Posted by leephillips 4 hours ago
Gemini says a firecracker releases 150 J, so yeah not a lot.
indeed, in the most natural systems of units in this area, we set c = 1 as to simplify the equations
For a tiny number, that is still insanely high...
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?
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...
Liquid gasoline does not spontaneously explode like an action movie. You can put a match in the fuel tank and (presuming infinite oxygen availability) it'd just start a small fire. Heck, may even just give a little puff and then put out the match.
Antimatter in any sufficient fuel quantity, the moment it breaks confinement, will completely annihilate and release ALL it's energy in a single moment, setting off a chain reaction to the remaining antimatter. It's like sitting on an armed nuclear bomb, where you rely on electrified, highly sophisticated containment equipment never failing a single time for months to years... In a radiation-heavy environment known for causing sophisticated electronics to have errors.
And, yes, hydrogen cars were looked at critically because of the perception they can Hindenburg (I'm unsure if it's true or not). Which is a good example because you don't particularly see any hydrogen blimps anymore - we made them illegal because they're dangerous.
The difference is that antimatter annihilates with any normal matter that it comes into contact with. This means you can't just put it in a tank, the way you can with hydrogen. You can't e.g. combine it with some metal to make a metal hydride to make it safer to store, the way you can with hydrogen.
At an absolute minimum, you need extremely strong magnetic confinement and an extremely hard vacuum. And even then, you're going to get collisions with stray atoms and annihilation events which release gamma rays and other radiation products - although shielding is probably the least of your worries in this scenario.
A typical research lab at a university or large corporation can't make a vacuum strong enough to store even tiny quantities of antimatter for more than a few minutes, and they can't produce the magnetic confinement strength required to store macro quantities of it, either.
So the question with an antimatter-powered car is not if it's going to destroy the surrounding region and bathe it in hard radiation, but how many milliseconds (or less) it will take before that inevitably happens.
But probably luckily for us, this is all moot, because we have no way of producing enough antimatter for this to be an issue. If all the antimatter that's ever been created by humans annihilated simultaneously, only scientists monitoring their instruments closely enough would notice, because it's such a microscopic amount.
Edit: for perspective, you'd need about 7 billion times the 92 antiprotons transported in the truck in the story to produce the energy produced by a single grain of gunpowder.
Also, now your tank is just fuel as well.
With antimatter the tiniest leak will annihilate your ship.
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.
Antimatter production is so inefficient that they will be much more expensive per unit energy yield.
According to, Michael Doser, a prominent particle physicist at CERN, "one 100th of a nanogram [of antimatter] costs as much as one kilogram of gold."
S: https://www.abc.net.au/news/science/2023-02-19/antimatter-fa...
We can't afford to blow up ourselves that way.
There are plenty of other ways we can afford, so antimatter isn't top of anyone's worries.
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.
We're not going anywhere without a revolution in our understanding of the universe.
Maybe. Beamed propulsion makes a hell of a lot more sense in the solar system.
> 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...
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
Mirror: https://archive.ph/JkeMp