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Antimatter has been transported for the first time

nature.com

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Re: Antimatter has been transported for the first time

#191

Post by dbetteridge »

BobaFloutist wrote: post #150
TheOtherHobbes wrote: post #122

Earlier quoted context omitted.

Interstellar flight is a new physics problem, not a smash-the-tiny-rocks-together-to-make-bigger-bang problem. We're not going anywhere without a revolution in our understanding of the universe.

My memory is that 1g of constant acceleration grants sufficient relativity to make it to the edge of the known universe in a current human lifespan. Now, it's true, there's some slight issues such as radiation, food storage/production, psychological effects, and any random space rocks obliterating your craft, all of which could reasonably turn out to be enough to make it not work. We also don't have a fuel source tha…

Alpha Centauri yes, the edge of the universe no :D

Edge of observable universe is something like 46 billion light-years away, even at 0.9c thats 50 billion years of travel (22 billion years experienced by the traveller)

But yes, you can travel places by constant acceleration but unfortunately it still dwarfs in comparison to those places out of our reach.

Unfortunately also, the universe is expanding at a rate faster than the speed of light so you actually cant ever reach the edge

Re: Antimatter has been transported for the first time

#192

Post by voidUpdate »

nikhilisvalid wrote: post #49
voidUpdate wrote: post #5

Earlier quoted context omitted.

Wolfram Alpha says its approximately the kinetic energy of a mosquito in flight

Wolfram Alpha says it's approximately _one-sixth_ the kinetic energy of a mosquito in flight

Sorry, you're right, I misread the results (wow that makes me sound like an LLM, I'm not, I promise)

Re: Antimatter has been transported for the first time

#193

Post by voidUpdate »

AnimalMuppet wrote: post #20
voidUpdate wrote: post #3

If containment was to fail, it the total energy released would have been approximately 2.766 * 10 ^ -8 J, so it wasn't particularly dangerous

For 92 protons? So 3*10^-10 J per proton ? For a tiny number, that is still insanely high...

*184, a particle annihilates with its antiparticle and both of them are converted into energy, so 92 antiprotons will also destroy 92 standard protons. but yes, C^2 is a very big number

Re: Antimatter has been transported for the first time

#194

Post by M95D »

saalweachter wrote: post #168
M95D wrote: post #81

Earlier quoted context omitted.

The disadvantages of water-based life.

So it's hard to imagine biological life (chemical life?) without water or carbon, since they're such good solvents and building blocks, but we can at least imagine electronic or mechanical life which don't require them. But what you can't get away from is heat dissipation . Any life will use energy will generate heat will need to dissipate heat to maintain homeostasis. Could you dissipate enough heat to exist at Are…

Methane based life is considered a possibility.

Re: Antimatter has been transported for the first time

#195

Post by adrianN »

thaumasiotes wrote: post #126
garciasn wrote: post #115

Earlier quoted context omitted.

There are a lot of completely random statements about how much a gram costs floating around out there. Anywhere from $60T to $3,000T. 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...

> 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." Those aren't comparable costs. The cost given for antimatter is the cost of producing it from nothing. The cost given for gold is the market price of buying gold that already exists. Consider the cost of producing one kilogram of gold from nothing. (Consider also the…

The relevant cost for the buyer is how much they need to pay to obtain the object. So far we haven't discovered any primordial antimatter deposits that we could mine, so creating it from scratch is the only way.

Re: Antimatter has been transported for the first time

#197

Post by everforward »

mastersummoner wrote: post #87
ReptileMan wrote: post #84

Earlier quoted context omitted.

Not that great. Chances are you will destroy your country before you destroy some other.

That's just an engineering problem as well.

It’s a fundamentally different and riskier paradigm. Nuclear weapons at rest are inert, and can even be disarmed. If the lock falls off the gate at the compound, the nukes won’t spontaneously explode.

Antimatter is always “armed” and is only rendered safe by containment. If containment fails, it explodes. It’s more like keeping a massive stockpile of fluorine, but somehow worse and harder to contain.

Re: Antimatter has been transported for the first time

#198

Post by saalweachter »

M95D wrote: post #194
saalweachter wrote: post #168

Earlier quoted context omitted.

So it's hard to imagine biological life (chemical life?) without water or carbon, since they're such good solvents and building blocks, but we can at least imagine electronic or mechanical life which don't require them. But what you can't get away from is heat dissipation . Any life will use energy will generate heat will need to dissipate heat to maintain homeostasis. Could you dissipate enough heat to exist at Are…

Methane based life is considered a possibility.

Methane only gets you to 100K.

Re: Antimatter has been transported for the first time

#199

Post by andrewflnr »

mikewarot wrote: post #157

I wonder what would happen if you had a solid piece of antimatter, say a gram of anti-iron... and just set it down. Would it really annihaliate immediately on contact with air, a lab table, or anything... or would the normal forces that keep us from falling through things still be in effect? Either nothing would happen, or like molten salt in water, the joule currents would be instant and drive it all to go boom in a…

I'm not sure I ever got a straight answer about whether the reason we don't fall through things is actually Pauli exclusion or electrostatic repulsion, but I'm pretty sure even Pauli exclusion won't apply to different kinds of particles trying to occupy the same space. And electrostatic repulsion definitely won't work to keep electrons and positrons apart. I think the positrons and electrons in the outer shells would make contact instantly, and everything would unravel from there.

Re: Antimatter has been transported for the first time

#200

Post by andrewflnr »

estimator7292 wrote: post #163
csense wrote: post #37

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?

I don't like antimatter because it's the most volatile fuel possible. If power is ever interrupted for any reason for any amount of time, the entire mass explodes. A slightly less insane fuel source is a micro black hole. Drag a tiny black hole behind your ship and drip-feed it any kind of mass you come across. You still get >90% mass-energy efficiency which is far beyond anything else we know of. Besides, one of the…

Black holes have similar problems to antimatter. A micro black hole is pretty close to an ongoing antimatter explosion in terms of effects on its surroundings. If any part of your shielding fails, it irradiates you or melts you. Their radiation increases as they get smaller, and if not fed they're always getting smaller, until they "explode" (yes, but even more so) and disappear. So you still have the problem that if you don't maintain it just right, it will annihilate your ship. So, "less insane" is dubious IMO. (Still my favorite starship idea, though.)
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