 What is the result of this supertask? Their answer is that none of the particles remain in space. They cannot be anywhere in space, since for each horizontal position that a given particle can occupy there is a time before 1 second that it is pushed out of that position by a collision. The worldline of any one of the particles from this supertask can be illustrated using Figure 1.4.3. This is what Malament (2008, 2009) has referred to as a “space evader” trajectory. The time-reversed “space invader” trajectory is one in which the vacuum is spontaneously populated with particles after some fixed time.