Thanks for sharing this interesting blog (that I almost missed ;) ).

I would say that even defining physics itself is not that trivial because of the diversity of the domains it covers. What unify all these subdomains is the methods, the tools and the approach that are used, rather than the topics themselves.

I now have a remark on the following sentence:

All of the above is due to the fact that the main method of physical science is experimentation, [...]

In fact, we could even go one step further and including experimentation, modelling and conceptualisation. All these three are necessary and very relevant, IMO.