This episode is brought to you by Brilliant. In response to new Quantum theories, Einstein
quipped âGod does not play diceâ. One wonders what he would have said if he
knew some of those dice are also highly explosive! Antimatter is the most destructive material
in existence--to regular matter anyway. A gram of antimatter coming into contact with
a gram of matter would destroy both, releasing 50 million kilowatt-hoursâ energy. If done
suddenly, it would explode with almost 3 times the power of the Hiroshima Bomb, and if we
can figure out how to mass produce and store the material, it could serve as both the greatest
weapon and greatest starship fuel. But we can also use it for more peaceful, mundane
and smaller applications, which weâll be discussing today.
When it comes to Antimatter weâve got 5 areas we need to discuss. The first is what
it is and what it is not, the second is how we could mass produce it, the third is how
we could store it for long periods, the fourth is how we could keep this dangerous material
secure from accident, theft, and sabotage, and the fifth is all its applications and
uses as an amazing form of stored energy and initiator of desirable nuclear reactions.
This is going to be one of our longer episodes and weâll be dipping into particle physics
fairly deeply, so nowâs a great time to grab a drink and snack to power your brain.
Antimatter, also known as Mirror Matter, is a material thatâs prone to a lot of misconceptions
and confused discussion in both science-fiction and popular science, and we need to clear
some of that up. First, while antimatter in bulk form is quite rare, it is something you
encounter all the time, indeed you have particles of it kicking around your body, though only
briefly. So getting hit by one antiparticle will not make you explode.
Youâve probably heard that bananas are mildly radioactive, and this is true. In rare cases
this represents antimatter in action. Potassium-40 is an isotope with a half-life of around a
billion years and one of its decay modes results in the creation and emission of a positron,
the antiparticle of the electron, and this is an example of Beta Decay and Beta Radiation,
terms which apply to both the emission of electrons, and the emission of antimatter
positrons. Beta Decay happens every time any atomic nucleus decays in a way that changes
the electric charge of the nucleus. This positron emission should not be confused with the atom
âcontainingâ a positron; it does not. This makes it totally different than an antimatter
atom, which has shell(s) of positrons around a nucleus composed of antiproton(s) and antineutron(s).
In the case of the simplest antiatom, antihydrogen, there are no antineutrons.
This gets at a key notion: every particle type with an electric charge has an opposite
version with the reverse charge. For complex reasons our Universe ended up with vastly
more protons, neutrons and electrons than anti-protons, anti-neutrons and anti-electrons,
or positrons. Weâre not precisely sure why, and itâs quite possible there are Universes
where the exact opposite happened, so that protons and electrons are rare instead. Such
Anti-Universes would be identical to ours in their behavior, except all the people in
them would be evil and have goatees, in accordance with the Law of Conservation of Evil.
Now, anti-matter is not just reverse charge, itâs specifically a particle of the same
mass but with opposite electric charge, which is like static electricity, not flowing charge
like electric current. Thereâs more than just electric charge too, there is also opposite
Parity, meaning chirality, or in everyday terms, which way the thread of a screw goes,
clockwise or counter-clockwise. At a deeper level there are differences which help to
define the various particle families, such as color charge, with antimatter having anti-colors.
Donât worry if you are unfamiliar with many of these terms, just know that there are aspects
of subatomic particles which make for many unique kinds and characteristics. They can
combine in many ways, as dictated by those characteristics. Where they canât combine,
it is like oil not mixing with water: they just behave in their own ways. All these unfamiliar
traits might just as well have been described in other ways, like shapes, sounds or textures.
