Scientists Invented A Camera That Can Read Closed Books

MIT researchers have developed a camera that has the ability to read the text on pages of a book, without it having to be open.

In a breakthrough that appeals to spies, historians and extremely lazy people equally, the team have used terahertz radiation to peer through the cover of a closed book and read it.

What the hell is a Terahertz?

Sorry – couldn’t resist a nod to Back to The Future there...

Well, Terahertz radiation falls in the spectrum between microwave and infrared – which has different reactions to different chemicals.

A different chemical (let’s say ink) will react and show up different on a camera compared to the paper. That means the research team were able to tell the difference between the blank paper and ink letters.

That must have required a special camera…

You’d be right – complex software and algorithms are needed to translate the frequencies being captured by the camera.

But you also need to control the level of radiation too, which the software computes also.

With precise timing of how long it takes for the short bursts of terahertz radiation to reach through the 20-micrometer-thick air gaps between the pages of a book, it can show you when it moves from page to page. That means you won’t get lost in the book!

I don’t feel like turning pages anymore… When can I get my hands on one?

Probably not for consumer use I’m afraid, but more work is actually needed.

In its current state, the camera can distinguish characters on a page to the depth of roughly nine pages. And the device also requires those pages to have a level of transparency to them.

Spatial resolution, spectral contrast, and occlusion are three major bottlenecks in current imaging technologies for non-invasive inspection of complex samples such as closed books. We empower the time-of-flight capabilities of conventional THz time domain spectroscopy and combine it with its spectral capabilities to computationally overcome these bottlenecks.

But as the world of detectors and emitters moves on, and the technology becomes further refined, this could be great for the future of reading historical documents without compromising them.

In a museum, kids wouldn’t get their sticky fingers on important documents – they could just read without actually having to touch them.