Entanglement - Some Myths
A brief look at quantum entanglement.
What it is.
What it isn’t.
I feel that entanglement is often misunderstood by the backyard physicist, they read a brief description and think “amazing instantaneous information transfer.” Well sorry everyone but that’s just not what’s happen.
There is no information transfer!
So, what is going on? I’m going to try and answer this with taking a condition.
Firstly we need to create our entangled particles, there are many ways of doing this, so I wont go into details but we end up with two particles i and ii, let’s say 2 electrons. The method used for creating them means that 1 will have spin up and 1 will have spin down. But importantly just after creation they are both in a superposition state of both up and down.
Person A takes electon i and drives 100miles away, leaving ii with person B, and measures the spin of the electron, he measures it as down, he instantaniously knows that the spin of electron ii must be spin up. So for person A the superposision state of both particles is destroyed, and if person B measures electon ii they will measure that it is indeed spin up.
If person A tries to tell person B this before they measure it, the can’t send the information faster than the speed of light, they also cannot travel back to electron ii to check it’s spin any faster than the speed of light.
One thing that people get confussed about is that if person A does something to electron i to make sure that it’s spin up they can then force electron ii to be spin down, but there doesn’t seem to be any method of forcing an electron to be in a spin state (or any of the other methods of entanglement) that does not break the entanglement meaning the two results will no longer be tied together and each electron is completely independent of the other. Again meaning you can’t send information faster than the speed of light.
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