'em fig fix'

ch01/note02.md

@@ -18,7 +18,12 @@
 
 ### Spectrum of electromagnetic waves
 
-![](./images/lec1_EMspec.jpg)
+
+:::{figure-md} markdown-fig
+<img src="./images/lec1_EMspec.jpg" alt="EM" class="bg-primary mb-1" width="300px">
+
+Electromagneitc radiation has perpendicular electric and magnetic components which propogate with a speed of light. Unlike other forms of waves (water, sounds) light needs to medium and can travel in vaccum! 
+:::
 
 
 - **High-frequency waves carry much higher energy.** This means X-ray or Gamma-rays can only be generated by heating “stuff” up at very high temperatures. This happens naturally at the core of the sun!