Via Matt Yglesias, we get the news that teleportation technology is not going to happen. The basic gist of the problem is that the amount of information required to fully reconstruct the human brain and body would be so large that it's inconceivable that it could ever be superior to more traditional modes of transport.
Interesting stuff. As he mentions, it's long seemed likely to me that teleportation would be most efficient for transporting goods, rather than individuals.(Of course, if you have the technology to reconstruct goods using stored information, you wouldn't need the original item, and the technology would be closer to a Star Trek-type replicator rather than teleporter.) However, there's reason to be skeptical about any definitive conclusions. I, for one, am not ready to throw in the towel for teleportation just yet.
It's easy enough to say "we don't know what will happen with future technology." If we did, it would be happening now, and it wouldn't be in the future. Predicting technological advances is inherently problematic for this reason.
But even more than just this, we know that many of the greatest inventions we have now would obviously have been inconceivable for our ancestors. And this is precisely because many inventions required paradigm shifts in science that made us think about the world and particular problems in a completely new way. If teleportation is to be a viable technology, it seems likely that it would require some kind of paradigm shifting revelation.
After all, one way around the information constraint problem Yglesias cites is not to worry about information transfer at all! Instead of scanning an item, destroying it, and reconstructing it elsewhere, you could move the item through space-time in such a way that it wasn't constrained by the usual problem of distance. Such an achievement could be possible if small, isolated, and controllable wormholes were technologically possible.
Obviously, that requires a stretch of the imagination; but then, so does a complete sub-atomic scan and reconstruction of an object. Given the information quantities needed for scan-based teleportation, my money is on wormhole-based teleportation.
And as an added bonus, wormhole-based transportation of animals (including humans) evades any metaphysical personal identity worries we might have about scan-based teleportation. The worry is that if the physical continuity of my body is disrupted, by being deconstructed and then reconstructed, the person who comes out the other side might not be me. Derek Parfit famously concludes that such worries are erroneous, but this is controversial, and even he acknowledges that he would hesitate to to undergo scan-based teleportation. Assuming the physics work out, wormhole-based teleportation would preserve physical continuity, and thus raise no metaphysical worries. For this reason, I've always preferred wormhole-based teleportation, and am not disheartened by its rival's potential pitfalls.