Karl Popper and the philosophy of science

I recently found a textbook by chance about "philosophy of science", in spanish, written by J. A. Díez and C. Ulises Moulines and titled (translated into english) "Foundations of philosophy of science", and thought "what the ... is this?".

We could think of philosophy of science as the "part" of the Philosophy whose main aim is to analyse the validity of the scientific discovery from a "formal" point of view.

I got my BSc in physics in 1999. I am trying to remember if this subject was elegible during my career and does not seem so to me. Why?. I do not know, but I might make myself an idea...

I am really sorry to have lost the ideas and work of Sir Karl Popper until just recently.