That would raise the possible existence of distant antiworlds with antipeople in some distant corner of the universe. It would be the last family reunion you'd ever have. Despite his participation, Salamon doubts the experiment will find cosmic antimatter because such a discovery would overturn fundamental physics theories that explain why the observable universe is made of matter. So Salamon helped convince Ting to modify the experiment so it also can detect gamma rays. Based on motions of galaxies, scientists believe perhaps 95 percent of the universe is made of unseen dark matter, but they haven't identified what it all is.
Antimatter is just like matter except it's sort of the opposite.
Once you get used to it, it's just like regular stuff. Matter is made up of particles such as protons, neutrons and electrons in atoms. Antimatter particles have the same mass but opposite electrical charge of their matter counterparts. Positrons and antiprotons made by atom smashers survive only an instant and in amounts too tiny to cause big explosions. In our corner of the universe, exploding stars produce antimatter positrons.