Nick V said:
Is the collapse of the wave function of the electron in the double slit experiment based purely on the act of observation? Or could it be that the way the instrument used to measure the electron caused it to collapse by how it physically interacted with the electron? Keep in mind the delayed choice experiment.
You might not realize it but I believe the question you are asking is actually a very important one. The lack of particularly helpful responses is largely because "we don't know". That is to say, the common quantum physicist doesn't know, though they'd never admit it.
Your question pertains to a well known problem with what it is properly called the "Von Neumann chain". As you correctly intuit, there is some ambiguity in the Copenhagen interpretation of QM with regards to what exactly qualifies as an "observation". Does the detector actually "observe" the particle or is the detector just another part of the system?
Taking the double slit experiment as an example, when the electron or photon leaves the gun, it ceases to be localised precisely in space time, it becomes describable only in terms of probabilities. You can think of it as existing only in a sort of suspended state, it really takes on a superposition of possible states. To simplify the problem we assume there are only two possible outcomes, either the electron goes through the left slit or the right one. So for the period of time between firing and detecting the particle, it actually exists as a superposition of both states. It is in limbo, so to speak.
Now, suppose you set up a detector of some kind on the other side of the screen to check which slit to particle went through. But now suppose you leave the room... Lock the door and let it all happen. The electron will acquire the superposition, travel (as a wave) through the slits, the two waves will interfere and ultimately reach the detector but then what happens? A decision needs to be made. Does the detector record the electron or not? There is a very important question here. Has the system "collapsed"? Or is the detector now part of the system? Is the detector in limbo just like the electron was? The laws of quantum mechanics to not pick and choose. The principle states that everything in the universe is fundamentally a quantum system and so, logically, the answer is yes, the detector does pick up the quantum dichotomy. The detector has become a part of the system and has not been collapsed, it is now a superposition of two states, one in which the electron was detected, and one in which it wasn't.
Now, think about this. You could extend this chain of detectors detecting detectors for as long as you wanted and surely, each subsequent detector would simply pick up the superposition. This chain is interactions is called the Von Neumann chain and the million dollar question in all this is, "Where does it end?". We know it has to end somewhere because well... what happens when you walk in the room and look at the detector? Do you pick up the dichotomy as well? Maybe you do, there are theories to suggest that you split in two as it were, but you are only capable of experiencing one outcome per universe. Whatever the case, something special seems to happen whenever a "sentient being" observes the system. The chain is clearly broken, there is something fundamentally important about us in this way. Perhaps this is what it means to be "aware".
But this is not the place for philosophy, I merely bring this idea to your knowledge as I believe this may be exactly what you are looking for.
For further reading on the subject I suggest you acquire a copy of "The Self-Aware Universe" by Dr. Amit Goswami PhD.