From a layman's point of view antimatter seems like an ideal spacecraft fuel. It's as energy dense as E = mc^2 allows, and if you have infrastructure to make it, the only input you need to produce it is electricity.
Being able to transport it seems like an important piece of that puzzle.
Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?
From a layman's point of view, I'm more interested in antimatter's potential as a weapon.
Not necessarily because I want to use it, but because I have a vague idea of what it's capable of, and what that would mean in the hands of certain groups capable of producing it.
> If you're ok with the looming threat of total annihilation.
Don't you have that problem with any energy-dense fuel? It's just that it doesn get more dense than that, so you can be very space and weight efficient.
It's like everybody saying that a hydrogen car is a rolling bomb because of the energy stored in the hydrogen. Well, sure, but gasonline has just as much energy stored. Which is the whole point of fuel. To store energy. It's not like you are bringing 100x as much energy with you just because it's hydrogen. So that doesn't make an ICE car any less of a bomb...
Antimatter reactions are about a million times more powerful than conventional combustion. They surpass even nuclear explosions in energy release. That means even a small mishap becomes a large mishap.
Average human threat perceptions simply aren't useful here. People will also make wild assumptions about what kind of catastrophic thing could happen in aviation and then happily enter their car to drive somewhere without a thought in the world. In fact noone thought about designing gasoline fuel tanks in a safe way before we had cars. Not even really until people started burning. If we're already thinking about transporting antimatter safely today, this kind of technology will probably have an even better track record than planes.
Not familiar with the subject so genuine question. HOW would antimatter be used as fuel? There is energy released in matter antimatter annihilation, but where would the force to move a spacecraft come from?
> Various antiproton-powered rocket systems have been proposed. All of which rely on the particles released to supply direct thrust or to heat a working fluid by interparticle collisions or by heating a solid core first [14]. There is also the possibility to use the heated working fluid to generate electricity for electric propulsion systems [14].
> Following Fig. 9, beam core and plasma core configurations can produce direct thrust by directing the charged particles produced into an exhaust beam using a magnetic nozzle. Gas core systems use the energy released from the reaction to heat a gas that is exhausted for thrust. Finally, solid core configuration heats a metal core like Tungsten that acts as a heat exchanger to a propellant that is then exhausted from a regular nozzle.
my absolutely-non-expert guess is that it would work much like any other fuel? Combine with matter, get a lot of head out of it and use that in the best way we know.
When I visited CERN, they mentioned that there were some large number of protons in the ring at a time, and the runs would last a significant amount of wall clock time. (Don’t remember the exact numbers, but I think it was like 10^19 atoms of H, and days of wall clock)
The upshot was, it was likely that less than a mol of hydrogen had been run through the ring.
If humanity doesn't perish in the next hundred year and masters interplanetary spaceflight, antimatter drive is the logical next step in propulsion after fusion.
Interstellar spaceflight will become (barely) feasible once spaceships can reach velocity between 0.02 to 0.1c are possible. Even assuming non-100% conversion efficiency, antimatter has enough energy density to provide this capability.
I'm not sure! One is just barely within human scale and one isn't. I think I could feel the impact of a mosquito on a sufficiently sensitive patch of skin. I'm not sure I could do the same with one sixth of a mosquito. Its like the difference between something I can lift (100 lb) and something I definitely cannot lift (600lb)
It was on the radio here (I live on its route)- the ‚receiving’ physicist said it would be way less than what we catch anyway from daily cosmic radiation.
I am curious about how much energy needs to be expanded to contain the anti-matter. Say it the matter/anti-matter is to be used for propulsion/energy generation can we reach a threshold were we are actually energy positive
“Antimatter in a truck” is great headline material, but the actual advance is portable precision instrumentation.
CERN can make/store the antiprotons, but not measure them as cleanly as they want because the facility itself introduces tiny magnetic fluctuations. So this is really a story about moving the sample to a quieter lab, not moving toward sci-fi antimatter batteries... for now
It almost could be a Hollywood movie in the vein of Sorceror. Couple of grizzled CERN vets transporting a volatile load of antimatter across a post-apocalyptic wasteland while being chased by energy terrorists.
Unless we'd be fighting literal alines in space, and need a weapon for them, I think this would be many many many orders of magnitude too expensive / tricky for earth use. We have plenty of non sci-fi big boom sticks already as it is...
How could we make enough antimatter to do something useful? Would we need to go hang out near the sun or deorbit Jupiter's moons with superconducting coils to get enough energy?
