Due to people who think they know what they are talking about i have heard different anwsers to the same question. By observing a wavefunction of an electron in an experiment such as young's double slit. Does the act of physically being observed with a photon collapse the wavefunction or does the knowledge of it being there force it to collapse? Also, a question on quantum entanglement. How do we know that the entangled particles haven't already "choosen" a spin direction? Why do we believe that after observation that they will "choose" opposite spins?