Jun 19, 2019 · The wave vector is perpendicular to the direction of motion of waves, by definition. Let's say you observe these waves and you'd want to count number of waves per unit length in a particular …

Oct 16, 2016 · I would like to point out that the concept of the wave vector in lattice vibrations (or vibrations in general) has nothing to do with Quantum theory, it is a purely classical concept. If you …

Feb 26, 2016 · In contrast, for a free particle, the energy eigenstates can be labelled by the particles momentum, which is proportional to a three-dimensional vector, $\vec k$, the so-called wave vector: …

The direction in which the wave vector points must be distinguished from the "direction of wave propagation". The "direction of wave propagation" is the direction of a wave's energy flow, and the …

Sep 11, 2018 · The wave vector is normal to the surfaces of constant phase ('wave fronts') with a length inversely proportional to wavelength. It corresponds to wave momentum, and is one way to describe …

My notation here is that k is the wave vector and Em is the magnitude and direction of the wave. Plugging this into the wave equation gives us the following: $$ k_x^2 +k_y^2 + k_z^2 = \frac {w^2} …

$ {\bf E} \times {\bf B}$ (which is the Poynting vector multiplied by $\mu_0$) should be in the direction of wave motion. I you want an aide-memoire, if you imagine taking a screwdriver and turning a …

Oct 9, 2022 · I am trying to understand the physical meaning of the wavenumber, which as explained in wikipedia, is the magnitude of the wave vector, which, if I am not mistaken, the wave vector gives …

Feb 20, 2025 · In other words, $\xi = \arg ( {\bf E})$ is clear enough for a vector valued solution to the d'Alembert equation, by identifying the vector with a point in the complex plane. What is the …

The basic classical interpretation of this expression is that EM waves, or any wave described by a null 'wave-4-vector' like gravitational waves, travel at the speed of light.