> Why does observation cause the wave function to collapse? According to the Many-Worlds Interpretation, it doesn't. Both the thing being observed and the obs

> Why does observation cause the wave function to collapse? According to the Many-Worlds Interpretation, it doesn't. Both the thing being observed and the observer exist in many states simultaneously (a superposition of states). Before the observation, those states were independent; the act of observation causes the observer and observed to become entangled, so each state of the observer corelates to a single state of the thing observed. From the observer's points of view, there appears to have been a collapse; but the result of the "collapse" will be different for each of the observer's states. (Caveat: I am not a physicist, and it's possible the above is not even wrong.)