Why weren't we pushing towards economic fusion
and new materials and new methods of heat extraction
and so forth?
Because everybody knew fusion was 40 years away.
And now it's four years away.
The following is a conversation with Dennis White,
nuclear physicist at MIT and the director
of the MIT Plasma Science and Fusion Center.
This is the Lex Friedman podcast.
To support it, please check out our sponsors
in the description.
And now, dear friends, here's Dennis White.
Let's start with a big question.
What is nuclear fusion?
It's the underlying process that powers the universe.
So as the name implies, it fuses together
or brings together two different elements,
technically nuclei, that come together.
And if you can push them together close enough
that you can trigger essentially a reaction,
what happens is that the element typically changes.
So this means that you change from one element
to another, the chemical element to another.
Underlying what this means is that you change
the nuclear structure, this rearrangement
through equals MC squared releases large amounts of energy.
So fusion is the fusing together of lighter elements
and to heavier elements.
And when you go through it, you say, oh, look,
so here were the initial elements, typically hydrogen.
And they had a particular mass, rest mass,
which means just the mass with no kinetic energy.
And when you look at the product afterwards,
it has less rest mass.
And so you go, well, how is that possible?
Because you have to keep mass,
but mass and energy are the same thing,
which is what equals MC squared means.
And the conversion of this comes into kinetic energy,
namely energy that you can use in some way.
And that's what happens in the center of stars.
So fusion is literally the reason life is viable
in the universe.
So fusion is happening in our sun.
And what are the elements?
The elements are hydrogen that are coming together.
It goes through a process,
which is probably gets a little bit too detailed,
but it's a somewhat complex catalyzed process
that happens in the center of stars.
But in the end, stars are big balls of hydrogen,
which is the lightest, that's the simplest element,
the lightest element, the most abundant element,
most of the universe is hydrogen.
And it's essentially a sequence
through which these processes occur
that you end up with helium.
So those are the primary things.
And the reason for this is because helium has features
as a nucleus, like the interior part of the atom,
that is extremely stable.
And the reason for this is helium has two protons
and two neutrons.
These are the things that make up nuclei,
that make up all of us, along with electrons.
And because it has two pairs, it's extremely stable.
And for this reason, when you convert the hydrogen
into helium, it just wants to stay helium
and it wants to release kinetic energy.
So stars are basically conversion engines
of hydrogen into helium.
And this also tells you why you love fusion.
I mean, because our sun will last 10 billion years
approximately, that's along the fuel will last.
But to do that kind of conversion,
you have to have extremely high temperatures.
It is one of the criteria for doing this,
but it's the easiest one to understand.
And why is this?
It's because effectively what this requires
is that these hydrogen ions,
or which is really the bare nucleus,
so they have a positive charge,
everything has a positive charge of those ones,
is that to get them to trigger this reaction,
they must approach within distances
which are like the size of the nucleus itself.
Because the nature, in fact, what it's really using
is something called the strong nuclear force.
There's four fundamental forces in the universe.
This is the strongest one,
but it has a strange property is that it,
while it's the strongest force by far,
it only has impact over distances
which are the size of a nucleus.
So to get, let's put that into, what does that mean?
It's a millionth of a billionth of a meter, okay?
Incredibly small distances.
But because the distances are small
and the particles have charge,
they want to push strongly apart.
Namely, they have repulsion
that wants to push them apart.
So it turns, when you go through the math of this,
the average velocity or energy of the particles
must be very high to have any significant probability
of the reactions happening.
And so the center of our sun
is at about 20 million degrees Celsius.
And on earth, this means it's one of the first things
we teach, you know, entering graduate students,
you can do a quick,
you can do a quick basically power balance
and you can determine that on earth
that it requires a minimum temperature
of about 50 million degrees Celsius on earth.
To perform fusion.
To get enough fusion that you would be able
to get energy gain out of it.
So you can trigger fusion reactions at lower energy,
but they become almost vanishingly small
at lower temperatures than that.
First of all, let me just link around some crazy ideas.
So one, the strong force,
just stepping out and looking at all the physics,
is it weird to you that there's these forces
and they're very particular?
Like it operates at a very small distance
and then gravity operates at a very large distance
and they're all very specific in the standard model,
describes three of those forces extremely well.
And there's-
And this is one of them.
Yeah, this is one of them.
And it's just all kind of works out.
There's a big part of you that's, you know, an engineer.
Did you step back and almost look at the philosophy of physics?
So it's interesting because as a scientist,
I see the universe through that lens of essentially
the interesting things that we do are through the forces
that get used around those.
And everything works because of that.
Richard Feynman had, I don't know if you ever read Richard Feynman.
It's a little bit of a tangent, but-
He's never been on the podcast.
He's never been on the podcast.
He was unfortunately passed away,
but one of like a hero to almost all physicists.
And part of it was because of what you said.
He kind of looked through a different lens at these,
what typically look like very dry,
like equations and relationships.
And he kind of, I think he brought out the wonder of it
in some sense, right?
For those, he posited what would be,
if you could write down a single,
not even really a sentence, but a single concept
that was the most important thing scientifically
that we knew about, that in other words,
you had only one thing that you could transmit
like a future or past generation.
It was very interesting.
It was, so it's not what you think.
It wasn't like, oh, strong nuclear force
or fusion or something like this.
And it's very profound, which was,
he was that the reason that matter operates
the way that it does is because all matter
is made up of individual particles
that interact each other through forces.
That was it.
So just that atomic theory, basically.
Yeah.
Which is like, wow, that's like so simple,
but it's not so simple.
It's because like, who thinks about atoms
that they're made out of?
Like, there's a good question I give to my students.
How many atoms are in your body?
Like almost no students can answer this.
But to me, that's like a fundamental thing.
By the way, it's about 10 to the 28.
10 to the 28.
So that's, you know, trillion, you know,
million trillion trillion or something like that.
Yes, yeah.
So one thing is to think about the number
and the other is to start to really ponder the fact.
That it all holds together.
Yeah, it all holds together and you're actually that.
You're more that than you are anything else.
Yes, exactly, yeah.
No, I mean, there are people who do study
such things of the fact that if you look at the,
for example, the ratios between those fundamental forces,
people have figured out, oh, if this ratio was different
by some factor, like a factor of two or something,
I was like, oh, this would all like not work.
And I look, you look at the sun, right?
It's like, so it turns out that there are key reactions
that if they had slightly lower probability,
no star would ever ignite.
And then life wouldn't be possible.
It does seem like the universe set things up for us
that it's possible to do some cool things,
but it's challenging.
So they keeps it fun for us.
Yeah, yeah, that's the way I look at it.
I mean, the, you know, the multiverse model
is an interesting one because there are, you know,
quantum scientists who look at and figure,
I was like, oh, it's like, oh yeah.
Like quantum science perhaps tells us
that there are almost an infinite, you know,
variety of other universes.
But the way that it works probably is,
it's almost like a form of natural selection.
It's like, well, the universes that didn't have
the correct or interesting relationships
between these forces, nothing happens in them.
So almost by definition,
the fact that we're having this conversation
means that we're in one of the interesting ones by default.
Yeah, one of the somewhat interesting,
but there's probably super interesting ones
where I tend to think of humans as incredible creatures.
Our brain is an incredible computing device,
but I think we're also extremely cognitively limited.
I can imagine alien civilizations
that are much, much, much, much more intelligent
in ways we can't even comprehend
in terms of their ability to construct models of the world,
to do physics, to do physics and mathematics.
I would see it in a slightly different way.
It's actually, it's because we have creatures
that live with us on the earth that have cognition, right?
That understand and move through their environment.
But they actually see things in a way,
or they sense things in a way
which is so fundamentally different.
It's really hard, it's the problem is the translation,
not necessarily intelligence.
So it's the perception of the world.
So I have a dog, and when I go out and I see my dog,
like smelling things, there's a realization that I have
that he sees or senses the world in a way
that I can never, like I can't understand it
because I can't translate my way to this.
We get little glimpses of this as humans though,
by the way, because there are some parts of it,
for example, optical information, which comes from light,
is that now, because we've developed the technology,
we can actually see things, I've had,
I get this as one of my areas of research is spectroscopy.
So this means the study of light.
And I get this quote unquote,
see things or representations of them from the far infrared
all the way to like hard, hard X-rays,
which is several orders of magnitude of the light intensity,
but our own human eyes,
like see a teeny, teeny little sliver of this.
So that even like bees, for example,
see a different place than we do.
So I don't, I think if you think of,
there's already other intelligences like around us
in a way, in a limited way,
because of the way they can communicate,
but that's like, those are already baffling,
in many ways, yeah.
If we just focus in on the senses,
there's already a lot of diversity,
but there's probably things we're not even
considering as possibilities.
For example, whatever the head consciousness is,
could actually be a door into understanding
some physical phenomena we're not,
haven't even begun understanding.
So just like you said, spectroscopy,
that could be a similar kind of spectrum for consciousness,
that we're just like, we're like these dumb,
descendants of apes like walking around,
it sure feels like something to experience the color red,
but like we don't have,
it's the same as in the ancient times,
you experienced physics, you experienced light.
It's like, oh, it's bright and you know.
Yeah, yeah.
And you could start kind of semi-religious explanations.
We might actually experience this faster than we thought,
because we might be building another kind of intelligence.
Yeah, and that intelligence will explain to us
how silly we are.
There was an email thread going around the professors
in my department already of,
so what is it going to look like to figure out
if students have actually written their term papers,
or it's chat, the chat GPT, it was,
so as usual, where we tend to be empiricists in my field,
so of course they were in there like trying to figure out
if it could answer like questions for a qualifying exam
to get into the PhD program at MIT,
which they didn't do that well at that point,
but of course this is just the beginning of it,
so we have some interesting ones to go for.
Eventually both the students and the professors
will be replaced by chat GPT, and we'll sit on the beach.
I really recommend, I don't know if you've ever seen them,
it's called The Day the Universe Changed.
Is that a movie?
This is James Burke.
He's a science historian based in the UK.
He had a fairly famous series on public television
called Connections, I think it was,
but the one that I really enjoyed
was The Day the Universe Changed,
and the reason for the title of it was that,
he says the universe is what we know and perceive of it,
so when there's a fundamental insight
as to something new, the universe for us changes.
Of course the universe from an objective point of view
is the same as it was before, but for us it has changed.
So he walks through these moments of perception
in the history of humanity that changed what we were, right?
And so as I was thinking about coming to discuss this,
people see fusion, oh, it's still far away,
or we've been, it's been slow progress.
It's like when my godmother was born,
like people had no idea how stars worked.
So you talk about that day, that insight,
the universe change is like, oh, this is the,
I mean, and they still didn't understand
all the parts of it, but they basically got it.
It was like, oh, because of the understanding
of these processes, it's like we unveiled the reason
that there can be life in the universe.
That's probably one of those days
the universe changed, right?
And that was in the 1930s, yeah.
It seems like technology is developing
faster and faster and faster.
I tend to think just like with Chad GPT,
I think this year it might be extremely interesting,
just with how rapid and how profitable
the efforts in artificial intelligence are,
that just stuff will happen
where our whole world is transformed like this,
and there's a shock, and then next day
you kind of go on and you adjust immediately.
You probably won't have a similar kind of thing
with nuclear fusion, with energy,
because there's probably going to be
an opening ceremony and stuff like this.
An announcement that take months,
but with digital technology,
you can just have a immediate transformation of society,
and then it'll be this gasp,
and then you kind of adjust like we always do,
and then you don't even remember,
just like with the internet and so on,
how the days work before.
And how it worked before, right?
I mean, fusion will be, because it's energy,
it's nature is that it will be,
and anything that has to do with energy use
tends to be a slower transition,
but they're the most, I would argue,
some of the most profound transitions that we make.
I mean, the reason that we can live like this
and sit in this building and have this podcast
and people around the world is, at its heart,
is energy use, and it's intense energy use
that came from the evolution of starting to use
intense energies at the beginning
of the Industrial Revolution up to now.
It's like, it's a bedrock, actually, of all of these,
but it doesn't tend to come overnight.
Yeah.
And some of the most important,
some of the most amazing technologies,
one we don't notice, because we take it for granted,
is it enables this whole thing.
Yeah, exactly.
Which is energy, which is amazing
for how fundamental it is to our society
and way of life is a very poorly understood concept,
actually, just even energy itself.
People confuse energy sources with energy storage,
with energy transmission.
These are different physical phenomena,
which are very important.
So for example, you buy an electric car and you go,
oh, good, I have an emission-free car.
And, ah, but it's like, so why do you say that?
Well, it's because if I draw the circle around the car,
I have electricity and it doesn't emit anything.
Okay, but you plug that into a grid
where you follow that wire back,
there could be a coal power plant
or a gas power plant at the end of that.
Oh, really?
I mean, so this isn't like carbon-free?
Oh, and it's not their fault, it's just, you know,
they don't, like the car isn't a source of energy.
The underlying source of energy
was the combustion of the fuel back somewhere.
Plus there's also a story of how the raw materials are mined
in which parts of the world with sort of basic respect
or deep disrespect of human rights
that happens in that money.
So the whole supply chain, there's a story there
that's deeper than just a particular electric car
with a circle around it.
And the physics or the science of it too
is the energy use that it takes to do that digging up,
which is also important and all that.
Yeah, anyway, so we wandered away from fusion,
but yes.
Oh, it's a beautiful straw.
But it's very important actually
in the context of this, just because, you know,
those of us who work in fusion
and these other kinds of sort of disruptive energy technologies,
it's interesting that I do think about like,
what would it, what is it going to mean to society
to have an energy source that is like this,
that would be like fusion, you know,
which has such completely different characteristics.
For example, you know, free unlimited access to the fuel,
but it has technology implications.
So what does this mean geopolitically?
What does it mean for how we,
how we distribute wealth within our society?
It's very difficult to know, but probably profound.
Yeah.
We're going to have to find another reason
to start wars instead of resources.
We're going to have to figure something out.
We've done a pretty good job of that
over the course of our history.
So we talked about the forces of physics
and again, sticking to the philosophical
before we get to the specific technical stuff.
E equals MC squared, you mentioned.
How amazing is that to you that energy and mass are the same?
And what does that have to do with nuclear fusion?
So it has to do with everything we do.
It's the fact that energy and mass
are equivalent to each other.
They're just, the way we usually comment to it
is that they're just energy just in different forms.
Can you intuitively understand that?
Yes.
But it takes a long time.
I haven't for a while, but usually,
often I teach the introductory class
for incoming nuclear engineers.
And so we put this up as an equation
and we go through many iterations of using this,
to how you derive it, how you use it and so forth.
And then usually in the final exam,
I would basically take all the equations
that I've used before and I flip it around.
I basically, instead of thinking about energy is equal to mass,
it's sort of mass is equal to energy.
And I ask the question in a different way
and usually about half the students don't get it.
It takes a while to get that intuition.
Yeah.
So in the end, it's interesting is that this is actually
the source of all free energy because that energy
that we're talking about is kinetic energy
if it can be transformed from mass.
So it turns out even though we used equals MC squared,
this is burning coal and burning gas
and burning wood is actually still equals MC squared.
The problem is that you would never know this
because the relative change in the mass is incredibly small.
By the way, which comes back to fusion
which is that equals MC squared.
Okay, so what does this mean?
It tells you that the amount of energy
that is liberated in a particular reaction
when you change mass has to, because C squared
is that's the speed of light squared.
It's a large number.
It's a very large number
and it's totally constant everywhere in the universe
which is another weird thing.
Which is another weird thing and in all rest frames
and actually the relativity stuff gets more difficult
conceptually until you get through.
Anyway, so you go to that and what that tells you
is that it's the relative change in the mass.
We'll tell you about the relative amount of energy
that's liberated.
And this is what makes fusion
and you asked about fusion as well too.
This is what makes them extraordinary.
It's because the relative change in the mass is very large
as compared to what you get like in a chemical reaction.
In fact, it's about 10 million times larger.
And that is at the heart of why you use something like fusion.
It's because that is a fundamental of nature.
Like you can't beat that.
So whatever you do, if you're thinking about
and why do I care about this?
Well, because mass is like the fuel, right?
So this means gathering the resources
that it takes to gather fuel, to hold it together,
to deal with it, the environmental impact it would have.
And fusion will always have 20 million times
the amount of energy release per reaction
that you get of those.
So this is why we consider it the ultimate
like environmentally friendly energy source
is because of that.
So is it correct to think of mass broadly
as a kind of storage of energy?
Yes.
You mentioned it's environmentally friendly.
So nuclear fusion is a source of energy.
It's cheap, clean, safe.
So easy access to fuel and virtual limited supply,
no production of greenhouse gases,
little radioactive waste produced allegedly.
Can you sort of elaborate why it's cheap, clean and safe?
I'll start with the easiest one, cheap.
It is not cheap yet
because it hasn't been made at a commercial scale.
Ryan flies when you're having fun.
Yes.
Yeah, yeah.
But yes, not yet.
We'll talk about it.
Actually, we'll come back to that
because this is cheaper
or a more technically correct term
that it's economically interesting
is really the primary challenge actually,
a fusion at this point.
But I think we can get back to that.
So what were the other ones you said?
So actually, when we're talking about cheap,
we're thinking like asymptotically,
like if you take it forward several hundred years,
that's sort of because of how much availability
there is of resources to use.
