I learned that particle accelerators have been able to create minute quantities of antihydrogen, by blasting a beam of high-energy protons into a target using the accelerator, thereby creating a shower of subatomic debris. Powerful magnets separate out the antiprotons, which are slowed down to very low velocities and then are exposed to the antielectrons that are naturally emitted from sodium-22. When the antielectrons orbit around the antiprotons, they create antihydrogen, since hydrogen is made up of one proton and one electron. In a pure vacuum, these anti-atoms might live forever. But because of impurities and collisions with the wall, these anti-atoms eventually strike ordinary atoms and are annihilated, releasing energy.
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