Why is teleportation bad

Every electron is perfectly identical to every other electron, and the same is true for quarks. But how much would a copy of you still be you? Well, it depends on two things.

The first is the resolution of the technology that scans and prints you. Can it read and print your cells? Your molecules? Your atoms, or even your individual particles? What level of detail does it take for the copy to still be considered you? It turns out that this is an open question, and the answer might depend on how quantum your sense of self is. How much information would have to be recorded in order to create a faithful copy of you? Is knowing the location and type of every cell and connection in your body enough?

Or do you also need to know the position and orientation of every molecule in your body? Or if you drill down deeper, do you also need to record the quantum state of every particle? Every particle in your body has a quantum state. But is that quantum uncertainty an important part of what makes you you? At first glance, it seems unlikely that the quantum information in each of your particles would make a difference in making you who you are.

For example, your memories and your reflexes are stored in your neurons and their connections, which are pretty big compared to particles. At that scale, quantum fluctuations and uncertainty tend to average out. If you were to subtly scramble the quantum values of a few of the particles in your body, would you be able to tell the difference? Debating the answer to this question might be more appropriate for a philosophy book, not a physics book, but here we can at least consider the possibilities.

This means that you just have to record the location of all your small bits and pieces and then put them together in the exact same way elsewhere. This is like taking a LEGO house apart, writing out the instructions, and then sending those instructions to another person to build. Modern technology seems to be well on its way to someday achieving this. Would it be like sending a JPEG version of an image instead of the full picture? Would you come out the other end a bit fuzzy around the edges, or not feeling quite like yourself?

What if the magic, or the indelibleness of you, lies in the quantum uncertainty of every particle in your body? The bad news is that this makes the problem of teleportation much harder. Really, anything quantum is hard, but the idea of copying quantum information is doubly hard. How, then, do you make a quantum copy with the same probabilities as the original?

To copy a particle down to the quantum level means that you want to copy its quantum state. The quantum state of a particle includes the uncertainty about its position and velocity, or about its quantum spin, or any other quantum property.

The problem is that to extract quantum information from a single particle, you have to probe that particle somehow, which means perturbing it. Even just looking at something involves bouncing photons off of it. If you shoot photons at an electron, you might learn about its quantum state, but you will also scramble it. This is great for things like quantum cryptography, the use of entangled photons as a secure method of communication between two distant parties.

In , researchers in Denmark succeeded in entangling a pair of gas clouds containing about a trillion atoms each, separated by a few millimeters. This is tricky because any entanglement only lasts as long as nothing else interacts with the system.

It takes a great deal of effort to keep two particles entangled. It is extremely difficult to get more than a few atoms to vibrate together, perfectly synchronized, because of interference. In the real world, objects interact constantly with the environment, and decoherence occurs instantaneously.

If I tried to teleport information about every single atom in my body via quantum entanglement, decoherence would scramble things in an instant.

Follow her on Twitter JenLucPiquant. We long to return. And we can. Because the cosmos is also within us. We are still working out how to teleport photons. Assuming somehow we discovered how to teleport atoms, then molecules — perhaps in the next decade, as upbeat pop physicist Michio Kaku has suggested — the amount of bits to record and transmit is unthinkable. According to a highly entertaining University of Leicester study into the computing power required to teleport a human being, your cells, broken down into data, equates around 2.

You would require stupendous bandwidth and roughly 10tn gigawatt hours of power. Teleporting one human being would therefore require hogging the entire UK power supply for more than a million years and take some 4. It would literally be quicker to walk. And after such a long wait, you might not even survive the transfer. Even our top 3D printers, materials and scanners are unable to faithfully reproduce a cowpat, much less a human with their neurons, memories, thoughts or personality.

Even then, would you not be transmitting a copy? What happens to the you at point x when you at point y appears? Will original you be zapped?