From 42d409fa774efb8206ae5c701d5cbcc4ae1d9cad Mon Sep 17 00:00:00 2001 From: Prefetch Date: Tue, 14 Sep 2021 21:20:30 +0200 Subject: Expand knowledge base --- content/know/concept/electromagnetic-wave-equation/index.pdc | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'content/know/concept/electromagnetic-wave-equation/index.pdc') diff --git a/content/know/concept/electromagnetic-wave-equation/index.pdc b/content/know/concept/electromagnetic-wave-equation/index.pdc index 68fe062..84946bb 100644 --- a/content/know/concept/electromagnetic-wave-equation/index.pdc +++ b/content/know/concept/electromagnetic-wave-equation/index.pdc @@ -118,14 +118,18 @@ $$\begin{aligned} \vb{E}(\vb{r}, t) &= \vb{E}_0 \exp\!(i \vb{k} \cdot \vb{r} - i \omega t) \\ - \vb{H}(\vb{r}, t) - &= \vb{H}_0 \exp\!(i \vb{k} \cdot \vb{r} - i \omega t) + \vb{B}(\vb{r}, t) + &= \vb{B}_0 \exp\!(i \vb{k} \cdot \vb{r} - i \omega t) \end{aligned}$$ -In fact, thanks to linearity, these solutions can be treated as +In fact, thanks to linearity, these **plane waves** can be treated as terms in a Fourier series, meaning that virtually *any* function $f(\vb{k} \cdot \vb{r} - \omega t)$ is a valid solution. +Keep in mind that in reality, $\vb{E}$ and $\vb{B}$ are real, +so although it is mathematically convenient to use plane waves, +in the end you will need to take the real part. + ## Non-uniform medium -- cgit v1.2.3