Wave Physics and Simulations

A wave is a disturbance that travels through space or a material medium, carrying energy from one place to another without permanently transporting the medium itself. Mechanical waves, such as those on a stretched string or ripples on water, require a medium; electromagnetic waves, such as light, can also travel through a vacuum. Waves are described by their wavelength, frequency, amplitude and speed, related by the equation that wave speed equals frequency multiplied by wavelength.

Several behaviours appear across all wave types. Reflection occurs when a wave bounces off a boundary; refraction is the bending of a wave as it passes into a region where its speed changes; and diffraction is the spreading of a wave around obstacles or through openings. When two waves overlap they superpose, producing interference patterns of reinforcement and cancellation. Christiaan Huygens proposed that every point on a wavefront acts as a source of secondary wavelets, a principle that explains refraction and diffraction geometrically. The Doppler effect describes the change in observed frequency when a source and observer move relative to one another.

Interactive simulations, including the classic ripple tank, let learners vary frequency and barrier geometry to watch interference fringes, standing waves and refraction form in real time. A vibrating string fixed at both ends supports standing waves at discrete resonant frequencies called harmonics, illustrating how boundary conditions select allowed wave patterns. Such visual models make the mathematics of wave motion easier to connect to observable behaviour.

Frequently asked questions

What is the difference between a transverse and a longitudinal wave?

In a transverse wave the medium oscillates perpendicular to the direction of travel, as on a string. In a longitudinal wave the oscillation is parallel to the travel direction, as in a sound wave.

What causes a standing wave?

A standing wave forms when two waves of equal frequency travel in opposite directions and interfere, producing fixed nodes and antinodes. On a bounded string this happens at specific resonant frequencies.

Why does a wave bend when entering a new medium?

Refraction occurs because the wave changes speed in the new medium. The change in speed bends the direction of travel, an effect described by Snell's law for light.