Teleportation is the theoretical transfer of matter or energy from one point to another without traversing the physical space between them. Popularized by sci fi movies like Star Trek, the idea has inspired generations of scientists to find a way to make it real.
What did scientists achieve so far and how close are they to achieving the goal? In order to answer this question, we first need to dive a little bit deeper into the aspects of teleportation.
Recent reports of successful teleportation of particles might have given you the impression that teleporting humans should be possible in the near future. This is definitely not the case. But why not? To put it short, what modern science has achieved is only teleportation of quantum information.
Current research on teleportation is primarily based on a curious phenomenon in quantum mechanics called entanglement, which has no good explanation and was even discarded as a “spooky action at a distance” by Einstein himself. Nevertheless, it does exist and does allow teleportation of the state of a particle, i.e. the quantum information it carries.
How does quantum entanglement work? It is basically the ability of two or more (entangled) particles to share a common quantum state regardless of the distance between them. This practically means that changing the state of one of the particles changes instantly the state of another even if it is on the other side of the universe.
This phenomenon is the foundation of quantum teleportation, which is basically a method of transferring the exact same quantum state of one particle to another particle at an arbitrary distance. The first particle is then considered teleported to the second one, while in fact the second one is just an exact copy of the first one.
It is important to point out that there is no real copying in the process because teleportation actually destroys the quantum state of the original particle. Thus, the result is in fact moving a particle from one place to another, since physics implies that if two objects are identical, then they are the same.
What about the “real” teleportation which transfers matter and even human beings?
Unfortunately, quantum teleportation has only been successfully applied to simple particles and atoms. It is not yet clear if the approach scales to molecules or anything larger. So teleportation of matter remains so far practically impossible and there is still a long way to go before teleporting anything the size of a human.
Another important limitation of quantum teleportation is the fact that it requires classical communication to reconstruct the same quantum state at another location. Simply said, teleportation will never be possible with a speed greater than the speed of light.