When we refer to waves having two dimensions, frequency and amplitude, we are specifically talking about the properties that describe the wave itself, not the physical space in which the wave propagates. The world we live in is indeed three-dimensional, but waves can exist and propagate within this three-dimensional space.
Let's break down the dimensions of a wave:
Amplitude: Amplitude refers to the magnitude or intensity of the wave. It represents the maximum displacement or height of the wave from its equilibrium position. In the case of a sound wave, the amplitude corresponds to the loudness of the sound. In an electromagnetic wave, such as light, the amplitude represents the brightness or intensity of the light.
Frequency: Frequency refers to the number of complete cycles or oscillations of the wave that occur per unit of time. It is measured in hertz (Hz), which represents cycles per second. Frequency determines the pitch of a sound wave and the color of light in the case of electromagnetic waves.
While amplitude and frequency are important properties of a wave, they do not solely define its behavior or interaction with the three-dimensional space. Waves can have additional characteristics such as wavelength, phase, direction of propagation, and polarization, which provide a more complete description of the wave.
For example, wavelength is the distance between two consecutive points of a wave that are in phase (e.g., crest to crest or trough to trough). Waves can propagate in any direction in three-dimensional space, and their behavior can be influenced by the medium through which they travel.
In summary, waves exist and propagate within the three-dimensional world we inhabit, but when we discuss waves in terms of their two dimensions (frequency and amplitude), we are specifically referring to the properties that describe the wave itself, rather than the full extent of its interaction with the three-dimensional space.