Apparently, Italians find physics more sexy than S&M – at least for reading material. Since it was published last September, Carlo Rovelli's book Seven Brief Lessons on Physics has sold more copies in Rovelli's native country, Italy, than E.L. James' smash hit Fifty Shades of Grey, The Spectator reported.

And the translated English copy has quickly risen to become Penguin's fastest-selling science debut in the publishing company's history. So what's Rovelli's secret?

After all, it's not like physics is a topic that people flock toward. In fact, physics has been the least popular STEM (science, technology, engineering, and mathematics) major for US undergraduates since the late '60s.

Well, for starters, Rovelli is an expert on the topic. He's a theoretical physicist by profession with a focus in quantum gravity – a field that attempts to join one of the greatest two theories in history: Isaac Newton's theory of gravity and Albert Einstein's general theory of relativity.

Rovelli is also an avid writer of popular science, so he has a knack for transforming complex ideas into clear, simple concepts.

"Rovelli has a rare knack for conveying the top line of scientific theories in clear and compelling terms without succumbing to the lure of elaborate footnotes," Nicola Davis, the commissioning editor of Tech Monthly, reported in The Guardian.

Another advantage is that his book is only 78 pages long – not so scary a length for such an intimidating subject. And the topics don't throw any of its readers off the deep end, according to the author.

"It covers modern physics and is written for people who know nothing about modern science," Rovelli said in a promotional video by Penguin. "What is heat? What is space? What is time? And especially … how many mysteries are still [out] there? It focuses on the large amount of things we don't know rather than what we do know."

You can learn more about Rovelli's book on There, you can listen to brief excerpts from the book, read by Rovelli, as well as play around with the interactive web pages associated with each of the book's seven sections.

Check out more about Rovelli and his latest book on YouTube, or below:

This article was originally published by Business Insider.

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