Of the fuel.
You have the fuel.
We should separate those two.
The fuel is already cheap.
It's basically free, right?
What do you mean by basically free?
So if we were to be using fusion fuel sources
to power your, and it's like,
that's all we had with fusion power plants around.
And we were doing it,
the fuel costs per person
are something like 10 cents a year.
It's free, okay.
This is why it's hard to,
in some ways I think it's hard to understand fusion
because people see this and go,
oh, if the fuel is free,
this means the energy source is free
because we're used to energy sources like this.
So we spend resources and drill to get gas or oil
or we chop wood or we make coal.
We find coal or these things, right?
So fusion, this is what makes fusion.
And it's also, it's not an intermittent
renewable energy source like wind and solar.
So it's like, but this makes it hard to understand.
So as you're saying, the fuel is free.
Why isn't the, like why isn't the energy source free?
And it's because of the necessary technologies
which must be applied to basically recreate the conditions
which are in stars, in the center of stars, in fact.
So there's only one natural place in the universe
that fusion energy occurs.
That's in the center of stars.
So that's going to bring a price to it
depending on the cost and, sorry,
the size and complexity of the technology
that's needed to recreate those things.
And we'll talk about the details of the technologies
and which parts might be expensive today
and which parts might be expensive in two or three years.
Exactly.
It will have a revolution, I'm certain of it.
So about clean, so clean is, at its heart,
what it does is convert, it basically converts hydrogen
into, it's heavier forms of hydrogen,
the most predominant one that we use on Earth,
and converts it into helium and some other products
but primarily helium is the product that's left behind.
So helium, safe, inert, gas, you know.
In fact, that's actually what our sun is doing
is eventually going to extinguish itself
because it'll just make so much helium
that it doesn't do that.
So in that sense, clean because there's no emissions
of carbon or pollutants that come directly
from the combustion of the fuel itself.
And safe.
Safe, yeah.
We're talking about very high temperatures.
Yeah, so this is also the counterintuitive thing.
So I told you temperatures which are like 50 million degrees
or it actually tends to be more like about 100 million degrees
is really what we aim for.
So how can 100 million degrees be safe?
And it's safe because it is,
this is so much hotter than anything on Earth
where everything on Earth is at around 300 Kelvin,
you know, it's around a few tens of degrees Celsius.
And what this means is that in order to get a medium
to those temperatures, you have to completely isolate it
from anything to do with terrestrial environment.
It can have no contact like with anything on Earth basically.
So this means, this is the technology
that I just described, is that it fundamentally,
what it does is it takes this fuel
and it isolates it from any terrestrial conditions
so that it has no idea it's on Earth.
It's not touching any object that's at room temperature.
Including the walls of the containment.
Even the concluding the walls of the containment building
or containment device or even air or anything like this.
So it's that part that makes it safe
and there's actually another aspect to it.
But that fundamental part makes it so safe.
And the main line approach to fusion
is also that it's very hot,
but there's very, very few particles at any time
in the thing that would be the power plant.
The actually the more correct way to do it is you say,
there's very few particles per unit volume.
So in a cubic centimeter and cubic meter or something like that.
So we can do this.
Right now we're, although we don't think of air really as a,
there's atoms floating around us and there's a density
because if I wave my hand,
I can feel the air pushing against my face.
That means we're in a fluid or a gas, which is around us.
That has a particular number of atoms per cubic meter, right?
So it's what this actually turns out to be 10 to the 25th.
So this is one with 25 zeros behind it, per cubic meter.
So we can figure out like cubic meters about like this.
The volume of this table, like the whole volume mistake.
Okay, very good.
So like fusion, there's a few of those.
So fusion, like the mainstream one of fusion,
like what we're working on at MIT,
will have a hundred thousand times less particles
per unit volume than that.
So this is very interesting because it's extraordinarily hot,
a hundred million degrees, but it's very tenuous.
And what matters from the engineering and safety point of view
is the amount of energy which is stored per unit volume.
Because this tells you about the scenarios,
and that's what you worry about,
because when those kinds of energies are released suddenly,
it's like what would be the consequences, right?
So the consequences of this are essentially zero
because that's less energy content than boiling water.
Because of the low density.
Because of the low density.
So if you take water is at about a hundred million
to a billion times more dense than this.
So even though it's at much lower temperature,
it's actually still, it has more energy content.
So for this reason, one of the ways that I explain this
is that if you imagine a power plant
that's like powering Cambridge, Massachusetts,
like if you were to, which you wouldn't do this directly,
but if you went like this on it,
it actually extinguishes the fusion.
Because it gets too cold immediately.
Yeah, so that's the other one.
And the other part is that it does not,
because it works by staying hot rather than a chain reaction,
it can't run out of control.
That's the other part of it.
So by the way, this is what very much distinguishes it
from fission.
It's not a process that can run away from you
because it's basically thermally stable.
What is thermally stable in me?
That means is that you want to run it
at the optimization in temperature
such that if it deviates away from that temperature,
the reactivity gets lower.
And the reason for this is because it's hard
to keep the reactivity going.
Like it's a very hard fire to keep going, basically.
Also, it doesn't run away from you.
It can't run away from you.
How difficult is the control there to keep it at that?
It varies from concept to concept,
but in generally, it's fairly easy to do that.
And the easiest thing,
it can't physically run away from you
because the other part of it is that there's just
at any given time, there's a very, very small amount
of fuel available to fuse at any way.
So this means that that's always intrinsically limited
to this.
So even if the power consumption of the device
goes up, it just kind of burns itself out immediately.
So you are just to take another tangent on a tangent.
You're the director of MIT's Plasma Science and Fusion Center.
That's right.
We'll talk about, maybe you can mention
some interesting aspects of the history of the center
in the broader history of MIT and maybe broader history
of science and engineering in the history of human civilization.
But also just the link on the safety aspect.
How do you prevent some of the amazing reactors
that you're designing?
How do you prevent from destroying all of human civilization
in the process?
What's the safety protocols?
Fusion is interesting because it's not really
directly weaponizable because what I mean by that
is that you have to work very hard to make these conditions
at which you can get energy gain from fusion.
And this means that when we design these devices
with respect to application in the energy field,
is that they, you know, while they will,
because they're producing large amounts of power
and they will have hot things inside of them,
this means that they have like a level of industrial hazard,
which is very similar to what you would have
like in a chemical processing plant or anything like that.
And any kind of energy plant actually has these as well too.
But the underlying underneath at core technology
like can't be directly used in an nefarious way
because of the power that's being emitted.
It just basically, well, if you try to do those things,
typically it just stops working.
So the safety concerns have to do with just regular things
that like equipment, malfunctioning, melting of equipment,
like all this kind of stuff that has nothing to do with fusion.
I mean, usually what we worry about is the viability
because in the end we build pretty complex objects
to realize these requirements.
And so what we try really hard to do
is like not damage those components,
but those are things which are internal to the fusion device
and this is not something that you would consider about
like it would, as you say, destroy human civilization
because that release of energy is just inherently limited
because of the fusion process.
So it doesn't say that there's zero,
so you asked about the other feature that it's safe.
So it is, the process itself is intrinsically safe,
but because it's a complex technology,
you still have to take into consideration aspects of the safety.
So it produces ionizing radiation,
instantaneously, so you have to take care of this,
which means that you shield it.
You think of like your dental x-rays
or treatments for cancer and things like this.
We always shield ourselves from this.
So we get the beneficial effects,
but we minimize the harmful effects of those.
So there are all those aspects of it as well too.
So we'll return to MIT's Plasma Science a few minutes later,
but let us linger on the destruction of human civilization,
which brings us to the topic of nuclear fission.
What is that?
So the process that is inside nuclear weapons
and current nuclear power plants.
So it relies on the same underlying physical principle,
but it's exactly the opposite,
which actually the names imply.
Fusion means bringing things together,
fission means splitting things apart.
So fission requires the heaviest instead of the lightest
and the most unstable versus the most stable elements.
So this tends to be uranium or plutonium,
primarily uranium, so take uranium.
So uranium 235 is one of the heaviest,
heaviest, unstable elements.
And what happens is that this is,
fission is triggered by the fact
that one of these subatomic particles, the neutron,
which has no electric charge,
basically gets in proximity enough to this
and triggers an instability effectively inside of this.
What is teedering on the border of instability
and basically splits it apart.
And that's the fission, right, the fissioning.
And so when that happens,
because the products that are roughly splits in two,
but it's not even that, it's actually more complicated,
splits into this whole array of lighter elements and nuclei.
And when that happens, there's less rest mass left
than the original one.
So it's actually the same, so it's again,
it's rearrangement of the strong nuclear force
that's happening, but that's the source of the energy.
And so in the end, it's like,
so this is a famous graph that we show everybody is basically,
it turns out every element that exists in the periodic table,
all the things that make up everything,
have a, remember you asked a good question,
it was like, so should we think of mass
as being the same as stored energy?
Yes.
So you can make a plot that basically shows
the relative amount of stored energy
and all of the elements that are stable
and make up basically the world, okay, in the universe.
And it turns out that this one has
a maximum amount of stability or storage at iron.
So it's kind of in the middle of the periodic table
because this goes from, you know, it's roughly that.
And so this, what that means is that if you take something
heavier than iron, like uranium,
which is more than twice as heavy than that,
and you split apart, if you somehow just magically,
you just split apart its constituents
and you get something that's lighter,
that will, because it moves to a more stable energy state,
it releases kinetic energy, that's the energy that we use.
Kinetic energy meaning the movement of things.
So it's actually an energy you can do something with.
And fusion sits on the other side of that
because it's also moving towards iron,
but it has to do it through fusion together.
So this leads to some pretty profound differences.
As I said, they have some underlying physics or science
proximity to each other, but they're literally the opposite.
So fusion, why is this, it actually goes in the practical implications of it,
which is that fission can happen at room temperature.
It's because there's this neutron has no electric charge
and therefore it's literally room temperature neutrons
that actually trigger the reaction.
So this means in order to establish what's going on with it,
and it works by chain reaction,
is that you can do this at room temperature.
So Enrico Fermi did this like on a university campus,
University of Chicago campus,
the first sustained chain reaction was done underneath a squash court
with a big blocks of graphite.
It was still, wait, don't get me wrong,
an incredible human achievement, right?
And then you think about fusion,
I have to build a contraption of some kind
that's going to get to 100 million degrees.
Okay, wow, that's a big difference.
The other one is about the chain reaction,
that namely fission works by the fact that when that fission occurs,
it actually produces free neutrons.
Free neutrons, particularly if they get slowed down to room temperature,
trigger, can trigger other fission reactions
if there's other uranium nearby or fissile materials.
So this means that the way that it releases energy
is that you set this up in a very careful way
such that every, on average,
every reaction that happens exactly releases enough neutrons
and slows down that they actually make another reaction,
exactly one.
And that means is that because each reaction releases
a fixed amount of energy, you do this and then in time,
this looks like just a constant power output.
So that's how our fission power plan works.
And so there's control of the chain reactions
is extremely difficult and extremely important for...
It's very important.
And when you intentionally design it,
that it creates more than one fission reaction
per starting reaction that it exponentiates away.
Which is what a nuclear weapon is.
Yeah, so how does an atomic weapon work?
How does a hydrogen bomb work, asking for a friend?
Yeah.
Yeah, so at what you do is you very quickly put together
enough of these materials that can undergo fission
with room temperature neutrons.
And you put them together fast enough that what happens
is that this process can essentially grow mathematically,
like very fast.
And so this releases large amounts of energy.
So that's the underlying reason that it works.
So you've heard of a fusion weapon.
So this is interesting is that it is...
But it's dislike fusion energy in the sense that what happens
is that you're using fusion reactions to...
But it's simply...
It increases the gain actually of the weapon rather than...
It's not a pure...
At its heart, it's still a fission weapon.
You're just using fusion reactions as a sort of intermediate catalyst
specifically to get even more energy out of it.
But it's not directly applicable to be used in energy source.
Does it terrify you just again to step back at the philosophical
that humans have been able to use physics and engineering
to create such powerful weapons?
I wouldn't say terrify.
I mean, we should be...
This is the progress of human...
Every time that we've gotten access...
The day the universe changed.
It was really changed when we got access to new kinds of energy sources.
But every time you get access...
And typically what this meant was you get access to more intense energy.
And that's what that was.
And so the ability to move from burning wood to using coal
to using gasoline and petrol.
And then finally to use this is that...
Both the potency and the consequences are elevated around those things.
It's just like you said.
The way that nuclear fusion would change the world...
I don't think...
Unless we think really deeply, we'll be able to anticipate some of the things we can create.
There's going to be a lot of amazing stuff.
But then that amazing stuff is going to enable more amazing stuff
and more unfortunately depending on how you see more powerful weapons.
Well, see, that's the thing.
Fusion breaks that trend in the following way.
So one of them...
So fusion doesn't work on a chain reaction.
There's no chain reaction. Zero.
So this means it cannot physically exponentiate away on you.
Because it works.
And actually this is why star...
By the way, we know this already.
It's why stars are so stable.
Why most stars and suns are so stable.
It's because they are regulated through their own temperature and their heating.
Because what's happening is not that there's some probability of this exponentiating away,
is that the energy that's being released by fusion basically is keeping the fire hot.
And these tend to be...
And when it comes down to thermodynamics and things like this,
there's a reason, for example, it's pretty easy to keep a constant temperature like in an oven and things like this.
It's the same thing in fusion.
So this is actually one of the features that I would argue fusion breaks the trend of this,
is that it has more energy intensity than fission on paper.
But it actually does not have the consequences of control and sort of rapid release of the energy.
Because it's actually...
The physical system just doesn't want to do that.
We're going to have to look elsewhere for the weapons with which we fight World War III.
Fair enough.
So what is plasma that you may or may have not mentioned?
You mentioned ions and electrons and so on.
I did not mention plasma.
So what is plasma? What is the role of plasma in nuclear fusion?
So plasma is a phase of matter or state of matter.
So unfortunately our schools don't...
It's like, I'm not sure why this is the case,
but all children learn the three phases of matter, right?
And what does this mean?
So we'll take McWater as an example.
So if it's cold, it's ice.
It's in a solid phase, right?
And then if you heat it up, it's the temperature that typically sets the phase,
although it's not only temperature.
So you heat it up and you go to a liquid.
And obviously it changes its physical properties because you can pour it and so forth, right?
And then if you heat this up enough, it turns into a gas.
And a gas behaves differently because there's a very sudden change in the density.
Actually, that's what's happening.
It changes by about a factor of 10,000 in density from the liquid phase
into when you make it into steam at atmospheric pressure.
All very good.
Except the problem is they forgot what happens if you just keep elevating the temperature.
You don't want to give kids ideas.
They're going to start experimenting and they're going to start heating up the gas.
It's good to start doing it anyway.
So it turns out that once you get above it's approximately 5 or 10,000 degrees Celsius,
then you hit a new phase of matter.
And actually that's the phase of matter that is for all,
pretty much all the temperatures that are above that as well too.
And so what does that mean?
So it actually changes phase.
So it's a different state of matter.
And the reason that it becomes a different state of matter is that it's hot enough
that what happens is that the atoms that make up, remember, go back to Feynman, right?
Everything's made up of these individual things, these atoms.
But atoms can actually themselves be, which are made of nuclei,
which contain the positive particles in the neutrons.
And then the electrons, which are very, very light, very much less mass than the nucleus,
and that surround us.
This is what makes up an atom.
So a plasma is what happens when you start pulling away enough of those electrons
that they're free from the ion.
So almost all the atoms that make us up in this water and all that,
the electrons are in tightly bound states and basically they're extremely stable.
Once you're at about 5,000 or 10,000 degrees, you start pulling off the electrons.
And what this means is that now the medium that is there,
its constituent particles have mostly have net charge on them.
So why does that matter?
It's because now this means that the particles can interact through their electric charge.
In some sense, they were when it was in the atom as well too.
But now that they're free particles, this means that they start,
it fundamentally changes the behavior.
It doesn't behave like a gas.
It doesn't behave like a solid or liquid.
It behaves like a plasma.
And so why is this, why is it disappointing that we don't speak about this?
It's because 99% of the universe is in the plasma state.
It's called stars.
And in fact, our own sun at the center of the sun is what clearly a plasma,
but actually the surface of the sun, which is around 5,500 Celsius,
is also a plasma because it's hot enough that is that.
In fact, the things that you see, sometimes you see these pictures from the surface of the sun,
amazing like satellite photographs of like those big arms of things
and of light coming off of the surface of the sun and solar flares.
Those are plasmas.
What are some interesting ways that this force data matters different than gas?
Let's go to how a gas works.
So the reason a gas, and it goes back to Feynman's brilliance
and saying that this is the most important concept,
the reason actually solid, liquid and gas phases work
is because the nature of the interaction between the atoms changes.
And so in a gas, you can think of this as being this room and the things,
although you can't see them, is that the molecules are flying around.
But then with some frequency, they basically bounce into each other.
And when they bounce into each other, they exchange momentum and energy around on this.
And so it turns out that the probability and the distances
and the scattering of those of what they do,
it's those interactions that set the, about how a gas behaves.
So what do you mean by this?
Well, so for example, if I take an imaginary test particle of some kind,
like I spray something into the air that's got a particular color,
in fact, you can do it in liquids as well too,
like how it gradually will disperse away from you.
