What fundamental truths exist in the universe?

This question, perhaps above all, is the basis for scientific inquiry.  Yet we rarely ask it in this way and we rarely step back to the very basic assumptions we hold about the possible form of answer we might expect.  For instance, is matter fundamental?  Meaning, if we could not talk about particles and mass, could we understand the universe as well (or better) than we currently do?

Einstein showed that there is an equivalence between matter and energy (E=mc^2), but what does that really mean?  Personally, I’m kinda stumped when it comes to understanding energy, and I suspect that many other people are too if they think about it.  Then there’s that pesky c^2 part of the equation, which seems even more nebulous.  Physics 101 tells us that c is the velocity at which light (a form of energy) travels, and that any velocity squared is acceleration.  Also we learn that velocity is distance over time…