It would depend on how it's distributed. If it's very homogeneous, totally anihilated. If there are galaxies of matter and galaxies of antimatter, more or less like us with a bit more background radiation.
It talks about symmetries, but has a nice story about this exact hypothetical scenario. (Someone else already replied why this probably isn't possible in our observable universe, but the episode is cool so I thought I'd share)
Mass in the universe appears to be (very) roughly uniformly distributed, so even if there are large bodies of antimatter far away in the universe there would have to be a transition boundary somewhere between here and there where the universe goes from being mostly matter to being mostly antimatter. The universe is big and stuff would sometimes cross this boundary and get annihilated, and if this happened it would be the brightest thing in the sky, briefly outshining entire galaxies. We’ve been watching the sky for a while now and have never observed a bright visual event with the spectral signature of a matter/antimatter annihilation, so we assume there is not such a transition boundary, and by extension that the universe is made up of mostly matter out to the edge of the observable universe.
Great explanation. One thing to add: annihilation happens with a very specific energy. Even if it was very far away and redshifted and dim, a "bubble" with a very uniform color (photon energy) would be plainly visible.
It would develop into "regions" of space that are entirely matter and others that are entirely antimatter. The boundaries between them would glow as stray particles drift between the regions and is annihilated by contact with the opposing particles.
The fact that we don't see these glowing boundaries in space is evidence that there are not antimatter regions and that the visible universe is almost entirely composed of matter.
You (briefly) have an antiproton in your possession around once a day, assuming you get an average amount of sunlight. Some days, you might even have two!
Every time I read one of these, I am amazed by how much stuff superconductivity allows, and how limited we are because it needs ultra low temperatures.
Imagine the poor post-doc in the back of the truck, no seatbelt, watching and noting anything going on, while the driver is doing donuts in a parking lot to really stress-test the magnetic containment.
Yes, only anti-truckers can haul anti-matter since normal CDLs only let you transport ordinary matter. You have to be very careful not to let the anti-trucker go to a ordinary truck stop because things really go down if they run into a ordinary trucker.
Being able to transport it seems like an important piece of that puzzle.
Production and storage would need to be scaled by many orders of magnitude, but that's merely an engineering problem...right?
Not necessarily because I want to use it, but because I have a vague idea of what it's capable of, and what that would mean in the hands of certain groups capable of producing it.
If you're ok with the looming threat of total annihilation.
I suppose at least it will kill you faster than your neurons can communicate so you wouldn't even notice.
Don't you have that problem with any energy-dense fuel? It's just that it doesn get more dense than that, so you can be very space and weight efficient.
It's like everybody saying that a hydrogen car is a rolling bomb because of the energy stored in the hydrogen. Well, sure, but gasonline has just as much energy stored. Which is the whole point of fuel. To store energy. It's not like you are bringing 100x as much energy with you just because it's hydrogen. So that doesn't make an ICE car any less of a bomb...
With antimatter the tiniest leak will annihilate your ship.
> Following Fig. 9, beam core and plasma core configurations can produce direct thrust by directing the charged particles produced into an exhaust beam using a magnetic nozzle. Gas core systems use the energy released from the reaction to heat a gas that is exhausted for thrust. Finally, solid core configuration heats a metal core like Tungsten that acts as a heat exchanger to a propellant that is then exhausted from a regular nozzle.
Not the same paper, but goes into more detail.
https://www.sciencedirect.com/science/article/pii/S266620272...
https://m.youtube.com/watch?v=eA4X9P98ess
The upshot was, it was likely that less than a mol of hydrogen had been run through the ring.
Interstellar spaceflight will become (barely) feasible once spaceships can reach velocity between 0.02 to 0.1c are possible. Even assuming non-100% conversion efficiency, antimatter has enough energy density to provide this capability.
Mirror: https://archive.ph/JkeMp
Gemini says a firecracker releases 150 J, so yeah not a lot.
For a tiny number, that is still insanely high...
CERN can make/store the antiprotons, but not measure them as cleanly as they want because the facility itself introduces tiny magnetic fluctuations. So this is really a story about moving the sample to a quieter lab, not moving toward sci-fi antimatter batteries... for now
It talks about symmetries, but has a nice story about this exact hypothetical scenario. (Someone else already replied why this probably isn't possible in our observable universe, but the episode is cool so I thought I'd share)
The fact that we don't see these glowing boundaries in space is evidence that there are not antimatter regions and that the visible universe is almost entirely composed of matter.
More accurately: we aren't sure if antineutrinos are the same or different from neutrinos!
https://arxiv.org/abs/2008.02110