Thank you all for your replies. They have been very helpful in understanding some of the basic physics in relation to more philosophical questions. As advised by Phinds, I will quit this forum and look for answers elsewhere.
I am sorry to hear that, but I understand now reading most of the reactions. I was actually looking for the perspective of a physicist, not that of a philosopher. It believe that both fields can learn from each other, but perhaps not on this forum apparently.
Thank you all for your replies, especially gmax137 for the picture of the calculator.
I am aware I have not given a clear definition of what a 'direct measurement' means and perhaps this is part of my question.
Perhaps I should have elaborated more on why I pose this question. I want to know...
Thanks for your reply. I am indeed looking for a definition of 'directly'. I think however that there is a difference in measuring photons for example, and time. What I mean with not being able to measure time directly, is that we always measure something else first, and then we use these...
I am interested in finding out what we can objectively measure. How to define what we can measure directly, without (human) models getting involved, as in model-dependent realism as described by Hawking and Mlodinow? It seems as if everything we measure is either mass or energy (or spin?).
Time...