 1: lithium blanket absorbs the neutrons and makes tritium for you.
Speaker 1: So this's called a breeder reactor, where the reactor itself
Speaker 1: helps you make the fuel for the next round.
Speaker 2: What a creepy name for reactor?
Speaker 1: A creepy name.
Speaker 2: It's kind of a creepy name anyway.
Speaker 1: It sounds like a groomer reactor or something. Yeah, you're
Speaker 1: gonna come back. There'd be like two reactors because they've
Speaker 1: been breeding. No, they don't make more reactors. They just
Speaker 1: make their own fuel, which is cool. So if you
Speaker 1: have a special kind of lithium called lithium six and
Speaker 1: you shoot it with neutrons, it will make tritium. That
Speaker 1: sounds great because neutrons are a byproduct of fusion, and
Speaker 1: so if you put your lithium six near your fusion boom,
Speaker 1: you get your tritium, which you need for your fusion
Speaker 1: happy days. The problem is that you need lithium six,
Speaker 1: which is a special kind of lithium. Most of the
Speaker 1: lithium out there is lithium seven, so lithium six is
Speaker 1: much more rare than lithium seven.
Speaker 3: You know, usually I'm the one who's like bumming people out,
Speaker 3: but I'm I'm feeling a little bit stressed listening to Utah.
Speaker 3: But we're gonna okay. So, but the point is, we
Speaker 3: haven't really tried this yet. Lithium six is hard to find,
Speaker 3: but it's out there, and maybe we could get good
Speaker 3: at this.
Speaker 1: Maybe, although you're right that we haven't really tried this.
Speaker 1: Like I asked a plasma physicist in my department, and
Speaker 1: he was pretty skeptical. He said, quote hid the list
Speaker 1: of fusion reactor items that have worryingly low technical readiness
Speaker 1: levels is the lithium blanket. Can it really produce enough
Speaker 1: tritium without requiring too much surface area around the reactor.
Speaker 1: So like, in principle, we can do this shoot neutrons
Speaker 1: at lithium six, but like, can we actually make this
Speaker 1: effective enough? And can we have enough lithium around the
Speaker 1: reactor to make enough fuel? It's like something nobody has
Speaker 1: figured out, and it's also complicated to get this lithium.
Speaker 1: For another reason, which is that lithium is in high
Speaker 1: demand by the electronic car industry. Everybody wants lithium for batteries,
Speaker 1: and so most of the lithium in the world goes
Speaker 1: towards batteries.
Speaker 2: They want lithium six, they.
Speaker 1: Don't actually care, they want lithium seven or six, they
Speaker 1: don't care, but they just gobble it all up anyway.
Speaker 1: So if you wanted to imagine like a best case
Speaker 1: scenario where fusion is providing like thirty percent of the
Speaker 1: power to the human race, you might think, like how
Speaker 1: much lithium do you need. You'd need like ten thousand
Speaker 1: tons of lithium six, which would mean you'd need to
Speaker 1: like divert it from the current lithium stream, which is
Speaker 1: very complicated and we're not good at that. And mostly
Speaker 1: the folks who are selling lithium just want to sell
Speaker 1: it to the electric battery folks and not like filter
Speaker 1: out the lithium six. But you know, there's ideas here,
Speaker 1: like recycling the lithium or something, but you know it's
Speaker 1: you see how it's complicated and fragile. Like to do fusion,
Speaker 1: you need treatium. To make treatium, you need lithium lithium
Speaker 1: is not that easy to find and in high demand
Speaker 1: by other folks. Bill Heidebrink told me, quote, there is
Speaker 1: great concern about having enough treatium for deterium tretium fusion.
Speaker 1: Like it's basically an unsolved problem. It's not unsolvea bowl,
Speaker 1: Like potentially we can find solutions to this, but like
Speaker 1: people haven't really gotten kracking on this. Been working on
Speaker 1: the physics part of it for a long time because
Speaker 1: that's fun, but digging into the details of like actually
Speaker 1: having a production pipeline for fuel for fusion to get
Speaker 1: enough of this going has not really been addressed.
