 In the previous section, we showed the existence of models of general relativity which seem to allow for a type of bifurcated supertask. Here, we ask: Are these models “physically reasonable”? Earman and Norton (1993, 1996) and Etesi and Németi (2002) have articulated a number of potential physical problems concerning Malament-Hogarth spacetimes. First of all, we would like Bob’s worldline to be reasonablly traversable. In the Anti-de Sitter model above, the half-curve \(\gamma\) has an infinite total acceleration. Bob would need an infinite amount of fuel to traverse it! (Malament 1985)