Quote (EndlessSky @ Mar 15 2019 11:20am)
This was done by japan in the 80’s. Look up a delayed choice quantum eraser. It proved that its still impossible to know which slit the photon went through even if you erase the information at the speed of light.
Also The act of observation doesnt collapse the waveform, more specifically measurement. The interference pattern is also a result of destructive interference between the waveforms in the beam of light.
Yep, but its a bit more general than measurement even, since its basically any interaction with a sufficiently "particle like" (positionally localized) particle.
If its interaction with a non positionally localized particle you get interferrence instead of "collapse".
To be honest I hate the idea that you "collapse a wave function". I think that interpretation is pretty outdated at this point.