Before you read this, I suggest you read posts 19.10 and 19.11. I introduced the idea of a wave in post 18.10 but, if you think about it, you will see that in that post and later posts (18.11, 18.12, 18.13, 18.14, 19.9) on waves, I have never defined exactly what I mean by the… Continue reading 19.12 The wave equation

Before you read this, I suggest that you read posts 17.4 and 18.10. In post 18.10 we saw that a one-dimensional wave could be represented by a wave function, ψ, that is a function (post 19.10) of position, x, and time, t. At a fixed point in space (x is constant), the wave function is… Continue reading 19.11 Partial differentiation