Is light a wave or a particle?

Light possesses both wave-like and particle-like characteristics.

The term "wavelength" denotes the wave-like characteristic of light. It is the distance light traverses in one oscillation, commonly given in the unit "nanometre". One nanometre is equivalent to one billionth of a metre. The human eye perceives light within a wavelength range of around 400 to 700 nanometres. This spectrum is referred to as visible light. Other wavelengths of light encompass X-rays, ultraviolet rays, and infrared rays. Although they are not clearly observable, these entities also belong to the family of light.

 

Conversely, light possesses the characteristics of a particle.

The luminosity fluctuates based on the quantity of particles. Bright light has a greater number of particles, whereas dark light comprises fewer particles. The entities of light are referred to as "photons."
 

Juxtaposing light and sound

We may examine the particle characteristics of light by contrasting it with sound using an oscilloscope. Sound is recognised for possessing wave-like qualities. As the intensity or volume of sound diminishes progressively, the auditory signal diminishes and ultimately vanishes. As light diminishes, the total intensity of its signal decreases; but, the few surviving pulses, which are exceedingly brief, remain detectable, and the magnitude of these individual signals does not diminish. This indicates that light cannot diminish in size and possesses characteristics of a "particle."