Because distance doesn't affect quantum entanglement, communication devices based on this effect wouldn't have any time lag, whether between Earthbound scientists and Martian science probes, or between Earth and the colonies on Rigel IV.

It would also allow completely secure, untracable, and unjammable communications, since there's no signal, wave, or photon to intercept or block.

Why not devise a communications system based on tachyons? Then the message could arrive before it was sent.

When they looked, they nudged the charge.

Michael: quantum information exists in corrleations between to data sets of measurements performed on identically prepared sets of specially prepared particles, which have been separated before measurement. In order for any information to be extracted, those data sets have to be compared to each other, albeit in a secure manner, but this is always done over a "classical" communication line.

In order for this to work, the quantum systems do have to be transported between the two spots. It's just that the correlations between two measurements will happen, more or less, instantaneously - which is the origin of the Einstein-Rosen-Podensky (EPR) paradox. Einstein considered this (nonlocality) to be impossible, and wanted to reject quantum theory because of it. To date, all known measurements have validified quantum theory within their uncertainty. This is less triumphant than you might imagine, as it implies a serious break-down of our common sense intuition about nature.

However, so quantum information is real, but I wouldn't hold your breath waiting for a quantum computer desktop.

mike:

That is the triumph.

If they actually do get large quantum computers function, modern cryptography goes out the window. Today's PCs, fast though they are, have to break strong codes by trying each possible key, and the keyspaces are just too gigantic. A quantum computer, if feasible, could check every key simultaneously.

Note that this solves the duplicate problem. The truth is that the researchers didn't teleport the information, they exchanged it. The quantum states of the original particles become disorded during this process so you can move quantum information around but you can't make a copy. So much for all of the arguments about how teleportation affects the soul.

This just proves that you can be two places at once when you're not anywhere at all.

Raoul,
And everything you know is wrong.

Roy, I knew that.

You fellas crack me up :D