If you are a Potter-head, you must know about that the apparate spell. Or if you’re a Marvel fan, you have seen Nightcrawler create a ruckus in the White House. Or in the movie Jumper, that talks about a complete society of people who can “jump” in or out of any place at any time. All these are instances of a character (or several) using the concept of teleportation. But what exactly is it?
Teleportation refers to the ‘transfer of matter from one point to another, without it traversing the space between them’. It has been used as a plot device in numerous movies, books, and stories. The concept is believed to have been first mentioned in 1878, which in turn was a reference to an earlier publication. There are some mentions of similar processes in older literature as well. The term, ‘Teleportation’ was coined in the year 1931 by American author Charles Fort in his book ‘Lo!’.
It was a combination of the Greek word ‘tele-‘ which means far, and Latin word ‘portare’ which means ‘to carry’. Hence, the word as a whole refers to carry something to a far off place or a location, It has been used, as mentioned before, as a plot point in multiple movies and works of literature. It is a very fascinating idea, and a superpower we dream of acquiring somehow. Sadly though, it is not possible.
An actual teleportation of matter has never been achieved as of March 2020. It is questionable that it would ever be because there is no known physical mechanism that would allow it. The transfer of matter, without traversing the space between them violates Newton’s Laws and hence is deemed unattainable.
There are scientific papers published frequently that are about teleportation, but they focus on something known as Quantum Teleportation. This differs from the usual idea of teleportation because it involves the transfer of Quantum bits of data, or information, instead of actual matter. It involves a lot of concepts, some of which are mentioned here.
Once called ‘Spooky Action at a Distance’ by Einstein, Quantum Entanglement is a lesser understood but an interesting concept nonetheless. By definition, it is the phenomenon that when a pair of particles are brought really close to each other spatially, or are generated together, their Quantum states are somehow connected and cannot be defined independently.
Let us understand this with a simple example. Suppose we have a conserved quantity known as the color of a particle. By conserved we mean that if we have a certain number of red and white particles, this number will not change with time. So, we take a couple of particles, one red and one white. We bring them close so that they ‘entangle’ and then we pull them apart. At this point of time, we do not know which one is red and which one is white; so we take an assumption that since they were entangled, they are reddish-white, as in the diagram below:
Since the quantity is conserved, upon measurement we would find that the color of individual particles would either be red or white. It is even possible that the particle on right is now red; even though they have now been moved far, far apart. To make things more interesting, we bring a third particle that is green in color and entangle it with the particle on the left, that is before we measured its color.
The particles would get entangled and would become a mix of red, white and green, Simultaneously, the particle on the right end, which is still entangled with the left particle, turns green-reddish-white at the same time. To add, if we measure its color, we might find out that the particle on the right is now green. If we look at the chronology, the particles initially were either red or white. We entangle them and move them apart. Then, we bring a third, green particle to the one on the left and all three are entangled. We find out that the particle on right is green; and in other words, we have teleported the green particle from the left end of the setup to the right.
All this sounds very abstract and mambo-jumbo, but this exact experiment has been performed in labs and has been verified by numerous scientists across the world. This was the first instance of teleportation ever experienced and observed.
Quantum Teleportation is a process in which we transfer what we call quantum information from one place to another using some concepts of classical communication and quantum entanglement. However, despite the name being inspired by the term ‘teleportation, Quantum teleportation does not transmit data faster than the speed of light, which is a bummer. This was observed in 1993 with a single photon. Later on, this was observed in atoms, ions, and superconducting circuits. The current world record for farthest communication using quantum teleportation is 1400 kilometers using the Micius Satellite by a group of Chinese Physicists.
So, the big question: Is teleportation possible? The answer is we don’t know and we don’t seem to be moving towards achieving it in the near future. The most we have done till now is achieving it for single particles. But who knows when the next breakthrough might come out?