 This supertask is modeled on an example of Benardete (1964), who considered a space ship that successively doubles its speed until it escapes to spatial infinity. Supertasks of this kind were also studied by physicists like Lanford (1975, §4), who identified a system of particles colliding elastically that can undergo an infinite number of collisions in finite time. Mather and McGehee (1975) pointed out a similar example. Earman (1986) discussed the curious behavior of Lanford’s example as well, pointing out that such supertasks provide examples of classical indeterminism, but can be eliminated by restricting to finitely many particles or by imposing appropriate boundary conditions.