In double slit experiment, if flux of electrons are very low, then..
if one "observes" the electrons before it has reached the slit, it "behaves" as a particle and this is due to the interaction (reflection?) of photons with the electrons.
The screen depicts an interference pattern but the individual spots are still due to particle nature. therefore we can say that whenever waves are interacting it interacts through particle/quanta (in this context).
Here are the questions:
If no one is observing, then the electron is suppose to behave as a wave.
Even when no one is observing, there should be interactions (collisions/reflection) between photons and electrons. If so, then how does it behave as a wave?
Is it something to do with the reference system? i.e. "observers" who observe the reflected photons observe that the electron is a particle and those who don't observe it as a wave?.. if so, why the information of the interaction is carried only by the photons and not retained in the electrons?