Will Teleportation Ever Be Possible?

Imagine if you were never late for an appointment again. That you could wake up ten minutes before you had to be at work and still have time for a shower and a decent breakfast. That you could rent a holiday home in Italy from your computer at home, and be there to pick up the keys thirty seconds later. That to get anywhere, you merely have to step into a small booth next to your front door and, provided you aren't mutated into a hideous insect monster in the process, you will arrive at your destination in an instant.

That is the dream of teleportation; the instantaneous transfer of matter from one point to another, favoured mode of transport for Captain Kirk and his crew. But is such an outlandish concept even theoretically possible? And if so, how close are we to realising it?

Even when Star Trek first aired in 1966, teleportation was not a new concept, and the theoretical principles behind it were relatively well formulated. Put simply, the idea is that the object to be transported is disassembled into its constituent atoms at point A, transmitted to point B by an energy beam, and then reconstructed into its original form. To do this, the system used must not only transmit the particles themselves, but also information describing the state of the atom – its size, composition, etc. - in such a way that it can be used as a 'blueprint' for reassembling the object at its destination. As one might imagine, bad things could happen if there was a mistake or accident during the process, and indeed the weird effects that might result are the subject of many a Star Trek episode.

So the question is, are we at all close to putting the theory into practice? The answer is... yes and no.

It is true that a process akin to teleportation has been achieved for individual photons, the particles of light. This process was first realised by physicists at the California Institute of Technology in 1998 and work has progressed steadily since, to the point that a group at the University of Geneva was able to 'teleport' a photon a distance of 25 kilometres in 2014. This process relies on quantum entanglement, a phenomenon that can exist between two particles such that changing the state of one particle can change the state of the other, irrespective of distance (this can be thought of as the first particle sending its quantum information to the second one).

In the experiments to date, the 'teleportation' has been achieved with two entangled photons at separate locations, and a third photon which has some property that needs to be teleported. By colliding the entangled photon at point A with the third photon, the state of the entangled photon is changed, and this changes the state at the photon at point B. However, thanks to the weirdness of quantum mechanics, neither photon's state can be measured without destroying it. Therefore, photon B is preserved by measuring the collision event at point A, which destroys both photons at this location, and sending the quantum information via fibre-optics to point B.

This may all sound very complex, and you would be right. But in doing this, in essence the third photon is teleported from point A to point B through the interaction of the entangled photons. Although this is not strictly 'teleportation' in the sense that the Star Trek sense, the process is identical in effect, the only difference being the origin of the final object's atoms. Researchers believe that this process may be used to perform calculations on data transferred through quantum teleportation; this could create a new class of ultra-fast computers called quantum computers.

So if individual particles can be teleported, can individual people? Unfortunately, the sheer number of particles present in an person makes this very difficult. The average person is made of approximately 10 to the power of 28 atoms, with a total information content of 2.6 x 1042 bits. According to research by the University of Leicester, to teleport all of this information by quantum teleportation would take 350,000 times longer than the age of the universe itself. Hardly practical. The energy requirement to do this would also be colossal; American physicist Lawrence M. Krauss, in his book 'The Physics of Star Trek', estimates the energy requirement of 'dematerializing' a person to be “the energy equivalent of a hundred 1-megaton hydrogen bombs”. This is even before we get into discussing the ethical implications of essentially killing a person in one location, and creating an exact likeness, Mysteron-like, at another.

So, will teleportation give us new supercomputers? Absolutely. Beaming ourselves down to faraway planets? For now, it remains a dream.

#Physics #Teleportation #FraserDarroch