That's great, thanks, but I thought (3) is a propagating wave that is attenuated with distance (propagating wave enveloped by a decaying exponential). Also, I was wondering what the physical difference between the two phenomena is that leads to the difference in the equations, ie why we don't...
Hi,
I'm a second year undergrad and we've covered the heat equation,
\begin{equation}
∇^{2}\Psi = \frac{1}{c^{2}}\frac{\partial^2 \Psi}{\partial t^2}
\end{equation}
and the wave equation,
\begin{equation}
D∇^{2}u= \frac{\partial u}{\partial t}
\end{equation}
in our differential equations...