First off, I'm new here so if this is in the wrong section I apologize. Now to the question: As dumb as this may sound to people that know more about physics then me (I'm a med student but I find myself reading about physics time to time) it makes perfect sense in my head (due to lack of knowledge most likely), anyway, I was once told a simple way to understand E=mc2, "if something is going at 10mph, it doesn't simply take twice the energy to go twice as fast, it requires exponentially more energy. As such, the faster you go, the heavier the object gets. So in order to get to lightspeed, you would need infinite energy, to get past lightspeed you would need infinite energy+x". Now for the question, couldn't the fact that the weight of the object moving is increasing infinitely somehow be used to create infinite energy? ie something moving 100mph weighing 100lbs could generate 100 units of energy and that energy could be used to move it at 101mph weighing x lbs which would then generate x units of energy etc?