1.1
Waves and Particles
1.2
Electromagnetic waves come in many forms, e.g., radio waves, light, and X-rays. In 1870, James Clerk Maxwell developed a formalism to describe these electromagnetic waves, in which the changing magnetic field creates an electric field and vice versa, forming a self-sustaining wave that propagates at a speed denoted by the symbol c, the speed of light, which is 3·108 m/s in a vacuum. Three properties describe waves: speed (c), wavelength (λ), and frequency (ν) (sometimes written as f ).