# How viable is using Quantum Entanglement for long distance communication? [duplicate]

In fiction, (notably Ernest Cline's novel Armada and Charles Stross's books Singularity Sky and Iron Sunrise) Quantum Entanglement is used for long distance communication.

In reality, given our current understanding, how feasible is this?

Is Quantum Entanglement potentially predictable enough and stable enough to act as a method of communication? I understand that our current level of technology might not be sofisticated enough to create such a device today (please correct me if I am wrong).

I am wondering if our current understanding of Quantum Entaglement today suggests that such a device may be possible in the future?

Or does our current understanding indicate that such a device would only be possible in the realms of fiction?

## marked as duplicate by Norbert Schuch, Conifold, John Rennie quantum-mechanics StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false, relativeToBody: true }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Jan 9 '18 at 6:51

• If simple communication is the aim, then since quantum entanglement cannot be used to send information faster than light, why not just use light? Light-speed communication is already widespread, and has been for many decades. – Allure Jan 8 '18 at 20:57
• @Allure my bad then, I was under the impression that two entangled particles would both operate instantaneously to each other - does the information from one entangled particle propagate to the other at the speed of light? – Jimmery Jan 8 '18 at 21:01
• Not exactly - the two entangled particles "communicate" instantaneously with one another, but this cannot be used to transmit information. It's not something that's easily understood without knowledge of QM unfortunately. Previous questions on this: physics.stackexchange.com/questions/9187/…, physics.stackexchange.com/questions/2206/… – Allure Jan 8 '18 at 21:08
• The advantage of entanglement for communication is not the mythical FTL thing: it's tamper-proofness. Using entanglement makes interception very detectable. – tfb Jan 8 '18 at 21:12