Speaker 3: So how much harder is deuterium deuterium fusion? If the
Speaker 3: tritium appears to be the hardest part to solve.
Speaker 1: It's possible. It just requires significantly higher temperatures, and so
Speaker 1: it makes the whole problem harder. Like we've barely gotten
Speaker 1: this going with deuterium and tritium. And if we gave
Speaker 1: up on tritium and said we're just going to do
Speaker 1: deuterium because you're right, there's more of it and it's
Speaker 1: easier to access and we don't have this whole production
Speaker 1: pipeline issue, it means that we have a much harder
Speaker 1: problem to solve on the physics side, So we're like
Speaker 1: now more decades away from really getting that to work.
Speaker 1: So it's about making the problem easier and deterium by itself,
Speaker 1: it just requires much higher temperatures.
Speaker 3: So tritium hard to get. Helium three. Now, let's move
Speaker 3: to helium three. So we're stuterium tritium reactors. We're focusing
Speaker 3: on helium three. You told us earlier that it is
Speaker 3: hard to get on Earth. It does exist on Earth, though,
Speaker 3: is there any way we can make it on Earth
Speaker 3: or do we need to find it naturally occurring?
Speaker 1: So helium three like existed on Earth a long time ago,
Speaker 1: but most of it bubbled out into space, and we
Speaker 1: can make it on Earth. Actually, we know how to
Speaker 1: do that. You know, you need to make helium three tritium. Yeah,
Speaker 1: so if you had plenty of tridium, making helium three
Speaker 1: would not be that hard. Fortunately, there's a huge supply
Speaker 1: of helium three right next door, and you know, every
Speaker 1: problem is easier by going out into space. And so
Speaker 1: it turns out that there is a significant amount of
Speaker 1: helium three on the Moon because it's been deposited in
Speaker 1: the upper layer by the solar wind, like stuff pumped
Speaker 1: out from the Sun. Helium three is made in the Sun,
Speaker 1: and the Sun is not just pumping out photons. It's
Speaker 1: pumping out protons and electrons and sometimes helium three nuclei,
Speaker 1: and those are deflected from the Earth because of our
Speaker 1: magnetic field or absorbed in the atmosphere. But the Moon
Speaker 1: has neither of those, and so it just like gathers
Speaker 1: up helium three. So a lot of people who talk
Speaker 1: about going to the moon and say, ooh, another benefit
Speaker 1: of going to the Moon is that it's really rich
Speaker 1: in this excellent fuel that we desperately need for fusion
Speaker 1: here on Earth. So tell us, Kelly, why is that
Speaker 1: actually a terrible idea?
Speaker 5: All right?
Speaker 3: Well, so first I'll say there's a space settlement advocate
Speaker 3: named Robert Zubrin, and I think he and I disagree
Speaker 3: on almost everything, but I think we feel the same
Speaker 3: way about helium three, which is to say, if we
Speaker 3: get fusion reactors going, and you're already living on a
Speaker 3: place like the Moon, then it's great that helium three
Speaker 3: is there and you can extract it and you can
Speaker 3: use it there, But is it going to be economically
Speaker 3: viable to collect it on the Moon and bring it.
Speaker 2: Back to Earth. All Right, this is going to be tough.
Speaker 3: So all right, first of all, the equipment that you
Speaker 3: would need to launch is going to be incredibly heavy,
Speaker 3: so it's going to be really expensive to get it there.
Speaker 1: This is equipment to like take regolith and extract the
Speaker 1: helium three out of it, which you're saying is not trivial.
Speaker 1: You're not just like finding cannisters of helium three in
Speaker 1: the moon.
