diff --git a/2025-05-20.md b/2025-05-20.md
index c00b56cd9..4e86f059e 100644
--- a/2025-05-20.md
+++ b/2025-05-20.md
@@ -6,7 +6,7 @@
   - [[magnetic gears]]
     - As in the little devices I've built
 - Today (actually yesterday) I saw a great video on the [[principle of least action]] and it blew my mind a bit. It also introduced me to diffraction grating effects -- which I had heard about but hadn't grokked/seen demonstrated.
-  - The fact that angular momentum is quantized and has the same units as action... wow.
+  - The fact that angular momentum is quantized... wow. Also it introduced me to [[diffraction gratings]], which I had heard of only in passing.
   - This all made me think also of...
     - Could you use diffraction gratings at astronomic scales to see into the past? E.g. by making visible light from a star that has taken a longer (slower) path to get to us.
     - The effect that makes lights 'stretch out' in one direction in some mediums, like water (think of night lights reflected on a lake) or... the effect that is apparent in my chrome kitchen countertop that is quite something and I sometimes call the [[rainbow folding]] as per Heinali's great track :)