In the last episode we have discussed about spins, directions, and why the Z and X axes are fundamentally incompatible measurements. If you haven’t read it yet, I strongly recommend starting there (read here).
we ended the episode with a deceptively simple question:
Your task is to prepare a spin in advance. Later, I will measure the spin. However, I will only decide at the last moment whether to measure it along the Z axis or along the X axis.
The question is: Can you prepare the spin in such a way that you can predict the measurement outcome with certainty, no matter which axis I choose to measure?
And the answer was: No.
This is not a technical limitation. It is not about imperfect equipment. It is built into the structure of quantum mechanics.
So probability — true indeterminacy — appears to be at the heart of the theory.
But here’s the crucial question:
