Observation means interaction in any form with the observer (edited as per Koshkin's comment). Most things in the universe in practice have interacted or will i

Observation means interaction in any form with the observer (edited as per Koshkin's comment). Most things in the universe in practice have interacted or will interact. Interaction could be as subtle as a single photon reflecting off it and hitting your eye, or it could be you smashing your face into the object. When they present the hypothetical Schrödinger's Cat thought experiment, it's a thought experiment assuming somehow the box prevents all interaction between the cat inside and the outside world. In the real world however things like sound waves, light, x-rays, etc, will inevitably penetrate such a box. And even if the cat moves, it will cause some amount of detectable vibrations on the outside of the box. It would be impossible to theoretically prevent any energy from the cat inside the box to emanate outside as that would violate the law of preservation of information (even a black hole—the closest thing to an absolutely sealed box—releases information about its contents and expels energy). There is no explanation for why the wave function collapses due to interaction other than "god rolling dice" and picking a collapsed outcome once such an outcome becomes relevant (through interaction/observation). Other interpretations of wave function collapse don't even suppose the collapse happens. For example in the many worlds interpretation, instead of having a single observer (the universe and its participants), there are multiple universes and multiple observers. In this interpretation there is no collapse of the wave function. Instead of many possibilities and one getting picked, there are many observers each independently observing one of the possible outcomes. Here the dice rolling still happens, but happens for every observer constantly (when deciding what outcome is observed next).