Antimatter is real stuff, not just science fiction. Antimatter is firmly in the realm of science with some aspects even entering the technology realm. There is also a lot of speculation about what one might do with antimatter.
What is Antimatter?
Antimatter is matter with its electrical charge reversed. Anti-electrons, called "positrons," are like an electron but with a positive charge. Antiprotons are like protons with a negative charge. Positron, antiprotons and other antiparticles can be routinely created at particle accelerator labs, such as CERN in Europe, and can even be trapped and stored for days or weeks at a time. And just last year, they made antihydrogen for the first time. It didn’t last long, but they did it. Also, Antimatter is NOT antigravity. Although it has not been experimentally confirmed, existing theory predicts that antimatter behaves the same to gravity as does normal matter.
Technology is now being explored to make antimatter carrying cases, to consider using antimatter for medical purposes, and to consider how to make antimatter rockets.
Right now it would cost about One-Hundred-Billion dollars to create one milligram of antimatter. One milligram is way beyond what is needed for research purposes, but that amount would be needed for large scale applications. To be commercially viable, this price would have to drop by about a factor of Ten-Thousand.
And what about using antimatter for power generation? - not promising.
It costs far more energy to create antimatter than the energy one could get back from an antimatter reaction. Right now standard nuclear reactors, which take advantage of the decay of radioactive substances, are far more promising as power generating technology than antimatter. Something to keep in mind, too, is that antimatter reactions - where antimatter and normal matter collide and release energy, require the same safety precautions as needed with nuclear reactions.