First, as I understand it, "string theory" is now not so much a theory as a "landscape". What does this mean? That there are a very great many different theories which could all be called "string theory". How many? At least 10⁵⁰⁰. In my book a theory needs to be internally consistent (as well as consistent with all relevant, good observational and experimental results). Has string theory - any string theory - been shown to be internally consistent? I think so, in some cases (but those that have have been so shown are inconsistent with relevant, good observational and experimental results), but generally no. Is this physics? Is this science??

Second, "M Theory" is often called a theory, but, as I understand it, there is no such theory - there are only conjectures, suppositions, and rough sketches* of what such a theory might contain. Or, if you prefer, no one has (yet) written down any "M Theory" equations. Is this physics? Is this science??

I recently read "The Trouble with Physics", by Lee Smolin ... my comments above are a (very rough) summary of some of what that book contains.

If any reader of this post is aware of any errors in my post, I would appreciate that they be pointed out.

*Of course, these sketches are mathematical ...