In this context, âColorâ is the accepted term for certain properties of quarks, which
combine in sets of 3 to form protons, neutrons, and their other class members. Quark color
has nothing to do with visible color. We just found a property of quarks that came in three
types, each with a reverse, and they got labeled as red, green, and blue to make visualizing
them easier. They also come in anti-red, anti-green, and anti-blue though weâll often use cyan,
magenta, and yellow for them respectively. Again nothing to do with actual colors, we
just needed a term for something we had no intuitive concept for. In truth, electric
charge is made up too â ignoring that all words are made up â some terms for electricity
derive from terms used in artillery and cannons, where a charge is the gunpowder you put in
a canon. We also have the oddly-named quark âflavorsâ, with up and down â the most
common quarks â along with strange, charm, top, and bottom, and these have nothing to
do with actual flavor or personality traits. Itâs common to say that when you combine
anti-matter with regular matter âit explodes,â but thatâs not quite true. A photon for
instance has an anti-photon but its effectively just another photon, because photons donât
have any electric or color charge and when two are in the same place at the same instant
they obviously donât explode. Indeed, a positron and electron donât exactly explode
either, they are pulled together by their opposite charge and combine briefly, then
their tiny mass turns into a pair of energetic photons, gamma rays, which shoot off in opposite
directions. This leads to one of the easiest ways to discuss
the very tiny mass of the electron and other particles, using electron-volts. When you
collide a positron and electron, you get two photons whose total energy is equal to the
mass-energy of those two particles and you measure that, using Einsteinâs E=mc², and
now you know the mass, 511,000 electron-volts each, or .511 MeV, mega-electron volts per
electron. Twice that for an electron-positron pair, either created or destroyed. One electron-volt
(eV) is the energy which an electron or positron gains or loses when passing between electrodes
with a voltage difference of 1 volt. This is why you so often hear particle mass and
energy given in electron-volts, kilo, mega, giga, or tera electron-volts. Everything was
initially measured in terms of how an electron acted in an electric field of a certain voltage
and the nomenclature stuck for both mass and energy of tiny particles.
Anyway the âexplosive propertyâ of anti-matter has to do with what happens when two particles
of different net properties merge and give out new particles: usually some high-energy
photons and often other particles that may be unstable. These properties are carried
by leptons - a type of particle that includes things like electrons, positrons, and muons,
and by quarks, the constituents of neutrons, protons and mesons. So even though an anti-neutron
has no electric charge, it is a distinct object that will annihilate if it closely encounters
a regular neutron, or indeed a regular proton, but thereâs no opposite electric charge
sucking the two together so the interaction chance, often referred to as the cross-section
(in âbarnsâ), is quite low. The neutron, unlike the photon and some other particles,
is not its own antiparticle. Except in a perfect vacuum, collisions between free antiparticles
and normal particles is not a question of if, but when.
Also, itâs an example where the annihilation product isnât just photons, you can get
pions and kaons and gluons and other things too. Pions incidentally are two-quark particles,
so is the kaon but one of those quarks is a strange quark rather than an up or down,
and gluons bind quarks together, like electrons bind molecules together. In general such two-quark
particles are very short lived, and where quark-based annihilations are concerned, itâs
the quarks that are hitting anti-quarks. Itâs not really about if theyâre a proton or
a neutron. Itâs really if two particles are interacting
and if they just happen to be totally opposite you get a pure annihilation and new stuff
forming from all of it, be it photons, pions or other particles, with photons being more
easily observed. Normally stuff collides and interacts and most of the energy is just transmuting
into new particles that all act very locally, while photons will generally escape that atom.
Whenever we talk about nuclear fission or fusion and comment about how youâre only
getting a percent or less of the mass-energy out of the deal, thatâs basically why: virtually
all the interactions that produce them is basically just shuffling around the particle
types inside with a little energy released externally, but when it shuffles all that
into photons thatâs a 100% conversion into a type of energy that can both escape the
atom and be absorbed by other matter it runs into, like you. Neutrinos incidentally do
have an anti-particle, the anti-neutrino, but neutrinos interact with virtually nothing
so itâs not explosive the way we normally think of as anti-matter. Getting whacked by
hordes of neutrinos or anti-neutrinos isnât going to incinerate you, and a good thing
too. We are all constantly penetrated by passing neutrinos, mostly from the Sun, but only in
the rarest cases is there any change to us from that passing swarm.
We also should note that things like protons and neutrons arenât really made of just
three quarks. If youâve ever seen quark mass and compared it to a proton or neutron
mass youâd notice that those up and down quarks only mass about 2.2 and 4.7 MeV each,
about four and nine times an electron or positrons mass, whereas a proton or neutron is around
2000 times the electronâs mass, the neutron being a bit heavier because it has one up
and two down quarks instead of two up and one down, a tiny mass difference. Only around
1 percent of their apparent mass is actually the mass of those quarks. The other energy
is in gluons and we also have âsea quarksâ, which are the virtual particles popping in
and out of existence inside the nucleus all the time, the normal three quarks being known
as valence quarks. That notion of stuff popping in and out of
existence is worth keeping in mind because itâs a critical aspect of producing antimatter,
since matter is popping in and out of existence all the time as virtual particles, and it
always does so as a pair, a particle and its antiparticle. They generally annihilate near
instantly, but by separating them we can produce and collect antimatter.
I know this idea of seething stuff going in and out of existence tends to bug people but
this is mostly a product of trying to view quantum entities as stable classic objects
with a macroscopic analogue. Subatomic particles arenât little balls, theyâre stable or
not-so-stable energy packets smeared across a place and only certain combinations are
stable. At super-tiny time scales many more particles and paired particles can exist.
