# Faster than light data transmission using entanglement [duplicate]

I am not a scientist, so that's why I've come here...to hopefully find out if this would be possible.

Ok, so I started learning about quantum entanglement and I stumbled upon an idea for instant data transmission through space.

The idea is fairly basic, because quantum entangled particles are dependent on each other to create 1 shared state...(I think) we could separate two entangled particles and then modify one to create an instant change on the other particle.

This change would be read and computed as binary code 1-0-0-1-1-0-1-0 for example.

Here's the best way i can explain my theory,

Simply put as one question, is instant data transmission possible in this way? Or at least faster than light (laser arrays)?

• The answer is no, but this might be better for physics.stackexchange - even there they would say the answer is no. Any effort to send signals faster than light with entangled particles are doomed to fail. All you get are that random measurements are correlated, you just can’t control what measurements you get. Sorry. – Mark S Nov 1 '19 at 2:06
• Since the proposition of faster than light communication violates special relativity, everyone has and will respond (correctly) "no." But the concept you're proposing can be tweaked a bit to get to the physically realistic concept of superdense coding. – Jonathan Trousdale Nov 1 '19 at 12:58
• note that there is also a whole tag devoted to this sort of thing, have a look at the questions in physics.stackexchange.com/questions/tagged/… – glS Nov 2 '19 at 12:15
• @MarkS Thanks! If the OP is interested enough to reformulate and get the question reopened in that direction, I'd be happy to. – Jonathan Trousdale Nov 2 '19 at 12:45

No, you cannot use this for faster than light communication. The two typical ways that people think this could work are:

• Alice measures her qubit in a fixed basis, creating an instantaneous change in Bob's qubit. This is true, but the measurement outcome is random. Alice has no control over what measurement outcome she gets, so no information is transmitted in that protocol.

• Alice chooses a measurement basis, and that choice is the bit she tries to communicate. Bob's qubit is instantaneously updated, but he has no way do determine what basis she used.

Either way, there's no way around it.

• Why does Alice need to measure anything... A simple Change is all that is needed. – Gadget Guru Nov 2 '19 at 17:49
• I do not mean Write Data on a particle, I mean Flicker the particle to create a binary code – Gadget Guru Nov 2 '19 at 17:51
• What does “flicker the particle” mean? – DaftWullie Nov 2 '19 at 17:58
• Make Any Noticeable Change to the particle... I looked into it a bit more and they're trying to literally write binary onto the cubit ... 11 01 00 etc... I mean just make a change, from 1 to 0 .. And 0 to 1 ... Time is used as the base measurement – Gadget Guru Nov 2 '19 at 18:12
• Changes like that do not change the other qubit, so there is no communication. The only action that Alice can take that changes Bob’s qubit is a measurement. – DaftWullie Nov 2 '19 at 19:10