This is fundamentally set because of the way that those particles are bouncing into each other.
The probabilities of those particles bouncing.
The rate that they go at and the distance that they go at and so forth.
So this was figured out by Einstein and others at the beginning of the Brownian motion,
all these kinds of things.
These were set up at the beginning of the last century
and it was really like this great revelation.
Wow, this is why matter behaves the way that it does.
Like, wow.
So, but it's really like, and also in liquids and in solids,
like what really matters is how you're interacting with your nearest neighbor.
So you think about that one, the gas particles are basically going around
until they actually hit into each other though,
they don't really exchange information.
And it's the same in a liquid, you're kind of beside each other,
but you can kind of move around in a solid,
you're literally like stuck beside your neighbor.
You can't move like a man.
Plasmas are weird in the sense is that it's not like that.
So, and it's because the particles have electric charge,
this means that they can push against each other
without actually being in close proximity to each other.
It's not, that's not an infinitely true statement,
which we go together, it's a little bit more technical,
but basically this means that you can start having action
or exchange of information at a distance.
And that's in fact the definition of a plasma is that it says,
this has a technical name, it's called a Coulomb collision,
it just means that it's dictated by this force,
which is being pushed between the charged particles,
is that the definition of a plasma is a medium
in which the collective behavior is dominated by these collisions at a distance.
So, you can imagine then this starts to give you some strange behaviors,
which I could quickly talk about, like for example,
one of the most counterintuitive ones is as plasmas get more hot,
as they get higher in temperature,
then the collisions happen less frequently.
Like what? That doesn't make any sense.
When particles go faster, you think they would collide more often.
But because the particles are interacting through their electric field,
when they're going faster, they actually spend less time
in the influential field of each other,
and so they talk to each other less in an energy momentum exchange point of view.
Interesting.
Just one of the counterintuitive aspects of plasmas.
Which is probably very relevant for nuclear fusion.
Yes, exactly.
So, if I can try to summarize what a nuclear fusion reactor is supposed to do.
So, you have, what, a couple of elements?
What are usually the elements?
Usually deuterium and tritium, which are the heavy forms of hydrogen.
Hydrogen.
You have those and you start heating it.
And then as you start heating it, I forgot the temperature you said,
but it becomes plasma.
About 100 billion.
No, first it becomes plasma.
Oh, first it becomes plasma.
So, it's a gas and then it turns into a plasma at about 10,000 degrees.
And then so you have a bunch of electrons and ions flying around,
and then you keep heating the thing.
Yeah.
And I guess as you heat the thing, the ions hit each other rarer and rarer.
Yes.
So, oh man, that's not fun.
So, you have to keep heating it such that you have to keep hitting it
until the probability of them colliding becomes reasonably high.
And so, and also on top of that, and sorry to interrupt,
you have to prevent them from hitting the walls of the reactor somehow.
So, you asked about the definitions of the requirements for fusion.
So, the most famous one or some sense the most intuitive one is the temperature.
And the reason for that is that you can make many, many kinds of plasmas
that have zero fusion going on in them.
And the reason for this is that the average,
so you can make a plasma at around 10,000.
In fact, if you come, by the way, you're welcome to come to our laboratory
at the PSFC, I can show you a demonstration of a plasma
that you can see with your eyes and sit at about 10,000 degrees
and you can put your hand up beside it and all this.
And it's like, and nothing, there's zero fusion going on.
So, you have, sorry, what was the temperature of the plasma?
About 10,000 degrees.
You can stick your hand in?
Well, you can't stick your hand into it, but there's a glass tube.
You can basically see this with your bare eye.
Yeah.
And you can put your hand on the glass tube because it's,
what's the color? It's purple?
It's purple, yeah.
It is kind of beautiful.
Yeah, plasmas are actually quite astonishing sometimes in their beauty.
Actually, one of the most amazing forms of plasma is lightning, by the way,
which is instantaneous form of plasma that exists on Earth,
but immediately goes away because everything else around it's at room temperature.
Yeah, so there's different requirements in this.
So making a plasma takes about this,
but at 10,000 degrees, even at a million degrees,
there's almost no probability of the fusion reactions occurring.
And this is because while the charged particles can hit into each other,
if you go back to the very beginning of this, remember I said,
oh, these charged particles have to get to within distances
which are like this size of a nucleus because of the strong nuclear force.
Well, unfortunately, as the particles get closer,
the repulsion that comes from the charge, the Coulomb force,
increases like the inverse distance squared.
So as they get closer, they're pushing harder and harder apart.
So then it gets a little bit more exotic, which maybe you will like though,
that it turns out that people understood this
at the beginning of the age of after Rutherford discovered the nucleus.
It's like, oh, yeah.
It's like, how are we going to, how's this going to work, right?
Because how do you get anything within these distances?
It's like, inquire extraordinary energy.
And it does.
And in fact, when you look at those energies, they're very, very high.
But it turns out quantum physics comes to the rescue
because the particles aren't actually just particles.
They're also waves.
This is the point of quantum, right?
You can treat them both as waves and as particles.
And it turns out if they get in close enough proximity to each other,
then the particle pops through basically this energy barrier
through an effect called quantum tunneling,
which is really just the transposition of the fact that it's a wave
so that it has a finite probability of this.
By the way, you talk about, do you have a hard time conceptualizing this?
This is one of them.
Quantum tunneling is one of them?
Yeah.
This is like throwing a ping-pong ball at a piece of paper.
And then every 100 of them just magically show up on the other side of the paper
without seemingly breaking the paper to use a physical analogy.
And that phenomena as important is critical for the function of nuclear fusion.
Yes.
For all kinds of fusion.
This is the reason why stars can work as well too.
The stars would have to be much, much hotter actually to build them.
In fact, it's not clear that they would actually ignite, in fact, without this effect.
So we get to that.
So this is why there's another requirement.
So you must make a plasma, but you also must get it very hot
in order for the reactions to have a significant probability to actually fuse.
It actually falls effectively almost to zero for lower temperatures as well too.
So there's some nice equation that gets you to 50 million degrees.
Yeah.
Or you said, practically speaking, 100 million.
It's a really simple equation.
It's the ideal gas law, basically, almost.
In the end, you've got a certain number of these fusion particles in the plasma state.
They're in the plasma state.
There's a certain number of particles.
And if the confinement is perfect, if you put in a certain content of energy,
then basically, eventually, they just come up in a temperature
and they go up to high temperature.
This turns out to be, by the way, extraordinarily small amounts of energy.
And you go, what?
It's like I'm getting something to like 100 million degrees.
That's going to take the biggest flame burner that I've ever seen.
No.
And the reason for this is it goes back to the energy content of this.
So yeah, you have to get it to high average energy,
but there's very, very few particles.
There's low density.
How do you get it to be low density in a reactor?
So the way that you do this is primarily, again, this is not exactly true
in all kinds of fusion, but in the primer one that we work on magnetic fusion,
this is all happening in a hard vacuum.
It's like it's happening in outer space.
So basically, you've gotten rid of all the other particles,
except for these specialized particles.
So you add them one at a time.
No, actually, it's even easier than that.
You connect a gas valve and you basically leak gas into it.
In a controlled fashion.
Yeah.
Oh, this is beautiful.
It's a gas cylinder.
How do you get it from hitting the walls?
Yeah.
So now you've touched on the other necessary requirements.
So it turns out it's not just temperature that's required.
You must also confine it.
So what does this mean?
Confine it.
And there's two types of confinement, as you mentioned.
You mentioned the magnetic one.
Magnetic one.
There's the one called inertial as well, too.
But the general principle actually has nothing to do with, in particular,
with what the technology is that you use to confine it.
It's because this goes back to the fact that the requirement in this
is high temperature and thermal content.
So it's like building a fire.
And what this means is that when you release the energy into this
or apply heat to this, if it just instantly leaks out,
it can never get hot, right?
So you're familiar with this.
It's like you've got something that you're trying to apply heat to,
but you're just throwing the heat away very quickly.
This is why we insulate homes, by the way.
Things like this, right?
It's like you don't want the heat that's coming into this room
to just immediately leave because you'll just start consuming
infinite amounts of heat to try to keep it hot.
So in the end, this is one of the requirements.
And it actually has a name.
We call it the energy confinement time.
So this means if you release a certain amount of energy into this fuel,
kind of how long you sit there and you look at your watch,
how long does it take for this energy to leave the system?
So you can imagine that in this room,
that these heaters are putting energy into the air in this room
and you waited for a day,
but all the heat have gone to outside if I open up the windows.
Either that's energy confinement time.
So it's the same concept as that.
So this is an important one.
So all fusion must have confinement.
There's another more esoteric reason for this,
which is that people often confuse temperature and energy.
So what do I mean by that?
So this is literally a temperature,
which means that it is a system in which all the particles,
every particle has high kinetic energy
and is actually in a fully relaxed state,
namely that entropy has been maximized,
and it gets a little bit more technical,
but this means that basically it is a thermal system.
So it's like the air in this room, it's like the water,
it's the water in this.
These all have temperatures,
which means that there's a distribution of those energies
because the particles have collided so much that it's there.
So this is distinguished from having high energy particles,
like what we have in particle accelerators like CERN and so forth.
Those are high kinetic energy,
but it's not a temperature,
it doesn't count as confinement.
So we go through all of those.
You have temperature,
and then the other requirement, not too surprising,
is actually that there has to be enough density of the fuel.
Enough, but not too much.
Enough, but not too much, yes.
And so in the end, the way that there's a fancy name for it,
it's called the Lawson Criterion,
because it was formulated by scientists in the United Kingdom
about 1956 or 1957,
and this was essentially the realization,
oh, this is what it's going to take,
regardless of the confinement method.
These are, this is the basic,
what it is actually, power balance,
it just says, oh, there's a certain amount of heat coming in,
which is coming from the fusion reaction itself,
because the fusion reaction heats the fuel,
versus how fast you would lose it.
And it basically summarizes,
it's summarized by those three parameters,
which is fairly simple.
So temperature,
and then the reason we say 100 million degrees is because
almost always in,
for this kind of fusion, deuterium tritium fusion,
the minimum in the density
and the confinement time product is at about 100 million.
So you almost always design your device around that minimum,
and then you try to get it contained well enough,
and you try to get enough density.
So, you know, so that temperature thing sounds crazy, right?
That's what we've actually achieved in the laboratory,
like our experiment here at MIT when it ran,
its optimum configuration,
it was at 100 million degrees.
But it wasn't actually the product of the density
in the confinement time wasn't sufficient
that we were at a place that we were getting high net energy gain,
but it was making fusion reactions.
So this is the sequence that you go through,
make a plasma, then you get it hot enough,
and when you get it hot enough,
the fusion reactions start happening so rapidly
that it's overcoming the rate
at which it's leaking heat to the outside world,
and at some point it just becomes like a star,
like a sun and our own sun and a star
doesn't have anything plugged into it.
It's just keeping itself hot through its own fusion reactions.
In the end, that's really close to what a fusion power plant would look like.
What does it visually look like?
Does it look like, like you said, like purple plasma?
Yeah, actually, it's invisible to the eye
because it's so hot that it's basically emitting light
in frequencies that we can't detect.
It's literally, it's invisible.
In fact, light goes through it,
visible light goes through it so easy
that if you were to look at it,
what you would see in our own particular configuration,
what we make is in the end is a donut-shaped,
it's a vacuum vessel to keep the air out of it.
And when you turn on the plasma,
it gets so hot that most of it just disappears
in the visible spectrum.
You can't see anything.
And there's very, very cold plasma,
which is between 10 and 100,000 degrees,
which is out in the very periphery of it,
which is kind of, so the very cold plasma
is allowed to interact with the,
kind of has to interact with something eventually
at the boundary of the vacuum vessel.
And this kind of makes a little halo around it
and it glows as beautiful purple light, basically.
And these are, that's the,
that's what we can sense in the human spectrum.
I remember reading on a subreddit called Shower Thoughts,
which people should check out.
It's just fascinating philosophical ideas
that strike you while you're in the shower.
And one of them was, it's lucky that a fire,
when it burns, communicates that it's hot
using visible light.
Otherwise humans would be screwed.
I don't know if there's a deeper found truth to that,
but nevertheless, I did find it on Shower Thoughts subreddit.
Actually, I do have, this goes off in a bit of,
you're right, this is actually, it's interesting,
because as a scientist, you also think
about evolutionary functions and how we got,
like, why do we have the senses that we do?
It's an interesting question, right?
Like, why can bees see in the ultraviolet and we can't?
Then you go, well, it's natural selection.
For some reason, this wasn't really particularly important
to us, right? Why can't we see in the infrared
and other things can?
It's like, hmm.
It's a fascinating question, right?
Obviously, there's some, there's some advantage
that you have there that isn't there,
and even color distinguishing, right?
Of something safe to eat, whatever it would be.
I'll actually go back to this,
because it's something that I tell all of my students
when I'm teaching ionizing radiation
and radiological safety.
Whatever you say, there's a cultural concern
or that when people hear the word radiation,
like, what does this mean?
It literally just means light is what it means, right?
But it's light in different parts of the spectrum, right?
And so it turns out, besides the visible light
that we can see here, we are immersed
in almost the totality of the electromagnetic spectrum.
There is visible light, there's infrared light,
there is microwaves going around,
that's how our cell phone works.
It's way past our detection capability.
But also higher energy ones,
which have to do with ultraviolet light,
how you get a sunburn,
and even x-rays and things like this,
at small levels are continually being,
like from the concrete in the walls of this hotel,
there's x-rays hitting our body continuously.
We can go down to the lab at MIT,
we can bring out a detector and show you.
Every single room will have these.
By our body, you mean the 10 to the 28 atoms?
Yeah, the 10 to the 28 atoms,
and they're coming in and they're interacting with those things.
And those, particularly the ones where the light
is at higher average energy per light particle,
those are the ones that can possibly
have an effect on human health.
So it's interesting, humans and all animals
have evolved on Earth where we're immersed in that all the time.
There's natural source of radiation all the time,
yet we have zero ability to detect it, like zero.
Yeah, and our ability, cognitive ability to filter it all out
and not give a damn.
It would probably overwhelm us, actually, if we could see all of it.
But my main point is it goes back to your thing about fire
and self-protection.
If ionizing radiation was such a critical aspect
of the health of organisms on Earth,
we would almost certainly have evolved methods to detect it,
and we have none.
And the physical world that's all around is just incredible.
You're blowing my mind, Dr. Dennis White.
Okay, so you have experience with magnetic confinement.
You have experience with inertial confinement.
Most of your work has been a magnetic confinement.
But let's talk about the sexy, recent thing for a bit of a time.
There's been a breakthrough in the news
that laser-based inertial confinement was used by DOE's
National Ignition Facility at the Lawrence Livermore National Laboratory.
Can you explain this breakthrough that happened in December?
Yeah.
So it goes to the set of criteria that I talked about before
about getting high energy gain.
So in the end, what are we after in fusion
is that we basically assemble this plasma fuel in some way
and we provide it a starting amount of energy,
the ink of lighting the fire.
And what you want to do is get back significant excess gain
from the fact that the fusion is releasing the energy.
So it's the equivalent of we want to have a match,
a small match, light a fire, and then the fire keeps us hot.
It's very much like that.
So as I said, we've made many of the...
It's like the fusion community has pursued aspects of this
through a variety of different confinement methodologies.
Is that the key part about what happens,
what was the threshold we had never gotten over before
was that if you only consider the plasma fuel,
not the total engineering system, but just the plasma fuel itself,
we had not gotten to the point yet where basically the size of the match
was smaller than the amount of energy that we got from the fusion.
Is there a good term for when the output is greater than the input?
Yes, there is.
Well, there's several special definitions of this.
So one of them is that if you light a match and you have it there,
and it's an infinitesimal amount of energy
compared to what you're getting out of the fire,
we call this ignition, which makes sense.
This is like what our own son is as well too.
So that was not ignition in that sense as well too.
So what we call this is scientific.
The one that I just talked about, which is for some instance,
when I get enough fusion energy released
compared to the size of the match,
we call this scientific break-even.
Break-even.
Break-even.
And it's because you've gotten past the fact that this is unity now at this point.
What is fusion gain or as using the notation Q from the paper overview
of the spark takamak, using just the same kind of term?
Actually, so the technical term is Q, capital Q.
Oh, so people actually use Q.
We actually use capital Q or some days it's called Q.
Q is taken.
Q sub P or something like this.
Okay, so this is what it means is that it's in the plasma.
So all we're considering is the energy balance or a gain that comes from the plasma.
From the plasma itself.
We're not considering the technologies which are around it,
which are providing the containment and so forth.
So why the excitement?
Well, because for one reason it's a rather simple threshold to get over,
to understand that you're getting more energy out from the fusion,
even a theoretical sense than you were from the starting match.
Do you mean conceptually simple?
It's conceptually simple that you get past one,
that everybody under, like when you're less than one,
that's much less interesting than getting past one.
So there's a really big threshold to get past.
But it really is a scientific threshold because what QP actually denotes
is the relative amount of self-heating that's happening in the plasma.
So what I mean by this is that in the end in these systems,
what you want is something that where the relative amount of heating,
which is keeping the fuel hot, is dominated by from the fusion reactions themselves.
And so it becomes, it's sort of like thinking like a bonfire
is a lot more interesting physically than just holding a blow torch to a wet log.