Without virtual particles, many important aspects of our universe would not function
at all, fusion inside stars being a prime example. Stellar fusion cannot proceed until
some protons change into neutrons, but protons cannot change into neutrons except with the
aid of very heavy W bosons, which are more massive than entire iron atoms, and therefore
cannot be created as real particles in the not-super-high energy conditions inside normal
stars. But as virtual particles, W bosons can be called into existence there, very very
briefly. Quantum entities arenât objects but more
like patterns of energy, and only a handful of patterns donât collapse, and thereâs
always the mirror-image patterns that are equally viable, the antiparticles. When those
two meet they collapse and that energy forms something else, but that something is always
popping out with its own mirror image, photons just happen to be their own mirror image.
Related to these virtual particles is a virtual energy to spacetime. A little handful of space
has some energy in it in addition to all the atoms or photons actually passing through
it, and that base-level energy is constantly seething around forming a pattern and its
anti-pattern and pretty much falling right into each other to recombine and vanish. As
these were virtual patterns, they leave no residue of real energy.
Every so often stable matter or energy will bump through one of those virtual interactions
and something else will happen as that particle interacts with one of them and thatâs essentially
how all the various subatomic processes happen. But if you had a virtual electron-positron
pop up inside a very strong electric field â and this has to be very strong because
theyâre really close and opposites attract â you could pull them apart and make new
matter. This isnât free energy though, you have to provide real energy in order to make
the virtual pair become real. On their own, those base level energy fluctuations of spacetime
always return to the zero level, hence all the talk of quantum fluctuations and the vacuum
not really being a vacuum, but bubbling and seething with potential, or vacuum energy.
It really is often easier, and reasonably accurate, to just think of it as a big soup
of energy out of which some more packets of energy can sometimes linger as what we think
of as particles for long times, which in particle terms can be anything from a trillionth of
a trillionth of a second to trillions and trillions of years. Some energy configurations
are more stable than others; those we call particles, but the vast majority arenât
stable at all. Anyway, this is not a particle physics lecture
but we had to go over some of that to explain why it's so hard to make and store anti-matter,
and why itâs so useful if we can. Which is to say, it is stupidly easy to make antimatter
but itâs really hard to do it in a way that lets you grab those particles before they
ram into something else and go away, which is a big issue for production and storage.
Virtually all matter, at the molecular and macroscopic scale, is electrically neutral
or very close to it. If you try to cram protons or electrons, or their anti-particles, into
a box with just that one type in it, the amount of electric force they have would be massive.
Electromagnetism is trillions of trillions of trillions of times stronger than gravity,
so you canât make a box full of protons or a box full of electrons because the repulsive
force between them all is insane. Similarly you canât make a beam of electrons
or protons stay together because theyâre trying to shove off each other into a widening
cone, and if youâre mass producing anti-particles in some spot theyâre all trying to shove
off each other and scattering and running into other things that will blow them up.
You need to produce them as charged particles in order to separate the matter and antimatter
particles because they actively seek each out out if mixed together. But you need them
to be mostly electrically neutral if you want to store them at some useful density. Not
totally neutral though, so that you can actually move the stuff around electrically or magnetically.
We might have one possible mode of production and manipulation suggested, like the Stellaser,
by the fertile mind of Steve Nixon, a method thatâs still a bit out there but maybe could
be made to work. Youâve heard of using lasers as optical tweezers Iâd imagine, and theyâd
be one way to manipulate these particles without electrostatics or magnetostatics, allowing
us to play with electrically neutral antimatter. Since these things we call particles can be
thought of as really being energy patterns with specific wave-states, we might be able
to literally build them out of light, in the configuration and location of our choosing,
using certain extensions of 3D holography. Essentially using a specialized waveguide
to produce two equal and opposite interference patterns of intense light to pull the desired
particle pair out of the quantum foam and tease them apart, be it an electron and positron
or a proton and antiproton or a neutron and antineutron. Eventually even something much
bigger like a molecule and its anti-molecule, which would be a lot easier to store at a
desirable density. Thatâs pretty far out there and probably a topic worthy of its own
episode, but deserves a mention. Particularly since your ideal antimatter for
storage is something bigger and more stable than a gas of antihydrogen. Normally we talk
about creating anti-hydrogen by just getting an antiproton and positron to link up but
weâd infinitely prefer big macroscopic slabs or beads of some material like anti-iron,
which you could easily store by old-fashioned magnetic levitation in a small vacuum compartment
of some material thatâs not going to get wrecked by a very occasional single atom annihilation,
essentially a normal bit of radiation shielding material.
