Waves and Light

Key Knowledge

• 1Waves are disturbances that transfer energy without transferring matter.
• 2Key wave properties include wavelength, frequency, amplitude, and speed.
• 3Light is an electromagnetic wave that can travel through empty space.
• 4Light exhibits both wave-like properties (diffraction, interference) and particle-like properties (photons).
• 5The visible light spectrum is just a small part of the electromagnetic spectrum, which also includes radio waves, microwaves, infrared, ultraviolet, X-rays, and gamma rays.

Historical Context

The Dual Nature of Light

Throughout history, scientists debated whether light was a wave or a particle. In the 17th century, Newton proposed that light was made of tiny particles, while Huygens suggested it was a wave. In the 19th century, Young's double-slit experiment demonstrated light's wave-like properties. Later, Einstein's work on the photoelectric effect showed that light also behaves like particles (photons). Today, we understand that light exhibits both wave and particle properties - a concept known as wave-particle duality.

Key Figures