To the physicist's at this forum, could you please explain...?

[GhostFaceSaint]

This is a thread for educated people, science enthusiasts, Trekker's, and for those who just don't understand to post a question for any physicist to read and answer.

With respect to you doctors of physics, science and physics majors, students, please take the whatever complicated science subject we don't understand, summarize it to the best of your ability so that the rest of us can understand a little better what it is we don't fully grasp.

 

[GhostFaceSaint]

Ok here is the first question I have, and hopefully there will be many answered at this thread; so how do they create antimatter? I do understand that it is expensive as well as the properties of antimatter but I have never read how it was produced.

 

[FordSVT]

Are you talking about in real life or in Star Trek?

 

[Ronald Held]

Yes that would help.

 

[Bones2]

In theory, to create antimatter, they'd have to generate some sort of charge to negate a given matter particle just as it bursts into existence and before it is cancelled out by its equal and opposite antimatter particle. Or course, storing an antimatter particle wouldn't be easy, as it is potentially destructive to any other particle it comes into contact with, and that would also destroy itself. So it would have to be kept in a state of flux before its energy is utilised.



I've just made all that up. It's probably nonsense. Reckon I could write for Trek?

 

[CTM]

I understand that IRL they have found a way to produce Positrons (anti-electrons or positively charged electrons) using gold foil and lasers. I know it must be far more complicated than pointing a laser-pointer at some gold leaf, but I have no more specifics.

 

[GhostFaceSaint]

This is a thread for educated people, science enthusiasts, Trekker's, and for those who just don't understand to post a question for any physicist to read and answer.

With respect to you doctors of physics, science and physics majors, students, please take the whatever complicated science subject we don't understand, summarize it to the best of your ability so that the rest of us can understand a little better what it is we don't fully grasp.

Sorry I will be more specific, the questions to be asked are of Star Trek related science that is either just being developed or is still just theoretical, for example anti-matter has been produced but using it in a "Warp Drive" or in any practical way is still limited to the realm of science fiction but it is still fare game to ask what practical applications there could be for anti-matter.

If you have a question related to Trek please ask here, even if it is still just a theory related question that is still ok for this thread.

Hopefully that explained it.

 

[Myasishchev]

Ok here is the first question I have, and hopefully there will be many answered at this thread; so how do they create antimatter? I do understand that it is expensive as well as the properties of antimatter but I have never read how it was produced.

Simplistically, they accelerate regular protons to extremely fast speeds (and hence high energies) and then slam them into a target. The resulting release of energy generates matter, and when matter comes into existence, it always (afaik) does so as particle-antiparticle pair.* Through the use of magnetic lenses, the interesting part of that pair, the antiparticle, is separated from its regular-matter pair, so that the two don't annihilate, because particle-antiparticle pairs annihilate on contact. I actually forget/never understood why they do this--a little above my paygrade, although I'm interested if anyone has an answer.

*This may not be the case, however. We know from being alive that antimatter was not created in equal amounts in the first few moments of the universe. I am under the impression weak interactions, violating parity-symmetry, may be responsible for this.

Anyway, then you cool/slow the antiparticles, and store them in a vacuum bottle with a magnetic field that keeps it orbiting but never striking regular matter. I'm unsure what the record is at this time, but for positrons it is for a very long time (months iirc).

In Star Trek, I'm convinced that they still create antimatter with this basic method, using x-ray binaries, or other suitable natural power sources, to energize huge particle accelerators. Ultimately, they are working at (much) less than 100% efficiencies, just like you would expect. Charge/spin/flavor/color switching devices are, to say the least, a little impractical.

A great idea for long-term storage in the Trek universe, I think, was floated by somebody on Stardestroyer.net, and I have no notion whether it was original to him. The gist was to go to the (considerable) trouble of fusing antiprotons until you get antiiron, and using the ferromagnetic properties of antiiron bottles to store neutral antiproton/positron pairs, i.e. antihydrogen. That way you have less to worry about in terms of neutral antihydrogen being created accidentally, which would be virtually impervious to purely magnetic containment, or cooling the antihydrogen to a liquid or (as the TNGTM has it) slushy state.

 

[GhostFaceSaint]

Thank you, that was a good first answer, hopefully there will be more questions and answers here at this thread!

 

[Bill Morris]

Here's a link to one of many articles about creating positrons (antielectrons) with 1-mm gold plate and a laser. Storage bottles to allow use for spacecraft propulsion haven't really been developed yet, but they would use electromagnetism to confine the antimatter, and positrons seem to be more practical for this sort of usage than antiprotons, especially since they are cheaper and easier to make.

Making positrons with gold plate and a laser

Even before this discovery, NASA has been interested in positron antimatter for fueling interplanetary manned spacecraft. Here's an article they put up on their Web site before the gold & laser trick was discovered.

NASA: New and improved antimatter for missions to Mars

I've also suggested in the Science and Technology forum that a satellite with an array of large mylar balloons transparent on one side and reflective on the opposite interior side could be used to collect large amounts of sunlight to provide energy for making this type of antimatter for use by spacecraft as fuel for going back and forth to the moon or other destinations.

