[codethief]

> that is, although, for example, chemistry is subject to the laws of physics, we cannot infer the field of chemistry from our knowledge of physics

I mean we could, with infinite computing power and enough time to look into every interesting phenomenon (and to evaluate the corresponding multi-particle Schrödinger equation numerically) but there are simply too many such phenomena, Schrödinger equations are tough to solve, and quantum mechanics is also not a great level of abstraction for the reason you mentioned.

[the-mitr]

no, that is the point of the paper, even with infinite computing power you could not predict. it is a very strong case against reductionism in science. The phenomenological examples he considers in the paper cannot be derived from basic principles of quantum mechanics.

[smokel]

Hm, I can't say I really understand most of the paper, so I'm not sure if the paper actually implies this, but even then, I find this unconvincing.

Quantum mechanics allow for many things to happen at a macro level, such as magnetism. If you start from pure quantum mechanics, and try to predict something like that emerging, you'd have to be pretty lucky to find the correct initial conditions to lead to such a phenomenon. But that does not mean that it is impossible to predict it at all.

Another take on this might be that understanding phenomena at different levels requires different abstractions and different modes of understanding. In that sense, the knowledge at one level often does not help us to understand things at a higher level. But I think that says more about our limited intelligence than about the phenomena and emergence in themselves.

[codethief]

Huh, I find that very surprising. Looks like I need to have a deeper look at the paper then.

[trevyn]

I don’t think the paper rigorously addresses the case of infinite computing power.