I am having a tough tough stressful week trying to write an article about quantum mechanics. I know there was a question asked the same thing before, but I didn't understand nor I did not want to wake up an old thread.
The double slit experiment we all know, if we put an apparatus at the slit to detect which slit the electron has gone through but not look at the data it spits out, what happens to the screen? (Looking at the screen doesn't do any change right?)
1) If an active observer is not necessary for the wave function to collapse, the existence of a sensor will destroy the interference pattern because the sensor has interfered with the system.
2) If there needs to be an observer to read off the data from the sensor and acknowledge that the electron has acted like a particle and gone through either of the slit, the interference pattern will not be destroyed when the sensor is just there but no one has read the data.
Which one is it?