The difference being that yours being tails is actually not a fact and a probabilistic outcome? vs. it just always being tails and you not knowing?
how would we ever know the difference?
how would we ever know the difference?
Quantum mechanics allows you to measure the projection of the arrow along any one axis, and you'll always get +1 or -1. If the two people with entangled particles measure along the same axis, they will always get opposite results. But they are also free to measure along different axes.
The statistics of what results the two experimenters get when they measure their particles arrows along random axes in repeated trials are not the same as what you would get if the arrows had a predetermined direction all along.
Google "Bell inequality" for details.
Imagine two dice. There's no sense in which one die has a number until you throw it and one side lands upwards.
With entanglement, you have two dice but they're correlated. For example they may always land opposite sides up.
So if you see the value of one, you also know the value of the other. No matter where it is.
The hard questions are:
1. How does one dice/particle know the other has landed/been measured? This is really just a special case of the unsolved measurement problem, but over larger than usual distances.
2. Where does the entanglement information live? If you look at a single die/particle it has no physical property that shows it's entangled. Individually, entangled and unentangled particles are absolutely identical. So you have a correlation that can't be explained by the structure of each die/particle.
IANAQP but to me this suggests that you're looking at a 4D spacetime projection of an object which exists in some higher and/or more abstract space. So there's a single object in a hypothetical Quantum Space and we're seeing two views of it in our 4D spacetime. Entanglement somehow fixes the projection in a certain orientation.