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 ...

Physicist Richard Feynman invented them to describe the interactions between real particles. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. This ...