 Norton (1999) investigated whether there exists a direct quantum mechanical analogue of the kinds of supertasks discussed above. He began by considering the classical scenario shown in Figure 1.5.1 of an infinite lattice of interacting harmonic oscillators. Assuming the springs all have the same tension and solving the equation of motion for this system, Norton found that it can spontaneously excite, producing an infinite succession of oscillations in the lattice in a finite amount of time.