Author:
(1) Andrew Knight, J.D. (aknight@alum.mit.edu).
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Because closed timelike curves are consistent with general relativity, many have asserted that time travel into the past is physically possible if not technologically infeasible. However, the possibility of time travel into the past rests on the unstated and false assumption that zero change to the past implies zero change to the present. I show that this assumption is logically inconsistent; as such, it renders time travel into the past both unscientific and pseudoscientific.
I. INTRODUCTION
The possibility of time travel into the past is a staple of science fiction but is also taken seriously by the physics academy. For instance, “closed timelike curves,” the physicist’s phrase for time travel, are discussed widely in the physics literature [1–8].
Far from relegating time travel to science fiction, many celebrated physicists discuss it seriously both as being subject to scientific inquiry and as being physically possible, perhaps even technologically feasible in the nottoo-distant future. For example, Stephen Hawking [9] asserted that quantum theory “[should] allow time travel on a macroscopic scale, which people could use.”[1] Nobel Prize winner Kip Thorne [11] asserts that “If wormholes can be held open by exotic material, then [possibilities for time travel into the past] are general relativity’s predictions.” Crucially, he conjectures that time travel is simply a matter of technological feasibility as there are “no unresolvable paradoxes” in time travel.
I will argue in this paper that the possibility of time travel into the past rests on a logical contradiction. As such, it is not merely false but, more importantly, pseudoscientific as improperly treated as subject to scientific inquiry.
This paper is available on arxiv under CC BY 4.0 Deed license.
[1] A skeptic of the possibility of time travel, he articulated an unproven “chronology protection conjecture” [10] that would prevent it.