Check this out. If you haven't read Brian Greene's book THE ELEGANT UNIVERSE, and are even slightly curious about why you can clap your hands together without the atoms in one hand passing through the vast spaces between the atoms in the other, or string theory, or how many dimensions our universe contains, then you definitely should.
But now you can watch the book instead! They've turned it into a television program on PBS that you can view freely on the web!
NOVA | The Elegant Universe | Watch the Program | PBS