The four properties we are considering are: entanglement, decoherence, superposition, and the uncertainty principle.

Entanglement occurs when two newly created particles must always have the same spin (and all other quantum numbers), and when the spin of one is changed, the other also changes, although they are too far apart to communicate by signals even at the speed of light. It is as if the two particles were connected by an eternal string. (No pun intended. )

Decoherence is the opposite of entanglement. The connection (“string”) between two entangled particles is broken by interaction with the environment. This is why ordinarily entanglement is not observed in the everyday world, where other dense interconnections exist.

Superposition is the existence of two different quantum states for the same particle. It occurs by the addition of the two wave equations, as if by Fourier synthesis. Thus, while entanglement is a single state for two particles, superposition means two states for a single particle.

The Heisenberg uncertainty principle says that we cannot know the position and the momentum of a wave-particle at the same time, in the same experiment. Perhaps it is evident that a wave does not have position and a particle does not have frequency (by analogy with “the dolphin click”, an essay in this collection).

Scientific American (April 2000) has an article on teleportation, in this case of a photon, in which the concepts of these properties is used. It shows that the teleportation (transfer in space) is theoretically possible for a photon (and other elementary particles perhaps), though it has not yet been done in the laboratory. But it also argues that it is not even theoretically possible for a large complex physical object, such as a person. (Star Trek’s “Beam me down, scottie” will remain science fiction.)

It seems to me that this is because elementary particles are “fungible” (indistinguishable from one another) *, while large objects and persons are not. It is fundamentally impossible to preserve all the complex interrelationships in these larger bodies during spatial transfer. The information content exceeds all practical limits.

* See my essay From Fungibility to Personality in this collection.