A Few Thoughts On Ender's Game

On the recommendation of a friend, I recently finished reading Orson Scott Card's book, Ender's Game. This book has a lot to recommend it.  So much so that I have heard that it has been used in actual military education classes alongside Sun Tzu and von Clausewitz.  I found Card's anticipation of the Internet to be visionary, and there were twists in the plot of the book that I did not expect. There was one element of the story that bothered me, however.

Card is not a scientist, and why should he be?  He is a writer of fiction.  It is fiction: he is free to create the world as he sees fit.  We the readers should suspend our disbelief.  Yet, there is one aspect to the story that made it hard for me to suspend my disbelief.

In the book, Card discusses a device called the Ansible that allows instantaneous, faster than light communication.  We all know that such a notion as communicating faster than the speed of light violates relativity, but that does not particularly bother me.  It is not the only story to violate relativity; so why should such a thing be bothersome?

At several points in the book, Card invokes relativity, specifically the idea of time dilation.  It is through time dilation that characters are able to live fewer years in the same time that other characters live more years.  Such an idea, though perhaps impracticable is consistent with relativity.

If we admit, the idea of time dilation, however, the concept of simultaneity suffers consequences.  Two events that take place simultaneously at different locations, are only simultaneous for a given frame of reference.  For other frames of reference, one event occurs before the other event.

An instantaneous message is one that is received simultaneously with its transmission.  There is in relativity, however, no privileged frame of reference.  Suppose a message is sent from point A to point B instantaneously in a given frame of reference.  In other frames of reference, the transmission and reception will not be simultaneous, i.e., the message will not be instantaneous.

Even more problematic.  There will be frames of reference, in which the message is received before it is sent.    Such an occurrence constitutes causality violation.  Such a causality violation would enable one side or the other in the war to go back and change the outcome after the war was over.  That would be a weapon more formidable than Dr. Device (which already required me to suspend my disbelief).

Card's story is a great story, and we should endeavor to suspend our disbelief.  The fact that I had trouble doing so is not very interesting, but I thought that the reason I had this trouble might help shed some light on why faster-than-light travel is forbidden in relativity without having to introduce a lot of math.

I am of course aware of recent, hard-to-explain results regarding the speed of neutrinos, but that is something that makes that story so interesting.  If the finding is correct, what we understand about relativity must be fundamentally flawed in some way.  I am skeptical of the idea that the neutrinos were actually faster than light.  I suspect that we may be seeing issues related to defining passage in the correct frame of reference with respect to GPS signals used to synchronize the clocks, or some other similar issue.  Of course, I could be wrong about that.