There's a lot more dynamics, it's a lot more self-evolved and so forth.
And what we're excited as as scientists is that it's clear that in that experiment
that they actually got to a point where the fusion reactions themselves
were actually altering the state of the plasma.
It's like, wow, I mean, we'd seen it in glimpses before in magnetic confinement
at relatively small levels, but apparently it seems like in this experiment
it's likely to be a dominant, dominated by self-heating.
So that makes it a self-sustaining type of reaction.
It's more self-sustaining, it's more self-referential system in a sense.
And it sort of self-evolves in a way.
Again, it's not that it's going to evolve to a dangerous state,
it's just that we want to see what happens when the fusion is the dominant heating source.
And we'll talk about that, but there's also another element,
which is the initial confinement, laser-based initial confinement.
It's kind of a little bit of an underdog.
So a lot of the broad nuclear fusion communities have been focused on magnetic confinement.
Can you explain just how laser-based inertial confinement works?
So it says 192 laser beams were aligned on a deuterium-tradium-dt target smaller than a P.
This is like...
Maybe, actually, yeah.
Okay, well, it depends.
Not all P's are made the same.
But this is like throwing a perfect strike in baseball from a pitch...
This is like a journalist wrote this, I think.
This is like...
Oh, no, it's not a journalist, it's DOE wrote this.
Yeah, yeah.
Department of Energy.
We try to use all these analogies.
This is like throwing a perfect strike in baseball from a pitcher's mount,
350 miles away from the plate.
There you go.
Department of Energy.
The United States Department of Energy wrote this.
Okay.
Can you explain what the lasers...
What actually happens?
Yeah, actually, there's usually mass confusion about this.
So what's going on in this form of it?
So the fuel is delivered in a discrete...
The fusion fuel, the deuterium-tradium, is in a discrete spherical...
It's more like a BB.
Let's call it a BB.
So it's a small one.
And all the fuel that you're going to try to burn is basically there.
Okay.
And it's about that size.
So how are you going to get...
Literally, it's like at 20 degrees above absolute zero,
because the deuterium and tridium are kept in a liquid and solid state.
Oh, wow.
So the fuel is injected not as a gas, but as a solid.
It's actually...
And in these particular experiments,
they can introduce one of these targets once per day approximately,
something like that.
Because it's very...
It's kind of amazing technology, actually,
that I know some of the people that worked on this back in the day
is they actually make these things at a BB size of this frozen fuel.
It's actually at cryogenic temperatures.
And they're almost smooth to the atom level.
I mean, they're amazing pieces of technology.
So what you do in the end is think...
What you have is a spherical assembly of this fuel, like a ball.
And what is the purpose of the lasers?
The purpose of the lasers is to provide optical energy
to the very outside of this.
And what happens is that energy is absorbed,
because it's in the solid phase of matter,
so it's absorbed really in the surface.
And then what happens is that when it's absorbed in something called the ablator,
what does that mean?
It means it goes instantly from the solid phase to the gas phase.
So it becomes like a rocket engine.
But you hit it like very uniformly.
So there's like rocket engines coming off the surface.
Think of like an asteroid almost, where there's like rockets coming off.
So what does that do?
What does a rocket do?
It actually pushes by Newton's laws, right?
It pushes the other thing on the other side of it equal and opposite reaction.
It pushes it in.
So what it does is that the lasers actually don't heat.
This is what was confusing.
People think the lasers, oh, we're going to get it to 100 million degrees.
In fact, you want the exact opposite of this.
What you want to do is get essentially a rocket going out like this.
And then what happens is that the sphere like,
and this is happening in a billionth of a second or lasts actually,
this rapidly, that force like so rapidly compresses the fuel,
that what happens is that you're squeezing down on it.
And, you know, it's like, what was the...
See, BB, that's bad, actually BB.
I should have started with a basketball.
It goes from like a basketball down to something like this.
And a billionth of a second.
And when that happens, I mean, scale that in your mind.
So when that happens, and this comes from, almost from classical physics,
so there's some quantum in it as well too.
But basically, if you can do this like very uniformly and so-called adiabatically,
like you're not actually heating the fuel,
what happens is you get adiabatic compression such that the very center of this thing
all of a sudden just spikes up in temperature
because it's actually done so fast.
So why is it called inertial fusion?
It's because you're doing this on such fast time scales
that the inertia of the hot fuel basically is still finite
so it can't like push itself apart before the fusion happens.
Oh, wow.
So how do you make it so fast?
This is why you use lasers
because you're applying this energy in very, very short periods of time,
like under a fraction of a billionth of a second.
And so basically that, and then the force which is coming from this
comes from the energy of the lasers,
which is basically the rocket action which does the compression.
So is the force, is the inward facing force, is that increasing the temperature?
No, you want to keep the fuel cold and then,
and just literally just ideally compress it.
And then in something which is at the very center of that compressed sphere,
because you've compressed it so rapidly, the laws of physics basically require
for it to increase in temperature.
The effect is like if you know the thing,
so adiabatic cooling we're actually fairly familiar with,
if you take a spray can and you push the button,
when it rapidly expands, it cools.
This is the nature of a lot of cooling technology we use actually.
Well, the opposite is true that if you would take all of those particles
and jam them together very fast back in, they want to heat up.
And that's what happens.
And then what happens is you basically have this very cold,
compressed set of fusion fuel, and at the center of this,
it goes to this 100 million degrees Celsius.
And so if it gets to that 100 million degrees Celsius,
the fusion fuel starts to burn.
And when that fusion fuel starts to burn,
it wants to heat up the other cold fuel around it,
and it just basically propagates out so fast that what you would do,
ideally, you would actually burn in a fusion sense most of the fuel
that's in the pellet.
So this was very exciting because what they had done was,
it's clear that they propagated this,
they got this what they call a hot spot,
and in fact that this heating can propagate it out into the fuel,
and that's the science behind inertial fusion.
So the idea behind a reactor that's based on this kind of inertial confinement
is that you would have a new BB every like...
10 times a second or something like this.
And then there's some kind of...
So there's an incredible device that you kind of implied
that kind of has to create one of those BBs.
So you have to make the BBs very fast.
There's reports on this, but what does it mean?
The starting point is can you make this gain?
So this was a scientific achievement primarily.
And the rest is just engineering.
No, no, the rest is incredibly complicated engineering.
Well, in fact, there's still physics hurdles to overcome.
So where does this come from?
And it's actually because if you want to make an energy source out of this,
this had a gain of around 1.5,
that namely the fusion energy was approximately...
was 1.5 times the laser input energy.
This is a fairly significant threshold.
However, from the science of what I just told you,
is that there's two fundamental efficiencies
which come into it, which really come from physics, really.
One of them is hydrodynamic efficiency.
What I mean by this is that it's a rocket.
So it just has a fundamental efficiency built into it,
which comes out to orders of like 10%.
So this means is that your ability to do work on the system
is just limited by that, okay?
And then the other one is the efficiency of laser systems themselves,
which if the wall plug efficiency is 10%,
you've done spectacularly well.
The wall plug efficiency of the ones using that experiment
are like more like 1%, right?
So when you go through all of this,
the approximate place that you're ordering this
for a fusion power plant would be a gain of 100, not 1.5.
So you still...
and hopefully we see experiments that keep climbing up
towards higher and higher gain.
But then the whole fusion power plant is a totally different thing.
It's not one BB and one laser pulse per day.
It's like 5 or 10 times per second.
Like, like that, right?
So you're doing it there.
And then comes the other aspect.
So it's making the targets, delivering them,
being able to repeatedly get them to burn.
And then we haven't even talked about like,
how do you then get the fusion energy out?
Which is mainly because these things are basically
micro implosions which are occurring.
So this energy is coming out to some medium
on the outside that you've got to figure out
how to extract the energy out of this thing.
How do you convert that energy to electricity?
So in the end, you have to basically convert it
into heat in some way.
So in the end, what fusion makes mostly is
like very energetic particles from the fusion reaction.
So you have to slow those down in some way
and then make heat out of it.
So basically the conversion of the kinetic energy
of the particles into heating some engineered material
that's on the outside of this.
And that's, from a physics perspective,
is a somewhat solved problem,
but from an engineering, it's still...
Yeah, physics, I can draw the...
I can show you all the equations that tell you
about how it slows down and converts
kinetic energy into heat.
And then what that heat means, you know,
you can write out like an ideal thermal cycle,
like a Carnot cycle.
So the physics of that, yeah, great.
The integrated engineering of this is a whole other thing.
I'll ask you to maybe talk about the difference
between inertial and magnetic,
but first we'll talk about magnetic.
But let me just linger on this breakthrough.
You know, it's nice to have exciting things,
but in a deep human sense,
there's no competition in science and engineering.
Or like you said, we were broad.
First of all, we are a humanity altogether.
And you talk about this, it's a bunch of countries collaborating.
It's really exciting.
There's a nuclear fusion community broadly.
But then there's also MIT.
There's colors and logos, and it's exciting.
And you have friends and colleagues here
that work extremely hard and done some incredible stuff.
Is there some sort of...
How do you feel seeing somebody else
get a breakthrough using a different technology?
Is that exciting?
Does the competitive fire get...
All of the above.
I mean, I have...
Just to wave the flag a little bit.
So MIT was a central player in this accomplishment.
Interesting, I would say it showed some of our two best traits.
So one of them was that the...
How do you know that this happened?
This measurement, right?
So one of the ways to do this is if I told you
is that in the DT fusion,
what it actually... The product that comes out is helium.
We call it an alpha, but it's helium.
And a free neutron, right?
So the neutron contains 80% of the energy
released by the fusion reaction.
And it also, because it lacks a charge,
it basically tends to just escape and go flying out.
So this is what we would use eventually for...
That's mostly what fusion energy would be.
So what my colleagues, my scientific colleagues
at the Plaza Science and Fusion Center built
were extraordinary measurement tools
of being able to see the exact details
of not only the number of neutrons that were coming out,
but actually what energy that they're at.
And by looking at that configuration,
it reveals enormous...
I'm not gonna scoop them because they need to publish the paper,
but it reveals enormous amounts of scientific information
about what's happening in that process that I just described.
So exciting.
And I have colleagues there that have worked
for 30 years on this for that moment.
Of course, you're excited for them.
And there's one of those...
There is nothing...
It's hard to describe to people who aren't...
It's almost addicting to be a scientist
when you get to be at the forefront of research of anything.
When you see an actual discovery of some kind
and you're looking at it, particularly when you're the person who did it,
and you go, no human being has ever seen this or understood this.
It's like, it's pretty thrilling, right?
So even in proxy, it's incredibly thrilling to see this.
It's not rivalry or jealousy.
It's like, I can tell you already, fusion is really hard.
So anything that keeps pushing the needle forward is a good thing.
But we also have to be realistic about what it means
to making a fusion energy system.
I mean, these are still the early steps.
Maybe you can say the early leaps.
So let's talk about the magnetic confinement.
How does magnetic confinement work?
What's the talk of MAC?
Yeah, how does it all work?
So why inertial confinement works on the same principle that a star works?
So what is the confinement mechanism in the star?
What is gravity?
Because it's its own inertia of something the size of the sun
basically pushes a literally a force by gravity against the center.
So the center is very, very hot, 20 million degrees,
and literally outside the sun, it's essentially zero,
because it's vacuum of space.
How the hell does that do that?
It does that by, and it's out of,
why doesn't it just leak all of its heat?
It doesn't leak its heat because it all is held together
so that it can't escape because of its own gravity.
So this is why the fusion happens in the center of the star.
We think of the surface of the sun as being hot.
That's the coldest part of the star.
So of our own sun, this is about 5,500 degrees.
A beautiful symmetry, by the way.
So how do we know all this?
Because we can't, of course, see directly into the interior of the sun
by knowing the volume and the temperature of the surface of the sun.
You know exactly how much power it's putting out.
And by this, you know that this is coming from fusion reactions occurring
at exactly the same rate in the middle of the sun.
Is it possible as a small tangent to build an inertial confinement system
like the sun, is it possible to create a sun?
It is, of course, possible to make a sun,
although we do have stars, but it is not possible on Earth
because for the simple reason that it takes,
the gravitational force is extremely weak,
and so it takes something like the size of a star
to make fusion occur in the center.
Well, I didn't mean on Earth.
I mean, if you had to build a second sun, how would you do it?
There's not enough hydrogen around.
So the limiting factor is just the hydrogen.
Yeah, I mean, the forces and energy that it takes to assemble that
is just mind boggling.
So we wouldn't do that.
To be continued.
Yeah, to be continued.
So what are we doing it with?
So the one that I just described is like you say,
so you have to replace this with some force which is better than that.
What I mean by that is it's stronger than that.
So what I talked about the laser fusion,
this is coming from the force which is enormous compared to gravity,
like from the rocket action of pushing it together.
So in magnetic confinement, we use another force of nature,
which is the electromagnetic force.
And that's very, it's orders and orders of magnitude stronger
than the gravitational force.
And the key force that matters here is that if you have a charged particle,
that namely it's a particle that has an electric net electric charge,
and it's in the proximity of a magnetic field,
then there is a force which is exerted on that particle.
So it's called the Lorenz force for those who are keeping track.
So that is the force that we use to replace physical containment.
So in, so this again, how do you hold something at 100 million degrees?
It's impossible in a physical container.
This is not like, you know, it's not this plastic bottle holding in this liquid
or a gas chamber.
What you're doing is you're using, you're immersing the fuel in a magnetic field
that basically exerts a force at a distance.
This comes back again to again, like why plazas are so strange.
It's the same thing here.
And if it's immersed in this magnetic field,
you're not actually physically touching it,
but you're making a force go onto it.
So that's the inherent feature of magnetic confinement.
And then magnetic confinement devices are like a tokamak
are basically configurations which exploit the features of that magnetic containment.
There's several features to it.
One is that the stronger the strength of the magnetic field,
the stronger the force.
And for this reason is that if you increase the strength of magnetic fields,
this means that the containment,
because namely the force which you're pushing against it is more effective.
And the other feature is that there is no force.
So for those who remember magnetic fields, what are these things?
They're also invisible.
But, you know, if you think of a permanent magnet or your fridge magnet,
there are field lines which we actually designate as arrows which are going around.
You sometimes see this in school when you have the, you know, the iron filings on a thing
and you see the directions of the magnetic field lines.
Or when you use a compass, right?
So that's telling you north because we're living in an immersed magnetic field
made by the earth, which is that very low intensity magnet.
If it's strong enough, we can actually see what direction is it.
So this is the arrow that the magnetic field is pointing.
It's always pointing north and for us is that.
So an interesting feature of this force is that there is no force
along the direction of the magnetic field.
There's only force in the directions orthogonal to the magnetic field.
So this, by the way, is a huge deal in a whole other discipline of plasma physics,
which is like the study of like our near atmosphere.
So the study of Aurora Borealis, what's happening in the near atmosphere,
what happens when solar flares hit the magnetic field.
In fact, remember I said fusion is the reason that life is responsible in the universe?
Well, you could also argue so is magnetic confinement because the charged particles
which are being emitted from the galaxy and from our own star
would be very, very damaging on earth.
So we get two layers of protection.
One is the atmosphere itself, but the other one is the magnetic field
which just surrounds the earth and basically traps these charged particles
so they can't get away.
It's the same deal.
How do you create a strong magnetic field?
Yeah, so with a giant magnet.
Giant magnet, yeah.
So it's basically true.
Engineering is awesome.
There's essentially two ways to create a magnet.
So one of them is that we're familiar with like fridge magnets and so forth.
These are so-called permanent magnets.
And what it means is that within these the atoms arrange in a particular way
that it produces the electrons basically arrange in a particular way
that it produces a permanent magnetic field that is set by the material.
So those have a fundamental limitation how strong they can be
and they also tend to have this like circular shape like this.
So we don't typically use those.
So what we use are so-called electromagnets.
And what is this?
So the other way to make a magnetic field also go back to your elementary school physics
or science class is that you take a nail and you wrap a copper wire around it
and connect it to a battery then it can pick up iron filings.
This is an electromagnet.
And it's simplest what it is.
It's an electric current which is going in a pattern around and around and around.
And what this does is it produces a magnetic field which goes through it
by the laws of electromagnetism.
So that's how we make the magnetic field in these configurations.
And the key there is that it's not limited by the magnetic property of the material.
The magnetic field amplitude is set by the amount of the geometry of this thing
and the amount of electric current that you're putting through.
And the more electric current that you put through, the more magnetic field that you get.
The closest one that people maybe see is one of my favorite skits actually was Super Dave Osborn.
It's probably past you.
It's a show called Bizarre Super Dave Osborn which is a great comedian cult.
He was a stuntman and one of his tricks was that he gets into a car
and then one of those things in the junkyard comes down and picks up the car
and then puts it into the crusher.
This is his stunt which is pretty hilarious.
Anyway, but that thing that picks him up, how does that work?
That's actually not a permanent magnet.
It's an electromagnet.
And so by turning off and on the power supply, it turns off and on the magnetic field.
So this means you can pick it up and then when you switch it off,
the magnetic field goes away and the car drops.
So that's what it looks like.
Speaking of giant magnets, MIT and Commonwealth Fusion Systems, CFS,
built a very large high temperature superconducting electromagnet
that was ramped up to a field strength of 20 Tesla.
