The U.S. Air Force is quietly spending millions of dollars investigating ways to use a radical power source — antimatter, the eerie “mirror” of ordinary matter — in future weapons. The most powerful potential energy source presently thought to be available to humanity, antimatter is a term normally heard in science-fiction films and TV shows. But antimatter itself isn’t fiction; it actually exists and has been intensively studied by physicists since the 1930s. In a sense, matter and antimatter are the yin and yang of reality: Every type of subatomic particle has its antimatter counterpart. But when matter and antimatter collide, they annihilate each other in an immense burst of energy.
