Consider the idea of aura, of psychic energy, say. Now consider the ability to see it. What does it look like to you? After some consideration, I can see this energy as clouds of mist, vapor if you will, colored by mood but predominantly blue. They can be directed, shaped by will or emotion. But for the most part they just hover, expand and contract as we breathe.
Over time these clouds of milky blue expand to fill the spaces where we live, as sure as cigarette smoke will penetrate the covers of, say, your green velvet couch. And so when I say, for example, I can feel you next to me on the bed while you're at work, what is next to me is this misty cloud of blue that cycles into white, then grey, then back to blue. It is insubstantial, formless, but yet you. You are everywhere in this apartment and I am close to you, always, when I am here.