#### morrobay

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Initially, the spin directions for Alice's and Bob's particles are completely undetermined.

This nonlocal model (the "collapse" interpretation) explains the probabilities, but at the cost of nonlocality; Bob's particle's state changes instantaneously when Alice finishes her measurement. [edit: probabilities in 5 corrected; originally there was a missing factor of 2]

- When Alice measures the spin of her particle, she randomly gets [itex]\pm 1[/itex], with 50/50 probability of each outcome.
- If Alice measures +1 at direction [itex]\alpha[/itex], then Bob's particle "collapses" to the state with spin direction [itex]\phi = \alpha - \pi[/itex].
- If Alice measures -1 at direction [itex]\alpha[/itex], then Bob's particle "collapses" to the state with spin direction [itex]\phi = \alpha[/itex].
- Later, when Bob measures the spin of his particle at direction [itex]\beta[/itex], he gets +1 with probability [itex]cos^2(\frac{\beta - \phi}{2})[/itex] and -1 with probability [itex]sin^2(\frac{\beta - \phi}{2})[/itex].

[edit 2: sign of [itex]\phi[/itex] in 3 was changed]

After Bob makes his one spin measurement later at direction β what additional measurement is made that detects that his particle had collapsed to state with spin direction Φ (2. or 3. above) that is then applied in the two formulas ? If there is no additional measurement the how is Φ determined ?

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