Speaker 3: Yeah, there's not like helium three ingots that you can
Speaker 3: like go and collect and it's in the regolith, but
Speaker 3: it's not There's more of it than you find in
Speaker 3: like typical dirt here on Earth, but there's not loads
Speaker 3: of it. So you're still going to need to like
Speaker 3: sort through like football fields worth of this stuff in
Speaker 3: order to get like small quantities. And we've talked about
Speaker 3: that regolith. It's super abrasive. It's going to beat up
Speaker 3: your equipment that was probably expensive to send there already.
Speaker 3: It's in this harsh environment, the vacuum of space. If
Speaker 3: you're at the equator, there are these massive temperature swings
Speaker 3: that are like really hard to even make lubricants for,
Speaker 3: so that your equipment can run. So this is going
Speaker 3: to be a very difficult environment to work in. It's
Speaker 3: going to be very far away. It's hard for me
Speaker 3: to imagine that this could possibly be economically viable in
Speaker 3: many decades to come. So I'm not convinced by people
Speaker 3: who are like, oh, let's go out there and collect
Speaker 3: helium three for nuclear reactors that don't even exist yet,
Speaker 3: and that's going to make the moon profitable.
Speaker 2: Anyway.
Speaker 3: I could go on, but I'm spitting on the screen
Speaker 3: already and all stop there.
Speaker 2: It's gonna be difficult.
Speaker 1: Yeah, which is a bummer. It feels like all these
Speaker 1: potential sources of fusion I'm like right around the corner,
Speaker 1: just at our fingertips. But then there's always some frustrating
Speaker 1: technicolity between us and it. The fact that the helium
Speaker 1: three is there and on the moon, and just like
Speaker 1: if we could somehow get it here, it would be
Speaker 1: so great. But that process of getting it here can
Speaker 1: just like instantly rearrange the universe the way you want
Speaker 1: it to be, right. Unfortunately, that takes energy, it takes time,
Speaker 1: and it takes money. And these are all the realistic
Speaker 1: obstacles to getting fusion to work.
Speaker 3: All right, so say tomorrow commonwealth fusion is like bam,
Speaker 3: we hit break even and now we're gonna fly past it.
Speaker 3: Do you feel like there could be a way that
Speaker 3: we could have fusion powering every home on the planet,
Speaker 3: or these problems, just like insurmountable fusion at its best
Speaker 3: could only service a small portion of humanity.
Speaker 1: I think the answer is we don't know yet. There
Speaker 1: are important technical challenges between us and everybody has a
Speaker 1: fusion reactor at home or even this like a neighborhood
Speaker 1: fusion reactor or whatever. Can we make enough tritium scaling up?
Speaker 1: Can we find enough lithium six? Probably? I think the
Speaker 1: answer is probably. But these are hard problems and they
Speaker 1: haven't really been dug into, which means there are hard
Speaker 1: problems we haven't discovered yet. You know, when you really
Speaker 1: get into the nitty gritty, you're like, oh, wow, actually
Speaker 1: we thought this was going to be dot dot We're there.
Speaker 1: Turns out there's a really tricky bit here that nobody's solved,
Speaker 1: and you've got to struggle with it for ten years,
Speaker 1: which is why fusion has taken so long. You know,
Speaker 1: people have like skimmed over the surface of the concepts
Speaker 1: been like, oh, we understand the physics, it happens in
Speaker 1: the stars. I'm sure we'll figure it out. Well, figuring
Speaker 1: it out has taken decades, and this just means that
Speaker 1: there are decades more than even reasonable moderates about fusion
Speaker 1: tell us, because there are so many more pieces to
Speaker 1: this chain for actually integrating it into our society.
Speaker 3: But to sort of throw everybody for a loop here,
Speaker 3: I'm going to be a bit of an optimist because, like,
Speaker 3: I know, I know, hold on, even are you well, no,
Speaker 3: it's you know, it's qualified.
Speaker 2: It's qualified.
