This is totally bizarre, no precedent for it really. The reality of the prize means that less and less are the winners names every physicist has heard of, but even today they're still big names in each subfield. For e.g. Kosterlitz, Thouless and Haldane weren't exactly household names but they really deserved the prize in 2016.
In this case, there's a good argument that Hopfield had conducted strong work as a physicist and in physics, but Geoffrey Hinton has never worked as a Physicist, at best adopting some existing things from physics into cognitive science use cases. In any case, what they've been given the prize for is work where they've not contributed to the understanding of the world of physics - it's not even really an arguable case where this is work that crosses over between Physics and another field either. It'd be like if Black or Scholes had been given the Physics prize rather than Economics because their famous equation can be re-written in Schrodinger equation form.
The citation has a large section on the impact of DNNs on physics research practice. They cite mega-projects that depend on this tech, for example. Hinton's inventions are a contribution to physics, not a contribution in physics. Hopfield of course was a bone fide physicist.
I just find that justification really strange - you could have made the same argument about K&R or John Backus because C and Fortran have had enormous impacts on Physics research, much more so than AI has to date.
The key is field. A physicist use maths will not get maths prize if just use it for physics.
He use words and its lyrics has meaning, like any literature. Cannot say poetry is not literature. Then why not poetry with music, probably more traditional as many poems are songs. In some culture, it must be singable.
These use physics but not in the field of physics. Otherwise anyone use qm can get Nobel prize and chemistry people can get one as they all use physics. Really need to be in the physics field. You can use other method like computer, maths.
In this case, there's a good argument that Hopfield had conducted strong work as a physicist and in physics, but Geoffrey Hinton has never worked as a Physicist, at best adopting some existing things from physics into cognitive science use cases. In any case, what they've been given the prize for is work where they've not contributed to the understanding of the world of physics - it's not even really an arguable case where this is work that crosses over between Physics and another field either. It'd be like if Black or Scholes had been given the Physics prize rather than Economics because their famous equation can be re-written in Schrodinger equation form.