There is a type of Titanium we believe is produced by white dwarf collisions and their
resulting supernovas, called Titanium 44, which is highly radioactive and decays only
by electron capture, then goes on to produce antimatter positrons. We see its telltale
antimatter annihilation gamma ray signature near our crowded galactic core, but it is
produced throughout the galaxy. Titanium 44 has a half-life of 60 years, but it is believed
its half-life increases with ionization and becomes stable when fully ionized. It might
not be antimatter itself, but may allow us to safely and more easily use its positron
antimatter decay product in our matter world. Eventually we may send harvesters to collect
Titanium 44 from white dwarf supernovae, or learn to produce it efficiently locally.
Now on the production end in the more near-term and tested fashion, youâve probably heard
we need to dump many million of times more energy in to get antimatter out. Weâve been
getting better at that, and itâs worth noting we donât normally set up particle accelerators
with mass production of antimatter in mind. Theyâre normally just particle experiments
to find and measure exotic particles, not mass produce them. Weâve had design concepts
for mass production for decades that were thought to be able to do more like 10,000:1,
which sounds terribly inefficient but surprisingly would be very useful. Back in 1995, in his
book âIndistinguishable from Magicâ, Robert L. Forward suggested using a large solar array
about 100 kilometers across with a power output of about 10 terawatts to produce about a gram
of antimatter a day. Again, thatâs inefficient as heck but weâve
talked before about possibly shading the Earth to cool it, and such a panel would help with
that. Or to switch over to using power satellites to beam energy down to Earth, and since you
always want more output capacity than you need and solar panels have no fuel they burn,
you could use the surplus capacity or excess outside peak hours and days to run such antimatter
factories. Similarly weâve talked about the simplest of Dyson Spheres, Swarms of thin
mirror power satellites, statites, or lagites englobing the Sun, which could be constructed
using relatively little mass, exactly the sort of manufacturing a simple and early-design
clanking self-replicating machine would excel at.
Something like that built by such machines could probably be assembled over a vastly
shorter timespan than it would take for human populations to reach the number needed to
fill out a Dyson Swarm of habitats. Folks often ask what youâd do with all that power.
Producing antimatter that way, even at 10,000:1 efficiency, is one example of what you could
do, producing a few million tons of antimatter a day. After all, minus the ecliptic plane
the planets are on, we donât use any of that sunlight and it just goes to waste in
the void, so we might as well get use out of it, even if itâs inefficient use; 1%
of 1% is far better than zero, especially when talking about starting with 2 billion
times more energy than received by the entire Earth.
It's worth noting though that there are some natural sources of antimatter. Cosmic rays
tend to produce it and we estimate about a kilogram of anti-protons passes through our
solar system every second. We could potentially scoop it up from the upper atmospheres of
any of the planets and the gas giants have a lot more than we are producing now. Saturn
has about 250 micrograms produced each year. Still, that wonât get the job done for anything
but scientific uses or for sending off tiny probes. Though if those tiny probes are von
Neumann probes, self-replicators that can arrive at another star after making the journey
at a high fraction of light speed and unpack and build stuff, like the interstellar laser
highway system weâve discussed using before to let ships run on rivers of light between
stars. Thatâs another thing you can use the Sunâs excess power for.
Our local natural sources just canât be regarded as anything more than meager, but
it is worth nothing that things like black holes and neutrons stars can spew antimatter
out. They are essentially giant high-powered particle colliders with relativistic particle
jets, so those might become antimatter farms in a distant future, and I say farm rather
than mine because you could augment the process around them to fertilize production and harvest
antimatter. In many cases antimatter production might
simply be a byproduct of another process too. We talked about using surplus space-based
solar power to run production a moment ago, but you might get antimatter as a byproduct
of power production, too. Short of farming it in an extreme astrophysical
setting, itâs not very likely anyone would ever come up with a way to economically power
a civilization on antimatter, as even a high-efficiency method would still need more power input than
the antimatter produced would release, but we have a concept called antimatter catalyzed
fusion. Same as we can catalyze fusion in a hydrogen bomb by using a regular fission
bomb to set it off, itself usually set off by conventional chemical explosives, you can
catalyze fusion by using a tiny amount of antimatter. Current estimates say you need
about a microgram of antimatter to trigger a thermonuclear detonation and it need not
be a big one, making it rather ideal for things like pulsed-nuclear spaceships as we looked
at in the episode âThe Nuclear Optionâ. Ideally weâd like a spaceship that used
pure matter-antimatter reactions for fuel, but fusion driven ships are nothing to sneeze
at and antimatter-catalyzed fusion might be a good way to do this. You could also potentially
be using the power produced by the fusion event, which is much more than that released
by the antimatter catalyst, to power more antimatter production. Producing your antimatter
for this process while youâre in flight would be very handy, given the storage issues
with antimatter which have been mentioned. Weâll get back to them a moment.
