One basic thing about MWI is that it is a matter of physical fact that large objects tend to violate ‘laws of quantum mechanics’ as we know them (the violation is known as gravity), and actual physicists do know that we simply do not know what the quantum mechanics works out to at large scale. To actually have a case for MWI one would need to develop a good quantum gravity theory where many worlds would naturally arise, but that is very difficult (and many worlds may well not naturally arise).
large objects tend to violate ‘laws of quantum mechanics’ as we know them (the violation is known as gravity)
I cannot agree with this assertion. Except for the mysterious “measurement” thing, where only a single outcome is seen where many were possible (I’m intentionally use the word “seen” to describe our perception, as opposed to “occurs”, which may irk the MWI crowd), the quantum world gracefully turns classical as the objects get larger (the energy levels bunch tighter together, the tunneling probabilities vanish exponentially, the interaction with the environment, resulting in decoherence, gets stronger, etc.).
This has not been shown to have anything to do with gravity, though Roger Penrose thinks that gravity may limit the mass of quantum objects, and I am aware of some research trying to test this assertion.
For all I know, someone might be writing a numerical code to trace through decoherence all the way to the microscopic level as we speak, based on the standard QM/QFT laws.
Look up on quantum gravity (or rather, lack of unified theory with both QM and GR). It is a very complex issue and many basics have to be learnt before it can be at all discussed. The way we do physics right now is by applying inconsistent rules. We can’t get QM to work out to GR in large scale. It may gracefully turn ‘classical’ but this is precisely the problem because the world is not classical at large scale (GR).
One basic thing about MWI is that it is a matter of physical fact that large objects tend to violate ‘laws of quantum mechanics’ as we know them (the violation is known as gravity), and actual physicists do know that we simply do not know what the quantum mechanics works out to at large scale. To actually have a case for MWI one would need to develop a good quantum gravity theory where many worlds would naturally arise, but that is very difficult (and many worlds may well not naturally arise).
I cannot agree with this assertion. Except for the mysterious “measurement” thing, where only a single outcome is seen where many were possible (I’m intentionally use the word “seen” to describe our perception, as opposed to “occurs”, which may irk the MWI crowd), the quantum world gracefully turns classical as the objects get larger (the energy levels bunch tighter together, the tunneling probabilities vanish exponentially, the interaction with the environment, resulting in decoherence, gets stronger, etc.).
This has not been shown to have anything to do with gravity, though Roger Penrose thinks that gravity may limit the mass of quantum objects, and I am aware of some research trying to test this assertion.
For all I know, someone might be writing a numerical code to trace through decoherence all the way to the microscopic level as we speak, based on the standard QM/QFT laws.
Look up on quantum gravity (or rather, lack of unified theory with both QM and GR). It is a very complex issue and many basics have to be learnt before it can be at all discussed. The way we do physics right now is by applying inconsistent rules. We can’t get QM to work out to GR in large scale. It may gracefully turn ‘classical’ but this is precisely the problem because the world is not classical at large scale (GR).
I am well aware of the QG issues. That was not my point. I will disengage now.