Coming back to your post (#4 in this thread)
AlwaysLearning said:
I want to know when & where the term "force" was invented & tossed into the vocabulary of w/e the people were speaking. I want to know when this term was used interchangeably & acknowledged by everyone, regardless of the variables. For example, a comet shooting across the night sky or me dropping a ball to the ground.
If I can't get a "January 5th, 2036 BC at 6:13 PM in Northern Asia off the Mountain of *** knows," then the least I can get is a general idea or a practical application that would give explanation.
What is it that you are exactly looking for ? The first usage of a word ? Why do you want to concern yourself with definitions and names of events ? It is only the understanding/reasoning/intuition behind that matters.
The point would be that there is
no short answer to your question of searching for 'real foundations'. Despite the growth of the internet/forums/online-courses/wikipedia, the best way (albeit long) to go about learning these concepts still remains to be a formal training in physics (a bachelors/a masters/ a phd?) at an institution. Both physics and mathematics have undergone tremendous revolutions since the 19th century, rewriting almost everything that was taken for granted since centuries earlier. Our current physical knowledge of the world has been extremely improved in the past years with general/special relativity, quantum mechanics, gauge theories and more recently M/string theories. For the common-man/engineer/non-theoretical-physicist, these theories explain almost all the aspects of our physical world that we might be encounter. It would take years of training for any person to truly realise the limitations of modern theories and understand the true unsolved problems in mathematics and physics.
In the slippery slope of 'why' questions, you begin to venture into metaphysics and philosophy (not that it is a bad thing*), which without the proper background/training could just end up in a lot of wasted time and wild goose chases.
Right know, your question appears to stand by itself and is in fact quite poorly defined. You can continue with your perpetual 'why' questions, but cannot expect to be taken seriously.
You would end up with an answer most probably looking like one of two possibilities:
a. because this is the explanation that we currently have that best fits the observed data as well as makes accurate predictions
b. your question doesn't make any 'physical' sense and deeper 'why' questions are just 'non-physical' issues for philosophers and theologians.
I am not firmly siding with the two answers above, but just stating the results of my pursuits of 'why' questions.
*I still remember one of my teachers remarking that at the deepest levels of science, it becomes indistinguishable from philosophy. (similar to Clarke's famous law on any sufficiently advanced technology being indistinguishable from magic). I personally am not against philosophy. I believe that some major advances to both the sciences and humanities have been a result of this branch of knowledge.