There is no empty space. All around us there are tiny atoms and molecules that are constantly rotating around eachother, basically like their own inividual solar systems. Their solar systems, however, intermingle much more frequently than the solar systems we're used to seeing. You see, their solar systems are so close together that there is no humanly measurable distance between them. Because of this, they are constantly loosing peices of their solar system (electrons) to other solar systems that pass by. As a result, matter is constantly changing all around us on a molecular level. Our bodys are made up of the same matter, constantly moving individual solar systems that meld to appear as the body we see. Everything else from concrete to water is made up of the same moving matter. Therefore there truly is no solid matter. Understanding that there is energy all throughout the universe and that our conscious state is actually energy in itself, we can understand how to separate our conscious state from the atoms that make up our body and then use the molecules and energy that is all around us to travel with our consciousness freely throughout the universe. This is truly experiencing existence.