First though, there is an alternate version of catalyzed fusion using muons rather than
positrons, antiprotons or antineutrons. Muons are short-lived and much more massive versions
of electrons, often generated in our upper atmosphere by cosmic ray proton collisions
that first yield pions, which then decay into muons. You get hit by thousands every minute
and theyâve got a good penetration value, they can bounce around a lot and this can
be used to catalyze fusion in deuterium or deuterium and tritium.
This is an amazing way to catalyze fusion, and to do it at room-temperature too, and
this one isnât theoretical, itâs been done in labs plenty of times for decades now.
It also produces antimatter as a small but significant byproduct while itâs at it.
However, it has got a couple problems. First, the muon will stick to an atom a bit less
than 1% of the time it hits one so it only bounces around so many times igniting fusion
events before it decays, and second, weâre quite inefficient at producing muons, much
like antimatter. If we were better at producing muons efficiently, that alone might solve
the problem, but it is possible we could set this up on a grander scale in some environments
that were more hospitable to this process, such as the upper atmospheres of gas giants.
Again as suggested by Steve Nixon, here are some methods of defeating the problems with
getting power from Muon Catalyzed Fusion. Getting some fusion energy is easy, but getting
useful net energy is not. First of all, the deuterium and/or tritium needs to be in a
very dense form, so that many useful muon collisions will occur during the brief lifetime
of each muon. That either means insanely high pressure, use of liquid isotopes of hydrogen,
or both. The usual method has been bombarding cryogenic liquid deuterium with muons, and
it works very well for warming the super-cold liquid, but that only consumes power, for
turning the gas back to liquid. The problem is the liquid is made at a much colder temperature
than the ambient temperature anywhere on Earth. That kind of refrigeration consumes a lot
of energy. To turn this fusion into an energy source,
the dense state must be achieved cheaply, and the warmed state must do net work, just
like the Rankine Cycle using water and steam in a normal steam-electric generating station.
Normally, like with any other gas, compressing hydrogen isotopes to high pressure as gases
uses a lot of energy and generates a lot of waste heat, so that is not a productive path.
BUT, if a very cold heatsink was available, like the middle-to-upper atmosphere of Neptune,
then the gas could be compressed and even liquified using a relatively small amount
of energy. Gas giants also contain vast amounts of deuterium. It can be separated from the
other gases by any of several methods, before, during or after compression and liquefaction.
By pumping that liquid deuterium up to fairly high pressure, which uses little energy since
liquids are essentially incompressible, then injecting negative muons into it, the liquid
will warm and partially boil at that high pressure. Then it can do work in a turbine,
generating power. The slightly warm gas exiting the turbine will now contain a little helium,
which can be removed in various ways while the deuterium fraction is recycled, cooled
and compressed again. That leaves the problem of making the muons. And some antiprotons
would be nice, we could export those. Antimatter is definitely worth the cost of hauling out
of deep gravity wells. Some deuterium may also be exported.
To make antiprotons, accelerate protons (atoms of normal hydrogen) to about 50 billion electron-volts,
then smash those together with similar protons going the opposite direction around the accelerator.
Result: a few proton-antiproton pairs, a lot of pions since they are the lightest mesons,
and some energetic photons. The pions decay very quickly into muons, from which the negative
muons are selected and sent into the fusion area. The energetic photons from all that
can be used to reheat the warm deuterium after some in-turbine expansion, and/or used to
further heat the high-pressure deuterium before the turbine. Waste heat from this heat engine
is still rather warm compared to the atmosphere outside, so that heat plus waste heat from
most of the other areas of this antiproton factory is transferred into one or more balloons
filled with light hydrogen gas. That provides lifting force to hold the entire antiproton
factory at the desired altitude in the sky of the gas giant.
You then accumulate antiprotons until there are enough to make a shipment, then launch
them into space, perhaps on a rocket using antiproton-catalyzed fusion of deuterium.
An extremely large number of these antiproton factories can operate all at once, in the
skies of many gas giants. Total production rate of antiprotons can be made rather high,
plus deuterium and even some helium-3 can be exported. Otherwise those gases will sit
there in those gas giants for billions or trillions of years, doing no good for anybody.
