The ancient Greeks speculated that it might be air, fire or water. A century ago, physicists felt sure it was the atom. Today, we believe that the deepest layer of reality is populated by a diverse ...

The particles that are in an atom: protons, neutrons and electrons The particles that are in protons and neutrons: quarks The four fundamental forces: gravity, electromagnetism, the strong force and ...

Scientists imagine virtual particles popping in and out of existence to explain how forces transfer between particles. koto_feja/iStock via Getty Images A clever mathematical tool known as virtual ...

Dipangkar Dutta receives funding from US Dept. of Energy and NSF. A clever mathematical tool known as virtual particles unlocks the strange and mysterious inner workings of subatomic particles. What ...