Researchers at MIT have developed a way to read a book without ever cracking it open. As Gizmodo reports, their new camera uses terahertz radiation to penetrate the cover of a book and detect the text inside.

The imaging system, which is detailed in a recent issue of the journal Nature Communications, depends on complex algorithms and software to function. Terahertz radiation, which falls between microwave and infrared radiation, is unique in that different chemicals will produce specific frequencies upon coming in contact with it. The frequency signature emitted by ink, for instance, is distinct from the one emitted by a blank page. Algorithms process this data as it's transmitted to the camera, allowing researchers to identify letters on a page in a way that's not possible with X-rays.

The nature of terahertz radiation also allows researchers to measure how far it reaches into a book. Because the radiation can be emitted in brief bursts, scientists are able to estimate how far it travels based on the difference between emission time and the point when the reflected waves bounce back. By calculating how long it takes the bursts to cross the 20-micrometer air pockets that separate the pages in a book, they can better determine which page the radiation falls on.

The prototype has already been tested in the lab on a stack of papers. Each sheet was printed with a different letter, and the mechanism correctly identified the characters on the first nine pages. As the technology improves, it could become a useful tool for the museums and institutions that house rare books too delicate to open.

MIT researcher Barmak Heshmat said in a release, “The Metropolitan Museum in New York showed a lot of interest in this, because they want to, for example, look into some antique books that they don’t even want to touch.”

[h/t Gizmodo]

Know of something you think we should cover? Email us at tips@mentalfloss.com.