Charge

Charge is a physical property of matter, which causes it to experience electromagnetism. In pilitron physics, charge is defined by a charge parameter, denoted $$\bar{q}$$. The electron is described as having a charge parameter of -1, and a proton has a charge parameter of exactly 1. Like charges attract and unlike charges repel.

Since electromagnetism is mediated by photons, they define charge. The total (net) charge of a system is defined as the sum of charges of its sub-systems:


 * $$Q = \sum \bar{q}$$

Basic compound particles like electrons get their charge from interactions with photons in the background.