In classical physics, light is described as an electromagnetic wave, and its amplitude corresponds to the strength or intensity of the wave. In this context, the amplitude represents the maximum displacement of the electric and magnetic fields associated with the wave.
If we consider a light wave with zero amplitude, it would mean that the electric and magnetic fields have no displacement or intensity. In other words, there would be no oscillation or energy associated with the wave.
However, in the framework of classical physics, a light wave with zero amplitude would essentially be considered as nonexistent or not present at all. The presence of light is fundamentally associated with the existence of an electromagnetic wave, which requires some nonzero amplitude to carry energy.
It's worth noting that in the quantum mechanical description of light, photons are considered as discrete particles or quanta of light, and their properties are described by wavefunctions. In this context, a flat or zero-amplitude wavefunction would represent a state of no photons or no light particles.
In summary, within the classical understanding of light, a light wave with zero amplitude would not exist as it would not carry any energy. In the quantum mechanical framework, a zero-amplitude wavefunction would correspond to the absence of photons or light particles.