I said a bit ago that it would be nice if you could produce your antimatter while in
motion on a spaceship, and that brings us to the storage issue. We have a device called
a Penning Trap that is basically just a magnetic field, usually inside a cylindrical body,
that can keep particles with an electric charge confined within it instead of hitting the
sides. Now the best we can do at the moment with these is keep stuff confined for about
half an hour before the particle just happens to get a trajectory that isnât confined
enough and hits the side, but that can be dealt with by size and temperature.
Antimatter we make now is very hot, it has a ton of kinetic energy when made by the processes
we use, ultra-relativistic collisions, and such bottles arenât big, which means it
bounces around a ton of times in a short period. Double the size of the vessel and you double
the lifespan of the stuff inside it since it has to cover more distance between bounces
and interactions. Lower the temperature and you achieve similar.
Cooling antimatter is rather tricky since at that scale cooling is achieved by slowing
a particle down, which is usually via collisions with other stuff moving slower. But you could
do this via an electric field or optical molasses, and also produce your antimatter at lower
energies. As I mentioned before, we donât really make the stuff with mass production
in mind and your typical supercollider operates at particle temperatures far beyond the inside
of any starâs core. This is an example where scale helps, and while antimatterâs portability
is a big part of its value, so that we wouldnât want giant Penning Traps, itâs perfectly
fine to have an antimatter factory with hundreds of kilometers of length to be used to slow
down or cool antimatter to be transferred into something smaller once thatâs done.
The same is the case for trying to build large chunks of antimatter, as pellets of something
like anti-carbon or anti-iron or whichever that just had enough ionization to let you
hold the pellet in magnetic levitation in a vacuum flask.
Your default ideal storage device would be one with an equal mass as the antimatter within,
since that becomes a self-contained device. Antimatter by itself produces no energy, anymore
than regular matter does. What does the job is antimatter and an equal amount of matter,
with both being converted into energy, and again a gram of the stuff is equivalent to
a 43 kiloton atomic warhead, since 2 grams are destroyed. And if itâs a weapon you
donât have to worry about a source of matter because thatâs provided by the target it
strikes. Your typical bullet has a mass of 20 to 40 grams, though varying widely on caliber,
which means a bullet of antimatter can produce an explosion big enough that only someone
using a very long-range rifle wouldnât be in the blast zone of their own weapon.
You could obviously do much smaller bullets or ones with less antimatter in them, and
if youâre good at manipulating and storing the stuff, it also gives you an alternative
to chemical-powered firearms. While electromagnetic rail guns are a popular idea, getting those
compact and high powered enough to be man-portable is no easy thing, whereas antimatter is as
superior a substitute for gunpowder as it is rocket fuel and would allow you to fire
shots at very high speed, only limited by friction in the air, and up in space it allows
weapons to move at relativistic speeds as an alternative to laser and particle beam
weaponry. Needless to say it lets you pack quite a warhead into the shot too.
Which raises the physical security issue. Now, while I and others have raised the concern
that a society might collapse simply from having technologies so dangerous and easy
to produce that any lone lunatic could manufacture a doomsday device in their basement, and while
antimatter is a common example, in practice itâs very unlikely it would be. You would
not mass produce antimatter on planets in all likelihood for the inefficiency and waste
heat reasons we outlined earlier, but itâs also a power glutton and that makes it easy
to detect if someone is making it on a planet. At best youâre producing it by using the
same amount of energy as it will eventually produce and in all probability even the most
efficient process is going to be an order of magnitude less than whatever fuel and power
system youâre using to make it. Itâs not free energy, and some would-be terrorist is
going to be given away by the giant electric bill and huge thermal blossom at their facility.
Youâre going to notice someone using ten times the normal electric consumption they
should be and if that were a regular American household, that roughly 40 billion joules
theyâd normally use a year is only going to net them the equivalent of 10 tons of TNT,
nothing to laugh at but theyâd need thousands of years at that rate to get it up to atomic
bomb levels of explosives. You probably could get away with producing
it a couple orders of magnitude faster and you donât need a gram of antimatter to wreak
nuclear havoc. We talk about suitcase nuclear bombs but the antimatter equivalent is a pen-sized
bomb or even a pinhead nuke, just depending on how small your Penning Trap or alternative
storage method is. And letâs not forget it can be used as a fusion catalyst. If a
milligram of antimatter is suddenly injected into 1 liter of liquid deuterium, the results
may be very like a nuke, but with no need for fissionables or even high explosives to
kick off the bang. Now, that said, youâd almost have to smuggle
something like that in from offworld for anything in the kiloton or higher explosive range unless
a very big group or country was involved to obscure your power usage or let you siphon
from their own stores, and antimatter is the sort of thing youâd store in quantities
as small as you could for fear of accidents and as large as you needed to ensure efficient
and solid security on it, while being economical with your security assets. I donât think
youâd store it on-planet in quantities big enough to go off as a nuke when you could
distribute it to more the scale weâd associate to a modern fuel depot going up in an explosion.
