This is the form of the wave equation. So, Maxwell’s equations do say that light is a wave. 2. ... These light “things” have energy that depends on the wavelength such that: ...

Since the accelerating wave equation can be derived from geometrical considerations, it is general, ... In such cases, energy conservation is locally violated," Ornigotti says.

[3] Energy Decay for a Nonlinear Wave Equation of Variable Coefficients with Acoustic Boundary Conditions and a Time-Varying Delay in the Boundary Feedback. Nonlinear Analysis (2015).