I have done a lot of thinking about what it means to know, and I know (so to speak) that a lot of people smarter than me have written a lot on the subject. In spite of that, I still do not know what it means to know something.
So, what I try to make clear is that if by 'knowing' you mean that you are in possession of some absolute truth, then there is precious little, if anything that qualifies. In this special case, I qualify my use of the word 'know' with the phrase 'for sure'.
Now, as for the useful information that gives us power, we have the question, Is this knowledge? Well...ah. It isn't apprehension of absolute truth, but it isn't worthless either. It works, has value, and should have a name. Maybe not 'knowledge'. Maybe we should coin a new word for it like, 'goodguess'.
***The idea that empirical science is equal to knowledge is wrong.***
Restating this in the new terminology we get, The idea that a goodguess is equal to knowledge is wrong. I agree with that.
***And it has proven dangerously so many times. Science proceeds by trial and error, reasoning, record keeping, peer review etc.***
I agree. I agree.
***Will you explain why you don't allow proofs in chemistry and physics?***
If a chemist or a physicist performs an experiment and the results are consistent with the predictions of a theory, the best you can say about it is, "so far, so good", and, we have a goodguess. There is no way of knowing for sure that the very next run of the experiment won't give contradictory results. Aside from experimentation, I know of no other proofs in chemistry or physics. And that is why I don't allow proofs in chemistry and physics.
***I completely reject the assertion that we "know" things if our little contraptions "work" so far. ***
So do I.