MIT’s Groundbreaking Terahertz Radiation Algorithm Enables Reading Closed Books

According to the age-old adage, one should never judge a book by its cover. Interestingly, a team of innovative researchers at the Massachusetts Institute of Technology (MIT) have developed a technology that allows you to both literally and metaphorically obey this saying, while revealing the contents of a book without flipping a single page.

The team proudly announced their breakthrough in a post, in which they elaborated on their development of a cutting-edge camera capable of ‘reading’ through the closed pages of a book.

At the heart of this system is the use of terahertz radiation, the band of electromagnetic radiation nestled between microwaves and infrared light. Terahertz radiation holds several advantages over other types of waves that can penetrate surfaces, such as X-rays or sound waves. Crucially, terahertz frequency profiles can distinguish between ink and blank paper, a feat that X-rays simply can’t achieve.


This novel technology presents an entirely different way to interpret the physical world. As the radiation penetrates the pages of a book, it interacts with the various chemicals that compose the book’s pages. Using specially designed algorithms, the camera can translate these chemical interactions into readable words. In other words, by simply resting on a book’s cover, the camera can ‘read’ the book, with terahertz signals yielding superior results compared to X-ray technology.

This is not the first time terahertz technology has been put to use. In the past, similar techniques have been employed for security screening to decipher the chemical components of materials such as clothing and bags.

However, as with any ambitious technology, there currently exist limitations. At present, the algorithm can only differentiate between the first 20 pages of a book, and read the text of the initial 9 pages with clarity. The energy of the signal weakens past the first 9 pages, resulting in ‘noise’ that makes further page contents unreadable. This phenomenon, known as attenuation, typically degrades the quality of signals over a distance.

Despite these limitations, the researchers at MIT are optimistic about the future of their pioneering system. They are steadfast in their mission to develop the algorithm further, with the goal of reading an entire book eventually.

The practical applications of this technology are profound. For instance, museums housing rare and delicate ancient books that have piqued public interest could use this non-invasive method to digitise and share unreadable historical texts with the world.

The inspiring team behind this revolutionary project includes Barmak Heshmat, Ramesh Raskar, and Albert Redo Sanchez, all based out of MIT, while Justin Romberg and Alireza Aghasi contributed from Georgia Tech.