Recall that ℏ is Dirac’s version of Planck’s constant (h/2 π) (and i = √–1) and that the operator ∂/∂t (partial differentiation with respect to time) acting on |ψ〉 simply means the rate of change of |ψ〉 with respect to time. Schrödinger’s equation states that 〈‘H|ψ〉’ describes how |ψ〉 evolves.
