The Tangler exists!

[Nigel_Strange]

Well, sorta.

It will take some time to develop instantaneous communication technology based on entanglement...but they have started.

http://www.scientificamerican.com/artic ... a-paradox/

[Onirim]

Looks cool but I don't quite get it. How far apart entagled particles can be? Really? instant comm one day?

[Marvin]

Well, I guess that explains how a player can exit EM multiplayer then come back and find his name listed twice.

[DaveK]

Or see his name even thrice

In theory the entangled particles can be at the opposite ends of the universe.

The main issue about using it for instantaneous comms though is that the entangled photons have to be made and then one half of the pairs have to be transported to where the messages will be received and replies sent. And nothing can physically travel faster than the speed of light so it will take a long time to deliver the photons. In effect you would have to send a continual stream from the producer to the recipient to replenish the supply. Or you would only have a limited amount of comms capacity before the supply ran out.

So even if the entanglement tech exists today and the entangled pairs can be protected for long periods of time it still won't be instant comms tomorrow - more like the end of the century

[Marvin]

Unless the entanglement is as you specified in your second sentence?

[Nigel_Strange]

Exactly. It's binary information, so I figure you can probably fit a lot of data in a small amount of space, given the size of photons.

[DaveK]

Exactly. It's binary information, so I figure you can probably fit a lot of data in a small amount of space, given the size of photons.

Sadly, though a photon is stable, comms-wise a photon is massless, has no electric charge and only has two possible polarization states. Hence it can only encode a single bit of information. The issue isn't how small the 'space' it takes up, it's how many entangled bits you have available to create you message: one photon = one bit; typically one byte = eight bits; one letter =one byte. A simple sentence like: 'Good Morning, Houston' would require 168 entangled photon pairs. This answer would require 6304 photons

The fact that photons can have an infinite number of wavelengths/frequencies is irrelevant since a specific photon (and it's entangled partner) can only have one specific value and that one is determined at the point of its creation, not its use

[Marvin]

All those restrictions remind me of how, not so long ago, Bill Gates declared (catagorically) that there would never be a need for more than 640 kilobytes of computer memory.