I mean that if we could only measure the spin of a particle by applying an electromagnetic field, and since there must be an effect on the particle by some electromagnetic field, then is there a point in saying that we must apply some electromagnetic field to measure it? Will there be any...
If I am unable to distinguish the spin of a particle in an absence of an electric field or magnetic field, how am I able to determine whether there is an electric or magnetic field in a real-life context?
How is it that we can be sure of the uncertainty of the spin of particles if we are unable...