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Antimatter Space Drive
sckienle writes "Space.com has an article on using anti-matter for propulsion in space. It isn't true Star Trek warp stuff, in fact it is a variation on an fusion based pellet design I saw in the late 70's, but interesting concept. The concept is still somewhat of a dream, as stated in the article: 'The real hub is the storage [of antimatter]. There's a lot of technology between here and there.' Later on it also mentions that we can't produce a lot of antimatter efficiently yet. Still it might be worth the effort if the theoretical acceleration proves out." The BBC has a story about studying antimatter in a lab.
...At least to provide thrust for a vessel of any kind since it costs more energy (incredibly more, with current technology) to produce than it actually stores. The only advantage to using an antimatter/matter reaction as a propellant is the sheer efficiency of the reaction. You get a lot more push out of a lot less 'fuel'. If you can get away with carrying less total mass, then you don't have to accellerate or decelerate as much.
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Example: a dude sitting on a sled on a frozen pond, with a sackful of bricks. When he throws a brick off the sled in one direction, the sled moves in the other direction. Because there is very little friction between the sled and the ice, the sled keeps moving. Throw more bricks, and the sled will go faster.
To make everything clear: the sled is like a rocket, the bricks are like fuel, and space has even less friction than a frozen pond. Because the total momentum of the system must be conserved, as fuel is burned and exhaust is generated, the rocket moves forward.
My focus isn't particle physics, but maybe I can offer a correction for your approach. In #2 you presuppose that antimatter and matter are produced in equal amounts; actually, nature seems to favor production of matter over the anti counterpart. Look up CP violation for more on this. So at the Big Bang, all the antimatter annihilated with much of the matter, but since there was an imbalance in the initial production, there was still some matter left over. This is the stuff you and I are made of.
As far as difficulty in production, it happens that most of the particle-pair interactions that decay into antimatter particles only occur at very high energies compared to what our accelerators can achieve, and even then at low probabilities. Then there is the matter of containment. Current methods involve redirection with magnetic fields or trapping with lasers, both of which are extremely difficult and therefore expensive.
As usual, the big problem with this bit of physics is the funding. Going out on a limb, particularly in longterm scientifics, is not promoted as a safe or particularly clever business strategy. This leads to what is not exactly the most logical method of pursuing progress, but I digress in my bias.
Some of the Russian Venera and Luna probes took the first approach--deliberately crashing into Venus or the Moon, respectively. NASA's Voyager craft did a tremendous amount of good science with just flybys. Galileo (the spacecraft, not the Italian scientist) dropped a probe into Jupiter's atmosphere and then settled into two years of orbiting the planet.
~Idarubicin