The most powerful magnetic field of its kind ever created down on Earth.
Because I enjoy this kind of thing.
Can you please tell me about this magnet?
Yeah, sure.
Oh, it was, it's fun.
There's a lot to parse there.
So we already explained an electromagnet,
which in general is what you do is you take electric current
and you force it to follow a pattern of some kind,
typically like a circular pattern around and around and around and around.
The more current and the more times it goes around,
the stronger the magnetic field that you make.
And as I pointed out, it's like really important in magnetic confinement
because it is the force that's produced by that magnet.
In fact, technically it goes like the magnetic field squared
because it's a pressure which is actually being exerted on the plasma
to keep it contained.
Just so we know for magnetic confinement,
what is usually the geometry of the magnet?
What are we supposed to imagine?
Yeah, so the geometry is typically that,
typically is what you do is you want to produce a magnetic field
that loops back on itself.
And the reason for this goes down to the nature of the force that I described,
which is that there's no containment or force
along the direction of the magnetic field.
So here's a magnetic field.
In fact, what it's more technically or more graphically what it's doing
is that when the plasma is here, here's plasma particles here.
Here's a magnetic field.
What it does is it forces all those, because of this Lorentz force,
it makes all of those charged particles
execute circular orbits around the magnetic field.
And they go around like this,
but they stream freely along the magnetic field line.
So this is why the nature of the containment
is that if you can get that circle smaller and smaller,
it stays further away from Earth, temperature materials.
That's why the confinement gets better.
But the problem is that because it free streams along,
so we just have a long straight magnetic field,
okay, it'll just keep leaking out the ends like really fast.
So you get rid of the ends.
So you basically loop it back around.
So what these look like are typically donut shaped
or more technically toroidal shaped,
donut shaped things where this collection of magnetic fields
loops back on itself.
And it also, for reasons which are more complicated to explain,
basically it also twists slowly around in this direction as well too.
So that's what it looks like. That's what the plasma looks like
because that's what the fuel looks like.
So then this means is that the electromagnets
are configured in such a way that it produces
the desired magnetic fields around this.
How precise does this have to be?
You were probably listening to our conversation
with some of my colleagues yesterday.
So it depends on the configuration about how you're doing it.
The configuration of the plasma?
The configuration of the electromagnets
is giving this requirement.
It's fairly precise, but it doesn't have to be
particularly in something like a tokamak.
What we do is we produce planar coils,
which means they're flat, and we situate them.
So if you think of a circle like this,
what does it produce if you put current through it?
It produces a magnetic field which goes through the circle like this.
So if you align many of them like this, this, this, this,
these things online, you can go see the picture.
You keep arranging these around in a circle itself.
This forces the magnetic field lines to basically
just keep executing around like this.
So you tend to align.
That one tends to, while it requires good confine,
or good alignment, it's not like insane alignment
because you're actually exploiting the symmetry
of the situation to help it.
There's another kind of configuration of magnetic,
of this kind of magnetic confinement called a stellarator,
we have these names for historic reasons.
Which is different than a tokamak.
It's different than a tokamak,
but actually works on the same physical principle
that namely, in the end, it produces a plasma
which loops in magnetic fields,
which loop back on themselves as well.
But in that case, the totality basically,
the totality of the confining magnetic field
is produced by external three-dimensional magnets.
So they're twisted.
And it turns out the precision of those is more stringent.
So our tokamaks by far more popular
for research and development currently than stellarators.
Of the concepts which are there,
the tokamak is by far the most mature
in terms of its breadth of performance
and thinking about how it would be applied
in a fusion energy system.
And the history of this was that many,
in fact, you asked if we go back to the history
of the plasma science and fusion center,
the history of fusion is that people,
scientists had started to work on this
in the 1950s.
It was all hush-hush and cold war and all that kind of stuff.
And they realized, holy cow, this is really hard.
We actually don't really know what we're doing
because everything was at low temperatures.
They couldn't get confinement.
It was interesting.
And then they declassified it.
And this is one of the few places
that the West and the Soviet Union actually collaborated on
was the science of this.
Even during the Cold War.
Even during the middle of the Cold War.
It was really, and this actually perpetuates all the way
till now for, we can talk about the project
that that is sort of captured in now.
But in the reason they declassified it
was because everything kind of sucked basically,
about trying to make this confinement
in high temperature plasma.
And then the Russians, then the Soviets,
came along with this device called a Tokamak,
which is a Russian acronym, which basically means
magnetic coils arranged in the shape of a donut.
And they said, holy cow, everyone was stuck at
like a meager, like half a million degrees,
or half a million degrees,
which is like in fusion terms is zero basically.
And then they come along and they say,
oh, we've actually achieved a temperature
20 times higher than everybody else.
And it's actually started to make fusion reactions
and everyone just go, oh, you know, no way.
It's just hype from the, it's like there's no way
because we've failed at this.
It's a great story in the history of fusion is that then,
but they insisted, they said, no, look,
you can see this from our data.
It's like this thing is really hot
and it seems to be working.
This is, you know, late 1960s.
And there was a, there was a team
that went from the United Kingdom's
fusion development lab and they brought this
very fancy, amazing new technology called a laser.
And they use this laser and they shot the laser beam
like through the plasma.
And by looking at the scattered light that came from that,
they go, that basically the scattered light gets more
broadened in its spectrum if it gets hotter.
So you could, you could exactly tell the temperature of this.
And even though you're not physically touching the plasma,
it's like, holy cow, you're right.
It is like, it is 10 million degrees.
And so this was one of those explosions of like everyone
in the world then wanted to build a token back
because it was clearly like, wow,
this is like so far ahead of everything else
that we tried before.
So that actually has a part of the story to MIT
and the Plasma Science and Fusion Center was,
why is there a strong fusion and a major fusion program at MIT?
It was because we were host to the Francis Bitter Magnet
Laboratory, which is also the National High Field Magnet
Laboratory.
Well, you can see where this goes, right?
From this, you know, we're kind of telling the stories
backwards almost, but, you know, the advent of a Tokamak,
along with the fact that you could make very strong
magnetic fields with the technology that had been
developed at that laboratory, that was the origins of
sort of pushing together the physics of the plasma
containment and the magnet technology and put them
together in a way that I would say is, you know,
a very typical MIT success story, right?
We don't do just pure science or pure technology.
We sort of set up this intersection between them.
And there were several pioneers of people at MIT,
like Bruno Kopp, he was a professor in the physics
department, and Ron Parker, who was a professor in
electrical engineering and nuclear engineering.
It's like even the makeup of the people, right?
He's got this blends of science and engineering in them.
And that's actually was the origin of the Plasma Science
and Fusion Center was doing those things.
So anyway, so back to this.
So yes, Tokamaks have achieved the highest in
magnetic fusion by far, like the best amounts of
these conditions that I talked about.
And in fact, pushed straight up to the point where
they were near QP of one.
They just didn't quite get over one.
So can we actually just linger on the collaboration
across different nations, just maybe looking at the
philosophical aspect of this, even in the Cold War,
there's something hopeful to me besides the energy that
these giant international projects are a really powerful
way to ease some of the geopolitical tension,
even military conflict across nations.
There's a war in Ukraine and Russia.
There's a brewing tension and conflict with China.
Just the world is still seeking military conflict,
cold or hot.
What can you say about sort of the lessons of the 20th
century and these giant projects and their ability
to ease some of this tension?
It's a great question.
So as I said, there was a reason because it was so hard
that was one of the reasons they declassified it.
And actually they started working together in some
sense on it as well too.
And I think it was really there was a heuristic or
altruistic aspect to this.
It's like this is something that could change the future
of humanity and its nature and its relationship with
energy.
Isn't this something that we should work on together?
And that went along in those ones.
And in particularly that any kind of place where you can
actually have an open exchange of people who are sort of
at the intellectual frontiers of your society,
this is a good thing of being able to collaborate.
I've had an amazing career.
I've worked with people from it's like hard to throw a dart
at a country on the map and not hit a country of people
that I've been able to work with.
How amazing is that?
And even just getting small numbers of people to bridge
cultural and societal divides is a very important thing.
Even when it's a very tiny fraction of the overall
populations, it can be held up as an example of that.
But it's interesting that if you look at then that
continued collaboration, which continues to this day,
is that this actually played a major role in fact in
East-West relations or Soviet-West relations,
is that back in the Reagan-Gorbachev days,
which of course were interesting in themselves
of all kinds of changes happening on both sides, right?
But still like a desire to push down the stockpile
of nuclear weapons and all that, within that context
there was a fairly significant historic event
that at one of the Reagan-Gorbachev summits
is that they had really, they didn't get there.
Like they couldn't figure out how to bargain to the point
of some part of the treatise anymore, the details of it anymore.
But they needed some kind of a symbol almost to say,
but we're still going to keep working towards something
that's important for all of us.
What did they pick?
A fusion project.
And that was in the mid-1980s and actually then after,
so they basically signed an agreement that they would move
forward to like literally collaborate on a project
whose idea would be to show large net energy gain
in fusion's commercial viability and work together on that.
And very soon after that, Japan joined,
as did the European Union.
And now that project, it evolved over a long period of time
and had some interesting political ramifications to it.
In the end, this actually also had South Korea, India,
and China join as well too.
So you're talking about make major, a major fraction of,
and now Russia, of course, instead of the Soviet Union.
And actually that coalition is holding together
despite the obvious political turmoil that's going around
on all those things.
And that's a project called ETER,
which is under construction in the south of France right now.
Can you actually, before we return to the giant magnet,
and maybe even talk about Spark and the stuff going,
all amazing stuff going on at MIT, what is ETER?
What is this international nuclear fusion mega project
being built in the south of France?
So its scientific purpose is a worthy one
that it's essentially in any fusion device,
the thing that you want to see is more and more
relative amounts of self-heating.
And this is something that had not been seen,
although we had made fusion reactions
and we'd seen small amounts of the self-heating.
We never got to it.
This actually goes to this QP business, okay?
The goal of ETER, and it shifted around a little bit historically,
but fairly quickly became,
we want to get to a large amount of self-heating.
So this is why it has a,
its primary feature is to get to QP of around 10.
And through this, this is a way to study this plasma
that has more higher levels of self-determination around on it.
But it also has another feature which was,
let's produce fusion power at a, you know, relevant scale.
And actually they're linked together,
which actually makes sense to you think about,
is that because the fusion power is the heating source itself,
this means that they're linked together.
And so ETER makes, is projected to make
about 500 million watts of fusion power.
So this is a significant amount.
Like this is what you would use, you know, for powering cities.
So it's not just the research,
it is the development of really trying to achieve scale here.
So self-heating and scale.
Yeah, yes.
So this meant then too is the development of an industrial base
that can actually produce the technologies
like the electromagnets and so forth.
And to do it with, it is a tokamak.
It is one of these, yes.
But very interesting.
It also revealed limitations of this as well too.
Well, it is, it's interesting is that it is clearly a,
on paper and in fact in in practice as well too,
the world, you know, and very different political systems
and you consider at least geopolitical
or economic rivals or whatever you want to use.
Like working towards a common cause.
And one that we all think is worthy is very like,
okay, that's very satisfying.
But it's also interesting to see the limitations of this.
It's because, well, you've got seven, you know, chefs in the kitchen.
So what is this, what does this mean in terms of the speed of the project
and the ability to govern it and so forth?
It's just been a challenge, honestly, around this.
And this is, I mean, it's very hard technically what's occurring.
But when you also introduce such levels of, I mean,
this isn't just me saying that there's like GAO reports
from the US government and so forth.
This is, it's hard to like steer all of this around.
And what that's tended to do is make it,
it's not the fastest decision making process.
You know, my own personal view of it was, it was,
it was interesting because you asked me,
you said about the magnet and common fusion systems.
It was, I worked most of my career on ETER
because when I came into the field in the early 1990s,
when I completed my PhD and started to work,
this was one of the most, like you can't imagine
being more excited about something like,
we're going to change the world with this project.
We're going to do these things.
And we just like pour it like an entire generation
and afterwards as well too,
it was just poured their imagination and their creativity
about making this thing work very good.
But at also at some point though, when, you know,
when it got to being another five years of delay
or a decade of delay, you start asking yourself,
well, is this what I want to do?
Right? Am I going to wait for this?
So it was a part of me starting to ask questions
with my students.
I was like, is there another way that we can get
to this extremely worthwhile goal?
But maybe, maybe it's not that,
maybe it's not that pathway.
And the other part that was clearly frustrating to me
because I, I'm an advocate of fusion.
You asked me about was I, you know,
I was like, well, it's laser fusion or inertial fusion
or magnetic fusion.
I just want fusion energy.
Okay.
Cause I think it's so important to the, to the world is that,
but the other thing, if that's the case,
then why do we have only one attempt at it
on the entire planet, which was Eater?
It's like, that makes no sense to me, right?
We should have multiple attempts at this
with different levels of whatever you want to think about
a technical schedule, scientific risk,
which are incorporated in them.
And that's going to give us a better chance
of actually getting to the goal line.
With that spirit, you're leading MIT's effort
to design Spark, a compact, high-field,
DT burning Takamak.
How does it work?
What is it?
What's the motivation?
What's the design?
What are the ideas behind it?
At its heart, it's exactly the same concept as Eater.
So it's basically a configuration of electromagnets.
It's arranged in the shape of a donut.
And within that we will do, we would do the same thing
that happens in all the other Tokamaks,
including in Eater and in this one.
Namely, you put in gas, make it into a plasma,
you heat it up, it gets to about 100 million degrees.
The differentiator in Spark is that we use
the actual deuterium tritium fuel,
and because of the access to very high magnetic fields,
it's in a very compact space.
It's very, very small.
What do I mean by small?
So it's 40 times smaller in volume than Eater.
But it uses exactly the same physical principles.
So this comes from the high magnetic field.
So in the end, like, why does this matter?
What it does is it does those things,
and it should get to the point where it's producing
over 100 million watts of fusion power.
But remember, it's 40 times smaller.
So Eater was 500 megawatts.
Technically, our design is around 150 megawatts.
That's about a factor of three difference,
despite being 40 times smaller.
And we see QP large, order of 10 or something like this.
At that state, it's very important scientifically
because this basically matches what Eater is looking to do.
The plasma is dominated by its own heating.
It's very, very important.
And it does that for about 10 seconds.
The reason it's for 10 seconds is that in terms of that,
that basically allows everything to settle
in terms of the fusion in the plasma equilibrium.
Everything is nice and settled.
So you know, you have seen the physical state
at which you would expect a power plant to operate
basically for magnetic fusion.
Like, wow, right?
But it's more than that.
And it's more than that.
It's because about who's building it and why
and how it's being financed.
So that scientific pathway was made possible
by the fact that we had access to a next generation
of magnet technology.
So to explain this real quick, why do we call it,
you said it in the words, a superconducting magnet.
What does this mean?
Superconducting magnet means that the materials
which are in the electromagnet have no electrical resistance.
Therefore, when the electric current is put into it,
the current goes around unimpeded.
So it could basically keep going around
technically for infinity.
And what that means, or for eternity,
and what that means is that when you energize
these large electromagnets,
they're using basically zero electrical power
to maintain them.
Whereas if you would do this in a normal wire,
like copper, you basically make an enormous toaster oven
that's consuming enormous amounts of power
and getting hot, which is a problem.
That was the technical breakthrough
that was realized by myself
and at the time my students and postdocs and colleagues
at MIT, was that we saw the advent
of this new superconducting material,
which would allow us to access much higher magnetic fields.
It was basically the next generation of the technology.
And it was quite disruptive to fusion,
that namely what it would allow,
that if we could get to this point
where we could make the round 20 Tesla,
we knew by the rules of Tokamax
that this was going to allow us
to vastly shrink the sizes of these devices.
So it wouldn't take, although it's a worthy goal,
it wouldn't take a seven nation international treaty
basically to build it.
You could build it with a company in a university.
So same kind of design,
but now using the superconducting magnets.
And in fact, if you look at it,
if you just expand the size of it,
they look almost identical to each other
because it's based on the,
and actually that comes for a reason, by the way,
is that it also looks like a bigger version
of the Tokamax that we ran at MIT for 20 years,
where we established the scientific benefits,
in fact, of these higher magnetic fields.
So that's the pathway that runs.
So we say, so what does this mean?
The context is different because it was made,
because it's primarily being made
by a private sector company spun out of MIT
because the way that it raised money
and the purpose of the entity which is there
is to make commercial fusion power plants,
not just to make a scientific experiment.
This is actually why we have a partnership, right?
Is that our purpose at MIT
is not to commercialize directly,
but boy, do we want to advance the technology
and the science that comes along this,
and that's the reason we're sort of doing it together.
So it's MIT and Commonwealth fusion systems.
So what's interesting to say about financing
and this seems like from a scientific perspective,
maybe not an interesting topic,
but it's perhaps an extremely interesting topic.
I mean, you can just look at the tension
between SpaceX and NASA, for example.
It's just clear that there's different financing mechanisms
that actually significantly accelerate
the development of science and engineering.
It's great that you brought that up.
We use several historic analogs,
and one of them is around SpaceX,
and an appropriate one because space,
putting things into orbit has a minimum size to it
and integrated technological complexity
and budget and things like this.
So our point when we were talking
about starting a fusion commercialization company,
people look at you like,
isn't this still really just a science experiment?
