Star Trek Transporter, Revisited
“Perhaps that’s the wrong way of looking at it: perhaps the scanner [transporter] actually somehow shoots protons, neutrons and electrons into the right places layer by layer: perhaps it does indeed scan across a cross-section at a time and build the reconstituted person from the feet up. It would need some clever mechanism to take account of the fact that real people aren’t made with a neatly laminated structure, and in fact it is going to have to be unbelievably accurate: given the importance of minute differences in the structure of neurons and the disposition of certain molecules within them, I suspect the tolerable error is actually zero. More awkwardly, it will have to allow for the fact that complex structures often require a particular assembly or construction sequence - this part has to be put in this way before that one goes in that way. If we start by scanning, let’s say, Captain Kirk’s feet into existence, the blood is going to start leaking out before we’ve done his shins, his tendons and muscles will lose their tension, and in general the whole thing will start falling apart in our hands. Perhaps, then, people get treated to the grisly sight of Kirk’s skeleton being constituted first, to hold all the other bits up: but the scanner would have to put in some tendons and connective tissue to hold the bones together: in fact, since we can’t have working muscles until the circulation is going, we might need extra ligatures or whatever which don’t feature in the finished Kirk but get removed before the job is completed. There’s still going to be a problem with that damn blood: we need to put all the vessels in place first and then fill them, which is tricky; and managing the filling and starting of the heart without a major problem will be difficult too.
But that won’t do at all, in any case, because we’re supposed to be reconstituting a dynamic system in full flight. It’s difficult enough to reconstitute a snooker table, but what we have to do is bring the table into existence as it was a moment after someone played a shot, with the balls already in motion in various directions. Kirk’s troublesome blood has to be flowing and all the right neurons have to be in mid-fire. The penalty if we can’t do that (and I don’t think we can) is that we have to reconstitute him in a slightly different, stable starting state, so that when Kirk is reconstituted he is unconscious and has suffered some loss of recent memory: when he comes round he doesn’t remember getting into the scanner or why he wanted to be scanned: in fact, the idea that this is the original Kirk, rather than a good copy, suddenly seems much less plausible.”