From the promo website for the new book, Imagining the Tenth Dimension, comes this little Flash video explaining the nature of the ten dimensions (and you thought there were only four. HA! You're soooo twentieth century- the future's all about quantuum physics and string theory, baby!). Physicists tell us that the subatomic particles that make up our universe are created within ten spatial dimensions (plus an additional dimension of time) by the vibrations of exquisitely small "superstrings". The video explains this all relatively simply, in terms that most of us can understand.
Superstring theory is yet anther instance in which science fiction has anticipated science. The idea of parallel universes and dimensions is an old one, and you don't even have to be a hard-core sci-fi geek to have been exposed to it: a screening of the Back to the Future movies will suffice to get the gist of it. According to the video, it would actually be theoretically possible to travel between parallel dimensions, or alternate realities, if you will. The only caveat is that since we, as humans, are limited to experiencing our reality within the context of the first three and a half dimensions (length, width, depth, and duration/time, but we don't really see this one as a whole, we simply experience it in a limited way as we travel through it), we don't even percieve the rest of the 'higher' dimensions.
This concept gels nicely with the subject of the book I'm currently reading, 2012: The Return of Quetzalcoatl, by Daniel Pinchbeck. He postulates that humanity is on the verge of a quantum leap in consciousness, where the paradigm of our very existence will change dramatically to encompass ideas and concepts that until now have been relegated to the realm of the spiritual, arcane, mystical, and psychedelic by mainstream, physical science. He puts forth that there are other dimensions to reality, such as the noosphere, which are out of our range of perception for now, because we are not equipped to perceive them (sort of like how we can't see light in the infrared spectrum, but in a spiritual, or quantum state), but that soon, humanity will transcend our current paradigm of existence and evolve into a higher state of being. He sets the date for this singularity event at or around 2012, according to (among other markers) the date in the Mayan calendar that corresponds to the ending of the fifth -and current- age of mankind. Hence the title of the book, as Quetzalcoatl is a Mayan deity.
It's strange that I'm coming across all this related information at the same moment. Chalk one up to synchronicity (although Pinchbeck addresses this phenomenon, albeit from a very psychedelic and mystical perspective. I don't know if I subscribe to his interpretation, but it makes for interesting reading).