But one of the things that we pointed to
was SpaceX to say, well,
tell me like 25 years ago how many people would have voted
that the leading entity on the planet
to put things into orbit is a private company.
People would have thought you were not so, right?
And what is interesting about SpaceX
is that it proved it's more than actually just financing.
It's really the purpose of the organization.
So the purpose of a,
and I'm not against public financing or anything like that,
but the purpose of a public entity like NASA
correctly speaks to the political,
because the cost comes from the political assembly
that is there, and I guess from us eventually as well too,
but its purpose wasn't about making a commercial product.
It's about fundamental discovery and so forth,
which is all really great.
Why did SpaceX, it's interesting because why did SpaceX
succeed so well is because the idea was,
it's like the focus that comes in the idea
that you're going to relentlessly like reduce cost
and increase efficiency is a drive that comes
from the commercial aspect of it, right?
And this also then changes the people in the teams
which are doing it as well too.
And in fact, trickles throughout the whole thing
the purpose isn't, while you're advancing things
like it's really good that we can put things
in orbit a lot less more cheaply,
like it advances science, which is an interesting synergy, right?
It's the same thing that we think is going to happen in fusion
that namely this is a bootstrap effect that actually,
that when you start to push yourself to think
about near term commercialization,
it allows the science to get in hand faster,
which then allows the commercialization to go faster
and up we go.
By the way, we've seen this also in another,
again, you have to watch out with analogies
because they only can go so far, but like biotech
is another one, like you look at the human genome project
which was, it's sort of like, to me,
that's like mapping the human genome is like,
that we can make net energy from fusion.
Like it's one of those like in your drawer that you go,
this is a significant achievement by humanity,
in the century.
And there's the human genome project,
fully government funded.
It's going to take 20, 25 years
because we basically know the technology.
We're just going to be really diligent,
keep going, da, da, da, da.
And then all of a sudden, what comes along?
Disruptive technology, right?
You can sequence, you know,
shotgun sequencing and computer, you know,
recognition patterns and basically, oh,
I can do this 100 times faster.
Like, wow.
So that's really the, you know,
to me that the story about why we started,
why we launched Comma Fusion Systems was more than
just about another source of funding,
which it is a different source of funding because it comes,
it's also a different purpose, which is very important.
But there's also something about
a mechanism that creates culture.
So giving power to like a young student,
ambitious student to have a tremendous impact
on the progress of nuclear fusion,
creates a culture that actually makes
progress more aggressively.
Like you said, when seven nations collaborate,
it gives more incentive to the bureaucracy
to slow things down, to kind of have,
let's first have a discussion and certainly
don't give voice to the young, ambitious minds
that are really pushing stuff forward.
And there's something about like the private sector
that rewards, encourages, inspires young minds
to say in the most beautiful ways,
F you to the boss,
and just say like, we'll make it faster,
we'll make it simpler, we'll make it better,
we'll make it cheaper.
And sometimes that brashness doesn't bear out.
You know, that's an aspect that you just take
a different risk profile as well too.
But you're right, it's this, you know,
of the, I mean, it was interesting,
our own trajectory at the fusion center was
like we were pushed into this place by necessity
as well too, because I told you we have,
and we had operated for a long time,
a tokamak on the MIT campus,
achieved these world records like a hundred
million degree plasma and stuff.
It's like, wow, this is fantastic.
But, you know, somewhat ironically,
I have to say is that it was like,
oh, but we're not, this isn't the future of fusion anymore.
Like we're not, we're just going to stop
with small projects because it's too small, right?
So we should need, we need to really move on
to these much bigger projects because that's
really the future of fusion.
And so it was defunded.
And this basically put at risk like,
like we were going to essentially lose MIT
in the ecosystem, really a fusion,
both from the research, but also clearly
important from the educational part of it.
So we, you know, we pushed back against this,
we got a lifeline, we were able to go,
and it was in this, it was in this time scale
that we basically came up with this idea.
It's like, we should do this.
And in the end, it was all of those,
the people who were in the C level of the company
were all literally students who got caught in that.
They were PhD students at the time.
So you talk about enabling another generation
that's like, yeah, there we go, right?
So Spark gave a lifeline.
A lifeline gave fuel to the,
the, the, the future of MIT that it continues.
But it's way more than that.
It was, it wasn't just about like surviving
for the sake of surviving.
In the end, for me, it became like this,
I remember the moment, you know,
you talk about these moments as a scientist,
and we were just like, we were working so hard
about figuring out like, does this really,
with this really work? Like, and is it's complex?
Like, does the magnet work?
Does the interaction with the plasma work?
Does all these things work?
And it was just a grind, push, push, push, push.
And I remember the moment because I was sitting
in my office in Brookline and,
and there was just like, I read like,
and I was in, I don't know, whatever,
20 or 40th slide or something into it.
And it was sort of that moment,
like it just came together.
And I like, I, I got, I couldn't even sit down
because all it was just like, my wife was like,
why are you walking around the apartment like this?
Like, I just couldn't, I said, it's going to work.
Like it's going to work.
Like, that moment of realization
is like kind of amazing,
but it also brings the responsibility
of making it work.
Yeah, how do you make it work?
So you mean like that magic realization
of this modern, uh,
magnet technology and you can actually
like, why do we need to work with Eater?
We can do it here. Yeah, yeah.
But it's interesting that Eater is
um, that one, one of,
one of the reasons that like,
we started with a group of six of us at MIT
and then once we got some funding
through the, through the establishment
of the company, it became a slightly larger.
But in the end, we had a rather small team.
Like this was like a team
of order of like 20 to 25 people
designed Spark in
like a, like about two years, right?
How does that happen? Well,
we're clever, but you have to give
Eater it's due here as well too.
That again, this is an aspect always
of the bootstrap up.
Like I go back to the human genome
project. So modern day genomics
would not be possible without the
underlying basis that came from
setting that up. It had to be there.
It had to be curiosity driven public
program is the same with Eater,
but we, because we had the tools
that were there to understand Eater,
we also had the tools to understand Spark.
So we, we parlayed those in
an extremely powerful way
to be able to tell us about what was going to happen.
So these things are never simple, right?
It's like people look at this go, oh, this means we should
like, should we really have a public based
program about fusion or should we have it all
in the private? It's like, no, the answer
is neither way because in all these
complex technologies, you have to keep pushing
on all the fronts to actually get it there.
So, you know, the natural question when people
hear breakthrough with the, with
the inertial confinement, with the magnetic
confinement is, so when will we have
commercial, um,
reactors, power plants that are actually
producing electricity? What's your
sense, um,
looking out into the future?
When do you think you can envision a future
where we have actual electricity coming from
nuclear fusion? Partly driven by us,
but in other places as well too.
So there's the advent, what's, you know,
what's so different now than three or four years
ago, like we launched
around four years ago. What's
so different now is, is the
advent of a very nascent
but seemingly robust
like commercial fusion,
you know, endeavor. So it's
not just Commonwealth fusion systems, there's
something like 20 plus, you know,
companies. There's a sector now.
There's a sector. They actually, they actually
have something called the Fusion Industry Association,
which is, if your viewers want
to go see this, this describes the different
and they've got this plethora of approaches
like I haven't even described all the approaches
I've basically described the mainline approaches,
um, you know, and they're all
at varying degrees of technical and
scientific maturity with
very huge different, you know,
balances between them. But
what they share
is that because they're going out and finding, getting
funding from the private sector
is that their stated goals are
about getting fusion
into place
so that both it meets the investors
demands, which are interesting,
right? And the time scales of that.
But also it's like, well, there's going to
and why? It's because it's easy.
There's going, there's this enormous push
driver
about getting carbon free energy sources
out into the market and whoever
figures those out is going to be
both very, it's going to be very important
geopolitically, but also economically
as well too. So
it's a different kind of
bat, I guess, or a different
kind of gamble that you're taking with fusion,
but it's so disruptive
that it's like there's, there's essentially
a class of investors and teams
that are ready to go after it as well too.
So what do they share in this?
They typically share
getting after fusion on a time
scale so that could it have any
relevance towards climate change,
battling climate change?
And I would say this is difficult,
but it's fairly easy because it's
math. So what you do is you actually go to some
target like 2050 or 2060
or something like this and say, I want to be
blank percent of the world's
market of electricity or something like that.
And we know historically
what it takes to evolve
and distribute these kinds of technologies
because every technology takes some
period of time, it's so called S-curve, it's
basically, everything follows a logarithmic
exponential type curve.
It's a straight line of log plot.
And like you look at wind, solar,
fission, they all follow
the same thing. So it's easy, you take that curve
and you go, that's slope and you work
backwards. And you go, if you don't start in
the early 2030s, like
it's not going to have
a significant impact by that time.
So all of them
share this idea. And in fact, it's not just
the companies now. The U.S.
federal government has a program
that was started last year that said
we should be looking to try to get
the first, and what do I mean by like, what does
it mean to start, that you've got something
that's putting electricity on the grid, a pilot
what we call it.
And if that can get started, like in the early
2030s, you know, the idea
of ramping it up, you know, makes sense.
That's math, right? So
that's the ambition, then the
question is, and actually this is different
because the government program
and they vary around in this. So for
example, the United Kingdom's government
idea was to get the first one on by
2040. And
China has ambitions probably
middle 2030s
or maybe a little bit later
and Europe, you know,
continental Europe is, it's
a little bit, I'm not exactly sure where it
is, but it's like later, it's like 2050 or
2060, because it's mostly linked to the Eater
timeline as well too.
The fusion companies
which makes sense, it's like, of course they've got the most
aggressive timelines. It's like, we're going to map the human
genome faster as well too, right?
So it's interesting about where
we are. And I think, you know, my
we're not all the way there, but
my intuition tells me we're probably going to
have a couple of cracks at it actually
on that timeline.
So this is where we have to be careful though
you say commercial fusion.
You know, what does that mean? Commercial fusion
to me means that you actually
have a
known quantity about what it costs,
what it costs to build and what it costs to
operate, the reliability
of putting energy on the grid. That's commercial
fusion.
So it turns out that that's not necessarily
exactly the first fusion devices
that put electricity on the grid, because you've got
there's a learning curve to get
better and better at it.
But that's probably
I would suspect the biggest hurdle is to get
to the first one. The work I've done
the work I continue to do with autonomous
vehicles and semi-autonomous vehicles, there's
an interesting parallel there where a bunch of companies
announced a deadline
for themselves in 2021-22
and only
a small subset of those companies have actually
really pushed that forward. There's
Google with Waymo
or Alphabet rather
and then there's
Tesla with
semi-autonomous driving in their autopilot
full-cell driving mode
and those are different approaches
so Tesla is achieving much
much higher scale
but the sort of the quality
of the dry semi-autonomous
I don't know if there's a metaphor
and analogy here and then there's Waymo
that's focusing on very specific cities
but achieving real
full autonomy with actual
passengers but the scales are much smaller
so I wonder like just like you said
there would be these kinds of similar kind of
really hard pushes.
Absolutely, so actually this is
what I, it's why I've been encouraged about
fusion and so fusion's still hard
let's let everyone be clear because
the science underneath it
of achieving the right conditions
for the plasma basically
is a yardstick that you have to
put up against all of them. What's
encouraging that I see in this
and it's actually what happens when you sort of
let loose the creativity
of this is maybe
I'll go back to first principles. So fusion
is also a fairly
strange, so if you think about
building a coal like
burning wood and coal and gas
it's actually not that much different from each other
because they're kind of about the same physical
conditions and you get the fuel and you light
into the fusion is very
remember I told you that there's this condition of the
temperature which is kind of universal
but if you take the density
of the fuel between magnetic
fusion and inertial fusion they're different
by about a factor of 10 billion
so this
and the density of fuel really matters and actually
so does the, this means energy confinement time
is also different by a factor of 10 billion
as well too because it's the product of those two.
So one's really dense and short
lived and the other one's really long
lived and actually under dense
as well too. So what
that means is that
the way to
the way to the, to get the underlying
physical state is so different
among these different approaches what
it lends itself to is
does this mean that eventual commercial
products will actually
fill different needs
in the energy system so it sort of goes to
your comment about
I have to suspect this
because anything that is high
tech and it's like a really
important thing in our economy
tends to never find its way as
one, only one manifestation
like look at transportation as well
too. We have scooters
Vespas
you know overland trucks
cars, electric cars of course
we have these because they meet different demands
in it. So what's interesting
you know that I find fascinating now is
that we have infusion it's going to look
like that that probably there's
the while the near-term
focuses on electricity production
there might even be different kinds
of markets that actually make sense in some
places less than others
it comes to trade-offs because we haven't
really talked about the engineering yet but the engineering
really matters like to the
to the operation of the device
and so it could be
that that you know I suspect what we'll
end up with is several different
configurations which have different features
which are trade-offs basically
in the energy market. What do you see as
the major engineering
or general hurdles
that are in the way? Yeah
so the first one is
just the cost of building
a single unit
so fusion has and
is actually interesting you talked about the different
models that you have so fusion
has
one of its interesting limitations
is that it's very hard
almost at some point becomes physically
impossible to actually make small
power units
like a kilowatt thousand watts
you know which is like a personal home
like you know this is about a thousand
or your personal use of
of electricity is about like a thousand watts
this is basically
impossible for a single
unit to do this
so like you're not going to have a fusion
like power plant like is your
furnace in or your electric heater
in your home and the reason
for this comes from the fact that fusion
relies on it being
it's not just that it's very hot
is that the fusion power is the
heating source to keep it hot so if
if you if you if you go too small
it basically just cannot keep it hot that's
so it's
interesting is that this so this is one of the hard
parts this means that the individual units
you know and it's it varies
from concept to concept but the
the national academies report
that came out last year sort of put the
the benchmark as being
like probably the minimum
size looks like around 50 million
watts of electricity which is like enough
for like a meat like a small to
you know midsize city
actually
so that is so that's sort
of like a scale challenge and in fact it's one
of the reasons why
commonwealth and another private sector
ones like we try to push
this down actually of trying to get
to these smaller units just
because it reduces the cost of it
then probably
obviously I
would say it's an obvious one like achieving
the fusion state itself and high gain
is is a hard
one but we already talked about what kind of
what kind of challenges that that's achieving
the right temperature density and energy
confinement time in the fuel itself
in the plasma itself and so some of the
so some of the
the configurations which are being chosen
have are actually
have quite a ways to go in fact I've seen
those but what their
consideration is oh yes but
by our particular configuration
the engineering simplicity confers
like an economic advantage even if we're behind
enough in sort of a science sense
okay which is fine that's
there's also what you get when you get
an explosion in the private sector
basically are distributing risks in different ways
right which makes sense
all of that good
but so what I would say is that the
the next hurdle to really overcome
is is about making that electricity
so like we need to see
a unit or several
units like put using fusion
in some way to put a meaningful amount
of energy on the grid because this
starts giving us real
answers
as to like what this is going to look
like the full end-to-end the full end-to-end
thing so Commonwealth School
is that I'll just comment
to Commonwealth because I'll take some
you know some I guess some credit for this
is that the origins
of Commonwealth were in fact
in examining that like we could see
this new technology coming forward
this this new superconducting material
and the origins of our thought process
were really around designing
effectively the pilot plant or the commercial
unit it's called ARC which is
actually the the step forward after spark
and that was the or the origins
of it so all the things that were other parts
of the plant like spark and the magnet
were actually all
informed totally by building
something that's going to put net electricity on the grid
and the timing of that we still hope
is actually the early 2030s
so spark is the design of the Takamaka
and ARC is the actual full end-to-end thing
is like a thing that actually puts the energy
on the grid so spark is named
you know intentionally that it's like it's
on for a short period of time
and it doesn't have a
you know it's the spark of
the fusion you know revolution or something
like that I guess we could call it
yeah so those
those are so those are sort of
the programmatic challenges of doing that
and you know it's
you asked about you talked about SpaceX
so what has evolved
even in the last year or so was
in fact in March of 2022
the White House announced
that it was going to start a program
that kind of looks like a SpaceX
analogy that namely
wow we've got these things in the private sector
we should leverage the private sector
and the advantages of what they obtain
but also with the things like this
is going to be hard and it's going to take
quite a bit of financing
so why don't we set up a program
where we don't really get in the way
of the private sector fusion companies but we help them
finance these difficult things which is how
SpaceX basically became successful
also through the COTS program fantastic
right and that's evolving as well too
so like the fusion
ecosystem is almost unrecognizable
from where it was like five years ago
around those things how important is it
for the heads of
the companies that are working
on nuclear fusion to have a twitter account
and to be quite you said
you don't use twitter I don't use twitter much
I mean there is some element
to and I don't think this should
be discounted whatever you think about
figures like Jeff Bezos
with Blue Origin or Elon Musk
with SpaceX there is
a science
communication to put it
in nice terms
that's kind of required to really
educate the public and get everybody
excited and sell the sexiness of it
I mean just even the videos of SpaceX
just being able to kind of
get everybody excited about going out to space
once again I mean there's all kinds of different
ways of doing that but
I guess what the companies do well
is to advertise themselves
to really sell themselves
well actually I feel like
one of the reasons on this podcast
so I don't have
an official role in the company
and one of the reasons for this
was also that
it's interesting because when you come from
like you're running a company
it makes sense that they're promoting their own product
and their own vision which totally
makes sense but there's also a very
important role for academics
who have knowledge
about what's going on but are
sufficiently distant from it that they're not
fully only self-motivated
just by their own projects
or so forth and for me this is
I mean
we see particularly the problems
of the distrust in technology
and then honestly
in the scientific community
as well too it will be
one of the greatest tragedies
I would say that if we go
through all of this and almost pull off
what looks like a miracle
like technologic and scientific wise
which is to make a fusion power plant
and then nobody wants to use it
because they feel that they don't trust
the people who are doing it
or the technology so we have
to get so far out ahead of this
like so I give
lots of public lectures or things like this
of accessing
a larger range of people
trying to hide anything
you can come and see, you know
come do tours of our laboratory
in fact I want to set those up virtually as well too
you might look at our plaza
size and fusion center YouTube channel
so we are reaching out through those media
and it's really important that we do those things
but it's also then
setting up the realistic expectations
of what we need to do
we're not there
like we don't have commercial fusion devices yet
and you ask like what are the challenges
I'm not going to get into any deep technical
questions of what the challenges are
but it is
the pathway
not just to make fusion
work technically but to make it
economically competitive and viable
so it is actually used out in the private sector
is a non-trivial task
and it's because
of the newness of it
like we're simultaneously trying to
evolve the technology
and make it economically viable
at the same time
those are two difficult couple tasks
so my own
my own research and my own
drive right now
is that fantastic common fusion systems
is set up, we have a commercialization
unit of that particular kind
which is going to drive forward a token mac
in fact I was just
there's discussions, there's dialogues
going on around the world with other kinds of ones
like stellarators which prefer different kinds
of challenges and economic advantages
but what we have to
I know what we have to have
is a new generation
of integrated
scientists, technologists and engineers
that understand like how
what needs to get done to get all the way
to the goal line because we don't have them now
so like a multi-disciplinary team
what's required, I mean you've spoken
about
you said that fusion is
the most
multi-disciplinary field you can imagine
yes, yeah
why is that?
