Feb
9
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admin
2/9/2010 11:51 PM
When we do finally manage to establish colonies around other stars, we'll probably want to communicate with them. It's pretty tough to carry on a conversation when the minimum response time is eight years, so scientists have long discussed means of communicating faster than the speed of light—or, better yet, instantaneously. One of the most discussed means of instantaneous communications across great distances would be to use an ansible, which is commonly designed to use a pair of quantum entangled particles.
At SPESIF, Raymond Jensen of Lake Superior State University will be presenting a paper entitled "On using Greenberger-Horne-Zeilinger three-particle states for superluminal communication." I'm not familiar with three-particle entangled systems, so I can't really speak to the viability of such a system, but I'm excited by the possibility. Long before interstellar travel becomes a reality, such communications devices could make communications to Mars probes or Jupiter orbiters, for example, much easier and more effective. Imagine being able to remotely control a Mars rover in real time, as opposed to issuing commands and waiting an hour or two for a response to see how it played out.
This technology will be useful as we spread throughout the solar system, but it will become absolutely vital if we are to expand throughout the local regions of the galaxy without each new world becoming its own independent civilization.
The complete abstract follows:
Using a three-particle entangled system (triple) of photons, it is possible in principle to transmit signals faster than the speed of light from sender to receiver in the following manner: First, let there be an emitter of triples between sender and receiver. For every triple, photons 1 and 2 are sent to the receiver and 3, to the sender. The sender is given the choice of whether to (a) measure polarization of photon 3 or (b) destroy such information. On the other hand, the receiver measures photon correlation vs. relative polarization angle between photons 1 and 2. These correlation statistics depend on whether photon 3 polarization was (a) measured or (b) destroyed. Since this dependence is nonlocal, it is a basis for superluminal i.e. faster-than-light communication.
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