# Teleportation through spacetime is possible

### Question:

Is beaming possible?

### Answer:

"Beaming" is known to most from the science fiction series "Star Trek". There, “beaming” means the use of a so-called teleporter. The teleporter ensures that an object (such as a person) disappears in one place and reappears in another. For example, when Captain Kirk calls out to his chief engineer: "Beam me up, Scotty", then disappears from a planet's surface and reappears in the transporter room of the Enterprise. It is very difficult to say if something will ever be possible. Instead, I'd like to explain how Star Trek's teleporter works and discuss whether it contradicts any physical principles.

To do this, I first have to describe some basics. Physicists see the world a bit like a giant Lego game: every object in the universe is made up of smaller parts, so-called elementary particles. Amazingly, it only takes five such elementary particles to build most things in the world! In addition, particles of one type can be converted into those of another. Energy is either consumed or released. Matter is thus a form of energy. Something is still missing in this “worldview”. For example, if we collect all the Lego bricks for a Lego car, we don't have a car yet. The stones must first be put together properly. The information about how the individual parts are connected to one another is also crucial. You also have to know that information is associated with a type of energy: For example, it is much easier to break a Lego car than to put it back together again. Now to the teleporter: This device measures all the particles that make up the object to be beamed, how they interact with the other particles and where they are. The object is then broken down into its individual parts and these particles are converted into those that can be transmitted, such as particles of light. These light particles are then transmitted to another location together with the information about their original state and transformed back there again. Until the late 1960s, scientists believed this was not possible. From their point of view, the critical step was to know the exact information about the state of each particle. Because in quantum physics there is the so-called Heisenberg uncertainty relation. This means that every measurement changes the state of the particle. If you determine exactly where a particle is, you unintentionally change its speed at the same time. Both the location and the speed of the particle cannot therefore be precisely determined. The so-called quantum teleporter, which the scientists working with Anton Zeilinger were almost able to recreate in 1993, offers a solution to this problem. (The theoretical preparatory work for this was provided by physicists working with C.H. Bennet.) The basic idea is the following: In the quantum world, pairs of particles can be generated that always behave in the same way - regardless of how far they are from each other. If one of these particles is "measured", this measurement also affects the second particle and changes its state. Einstein called this a “spooky long-distance effect”, scientists today speak of the Einstein-Podolsky-Rosen paradox. As a result, a teleporter does not have to completely measure the particle that it wants to beam. The information that he cannot measure is simply transmitted using the basic idea of ​​the Einstein-Podolsky-Rosen paradox. Beaming does not violate any physical principle. However, in Bennet's group, great efforts were required to teleport even a few particles. Beaming a whole person made up of around a thousand billion particles is likely to be much more difficult.