Now you don’t even have to open a book to read it! That’s right, scientists at MIT have invented a new camera that is able to read closed books. The new camera uses tetrahertz radiation to determine the position of ink within the book. It then uses image processing algorithms to determine exactly which page the ink is on. This system works with up to nine pages, although there is hope that it can be improved to work with longer documents.While the tetrahertz camera may not be practical for reading the latest novel, it should prove invaluable for examining historically significant, fragile documents. For more information, see Judging a book through its cover and MIT Invented a Camera That Can Read Closed Books.