Electromagnetic ForceThe fundamental force which binds electrons to atoms, and governs the physics of light. Any charge feels an electric force from another charge.
Electromagnetic Radiation(ee-LEK-troh-mag-NEH-tik ray-dee-AY-shun) Low-energy radiation that comes from the interaction of electric and magnetic fields.
ElectronA sub-atomic particle that has a negative electric charge.
Elementary Particle PhysicsThe study of fundamental particles (such as quarks and leptons) and their interactions (forces).
Energy DensityThe amount of energy per unit volume. The energy density affects, and is affected by, the expansion or contraction of the universe.
Energy SpectrumThe amount of energy emitted at a specific wavelength of light. For example, the Sun emits light at many wavelengths, which can be seen by passing…
EquilibriumTo be in a state of perfect balance. A spinning top is a kind of equilibrium untill it falls.
ERAA time period dominated by a particular physical process.