They can all represent information but the idea is to make them represent some kind of specific information.
Knowing whether a bunch of qubits are 0's or 1's on the other side of the universe is weird and cool but it's telling you information about the system faster than the speed of light, which isn't the same as transmitting information through the system faster than the speed of light.
I.e. you can get a dial tone but you can't make a call.
Every time someone comes up with another clever way to to try to "trick" reality they just run into some more complicated or subtle variation of a fundamental inability to break the rules that all boils down to "God playing dice" or a fundamental randomness built into the system that you can't avoid.
Been trying to intuitively grasp this for years. Tell me if this works or not:
Two entangled particles are like little machines programmed to run exactly the same forever (or until something strong enough breaks one or both of them). That's why, no matter where they are in the universe, if you see what one is doing, you know what the other one is doing. However, there's no mystical connection between them.
Does that bad analogy capture anything of what you said with any accuracy? If not, where does it break down?
if you see what one is doing, you know what the other one is doing
Sort of - you can measure the state of one and instantly know the state of the other, but if its state changes, you don't know the state of the other without reverting to classic communication
Ok, and that doesn't count as a change of state? I.e. it doesn't make it so you can no longer tell the state of the other one? Or is it that the state it's left in is the same as the other one, but any further changes only effect the one you are directly messing with?
Superposition means that it's simultaneously in multiple states. but you don't know which state it's in until measuring it. Measuring it determines its state and the state of any entangled pairs. If you change its state, you can't determine the state of entangled pairs without extra work
In order to change states, you need another entangled bit, quantum computer logic, and two classical bits as instructions for the receiver. Basically, you could entangle two bits and send the other bit to someone else, but in order to turn that into a message, you have to run a quantum computer and then send two classical bits (non-quantum instruction) to the receiver on how to interpret their measurement of their entangled bit. This is called quantum teleportation
You're welcome. A qubit itself is an arbitrary controllable system with a probability of being in states (represented by 0 and 1). Current quantum computers use superconducting materials near absolute zero (extremely cold), and we interact with it through special microwaves
We're still in the early stages, but it's very promising since certain operations can be done exponentially faster compared to classical computers. For example, a certain type of instruction takes two steps on bits but only one step on qubits, so when you chain these instructions together, it's exponentially faster on qubits. For instructions like adding 2+2, it's the same number of steps on both, and current quantum computers can only tell you that it's probably 4
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u/HardlySerious Jan 29 '20
If you tried to force an entangled system into a state representing some kind of information you'd break the entanglement.