That smuggling issue is not quite as bad as the tiny size implies. First, a pen is not
a small thing in terms of people or cargo going through ports of entry, and if weâre
talking spaceports you process through before going down to Earth, then weâre probably
talking pretty high tech scanning. I donât think you could hide even a small hollow and
magnetic cavity that was storing more than a milligram, or even micrograms, just from
the kinds of scanners we can make now, especially if those are being run by fairly decent AI
analyzing the scans such as those weâre starting to employ in a lot of medical scanning.
A milligram isnât anything to sneeze at either but itâs no worse than a large truck
bomb, at least as a pure antimatter bomb, the fusion catalyst option is worse.
Speaking of those scanners though, one example is an MRI, a Magnetic Resonance Imaging device,
key word there being âmagneticâ. Penning traps or other magnetic confinement systems
rely on very carefully keeping antimatter magnetically penned up, and disrupting that
magnetic field is going to have explosive results. Itâs also a defense against antimatter
weaponry, like torpedoes launched by spaceships or orbital platforms, since they could hit
the incoming devices with magnetic bursts as an alternative to shooting them down. You
proof such devices against that by either employing magnetic shielding or keeping the
antimatter inside very, very cold so that the particles inside arenât bouncing around
fast and it will take a little time to go off, and you counter that, for hidden bombs,
with quarantine periods. We also donât have any materials that are
much good at shielding from magnetic fields and those all rely on thickness, so barring
some advanced metamaterial that let you shield very strongly against magnetic fields and
with a very thin layer of shielding, youâre going to be able to detonate hidden bombs
with your scanner. Of course we might get those magnetic metamaterials in the not-to-distant
future, see our metamaterials episode for more discussion of that, which might be problematic
but on the bright side might also be useful for storing or making antimatter too, amongst
many other great applications. We also donât want to think only in modern
terms when it comes to detection, itâs entirely possible the customs and border security in
the future will be a trillion tiny little robots that go into someone looking around
up-close and personal, scanning for dangerous viruses, mysterious microscopic cavities in
bones with explosives or equipment in them, and so on.
Of course, if they find it, that person might detonate themselves, as would occur with the
magnetic scan. Now losing a spaceport or city security outpost to such a bomb is no laughing
matter but you could do small and isolated ones and potentially even telepresence for
the folks manning it, so they were far away from the worksite while scanning people. Also,
antimatter is not infinitely powerful, even an entire kilogram of the stuff going off
inside a tiny space station in high orbit is only going to get a fairly tiny amount
of your planetary orbital swarm and the real danger there would be setting off a Kessler
Syndrome event, see Orbital Infrastructure for more discussion of that.
We also might be able to get around some of the accidental explosions by not employing
normal matter. I suggested big slabs of anti-materials like anti-iron earlier, because itâs less
of a containment problem than anti-hydrogen gas if you can make it, but every particle
has anti-particles and that includes things not made out of up and down quarks, like strange
or charmed matter. You might make stable atoms with those types of quarks in them and others
with their anti-particles and use them as your antimatter power source, since they can
only annihilate with each other and strange and charmed quarks arenât exactly hanging
around our solar system in abundance. Needless to say, once we can start producing more of
it and turning our minds to dealing with it, we may come up with all sorts of other safety
mechanisms for storage. So, itâs quite a security issue but not
a boogeyman and probably rather manageable, like most security issues arising from new
technology. Itâs very useful stuff too, so as you get better at producing and storing
it, you figure out what level of usage is safe from accident or malign intent and employ
that. Obviously the big use besides weapons is spaceship
fuel, because itâs compact in so many ways. There is no better rocket fuel than antimatter,
it outperforms even Hawking Radiation drives on micro-blackholes and is easier to make
small ships out of. The only rival would be light stored inside a box that was a perfect
mirror, since thatâs also a mass-energy level device and is essentially what antimatter
is doing. You donât need a high-tech spaceship to get near light speed if antimatter is your
fuel, and it's also an amazing fuel at any other speed too. Thereâs no complexity in
its actual use, just the making and handling parts, you combine it with matter and you
get a ton of energy. But we donât always need a ton of energy
and thatâs where it has some novel applications. Given the security risks it sounds absurd
to have cars or appliances powered by antimatter, but keep in mind that itâs all about quantity.
