Morga said:
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?
Like has been pointed out already this is debatable, and might be given different descriptions depending on the fundamental view of things.
But FWIW,
to add a little bit of my personal view, I regard the wavefunction as a representation of a relation between the observer and what is observed. This means that logically speaking the wavefunction is not an objective property of what is observed, it is rather as much a function of the observer - a relation - or the description of the information of the object, relative to the observers full complexity, where the observers knowledge is obviously a part of defining the observer.
I picture that the way an observer "informs himself" about whatever he is observing is by means of physical interactions. So, physical interactions and communications are in my view at least various views of the same type of things. But if think of it as communication, a lot of the confusing things is not as confusing anymore.
It may argued that the experimental results from the above mentioned stuff stays the same wether there is a human observers or not, but the observer concept doesn't restrict itself to human observers, moreoever the human operating the measurement apparatous are hopefully not in direct interaction with the electron anyway. There obviously got to also IMO be a relation between the electron, and it's nearest surrounding - EM fields, slits and whatever else is there - included. In that case the physical interaction and information transfer seems to pretty much be the same thing.
If we are taking the viewpoint that the wavefunction represents information, relative to the observer, the answer seems natural. We update our bets(wavefunctions) upon arrival of new information, no earlier and no later.
Take the silly poker game analogy. When does a player A his strategy, by updating this calculations based on new evidence? When the player B for sure have finally decided what card to play, or when sight of the laid down/played card from B actually reaches A?
The answer is obvious, what is not so obvious though is what this has to do with physics and QM. Here I think a lot of people differ in opinon. So what's right? Personally I don't care what's right, I want to know what's useful! So IMO, whatever theory is "useful" and makes me survive and outperform threats and competitors is good. Like life in general, and that seems to be pretty successful if we think that it all came out of a terrible mess.
Like the poker player. He doesn't give a damn about what cards the other player REALLY has, as long as he wins! The winner is always "right"
/Fredrik
