Everything that exists is in a relation between mass and energy. It is like an equilibrium exists between energy and mass. If you observe energy, it's actually some particle with definite masses are at infinite speed. And when you observe mass, it actually when energy is not spread out in infinite space, but it is composed in a point or definite area. The things are very interesting to think about. Everything is made out of atoms and if you have a proper knowledge about energy and mass then you will be able to explain everything including how everything was created, how atoms were created and why electrons are outside but not composed in a definite point. You can assume things like this: A flow of energy is in front of you. Flowing at infinite speed. It's a wave, energy wave. Now you just grab some amount of the energy with your hand. The energy will continue flowing as usual, but the little part you grabbed in your hand is not energy anymore. It's some amount of mas...