The Coast interview this weekend with Lisa Randall was fairly decent. She speaks with a soft, clear, accurate, deep, precise, and exact voice. In particular the idea that matter with extension in other than the three spatial dimensions we believe we are familiar with includes the idea that some properties of that matter could interact in our three dimensions while most of the properties might not, which explains how gravity is such a weak force and how extradimensional effects of electromagnetism would be unobservable. That is, there could be a lot of invisible mass and energy in the greater universe and we would never know.