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| Teleportation |
Teleportation Meaning
What is teleportation? Roughly speaking, there is a Lab A and a Lab B, and each lab has a box. The goal of teleportation is to take any object that is placed in Box A and move it to Box B.
Of special interest to science fiction fans (among others) is human teleportation, where a brave telenaut enters Box A and uses the teleportation machine to travel to Lab B.
It turns out that human teleportation appears possible in principle, though is probably impossible in practice. Nev-
ertheless, teleportation of much smaller objects like individual spins is not only possible but has been accomplished
in the laboratory. Our goal here is to explain both how teleportation is done and why it is interesting.
The beginning and end of the following discussion are non-technical and should be accessible to most readers. In the
middle we will actually describe the teleportation process in the language of quantum mechanics.
The reason distance becomes relevant has to do with the distribution of entanglement which becomes harder as the separation between the two “labs” increases. A second related problem is the storing of entanglement which can only be done for very short periods, so in practice, most early experiments distribute the entanglement only moments before it is to be used for teleportation. However, these experiments were sufficient to convince most physicists that teleportation of spins is possible.
Since 1997 there have also been many improved versions of the teleportation experiment. For instance, the distance has
been increased in one experiment to 600 m, and the accuracy of the teleported state has also been slowly improving.
of freedom in addition to spin. In principle, we might also need to teleport the photons, gluons and other energy particles comprising a person. Teleporting all that is going to be significantly harder than a few thousand spins. It is probably a good guess that teleportation of humans will never be possible.
Are we at least sure that it is possible to teleport humans in principle? While most scientists expect that ten, hundreds and maybe even thousands of spins will be teleported in practice someday, the teleportation of a human being, even in principle, is actually still a controversial subject.
I would roughly divide people into three schools of thought.
The first group of physicists would argue that there is a soul, consciousness or spirit that permeates the human body that cannot be described by science. Unfortunately, in this view by definition, we are prevented from using science to determine if teleportation is feasible.
The second group of physicists would disagree with human teleportation because of something is known as the measurement problem. Roughly speaking, any object that is capable of performing quantum measurements cannot itself be a quantum object, and therefore cannot be teleported using quantum teleportation. In this view, small numbers of particles are quantum but at some point when you combine enough particles you end up with a classical or “observer” object, which cannot be described by the laws of quantum mechanics.
In principle, such a belief will have experimental consequences, as we should be able to determine at what point do
objects stop being quantum mechanical. At the moment there is neither any experimental evidence for such observer
objects nor even a conspiracy theory that could describe them. On the other hand, it is also true that presently it is very hard to experimentally study large quantum systems, and so it is quite possible that something interesting will happen when a large enough system is examined.
The third school of thought (which I am partial to) would say that all objects big and small are quantum mechanical, and therefore in principle can be teleported. What happened with the measurement problem? I would argue that However, at the time this document was written, most experiments have only teleported a single spin. In principle, if you can teleport one spin, then you can teleport many spins simply by repeating the experiment in a series many times. But this roughly only works on disjoint spins. To teleport a single object comprised of many spins is still out
of reach of present-day experiments. In the future, though, we should see experiments that teleport large numbers of spins. Certainly, if a practical quantum computer is ever built then the same technology would likely allow us to teleport a few thousand spins.
It is likely that this will happen within the next 30–50 years, if not sooner.
Real Experiment That Does Teleportation
A number of groups conducted experimental realizations of the quantum teleportation, using a variety of different systems such as the spin (or polarization) of photons and the spin1 of atoms. In many cases, Labs A and B were the left and right side of a table, and the spins were teleported roughly 50 cm. |
| Teleportation |
The reason distance becomes relevant has to do with the distribution of entanglement which becomes harder as the separation between the two “labs” increases. A second related problem is the storing of entanglement which can only be done for very short periods, so in practice, most early experiments distribute the entanglement only moments before it is to be used for teleportation. However, these experiments were sufficient to convince most physicists that teleportation of spins is possible.
Since 1997 there have also been many improved versions of the teleportation experiment. For instance, the distance has
been increased in one experiment to 600 m, and the accuracy of the teleported state has also been slowly improving.
Can we Able To Teleport human being!
There are some 1029 matter particles comprising a human person, each of which has a position and momentum degreesof freedom in addition to spin. In principle, we might also need to teleport the photons, gluons and other energy particles comprising a person. Teleporting all that is going to be significantly harder than a few thousand spins. It is probably a good guess that teleportation of humans will never be possible.
Are we at least sure that it is possible to teleport humans in principle? While most scientists expect that ten, hundreds and maybe even thousands of spins will be teleported in practice someday, the teleportation of a human being, even in principle, is actually still a controversial subject.
I would roughly divide people into three schools of thought.
The first group of physicists would argue that there is a soul, consciousness or spirit that permeates the human body that cannot be described by science. Unfortunately, in this view by definition, we are prevented from using science to determine if teleportation is feasible.
The second group of physicists would disagree with human teleportation because of something is known as the measurement problem. Roughly speaking, any object that is capable of performing quantum measurements cannot itself be a quantum object, and therefore cannot be teleported using quantum teleportation. In this view, small numbers of particles are quantum but at some point when you combine enough particles you end up with a classical or “observer” object, which cannot be described by the laws of quantum mechanics.
In principle, such a belief will have experimental consequences, as we should be able to determine at what point do
objects stop being quantum mechanical. At the moment there is neither any experimental evidence for such observer
objects nor even a conspiracy theory that could describe them. On the other hand, it is also true that presently it is very hard to experimentally study large quantum systems, and so it is quite possible that something interesting will happen when a large enough system is examined.
The third school of thought (which I am partial to) would say that all objects big and small are quantum mechanical, and therefore in principle can be teleported. What happened with the measurement problem? I would argue that However, at the time this document was written, most experiments have only teleported a single spin. In principle, if you can teleport one spin, then you can teleport many spins simply by repeating the experiment in a series many times. But this roughly only works on disjoint spins. To teleport a single object comprised of many spins is still out
of reach of present-day experiments. In the future, though, we should see experiments that teleport large numbers of spins. Certainly, if a practical quantum computer is ever built then the same technology would likely allow us to teleport a few thousand spins.
It is likely that this will happen within the next 30–50 years, if not sooner.
hu..! nye.
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