Is Quantum Mechanics Applicable to Everyday Life in the Macrocosm?

[SprocketPower]

Is QM really applicable to everyday life in the macrocosm? If it is, how? And does QM say there are no causes, only effects.

So, for example, in th e real world (macrocosm), there is a set of possibilities A, B, and C, and causal factors x, y, and z. However, x is an unknown or hidden factor, so we can't factor it into our predictions, and we estimate A as having the highest probability of happening. We are correct so B and C are null alternatives and impossibilities and x, y, and z are causes of A only, but because of our partial knowledge we see B and C as possibilities along with A. Would this assessment be right?

In MWI every cause and effect occurs in a different state of the universe and both the observed and observer are in superposition, and all of the macrocosm probabilities are considered possible and they all happen, but with this interpretation above, that might be called fatalistic, ony 1 is possible.

 

[arkajad]

There will be different answers to this question as not all physicists agree here. Here is one possible answer.

In real life you do not have an ensemble of identical situations. Every event is unique. You have material objects like tables and chairs. Events happen in real time. Quantum theory was not created for dealing with such phenomena. It has a different domain of applications.

Still macroscopic quantum devices (like superconductors) exist. But they require special situations.

It is not excluded however that some kind of an extension of QM that is able to deal effectively with microscopic and macroscopic single objects may exist and lead to a new experimental and theoretical paradigm.

 

[SprocketPower]

I think this is a very insightful summary of the situation and gives me a very good idea of it. Thanks.