I'm concerned about the nature of time. We treat it as a separate dimension, yet it does not behave like the other 3. We don't go back and forth along it, yet we treat it as if we were moving forward. There is no real "forward" motion. My hair does not blow downwind in the time tunnel. Motion is the change of position relative to a non-moving object. But everyone is "moving" at the same speed, so we aren't really moving, are we?? We talk about the past, but we really mean past states. There is no "place" called the past. We think we can measure time, but we really only measure rhythm and consistent repeatable processes. The future is really just the outcome of a series of possibly predictable processes. So what the heck is time?
I'm not smart enough to ponder this question, but I do anyway. It's frustrating. I've learned that time behaves differently near the speed of light. Since the speed of light is constant, then mass and time have to adapt to that reality. At the speed of light, time stops, Mass is infinite. And what is mass? It is what resists force in a change of direction. Would infinite mass move if it met infinite force? Force is some sort of energy, but energy is a form of mass, but what does that mean? Energy has mass and weight. What's the difference between kinetic and potential though? Is mass just potential energy? So a large mass in motion is really partly energy? Or is mass just a measure of energy's weight and resistance to change? If so, then everything is just energy. Mass is compressed energy that is not in motion? Does mass convert to energy at the speed of light?
And why can't things go negative past the speed of light? Would that explain some things? For instance, quantum tunneling or entanglement. If a particle exceeded the the speed of light, it would really just be at a previous location, since time would have folded back, and it would have the foreknowledge of space before it. If time is not real, then aren't we really saying the process reversed? The particle gained energy as it "moves" back in time, perhaps?