because most of our discussion that we've had
so far is really like a physics discussion
really so which don't
neglect physics at the
origin of this
but already we touched on plasma physics
and nuclear physics which are basically
two you know
somewhat overlapping independent disciplines
then when it comes to the engineering
it's almost everything
so why is this?
to build an electromagnet together
what is this going to take?
it's basically electrical engineering
computer so you understand
how it goes together
what happens
computational engineering to model
this very complex integrated thing
materials engineering
because you're pushing materials to their
limit with respect to stress and so forth
takes cryogenic engineering
which is sort of a sub-discipline
but cooling things to extremely low temperatures
chemistry thing in there too
which tends to show up in the materials
and that's just one of the sub-components
of it like almost everything
gets hit in this right so you're
and you're also in a very integrated
environment because in the end all these
things while you isolate them
from each other in a physics sense
in an engineering sense they all have
to work like seamlessly together
so it's one of those
I mean in my own career
I've basically done atomic physics
spectroscopy
you know, plasma physics
iron etching
so this includes
material science
something called
MHD, Magnetohydrodynamics
and now all the way through
I'm not even sure
how many different careers I've had
it's also by the way this is also
a recruiting
stage for young scientists thinking to come in
my comment to science is if you're bored
in fusion you're not paying attention
because there's always something interesting to go
and do
so that's a really important part
of what we're doing
which isn't new in fusion actually
in fact is in the roots of
what we've done at MIT
but holy cow like the proximity
of possibility of commercial fusion
is the new thing
so my catchphrase is
maybe you wonder like why weren't we doing
all these things like why weren't we pushing
the economic fusion and new materials
and new methods of heat extraction
and so forth because everybody knew fusion
was 40 years away
and now it's 4 years away
there is a history like you said
40-30 whatever the kind of
old joke
there's a history of fusion projects
that
are characterized by cost overruns
and delays
how do you avoid this? how do you minimize the chance
of this? you have to build great teams
it's one of them
it tends to be that the smaller
there's sort of
I'm not an expert in this
I've seen this enough integrated
are there any equations?
I've seen this from enough teams
I've seen also the futility
of lone geniuses trying to solve everything
by themselves
but also organizations that have 10,000 people
in them doesn't
lend itself at all to innovation
like one of our original sponsors
and a good friend
he's got fantastic ideas
about the right sizes of teams
and things that really innovate
and there is an optimum
place in there that you get enough
cross-discipline in ideas
but it doesn't become so overly bureaucratic
that you can't execute on it
so one of the ways
and this was one of the challenges of fusion
is that everything was leading towards
like I have to have
enormously large like teams
just to execute because of the scale of the project
the fact that now
through both
technology and argue
financing innovation
we're driving to the point where it's smaller
focus teams about doing those things
so that's one way to make it faster
the other way to make it faster
is modularize the problem
or parse the problem
so this is the other difficulty in fusion
is that you tend to look at this
it's like oh it's really just about
making the plasma into this state
you know here that you get this energy gain
no because
in the end if you can parse out
the different problems of making that
and then make it as separate as possible
from extracting the energy and then converting it
into electricity the more separate those are
the better they are because you get parallel
paths that basically mitigate risk
this is not new infusion by the way
and this is the way that we attack most
complex technological
integrated technological challenges
have you by any chance
seen some of the application
of artificial intelligence reinforcement learning
a deep mind has
a nice paper has a nice effort
on basically using
reinforcement learning for a learned control algorithm
for controlling nuclear fusion
do you find those
kinds of I guess you throw under the umbrella
of computational modeling
do you find those interesting promising
directions they're all interesting
so when people
I'll pull back maybe
a natural question is like why is it
different infusion like there's a long history
diffusion right it was going on for like I told
you like stories from the late 1960s
like what's different now right
so I think
from the from the technology point of view
there's two massive things which are different
so one of them you know I'll be parochial
it's the advent of this new superconducting
materials because the most
mature ways that we understand
about how we're going to get diffusion power plants
or magnetic fusion and by the fact that you've got
access to something which like
changes the economic equation
by an over an order of magnitude
is just a totally you know and that
that wasn't that long ago it was only September
of 2021 that we actually demonstrated
the technology that changes the
prospects there and the other one
is computing and it's across
the whole spectrum it's not just
in control of the fusion device
it's actually in the we actually use
machine learning and things like this in the
design of the magnet itself it's an incredibly
complex design space so
you use those tools the
simulation of the plasma itself
is actually we're at a
totally different place than we were
because of those things so those are
the two big drivers that I see
actually that make it different
and actually and it's interesting
both those things self
enforce about what you asked about before
like how do you avoid delays and things
by having smaller teams
that can actually execute on those
but now you can do this because
the new magnets
make the devices all smaller
and computing means your human
effectiveness about exploring
the optimization space is way better
it's like they're all interlinked to each other
plus the modularization like you said
and it's everything just kind of works together to make
smaller teams more effective move faster
and it's actually and it's through that
learned experience I mean you know
of the things that I'm the most proud of
about what came out in fact the origins
of thinking about how we would use
the high temperature superconducting
magnets came out of my design
class at MIT
and in the design class like
one of the features that I kept I mean
it was interesting I actually learned I really learned
along with the students about this but
like this insistence on the features like
we can't have so many
coupled integrated hard technology
developments like we have to separate
these somehow so we worked and worked
and worked at this and in fact that that's
what really in my opinion
the greatest advantage of the arc design
and when a you know and and built
into the Commonwealth fusion system idea
is like to parse out the problems
like how can we attack these in
parallel um yeah and
so it really comes to
we talked about philosophy it's like a design
philosophy like how do you attack
these these kinds of problems and
you know you do it like that and also
like you mentioned offline that there's a power
to you know as
part of a class
to design a nuclear
fusion uh
a power plan
and then make it a reality and I and it's
it's hard to imagine a more powerful
force than like 15 MIT
PhD students like working together
towards solving a problem
and what I always in fact we just
we recently just taught
the the most recent you know I say
I teach it I mean I I guide it
actually the most recent version of
this where they actually designed you know based
on this national academies report they
actually designed like the pilot
plant that has basis and
similarities to what we had done before but
you know I kept wanting to like push the
envelope and where they are it's like the
creativity and the
and the the energy
that they bring to these things is kind
of like it keeps me going like that's
you know I'm not gonna retire anytime soon
when I keep seeing that kind of dedication
and it's wonderful around on that
um it almost not to over
use a um
uh or to paraphrase something
right which is that you know the
famous um quote
by Margaret Mead you know never
doubt that a small group
of dedicated you know persons will
change the world indeed it's the only
thing that ever has I mean that's
just such a powerful and inspiring
thing for an individual
find the right team be part of that and
then you yourself your passion your
efforts could actually make a big change
a big impact I gotta ask
you so it's
um it's a whole other
different conversation I'm sure to have
but uh uh nuclear
power as it currently stands so using
uh fission
is extremely safe
despite public perception it is the safest
actually so that's a whole other conversation
but almost like a human
bureaucratic
physics
engineering
question of what lessons do you draw
from the
catastrophic events
where they
the the power plants did fail so Chernobyl
and Three Mile Island Chernobyl what lessons
do you draw she's Three Mile Island wasn't really
a disaster because nothing escaped from the thing but
Chernobyl and Fukushima
were have been you know had
consequences in the populations
that live nearby what lesson
do you draw from those they can
carry forward to fusion now I know
there's you can say that you're not gonna
have the same kind of issues but it's possible
that the same folks
also said there's not gonna be have those same
kind of issues we humans the human
factor we haven't talked about
that one quite as much but it's still there
so to be clear it's so
fusion has the intrinsic
safety with respect to it can't
run away those those are physics
bases technology
and engineering bases of running a
complex again anything that makes large amounts
of power and heats things up is got
intrinsic safety in it and
by the fact that we actually produce
very energetic particles this doesn't
mean that there's no radiation
involved in ionizing radiation
to be more accurate infusion
it's just that it's in a very
different order of magnitude
basically so what are the lessons
the infusion
infusion so so one of
them is make
sure that you're looking at
aspects of the holistic
environmental
and societal footprint that the technology
will have as technologists
we tend not to focus
on these and particularly in
early stages of development like we just
want something that works right
but if we if we come with just
something that works but doesn't actually satisfy
the societal demands
for safety and for
I mean we will have materials
that we have to dispose of out of fusion
just this is but there's
technological questions about what that looks
like so will this look like something
that you have to you know put in
the ground for a hundred years or five years
like and the consequences
of those are both economic
and societal acceptance and so forth
but don't bury those like
bring these up front talk to people
about them and make people realize
that you're actually you know the way
I would look is that you're making fusion
more economically attractive by making it
more societally acceptable as well
to and then realize
is that you know I think there's
a few interesting you know boundaries
basically so one of them
speaking of boundaries that successful
fusion devices I'm
pretty sure will require that you don't
have to have an evacuation
plan for anybody who lives
at the site boundary
so this has this has implications
for what we build
from a fusion engineering point of view
but has major implications for where you
can site fusion devices
right so in many ways it becomes
more like well you know we have fences around
you know industrial heat sources and things
like this for reason right for personal safety
it looks more like that right
it's not quite as simple as that but that's what it
should look like and in fact we have research
projects going on right now at MIT
that are like trying to push the
technologies to make it more look like
that I think that those are key
and then in the end as I said
like so Chernobyl is
physically impossible actually in a
fusion system from a physics
from a physics perspective you can't run away
like it did at Chernobyl which
was basically human error that you know
of letting letting the reactors
like run out of control essentially
human error can still happen nuclear
with fusion based so but in that
one if human error occurs then it just
stops and this is done
and all of those things this is the
requirement of us as technologists
and developers of this technology
to not ignore that
dimension in fact of the design
and that's why me personally
I'm actually pouring
myself more and more into that area
because this is going to be I actually
really think it is an aspect of the
economic viability of fusion because
it clearly differentiates
ourselves and also sets us up to be
about what we want fusion to be is that
again on paper fusion can supply
all of our energy like all
of it so this means I want it
to be like like really environmentally
benign but this takes
engineering ingenuity basically to do
that let me ask you some
wild out there questions
so for talking too much
you know
simple
practical things
in everyday life now only
revolutionizing the entire energy
infrastructure of human civilization yes
so cold fusion
this idea
this dream
this interesting
physical goals seem to be
impossible but perhaps
it's possible do you think it is possible do you think
down the line so we're in
in the far
distance it's possible to achieve fusion
at low temperature
it's very
very very unlikely
and this comes from
so this would
require a pretty fundamental
shift in our understanding
of physics as we
know it now and we know
a heck of a lot about how nuclear
reactions occur
by the way what's interesting is that
there's they actually have a different name
for it they call it leaner like low energy
nuclear reactions but we do have
low energy nuclear reactions we know these
because these come from
particularly the weak
the weak force
nuclear force
so it's at this point
you know as a
scientist you always keep yourself open
but you also demand proof
and that's the thing it almost requires a
breakthrough on the theoretical physics side
so something some deeper understanding
about quantum mechanics so the quantum
tunneling some weird
and people have looked at that but
even like something like quantum tunneling
has a limit as to what it can actually do
so there are people who are genuine
you know
that really want to see it but
it sort of goes to the extort
we know fusion happens
at these high energies
we know this
extremely accurately and I can show you
a plot that shows that as you go to
lower energy it basically becomes immeasurable
so if you're
going down this other pathway it means there's
really a very
different physical mechanism
involved so
all I would say is that
I actually poke in
my head once in a while to see what's going on
in that area
and as scientists we should always
try to make ourselves open
and
but in this one it's like but show me
something that I can
measure and that it's repeatable
and then it's going to take more
extraordinary effort and to date
this has not met that threshold
in my opinion
even more so than just mentioning
or in that question
thinking about people that are claiming
to have achieved cold fusion
I'm more thinking even about
people who are studying black holes
and they're basically trying to understand
the function
of theoretical physicists
they're doing the long
haul trying to
get like okay what is happening
at the singularity what is
this kind of
holographic projections on a plate
these weird freaking things
that are out there in the universe and somehow
accidentally they start to figure out
something weird
and then all of a sudden
there's weirdness all over the place already
somehow that weirdness will
I think on a timescale probably of 100 years
or so that weirdness will open
it just seems like
nuclear fusion
and black holes and all of this
they're next to our neighbors
a little bit too much for like
you'll find something interesting
let me tell you a story about this
it's a real story
so there are really
really clever
scientists in the
end of the late 1800s
in the world you talk about like James
Kirk Maxwell and you talk about Lord
Alvin and you talk about Lawrence
actually who named after these other ones
and on and on and on
and like Faraday and they discovered
electromagnetism holy cow
and it's like they figure out
all these things and
yet there were these weird
things going on
that you couldn't quite figure out
it's like what the heck is going on
with this right
we teach this all the time in
physics classes right so what was
going on well there's just a few
there's just a few kind of
things unchecked but
basically we're at the end of discovery because we
figured out how everything works
because we've got basically Newtonian
mechanics and we've got Maxwell's equations
which describe basically how matter
gets pushed around and how
electromagnetism works holy cow what a feat
but there are these few nagging
things like
for instance there's certain kinds
of rocks that for some reason like if you
put a photographic plate around it
it like it's burned or it gets an image
on it like
well where's the electromagnetism in that
there's no electromagnetic properties of this rock
huh oh yeah
and the other thing too is that if I
if I take this wonderful classical
derivation of how
something that is hot about how it
releases radiation
everything looks fantastic perfect
match oh until I
get to high frequencies
of the light
and then it basically just the whole thing falls
apart in fact it gives a physical
explanation which is total nonsense
it tells you that every object should
basically be producing an infinite
amount of heat
and by the way here's the sun
and we can look at the sun
and we can figure out it's made out of hydrogen
and Lord Kelvin actually made a very famous
you know calculation who is basically
one of the founders of thermodynamics
so you look at the hydrogen
hydrogen has a certain energy content
you know the latent heat basically of hydrogen
we know the mass of the sun because we knew
the size of it and he conclusively
proved that basically
there could only that the sun could only make
net energy for about two or three thousand
years so therefore all this
nonsense about like deep is like because
clearly the sun can only last for two
or three thousand years if you think about
the kept in this is basically the chemical energy
content of hydrogen and what comes along
in one decade
basically one guy sitting
in a postal office you know in Switzerland
figures out that all
these you know Einstein of course
which was like figured out all this
created like took these
seemingly unconnected things
and it's like boom there it is this is what
was interesting but it was like there's quantum
physics like this explains this other
disaster and then this other guy my hero
Ernest Rutherford experimentalist
did the most extraordinary experiment
which is like which was
that okay they had these funny rocks they emitted
these particles they in fact they called them alpha particles
alpha just a in the alphabet
right because it was the first thing that they discovered
and what were they doing so they were
they were taking these alpha
particles and I by the way do this to
all my students because it's a demonstration of
what you should be as a good scientist
so we took these alpha things and he's
classically trained physicists knew everything
about momentum scattering and so over
the like that and he took this
and these alpha which clearly were some kind
of energy but they couldn't quite figure out
what it was so let's try to figure that
we'll actually use this to try to probe the nature
matter so he took this
took these alpha particles
and a very very thin gold foil
and so what you wanted to see was that as
they were going through the way that they
would scatter based on classical in fact
the Coulomb collision based on classical
mechanics this will tell me reveal
something about what
the nature of the charge distribution
is in matter because they didn't know
like where the hell is this stuff coming from
even though they'd solved that electromagnetism
they didn't know like what made up charges
okay very interesting
on through it goes
and so what did you set up so it turns out
in the in these experiments what you did
was because if these out
these so-called alphas
which actually now we know something else
as they go through they would deflect
how much they deflect tells you how
strong an electric field they saw
so you put detectors because if you put
like a piece of glass in front of this
what will happen is that when the alpha particle
hits it literally gives a little
of light like this it scintillates
a little blue flash
so he would train his students or postdoc
or whatever the heck they were at the time
you have to train yourself because you have to put yourself in the dark
for like hours to get your eyes
adjusted and then they would start the experiment
and they would sit there and literally count
the things and they could see this pattern
developing which was revealing about what was going on
but there was also another part of the experiment
which was that
it's like here's the
alphas here's the source
they're going this they could tell they were going
in one direction only basically they're going in this direction
