Light is an electromagnetic radiation that is fundamental to our understanding of the physical world. It plays a crucial role in various scientific disciplines, including physics, chemistry, and optics. The study of light has paved the way for numerous technological advancements and has deepened our understanding of the universe.

Common equations:  c = λv   and  v = c / λ  

Variable defined as:  c = speed of light = 3.00 x 108 m/s (this is a constant)

λ = wavelength … usually given in m (based on the unit for speed of light)

v  = frequency … usually given in s-1 or 1/s 

At its most basic level, light is a form of energy that travels in the form of waves. These waves consist of electric and magnetic fields oscillating perpendicular to each other and to the direction of wave propagation. Light waves exhibit various properties, including wavelength, frequency, speed, and polarization.

Wavelength refers to the distance between two consecutive peaks or troughs of a light wave. It is often represented by the Greek letter lambda (λ) and is typically measured in units such as nanometers (nm) or meters (m). Different wavelengths of light correspond to different colors in the visible spectrum.

Frequency, denoted by the symbol nu (ν), represents the number of wave cycles that pass a given point per unit of time. It is measured in hertz (Hz) or cycles per second. The frequency of light waves is directly proportional to their energy. Higher frequency light waves have greater energy, while lower frequency light waves have lesser energy.

The speed of light, denoted by the letter c, is a constant in a vacuum and is approximately 299,792,458 meters per second (m/s). It is the fastest known speed in the universe and serves as a fundamental constant in physics. The speed of light remains constant regardless of the wavelength or frequency of the light wave.

Light exhibits various behaviors when interacting with matter. It can be absorbed, transmitted, or reflected by different substances. The reflection of light allows us to see objects and their colors, while the absorption and transmission of light enable energy transfer and various optical phenomena.

The wave-particle duality of light is another fundamental concept. While light behaves as a wave in terms of its propagation and interference patterns, it also exhibits particle-like properties known as photons. Photons are discrete packets of energy that carry light and exhibit particle behavior in phenomena such as the photoelectric effect.