Speaker 3: So I feel like, you know, if we figure the
Speaker 3: fusion thing out and it becomes clear that this could be,
Speaker 3: you know, not only a way to provide clean power
Speaker 3: to a bunch of people, but also a source of revenue,
Speaker 3: I imagine that you're gonna get like a bunch of
Speaker 3: startups and a bunch of like, you know, smart people
Speaker 3: working on this problem. And that doesn't solve all the problems,
Speaker 3: but I bet that once we get to that point,
Speaker 3: we're gonna unleash a lot of excitement and like maybe
Speaker 3: a lot of innovation, and maybe we'll be surprised at
Speaker 3: how fast this problem gets solved.
Speaker 1: I can hope that'd be wonderful, and I agree with you.
Speaker 1: I think we probably will figure it out. You know,
Speaker 1: we're smart, people work hard. There are brilliant creative people
Speaker 1: out there, young minds listening to this podcast inspired to
Speaker 1: go into fusion thinking I can solve this treating problem.
Speaker 1: Go do it. I think it probably is solvable, but
Speaker 1: it does need to be solved. And so it's not
Speaker 1: just like once we've cracked the physics case in step four,
Speaker 1: all the other steps just fall by the wayside. Still
Speaker 1: got to crack them. But for some people that's their jam,
Speaker 1: you know, like Ooh, I'm excited about working on lithium blankets.
Speaker 1: I've dreamed about it since I was a kid, or
Speaker 1: you know, these puzzles are exciting to people, which is great,
Speaker 1: and I love that about science that people who are
Speaker 1: going to nerd out on how to get these fuels
Speaker 1: or how to extract them, or how to manufacture them,
Speaker 1: or how to negotiate with the battery industry and make
Speaker 1: sure that our lithium six gets filtered out of the
Speaker 1: mining process and they can have the rest of it.
Speaker 1: You know. So yeah, I think probably we will solve it.
Speaker 1: I agree with you that once we make the fusion
Speaker 1: step work the physics part of it, we figure that out,
Speaker 1: the rest will There'll be so much excitement and so
Speaker 1: much pressure and momentum that we will figure it out.
Speaker 3: I mean, I imagine being the person who figures out
Speaker 3: the lithium six problem, like the implications of your life
Speaker 3: for life on this planet, Like that would just be
Speaker 3: incredible to feel like you had contributed to something so important.
Speaker 1: Yeah, it would be incredible.
Speaker 2: But I study bugs.
Speaker 1: I can't imagine it would be like to work on
Speaker 1: someone that's actually practically useful both for people day to day.
Speaker 1: And you know, I have this experience all the time
Speaker 1: because I meet people with my wife and we talk
Speaker 1: about what we do and they're like, oh, yeah, that's interesting.
Speaker 1: But then there have a million questions for Katrina, who
Speaker 1: works only you know, like the human health and the
Speaker 1: gut and what people eat, and she's like immediate knowledge
Speaker 1: that's relevant for people's day to day lives and like, hey,
Speaker 1: you're a nerd about either way the universe works. We
Speaker 1: can talk, But if you want advice about chia seeds
Speaker 1: and how to have you know, healthy bowel movements, talk
Speaker 1: to Katrina.
Speaker 2: Oh man, when do I get to meet Katrina?
Speaker 1: Yeah? Exactly. You see what I mean. She's more more
Speaker 1: interesting than it's like. It's fine. I've come to terms
Speaker 1: with it. No, I mean. One of reason I'm but
Speaker 1: into particle physics is because it had no immediate applications.
Speaker 1: My parents work at the laboratory in Los Alamos, the
Speaker 1: work on weapons programs. That's terrifying. I don't want my
Speaker 1: research to be used to build weapons of mass destruction
Speaker 1: that are pointed at civilian populations. But it also means
Speaker 1: that I can't really help anybody day to day except
Speaker 1: for stimulating their curiosity of.
Speaker 2: The universe, which you do so well.
Speaker 3: And we'll be back next time with more stimulating information
Speaker 3: about the universe.
Speaker 1: Thanks everyone for taking this ride with us. And I'm
Speaker 1: still in the end an optimist about fusion.
Speaker 2: Me too. Go fusion people, figure it out please.
Speaker 3: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio.
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