I am using Quantum Mechanics by McIntyre and I am trying to understand the motivation behind spin operators.
From the text, it says that an operator corresponds to an physical observable and that the only possible results of a measurement are the eigenvalues of an operator.
To try to understand how operators are used, I skimmed a couple sections ahead, but couldn't find examples spin operators acting on kets. For example, what is the meaning of a ket mapped by a spin operator?
What is the purpose of spin operators? Can you point me towards some demonstrative examples?
Thanks in advance.