Tiny machines with microscopic penning traps, or even nanoscopic ones, may be an ideal compact
power source for very long periods, at least for lower energy antimatter like positrons,
keeping in mind that antimatter is about a billion times more energy dense than the typical
chemical fuel and even more so than our best modern batteries, and probably can be made
tinier than a gas engine. If we were using some exotic matter, like strange quarks, we
might not even have to worry about an explosion if the containment got ruptured.
And again, if youâre substituting for a normal modern fuel, thereâs no more energy
there than that fuel already contains if it ruptures its tank and goes boom, indeed rather
less since you need to pay extra energy to tote your fuel and associated equipment around,
which is a very big deal for things moving fast like airplanes and especially like spaceships.
That is definitely a long way off, and quite probably never, but I really wouldnât be
too surprised if a time machine to the 23rd century saw folks walking around with tiny
bits of antimatter running their ultra-smartphone or personal cybernetics. That explosion issue
is also less important for military application than regular folks walking around on their
regular daily business, so might see first use in things like military vehicles, armored
exoskeletons, giant mecha or war robots, or power armor.
In the short term though, antimatter technology is already in use. Beta-decay atomic batteries
may see regular usage in coming decades and its medical applications are already there,
I mentioned MRI scans earlier but we also have PET Scans, and that is short for Positron
Emission Tomography, antimatter already being used to save lives, and weâve been experimenting
with using anti-protons for cancer treatments too.
Back in the early days of sci-fi we often heard folks say we were entering the nuclear
age, but antimatter is far more powerful than fission or fusion, so it might be that the
future isnât nuclear, but antimatter. Dangerous stuff, but if you donât antimind, it doesnât
antimatter. So we covered a lot of particle physics today,
and it can be a confusing topic considering how counterintuitive quantum mechanics often
feels. If youâd like to learn more about Quantum Mechanics, then Iâd recommend Brilliant.
Brilliant has an excellent course on Quantum Objects that will walk you through not just
the basics of Quantum, but even fairly advanced concepts, and do so in an interactive fashion.
In a time when more folks are embracing online education, Brilliantâs focus on fun and
interactive methods makes them a great choice, whether youâre a student, a parent trying
to enhance your kidâs education, a professional brushing up on cutting-edge topics, or someone
who just wants to use this time to understand the world better, you should check out Brilliant.
Try adding some learning structure to your day by setting a goal to improve yourself,
and then work at that goal just a little bit every day. Brilliant makes that possible with
interactive explorations and a mobile app that you can take with you wherever you are.
If you are naturally curious, want to build your problem-solving skills, or need to develop
confidence in your analytical abilities, then get Brilliant Premium to learn something new.
Brilliantâs thought-provoking math, science, and computer science content helps guide you
to mastery by taking complex concepts and breaking them up into bite-sized understandable
chunks. You'll start by having fun with their interactive explorations, over time you'll
be amazed at what you can accomplish. If youâd like to learn more science, math,
and computer science, and want to do it at your own pace and from the comfort of your
own home, go to brilliant.org/IsaacArthur and try it out for free.
So next week weâll be returning to the alien civilizations series to consider the notion
of aliens who come in peace, and actually mean it, in Benevolent Aliens. Then weâll
close out the month of May with our Monthly Livestream Q&A in our new SFIA studio, on
Sunday May 31st. Weâll then jump into June & Summer by returning to Jupiter to contemplate
the idea of making Jupiter into another Sun, and look at some techniques for how we might
do that and why we might want to, in Summer on Jupiter.
For alerts when those and other episodes come out make sure to subscribe to the channel,
and if you enjoyed this episode, hit the like button and share it with others. And if youâd
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or buy some awesome SFIA merchandise. Until next time, thanks for watching, and have a great week.
The boy is putting out videos faster than I can watch!
don't know if anybody reeds Schlock Mercenary but in that universe antimatter is stored in buckyballs. a single antiproton inside each carbon molecular sphere, the negative charge on the inner surface of the sphere repels the antiproton.
would be difficult to assemble but if you can pull it off you get antimater in easily handled form, stable under conditions you tend to maintain already and easily accessed as needed.
I was just reading about this! I'm so excited!
Made my day
Excellent stuff, negative protons seem like the great filter the stuff looks too dangerous to control.
Kinda of a showerthought but is positron radiation technically inozing? It annihilates an electron, and an atom from which electrons are missing.. is an Ion.
Idk why but this is the first episode ever that I got bored watching.