 

[David Schmidt]

In his great book "Voyage From Yesteryear", James Hogan hypothesized a more 'mass-production' method:

1. Place normal matter (such as deuterium) in a reaction chamber (protected by force-fields).
2. Increase the energy level until the temperature in the reaction chamber reaches that of the big bang, creating a 'soup' of basic strings. Smaller than quarks. These are the original ingredients of the universe, which 'congeal' into quarks>subatomic particles>atoms>molecules when the temperature drops.
3. Begin the cool the chamber. In our universe, the majority of these strings created normal quarks - and thus normal matter. Alter the parameters so that instead of normal quarks being produced, anti-quarks are produced.
4. As the temperature cools, anti-subatomic particles>antimatter atoms>antideuterium is produced. Chill it down to a slurry (like a heavy hydrogen slurpy), and store it in a force-field insulated bottle. The power needed to keep the field going is miniscule compared to the potential power stored as toms of antimatter.

 

[Myasishchev]

Problems:

1: The temperature of the Big Bang is many billions of Kelvins, requiring a power source of immense, well, power.
2:The particle/antiparticle pairs will annihilate with each other, preventing cooling if expansion is not permitted.
3:Baryogenesis would presumably be replicated, leading to an asymmetry between quarks and antiquarks. Leptons and antileptons would also presumably suffer the same fate.
4: Efficiency remains low, since a large amount of energy pumped in will be bled out as photons or electrically neutral leptons, which are impervious to magnetic force fields.

In other words, it seems like that's a recipe for extremely expensively synthesizing hydrogen.

 

[Jimmy_C]

Maybe they park a station around a binary star system - one with either a black hole or a neutron star as a companion. As the black hole accrues matter from the star, it creates the densities and energies required to create antimatter. Then you simply collect it from jets coming from the magnetic poles.

Of course, this doesn't say how they got to the black hole in the first place...

 

[Myasishchev]

Maybe they park a station around a binary star system - one with either a black hole or a neutron star as a companion. As the black hole accrues matter from the star, it creates the densities and energies required to create antimatter. Then you simply collect it from jets coming from the magnetic poles.

Of course, this doesn't say how they got to the black hole in the first place...

We do know from "Relics" that Dyson's spheres are way beyond "contemporary" engineering capabilities, so capturing the energy of a sun is unlikely. The great thing about neutron stars or black holes is that they're tiny, so power stations utilizing them wouldn't require as much macroengineering skill to pull off. Heck, Spacedock is almost as big as a neutron star.

And since neutron stars and black holes pulling in matter are also wonderful x-ray sources, there's no reason I can think of that Trek folk couldn't utilize those x-ray sources by encasing them with photon-utilizing mini-Dyson's spheres, albeit probably with insanely large cooling pylons.

Alternatively, small, orbiting standoff stations, while not nearly as cool, would still be operating much more efficiently than a standard solar power satellite.

Also alternatively, the strong magnetic fields of neutron stars, particularly ridiculously powerful exagauss magnetars, could be tapped to directly induce current and power the antimatter-refining devices. This may actually be the most efficient method, although both could be in use.

In any case, once you've tapped the x-ray source, you just run your particle accelerator, and, voila, for every few tons of useless gold or whatever you're smashing, you get a few micro/milli/full grams of antimatter, and you send it off in specialized tanker ships (each of which would incidentally make a very useful tool in the hands of a terrorist ).

It's deeply inefficient, of course, but the power source itself is free of charge.

If this actually caught on, it would also reintroduce material scarcity and economic realism to the Trek universe, but that's a topic for another thread and another time.

 

[Arpy]

Here's two:

1) How can one find anti-matter in outer space when it would react to contact with space-dust?

2) So is the universe infinite of finite? If it's infinite, how can we know how much it weighs or what color it is...would the number infinity pop up in a lot more equations...wouldn't the night sky be entirely white (eventually) with light from some distant star finally getting to us?

 

[Ronald Held]

There are antiparticles in cosmic rays. ther may be regions of antimatter in a universe, which are siolated enough not ot react with the surrounding matter.
How do you define a universe?

 

[kent]

In theory, to create antimatter, they'd have to generate some sort of charge to negate a given matter particle just as it bursts into existence and before it is cancelled out by its equal and opposite antimatter particle. Or course, storing an antimatter particle wouldn't be easy, as it is potentially destructive to any other particle it comes into contact with, and that would also destroy itself. So it would have to be kept in a state of flux before its energy is utilised.



I've just made all that up. It's probably nonsense. Reckon I could write for Trek?

You'd have to reverse the polarity of said particle, then store it in a magnetic containment chamber so as not to destroy positive matter. a teaspoon is the equivilant of 23-25 external fuel tanks of current shuttles exploding all at once, and would likely destroy most of boston.

To make even a spoonfull of antimatter would not only bankrupt the country, but would probably destroy a large section of it if it ever came in contact with positive matter.

 

[Myasishchev]

There are antiparticles in cosmic rays. ther may be regions of antimatter in a universe, which are siolated enough not ot react with the surrounding matter.
How do you define a universe?

I was under the impression that it was relatively certain that all the AM reacted away in the first few hundred thousand years, when the universe was very dense and hot and collisions could not be avoided. Afaik, all the antimatter that exists at present was created intermittently well after baryogenesis. Cosmic ray antiprotons striking our atmosphere are supposed to be the results of conventional high-energy cosmic ray proton collisions somewhere else.