Add ℎ = planck_constant

numbat/modules/physics/constants.nbt

@@ -16,7 +16,8 @@ let gravity: Acceleration = 9.80665 m / s²
 let g0 = gravity
 
 # The Planck constant
-let planck_constant = 6.62607015e-34 J / Hz
+let planck_constant: Action = 6.62607015e-34 J / Hz
+let ℎ = planck_constant
 
 # The reduced Planck constant
 let ℏ: AngularMomentum = planck_constant / 2π