What is antimatter and why does it matter?
Almost 80 years later, positrons and other antiparticles are still studied to try to answer fundamental questions about the universe and the matter it contains. Antimatter, as the name implies, can be described as the opposite of ordinary matter. Every particle in the universe has characteristics such as mass and charge. With antimatter, the mass remains constant, but the sign of the charge is reversed. All particles have an antimatter counterpart, even the chargeless neutron (Its constituent quarks do have a charge; the antineutron is composed of antiquarks). Unlike matter, antimatter is not common. Unless you’re in the upper atmosphere, or inside a particle accelerator, you’re not going to stumble across it. “Antimatter was not always so rare,” Stphane Coutu, Penn State particle physicist says. There was a time when it was as prevalent as matter itself. “Right after the Big Bang,” Coutu explains, “we believe there must have been exactly the same amounts of matter and antimatter…and
