Since ⟨ ⟨ p ( t ) ⟩ ⟩ = p 0 and σ σ p ( t ) = ℏ ℏ / ( 2 x 0 ) , this can be interpreted as a particle moving along with constant momentum at arbitrarily high precision. On the other hand, the standard deviation of the position is σ σ x = x 0 2 1 + ω ω 0 2 t 2 such that the uncertainty product can only increase with time as σ σ x ( t ) σ σ p ( t ) = ℏ ℏ 2 1 + ω ω 0 2 t 2