To Infinity And Beyond

Lisa Randall's theory of multiple dimensions was very interesting to me. Are multiple dimensions the same as parallel dimensions? I assume the dimensions she is speaking about could be parallel, perpendicular or of any infinite type. I started wondering about death, and those who seem to be able to maintain contact with some form or another after they "cross over". I had been having doubts lately about anything happening to us after we die,convincing myself that we just tell ourselves there is something after this life so it makes it easier to let loved ones go. My sister lost one of her best friends earlier this year in a car crash and there was a little girl at his funeral who had never even met him, who, having no motivation to lie or make anything up, said that she could see him and that he didn't like the things the preacher was saying (he was not religious and against the pleas of his friends, his parents insisted on a traditional christian ceremony) and that he was going to kick over a plant in the corner (it fell over a minute later). How do we explain examples like this? Could our energy, once freed of the physiological constraints of the body, pass through to another dimension still reachable by a small percentage of the population on this world? If so, does it remain on this dimension forever or is there another transition? Maybe once gravity is no longer an issue we are free to pass through the other dimensions at our leisure. The questions and the possibilities are endless.
The infiniteness of the universe (in both directions!) is incomprehensible. We are such a small part of something so big and yet, if you think about the world around us, there are billions of things smaller than us. Billions of atomic and subatomic universes at play around us at any given time of day. Sometimes, when walking on the golf course or when watering the back yard I stop and wonder how many universes I have destroyed today. Sitting and watching ants do their thing with my three year old and trying to teach him to observe them, not to kill them, puts things in perspective (slightly) in considering the relativity of everything. Time, space, size; it's all an illusion, something manifested by us as a source of measurement, but really amounting to nothing at all in the grand scheme of things. What if we are just one tiny universe out of millions of universes, all a part of some greater existence, invisible and incomprehensible to us. Does the ant think he is just an ant? Does he realize how small his world is compared to things around him, or is he oblivious and also unable to comprehend the existence of anything outside of his world?