Teleporting a person, as in Star Trek (see letter to the editor in Scientific American, August 2000) might produce an identical person, but not the same person. The original would die and a “Doppelganger” would be created. That is the letter writer’s argument. “Beam me down, Scottie” would be Captain Kirk’s last words, and his double would conduct the action on the exotic planet.

Identical twins are identical genetically, but they are not the same person. Fetal development and later experience make them different. Their neurons and their immune systems evolve (are selected) differently during development. Later, the synaptic patterns in their brains be different, producing differences in their memories and their learning.

But the hypothetical teleportation case is different: presumably, in science fiction, there are no developmental differences in Captain Kirk and his double. I recall the poem “Doppelganger”, in which a man walking along with his wife sees his double watching in the bushes, and by the end of the story he is hiding in the bushes while his double is walking off with his wife.

The above is the note I wanted to make, but forgot 3 times (1) before I found pen and paper. Did Someone not want me to know this? Why? Because, I suddenly realized, I myself am not the same from moment to moment. The continuity of the self is an illusion. I constantly die and my doppelganger takes my place. Is this the deepest secret of all? “I think, therefore I am” is not valid! The Doppelgangers think separately, like identical twins.

So not only in teleportation, but in reality, I am annihilated in every moment (how long? 200 microseconds?), to come back identical, but not the same. Or does form (morphology) bring about sameness (continuity), though of course the material base changes? I don’t know how we can ever test this.