UBC Theses and Dissertations
Time travel possibilities within a Gödelian space-time structure Betton, Carla D.
This thesis examines the question as to whether Paul Horwich has preserved the possibility of time travel into the past, within a Gödelian spacetime structure. In my thesis I argue that Horwich is not successful in his attempt to defend time travel. Horwich himself establishes conditions under which he determines that time travel to the local past would result in "bilking attempts" being manifested. Horwich sees this as unacceptable, as it would result in the past being changed, which gives rise to a logical contradiction. Horwich avoids having to posit a non-Gödelian space-time structure however, by attributing the non-existence of time travel within bilking range to excessive fuel requirements. However, fuel requirements to the spatially distant past are not technologically inaccessible, therefore Horwich claims time travel is still possible, as the spatiality distant past is outside of bilking range I argue that trips to the spatially distant past are subject to the same bilking conditions Horwich placed on the local past. Consequently time travel is not possible to any past, as it would result in either a logical contradiction , or multiple inexplicable coincidences. In Chapter I, I examine some of the work of Albert Einstein and Kurt Gödel that was relevant in sparking much of the modern literature on time travel. Kurt Gödel proposed a theory of a curved space-time based on field equations yielded by Einstein's General Theory of Relativity, that would mathematically allow for the existence of closed causal chains. This opened up the possibility of time travel into the past. Chapter II is an overview of the relevant literature on time travel. I have attempted to give a sampling of a number of theories in this area, on both sides of the debate. Chapter III is an in-depth look at Horwich's theories on time travel and backward causation, taken from Chapters 6 and 7 of his book Asymmetries in Time - Problems in the Philosophy of Science. Here he defends backward causation against the bilking argument, and attempts to defend time travel against four different paradoxes. In Chapter IV, I raise four concerns I have with Horwich's theories: 1) that he has avoided the issue of temporal parts, thereby overlooking an oddity that results from time travel. 2) that he uses backward causation to refute one of the paradoxes, yet by his own admission, time travel is a form of backward causation that requires bilking attempts of the form that violate the V-correlation, and therefore must be rejected. 3) that the spatially distant past is not out of bilking range as Horwich argues; and is therefore just as inaccessible as the local past and 4) that the spatially distant past as Horwich defines it is ultimately inaccessible as a journey back to the distant past would take longer than the proper duration of the lifetime of the system that was sent back.. I conclude that while Horwich may be successful in defending Gödelian space-time structure, he does not preserve the possibility of time travel within a curved space-time structure, It is my argument that time travel of any sort is impossible, as logical contradictions will be the end result.
Item Citations and Data