In a personal interview on February 10, 2007, Professor Craig Rueton, the Physics Chair at my college, explained to me that in order to make something invisible two hurdles must be overcome. First, you must find a way to transport light around the object. For example, for this board to be visible light must travel towards it. If something blocks that light it must become invisible. So you must find a way to transport light around the object without interference. Second, you must never illuminate the object. In order to keep the light from touching the object you must find a way for the object not to interact with the light that travels at it, otherwise the object would still be visible.