2.2 Production of electromagnetic waves

1.1 Displacement current
1.3 Maxwell's equations

2.1 Properties of electromagnetic waves
2.2 Production of electromagnetic waves
2.3 Energy density of electromagnetic waves
2.4 Intensity of electromagnetic waves
2.5 Momentum of electromagnetic waves
2.6 Radiation pressure
2.7 Poynting vector
2.8 Electromagnetic spectrum

The creation of all electromagnetic waves begins with a charged particle. This charged particle creates an electric field (which can exert a force on other nearby charged particles). When it accelerates as part of an oscillatory motion, the charged particle creates ripples, or oscillations, in its electric field, and also produces a magnetic field (as predicted by Maxwell's equations).

Once in motion, the electric and magnetic fields created by a charged particle are self-perpetuating—time-dependent changes in one field (electric or magnetic) produce the other. This means that an electric field that oscillates as a function of time will produce a magnetic field, and a magnetic field that changes as a function of time will produce an electric field. Both electric and magnetic fields in an electromagnetic wave will fluctuate in time, one causing the other to change.

Electromagnetic waves are ubiquitous in nature (i.e., light) and used in modern technology—AM and FM radio, cordless and cellular phones, wireless networks, radar, microwave ovens, etc.

Electromagnetic waves was first produced by Heinrich Rudolf Hertz in late 1880s.