UFOs and Aliens: Extraterrestrial Equals Interdimensional?

The world over, millions of people have seen and filmed UFOs. These strange things seem to pop in and out of reality in the blinking of an eye. Whilst we might think that such things originate from outer space, perhaps there are other explanations? These mysterious machines and the beings they transport may come from either inside planet earth or may slide into our universe from other hidden dimensions. This book examines these possibilities as a way of explaining extraterrestrial visitations.