One in a million
September 17, 2012 § Leave a comment
B3: In reading “Wormholes and Time Machines” from Kip Thorne’s Black Holes and Time Warps, several things became eminently clear to me. Among them, the fact that the hard science of these subjects is anything but eminently clear to me, though there are a number of astute specialists hard at work (or perhaps, more aptly, thought?) exploring this realm of knowledge. But above all, I came away with two overriding impressions:
1) There is a very, very small chance that wormholes (on anything more than a subatomic scale) and time travel are within the realm of possibility. And even if they are, mankind is very, very far away from being able to use them.
Thorne explains that no wormholes have ever been observed, and he proceeds to describe two possible strategies for their construction. The first would be to pull and expand a wormhole from “quantum froth.” Disclaimer(s): Mankind does not possess a microscope that could view matter on this level — let alone get remotely close. Especially since we have very little understanding of quantum gravity, expanding this wormhole is easier said than done. Oh, and one last thing, there’s a chance quantum foam doesn’t even exist. As for the second wormhole creation option, two holes would be torn in adjacent regions of folded hyperspace and sewn together. Alas, the act of tearing space also gets into the uncharted realm of quantum gravity, so it may not be possible after all.
After delving into time travel, Thorne ultimately admits the likely truth of Stephen Hawking’s chronology protection conjecture, which states, “Every time machine is likely to self destruct (by means of circulating vacuum fluctuations) at the moment one tries to activate it.” I found it funny that time travel could be dismissed by a provision at once laughably simple and scientifically complex. However, it is not the entire story, as Thorne follows up his summary of Hawking’s conjecture by concluding, “we cannot know for sure until physicists have fathomed in depth the laws of quantum gravity,” which leads me to:
2) If wormholes and time travel are, in fact, feasible, and humans acquire the understanding necessary to create and manipulate them, the possible applications are immense.
Thorne touches on several interesting aspects of time machines, but to me, the most compelling was the billiard ball case study prompted by University of Texas professor Joe Polchinski, who took the problematic human element out of the classic grandfather paradox. Eventually, Thorne and two students resolved the paradox (two solutions are displayed below).
What’s more, there are actually countless solutions to the paradox, with — according to quantum laws — various probabilities. To apply this concept broadly, time might work in a number of different ways, all resting on chance. One trip to the past might possess the capacity to produce future A, or B, or C, etc…, and there’s no way to tell. It makes the prospect all the more exciting, or dangerous, depending on your point of view.
It’s crazy that a genre grounded in a scientific base can turn so often to the highly improbable domain of time travel. Still, with its tantalizing possibilities, as long as it hasn’t been disproved, that appears to be enough for SF writers to keep coming back to it.
And honestly, that’s enough for me, too. If nothing else, time travel makes for some pretty cool stories…