Another answer, involving time

   Prompted by my answer to Rebecca's question, Fred has asked a related one:

I wonder, if you read a futuristic novel, let's say one of Asimov's, maybe The Foundation Trillogy where he dreams up "psychohistory" or one of the Robot novels where he dreams up the "positronic brain", does the skeptic in you refuse to believe that either of those would ever become fact? Or is there some room left over to dwell on it a second and say, "That's pretty cool, wonder if it'll ever be."? I love sci-fi, but I never believed that things such as the Star Trek communicators would ever be realized. Of course, cell phones look just like that now.

   It's funny that you ask that, Fred, because the issue has come up for me this very week. I have been rereading some books that have been sitting on my bookshelf untouched for going on twenty years. I just finished Ender's Game, by Orson Scott Card, and am now reading its sequel, Speaker For The Dead.
   Ender's Game surprised me, because I remember thinking it was the best thing since sliced bread when I first read it. Now, I find it almost juvenile in tone, like young adult fiction, rather than real adult science fiction. Still, there wasn't really anything in it that bothered my skeptical sensibilities. Well maybe one little thing that niggled at my subconscious, but I couldn't put my finger on it.
   Speaker For The Dead, on the other hand, while it is the work of a much more comfortable, confident and accomplished writer, made me stop and think about the real world implications of an aspect of the story.
   In the universe of Andrew (Ender) Wiggin, space travel is still limited by the speed of light. While spaceships can reach near light-speed relativistic velocities, they cannot travel faster than light. Communications technology, however, has developed into a device called an "ansible" which is capable of instantaneous communication over stellar distances. 
   What this means is, while it might take decades to travel from one solar system to the next, one can have a telephone conversation across stellar distances with absolutely no time lag. No problem so far.
   Except this: According to the story, travelling at near light speeds brings into effect time dilation, which means that, for a trip that takes twenty two years, the traveller ages less than two weeks. This is all accounted for by Einstein's theories, so I have been led to believe.
   But what about the instantaneous communications? Ender leaves his sister, Valentine, behind when he makes his journey. By the time he reaches his destination, only two weeks of subjective time have passed for him, but twenty two years have passed for Valentine, at his point of departure, and for the people at his destination. But if instantaneous communication is possible, and Valentine could have been talking to Ender for the twenty two years (her time) of that voyage, how could Ender have participated in twenty two years worth of conversation in his subjective two weeks?
   It's a problem. Potentially a paradoxical one. So much so that the author had to make his ansible not function on a space ship travelling at relativistic speeds, so that no communication is possible during periods when characters are experiencing different subjective passages of time. Enough of a problem to engage my skepticism; to make me doubt such a technology as the "ansible" is in any way possible.

   Of course, good speculative fiction is always about more than just the futuristic technology a writer can dream up. The best novels are about the characters, and how they react and interact in the situations a writer puts them in. In the case of Orson Scott Card, I am entertained and engaged enough by his writing to let his potentially impossible technological invention slide; to willingly keep my disbelief suspended in order to continue enjoying the the novel I am reading.
   I must point out that this is a rare instance, that I even noticed, and was jolted out of the narrative enough to think about the situation. In most cases I am willing to allow a huge amount of leeway to allow for potential future scientific advancement. In the example you quoted, I am perfectly willing to believe that we might develop a "positronic" brain given enough time. If you look at many of the things we take for granted today, and think about how short a time most of today's technology has been around, it is perfectly reasonable to expect the development of amazing things over the next several centuries.
   Psychohistory? Probably not so much.

tags: Skepticism, Books