Here is a riddle: What can the one who looks never see? The eye itself. Without a mirror, of course! So here is a mirror. Both the three external and seven internal dimensions of strings all resonate in the ways of both physical formations governing fields and fields governing these formations. External space time - that is, of the space relating to the three external dimensions governing physical matter, has been well studied. The seven internal dimensions are pertaining to thought, and have been far less studied by modern science. Thought is not a product of the brain. The brain transmits and converts certain intentions of will into physical actions. But thoughts are ripples and forms in internal space time, just as gross and subtle matter is, and follow the same laws as matter. For this to be clear, one has to see that we are not our thoughts and we are not matter - we are actually the empty space, the Mind. But because of delusion about its true nature, like the looker who never sees itself, the Mind has become attracted into and identified with the gravitational fields of mental and physical formations. One may notice how one's thoughts bend around the objects of it's attraction, along engrained pathways of internal space time. There are 10^500 realms of thought, which it is possible to travel to by mind, through branes, to visit their correlating external realms and inhabitants. When our internal strings dissolve from the external, these internal strings will enter into whichever universe they are resonating, with a body of that frequency, depending on how strongly they have been attached and attracted to objects, or how well we have managed to stay out of harm's way. But as humans we have free will, though we rarely exert it. That is, the free will to break away from following along the spacetime continuum of the past. Though it takes a lot of work, it's possible to take oneself out of a gravitational field, to untangle oneself from the strings of our attachment and identification to the external dimensions of matter and from the internal dimensions of thought. To do this we need to know and to see through the forces of desire which are pulling us in to things and situations we might not want to be getting pulled into! When we can understand the nature of our own body and our own mind, we won't get pulled into their gravitational fields, and so we can know ourselves as the pure mind, empty space, right here, right now, unbounded.