diff --git a/2025-05-20.md b/2025-05-20.md
index 001fff299..c00b56cd9 100644
--- a/2025-05-20.md
+++ b/2025-05-20.md
@@ -5,7 +5,7 @@
     - In general magnetism seems like an amazing way to transfer momentum?
   - [[magnetic gears]]
     - As in the little devices I've built
-- Today (actually yesterday) I saw a great video on the principle of minimum 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.
+- 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.
   - 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.