Hello everyone. I'm new to the boards so please excuse my ignorance. While I originally came here to ask one question, while I was here I came across some things that gave rise to new questions. If someone could explain these questions to me or give me a link that I could find my answer at, it would be greatly appreciated. 1) From what I understand, the theory of relativity states that motion can't exist because it needs a reference point before it can be defined as motion (i.e. The boy was moving at 4 miles per hour relative to the earth). How far off am I? And if I'm correct, where does E=mc^2 come in to play? 2) I read something that suggested that the "mirror world" isn't EXACTLY as it is in this world. How can that be? If everything in a mirror isn't really a world of it's own but just a reflection of this world, how can it be different? 3) What is a virtual particle? Is it matter or is it just something to help explain forces that we can't yet explain? And if it isn't matter, how does it give momentum to the particles that use them for propulsion? 4) What's the difference between Quantum Physics, Classical Physics, and General Physics? Ok, that's all of them. Sorry if they're too elementary to waste time on but even these simple questions are at the top of my understanding and I'm hoping to add to that. Thank you for your time.