and you put all these over here
because you want to see how they deflect and bend through it
but you put a control in the experiment
but you basically put glass
part of glass
glass plates back here
because obviously everything should
just deflect but nothing should bounce back
so it's a control in the experiment
but what did they see
they saw
things bouncing back
like what the hell
like that fit no
model of any idea
right but Rutherford like
refused to like ignore
what was a clear like they validated
it and he sat down
and based on classical physics he made
the most extraordinary discovery
which was the nucleus
which is a very very strange discovery
what I mean by that
because what he could figure out from this
is that in order for these particles
to bounce back
and hit this plate they were hitting
something that must be heavier than them
and that
basically something like 99.999%
of the mass
of the matter that was in this gold foil
was in something that contained
about one trillionth
of the volume of it
and that's called the nucleus
and until
and you talk about so how revealing is this
it's like this totally changes
your idea of the universe
because a nucleus is a very
unintuitive non-intuitive thing
it's like why is all the mass
in something that is like zero
basically is the realization that matter
is empty it's all empty
space and that changes everything
and it changes everything
until you had that like you had steam engines
by the way you had telegraph wires
you had all those things
but that realization
those two realization opened up everything
like lasers
you think about the modern world of what we use
and that set it up
so all I would point out is that there's a story already
that sometimes there's these nagging things
at the edge of science
that you know we seem
we pat ourselves on the back and we think we got everything under control
and of course
by the way that was the origin
but also that
think about this that was 1908
it took like another 20 some
years before people
put that together with that's the process
that's powering stars
is the rearrangement
of those nuclei not atoms that's why
Kelvin wasn't wrong
he just was working with the wrong assumptions
so fast forward to today
like what would this mean
there's a couple of things like this that sit out there in physics
and I'll point out one of them
that's very interesting
we don't know what the hell makes up 90% of the mass
in the universe
so the search for dark matter
what is it we still haven't discovered it
90% of the mass
of the universe is undetectable
like what
and then dark energy and again
black holes are the window
into this
I mean sometimes black holes are way better understood
than those things as well too
so all it tells us is that
we shouldn't have hubris about
the ideas that we understand everything
and when we you know who knows
what the next major
intellectual insight will be
about how the universe functions
and actually I think
Rutherford is the one who's
attributed at least that quote
that physics is the only real
science everything else is stamp collecting
right so there's
I'm sorry he's my hero but I'll slightly disagree
with that yes
well no offense to stamp collecting
that's very important too
but you know that you have to have humility
about the kind of disciplines that make
progress at every stage in
science
physics did make a huge amount of progress
in the 20th century but it's possible
that other disciplines start to step in
yeah but Rutherford couldn't imagine like mapping
the human genome because we didn't even know
about DNA or computers
really or computers he really probably didn't
think deeply about computation
here's a wild one what if like
the next great
revelation to humanity
about the universe is not done by the human mind
that seems increasingly
likely more likely
and then you start to ask deep questions
about what is the purpose of science
for example if
AI
system will design
a nuclear fusion reactor
better than humans do but we don't quite understand
how it works and the AI
can't we know that it works
we can test it very thoroughly but we don't know
exactly
what the control mechanism is maybe what the chemistry
the physics is
AI can't quite explain it
it's impenetrable to our consciousness
basically trying to hold it all together
and then okay so now we're living in that world
where many of the biggest
discoveries are made by AI systems
yeah
as if we weren't going big
yeah I say
let's again as a point out
when my godmother was born
none of this was in front of us
we live in an amazing time
it's like
my grandfather plowed
fields with a horse
I get to work on designing fusion reactors
yeah
pretty amazing time
but still there's humans so we'll see
if that's around 100 years
maybe it'll be cyborgs and robots
I think we're pretty resilient actually
that's one lesson from life
is it finds a way
let me ask even a bigger question
as if those weren't big enough
let's look out
maybe a few hundred years
maybe a few thousand years out
there's something called the Kardashev Scale
it's a method of measuring civilizations level
of technological advancement based
on the amount of energy it's able to use
so type one civilization
and this might be given all your work
is not no longer a scale
that makes quite make sense
but
it very much focuses on the source of fusion
natural source of fusion
which is for us the sun
and type one civilizations are able to leverage
sort of
collect all the energy that hits earth
and then type two civilizations
are the ones that are able to leverage
the entirety
of the energy that comes from the sun
by maybe building something
like a Dyson sphere
so when will we reach type one status
is get to the level
which where I think
maybe a few orders of magnitude away from
currently
and in general do you think about this kind of stuff
where energy is so fundamental to
like
of life on earth but also the expansion
of life into the universe
oh yeah so
one of the fun on a
weekend when I sat down
and figured out what would it mean for interstellar
travel like to have a DT
fusion in fact
I talked about my design class
one of my design classes was how you use
essentially
a special configuration
of a fusion device for not only
traveling to but colonizing Mars
so what would
you talk about energy use
being at the heart of civilizations
like so what if you want to go to Mars
not to just visit it but actually like
leave people there and make it something
and these massive amounts of energy
so what would that look like
and it actually transforms how you're thinking
about doing that as well too
oh yeah so we do those kinds of fun
and actually it was a fairly quasi-realistic
actually so do you think
it'll be nuclear fusion that
powers the civilization on Mars
well what we considered was something
so it turns out that there's thorium
which is a heavy element
so it's a so called fertile
element that we know
we still know fairly little
about the geology
of Mars in a deep sense
and we know that there's a lot of this
on the surface of Mars so one of the things we considered
was what would happen that it's
basically a combination of a fusion
device that actually
makes fuel from the thorium
but the underlying
energy one was
fission itself as well too
so this is one of the examples of being
trying to be clever around those things
or what is it you know
this also means is like interstellar travel
it's like oh yeah that looks almost like impossible
basically from an energy balance
point of view just because like the energy
required that you have to transport
to get there almost the only things that
would work are DT fusion
and basically
annihilation it's like Star Trek
right?
your sense is that interstellar
travel will require fusion
power oh it's almost
impossible with fusion power actually
it's so hard
because you have to carry the fuel
with you and the rocket
equation tells you about how much fuel you use
to take so
what you end up with is like how long does it take
to go to these places and it's like
staggering you know periods of time
so I tend to believe
that there's alien civilizations
dispersed all throughout
yeah but we might be totally isolated
from them so you think we're not there's none
in this galaxy
so like I guess
and the question I also have is what kind
do you think they have nuclear fusion
is it all the physics all the same
yeah oh the physics all the same yeah
right so this is the and this is the Fermi
paradox like where the hell is everybody
in the universe right
well there's some so you know the scariest
one of those is that
I would point out that there's been
you know there's you know order of many
tens of millions of species
on the planet earth and only
one ever got to the point of
sophisticated tool use
that we could actually start essentially
leveraging the power of
what's in nature
to our own will does this mean
that basically this means so almost
look there is almost certainly life
or DNA equivalents
or whatever would be somewhere I mean just because
you just need a soup and you need energy
and you get organics
and whatever the equivalent of amino acids
are and but you know most of the life
on earth has been that those are still
amazing but it's still like this it's not
very interesting are we are we
actually the accident of history this is
a very interesting one super
super rare super rare
and then of course the other part is that
also just the other
scary part of it which if you look at the
fairy paradoxes good good we got to this
point how long is it
been in humans
so humans homo sapien has been around
for whatever 100,000 years 200,000 years
on with
our ability in that timeline
to actually make an imprint on the
universe like for by emitting
radio waves or by modifying
nature in a significant way
has only been for about 100 of those
100,000 years
and you know are we it's a good
question so is it by definition
that by the fact that when you
are able to reach that a level
of being able to manipulate nature
and for example discover
you know
discover like fission
or other or
burning fossil fuels and all this
is that what it says oh you're doomed
because by definition
any species that gets the point that can
modify their environment like that
they'll actually push themselves
you know past that's one of the most
depressing scenarios that I can imagine
so basically
we will never line up in time
with this little teeny window in time
where civilization might occur
and you can never see it because you never
these sort of like
scatter like fireflies
around the galaxy and you never yeah
goes up and then explodes
destroys itself because of the exponential
and when we say destroy ourselves all
would have to do is that we basically go
if humans are all left
and we're still living on the planet
but all we have to do is go to
the technology of like you know
1800 and we're invisible
in the universe again
yeah so it was when I
when I listened to the I thought I wanted to
talk about this as well too because it
comes from a science point of view
actually of what it means but also to me
it's like another compelling driver of
telling us like why we should try
really hard not to screw this up
like we're in this unique place
of our ability to discover
and make it and I just
don't want to give up about thinking that
we can get through. Yeah I
tend to see that there's some kind of game
theoretic force like with the mutually shared destruction
that ultimately
in each human being there's
a desire to survive
and a willingness to
cooperate, to have compassion
for each other in order to survive
and I think that I mean
maybe not in humans
but I can imagine a nearly infinite
number of species in which
that overpowers
any
technological advancement that can destroy
or rewind the species so
I think if humans fail
I hope they don't
I see a lot of evidence for them not
but it seems like somebody will survive
and there you start to ask questions about
why we haven't met yet
maybe it's just space is large
oh spaces it's
I think in logarithms
and I can't even fathom
you know space this is
extraordinary right?
It's extraordinarily large
I mean there's so many places on earth
I just recently visited Paris for the first time
and there's so many other places I haven't visited yet
there's so many other places well I like to
you know it's interesting that we have this fascination
with alien life
we have what is essentially
alien life on earth already
like you think about the organisms that
develop around deep sea like
thermal vents one of my favorite books
of all time from Steven J. Gould
if you've never read that book
it kind of blows your mind
it's about the Cambrian explosion
of life and it's like oh you look at these
things and it's like
the chance of us existing as a
species like the genetic
diversity was larger back then
you know this is about 500
million years ago or something like that
it is a mind-altering trip
of thinking about our place in the universe
I have to say plus the mind itself
is a kind of alien
with almost
almost a mystery to ourselves
we still don't understand it the very
mechanism that helps us explore the world
is still a mystery
so that like understanding
that will also unlock
quite
quite possibly unlock our ability to
understand the world and maybe build
machines that help us understand the world build tools that
I mean it already has I mean
our ability to understand the world
is ridiculous almost
actually
and post the bottom
it's almost unbelievable
we've gotten all this too
so what advice would you give
to young folks
or folks of all ages who are lost
in this world looking for a way
looking for a career they can be proud of
or looking to have a life they can be proud of
yeah oh the first thing I would say is
don't give up I get to see
multiple sides of this
and you know there's seems to
be a level of despair
in a young generation
it's like
it's almost like the
multi python skit like I'm not dead yet
right I mean
we're not there
we're in a place that
you know
don't say the world's gonna end in 300 days
or something it's not okay
and what we mean by this is that
we have a robust society
that's figured out how to do like amazing things
and we're gonna keep doing amazing things
but that shouldn't be complacency
about what our future is
and the future for their children
as well too
and in the end I mean it's a very
it's a staggering legacy to think of what
we've built up primarily
by basically using carbon fuels like people
almost tend to think of this as an evil thing
that we've done I think it's an amazing
thing that we've done but we
owe it to ourselves
and to this thing
that we've built let me tell you about the end of the world
is this nonsense what it is
is the end of this kind of lifestyle
and civilization at this
scale and the ability to execute
on these kinds of things that we are talking about today
like we are extraordinarily privileged
we're in a place where
it's just it's
it's almost unfathomable compared to most
of the misery that humans have lived
in for our history so don't give up
about this okay but also roll up your
sleeves and let's get going
at solving and getting real solutions
to the problems that are in front of us
which are significant
you know it's
most of them are linked to
what we use in energy but it's not just that
it's around all the aspects of like
what does it mean
like what does it mean to have a distributed
energy source that lifts billions of people
out of poverty you know particularly
outside of like the western nations right
that seems to me a pretty
compelling you know
moral goal for
all of us
but particularly for this upcoming
generation and then the other
part is that we've got
possible solutions in front of us
apply your talents
in a way that
you're passionate about and
is going to make a difference
and that's only possible
with optimism, hope
and hard work yeah
what easy question
certainly easier in the nuclear fusion
what's the meaning of life
why are we here 42
is it 42
we already
discussed about the beauty of physics
that there's almost a desire to ask a why question
about why the parameters have these values
yeah it's very tempting
yeah it's
an interesting hole to go down
as a scientist because we're
a part of what people
have a hard time
who aren't scientists have a hard time understanding
what scientists do to themselves
and a great scientist does a very
non-intuitive or non-human
thing what we do is we train
ourselves to doubt ourselves like how
like that's a great scientist
we doubt everything we see
we doubt everything that we think
because we
we basically try to turn off
the belief valve
that humans just naturally have
so when it comes to these things
like I can
make my own comments to this it's like
personally you see these things
about the ratios of life and I made a comment
I said well you know a wrap my
some part of my brain that just goes
yeah well yeah because we're the only
interesting you know multiverse because
by definition it has to look like this
you know but there's
I have to say there's other times I can say
in the history of the hole
of what has happened over the last 10 years
there have been some pretty weird coincidences
like coincidences
that like you look at it and just go is
that really was that really a coincidence
is
something like pushing us
towards these things
and it's a natural it's a human instinct
because you know since the beginnings of
humanity we've always assigned
you know
human motivation and
and needs to these
somewhat you know empirical observations
and in some sense the stories
before
we understand the real explanations
the stories the myths
serve as a
as a good approximation
for the thing that we're yet to understand
and in that sense you said the antithesis
to sort of scientific doubt
is having a faith
in these stories
they're almost silly
when looked at from a scientific
perspective but just even the feelings
of it seems that love
is a fundamental fabric of human
condition and what the hell
is that
why are we so connected to each other
as a physicist I go it's
this is a repeatable thing
that's due to a set of synapses
that fire in a particular pattern
and all this you know that's kind of like
okay man what a drag that is
right to think of it this way
and you can have an evolutionary biology explanation
but there's still a magic to it
as a scientist some of my colleagues
do this as well too
what is spirituality
compared to science
my own feeling
in this is that
as a scientist
because I've had the pleasure of being able to
both understand what my predecessors did
but I also had the privilege
of being able to discover things
as a scientist
and I see that
in just the range of our conversations
like
that is my
it's the awe that comes
from looking at that
that is if you're not in awe
of the universe and nature
you haven't been paying attention
I mean my own personal feeling is that
I feel
if I go snorkeling
on a coral reef
I feel more awe than I could ever feel
like in a church
you kind of notice some kind of magic there
there's something about the way the whole
darn thing holds together
that just sort of escapes your
imagination and that's
to me this thing of
and then we have different words we call them holistic
or spiritual
the way that it all hangs together
in fact one of the interesting you asked about
what I think about one of the craziest things
that I think that how does it hold together
is like our society
like how does what
like how are
like you just think of the United States
there's 330 million people
kind of working like
this engine
about going towards making all these things happen
but there's like no one in charge of this
really
how the heck does this happen
it's kind of like it's
so these things these are the kinds of things
mathematically and organization wise
that I think of
just because they're sort of awe inspiring
and there's different
ideas that we come up together and we share them
and then there's
teams of people that share different ideas
and those ideas compete like there's
the ideas themselves are these kinds of different organisms
and ultimately somehow we build
bridges and nuclear reactors
and do those things well I have to give a shout out
to my daughter by the way who's
who's interested she's an applied math major
and she's amazing at math
and over the break she was showing me she's doing research
and it's basically about how
ideas and ethos
are transmitted within a society
so she's building an applied math model
that is explaining like
she was showing me
on this like this simulation she goes
oh look look at this and I said oh
that's like how political parties like
evolve right and even though it was a rather
you know quote unquote simple math
mathematical model it wasn't really
it's like oh wow
well maybe she has
a chance to derive mathematically the
the answer to the what's the meaning of life
there we go and maybe it is indeed 42
well
Dennis thank you so much for just
creating tools
creating systems exploring
this idea
that's one of the most amazing magical
ideas in all of
human endeavor which is nuclear fusion
I mean that's so interesting
you know it's almost like my
one of my lifelong goals
is like to make it it's not
magic it's like it's boring
and this means we're
using it everywhere right yeah
yeah and the magic
is then built on top of it
well thank you for everything you do
thank you for talking to me it's a huge honor
this was a fascinating and amazing conversation
thank you
thanks for listening to this conversation with Dennis White
to support this podcast please check out
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and now let me leave you with some words
from Albert Einstein
there are two ways to live your life
one is as though
nothing is a miracle
the other is though everything is a miracle
thank you for listening
I hope to see you next time