3
votes
3answers
346 views

What does it mean that a wavevector is null?

I have derived geometric optics for gravitational waves and I am trying to interpret one of the results. I have \begin{equation} k_{\rho}k^{\rho}=0 \end{equation} for the wavevector. For the case ...
-1
votes
4answers
287 views

What does the wave principle of light actually represent?

Light has a dual nature, one of photons and the other of waves. But energy doesn't really travel in waves. So what do the wave represent?