0.3 A physics work in progress - the beginning

I have only studied physics a little - however theoretical or philosophical physics is a subjective topic that could be speculated upon by lay people - some of this article could relate to how the universe was formed.

It would seem to me that physical particles have to combine in manner that makes sense, but the question is - what is logical physical connection? Is it logical for one particle to bond or interact with a different particle?

What is inside empty space? Could it be that there are small particles in empty space that aren't visible or have any interactions with other particles?

Maybe I can say that a 'particle' is the smallest unit of matter or the smallest unit of something that can be physically observed or actually exist - I don't know if someone else has defined something like that before.

There are different ways that different particles interact - they have charges and strong and weak forces - however, are those all the ways in which they can interact, bond, attract and repel each other, and so on and so forth?

What is the difference between energy and matter then? Energy is matter (or could be viewed as being matter), and matter is energy because both are physical substances. I could define the smallest particles as physical substances - but if they don't exist anywhere then maybe they can be transformed into different types of matter because they are pure energy - but does that statement even make any sense - all energy has to be matter because it has to physically exist.