Question: How does the quantum description of reality, which includes elements such as the superposition of states and wavefunction collapse or quantum decoherence, give rise to the reality we perceive?

Jose Eliel Camargo Molina answered on 14 Mar 2019:

Wow, good question, but also very very difficult to answer. I think it is still something up for discussion and there are philosophers of science that love to talk about this a lot.

However, the quantum description of reality works very well to describe quantum things like particles or atoms. At that scale, it is a pretty good description of what is going on.

We know for sure that when going to bigger scales, the effect of quantum “stuff” gets so tiny it does not really matter for the most part, but the transition from one to the other can get rather technical and not so enlightening.

We can connect things that are quantum to explanations of why we even exist. For example, the reason electrons can spin forever around an atom’s nucleus is that they are quantum thingies! Otherwise, the electrons would run out of energy and fall into the nucleus.

Transistors, which make your computer and phone work, are also possible because of quantum tunneling.

So there are a lot of connections between our world and the quantum world, but it is difficult to give an interpretation or explanation to the question of how quantum effects give rise to the reality we perceive. Even the whole idea of wavefunction collapse and decoherence are hot topics in research.

One thing is certain, the interpretation does not really matter when we have to calculate the things that happen at those scales, we still know pretty well how the quantum world works and we can calculate and predict the things that happen there.